machine: fix usb truncation?

Remove the sendUSBPacket maxLen param because this greatly confused the compiler. It also fixes a bug where the length provided to the hardware may not match the length of the packet. sendUSBPacket now panics if the sent packet is too big. I also fixed some of the string descriptor logic where we could create a packet without fully populating it. RP2* systems might require some more work since they are implemented very differently? I don't have any of those to test with yet, so maybe someone can deal with them in a seperate PR?
compiler/runtime: add element layout to sliceAppend
2026-07-27 07:08:42 +00:00 · 2025-12-30 15:51:27 -05:00 · 2025-12-26 21:27:24 -05:00 · 2025-12-22 13:15:06 +00:00 · 2025-12-18 21:59:18 +00:00 · 2025-12-18 20:52:12 +01:00
196 changed files with 4393 additions and 1841 deletions
@@ -92,16 +92,20 @@ commands:
            - /go/pkg/mod

 jobs:
-  test-llvm15-go122:
+  test-oldest:
+    # This tests our lowest supported versions of Go and LLVM, to make sure at
+    # least the smoke tests still pass.
    docker:
      - image: golang:1.22-bullseye
    steps:
      - test-linux:
          llvm: "15"
    resource_class: large
-  test-llvm20-go124:
+  test-newest:
+    # This tests the latest supported LLVM version when linking against system
+    # libraries.
    docker:
-      - image: golang:1.24-bullseye
+      - image: golang:1.25-bullseye
    steps:
      - test-linux:
          llvm: "20"
@@ -110,8 +114,6 @@ jobs:
 workflows:
  test-all:
    jobs:
-      # This tests our lowest supported versions of Go and LLVM, to make sure at
-      # least the smoke tests still pass.
-      - test-llvm15-go122
-      # This tests LLVM 20 support when linking against system libraries.
-      - test-llvm20-go124
+      - test-oldest
+      # disable this test, since CircleCI seems unable to download due to rate-limits on Dockerhub.
+      # - test-newest
@@ -16,36 +16,37 @@ jobs:
    name: build-macos
    strategy:
      matrix:
-        # macos-13: amd64 (oldest supported version as of 18-10-2024)
-        # macos-14: arm64 (oldest arm64 version)
-        os: [macos-13, macos-14]
+        # macos-14: arm64 (oldest supported version as of 18-11-2025)
+        # macos-15-intel: amd64 (last intel version to be supported by github runners)
+        # See https://github.com/actions/runner-images/issues/13046
+        os: [macos-14, macos-15-intel]
        include:
-          - os: macos-13
-            goarch: amd64
          - os: macos-14
            goarch: arm64
+          - os: macos-15-intel
+            goarch: amd64
    runs-on: ${{ matrix.os }}
    steps:
      - name: Install Dependencies
        run: |
          HOMEBREW_NO_AUTO_UPDATE=1 brew install qemu binaryen
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
        with:
          submodules: true
      - name: Extract TinyGo version
        id: version
        run: ./.github/workflows/tinygo-extract-version.sh | tee -a "$GITHUB_OUTPUT"
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Restore LLVM source cache
        uses: actions/cache/restore@v4
        id: cache-llvm-source
        with:
-          key: llvm-source-19-${{ matrix.os }}-v1
+          key: llvm-source-20-${{ matrix.os }}-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
@@ -70,7 +71,7 @@ jobs:
        uses: actions/cache/restore@v4
        id: cache-llvm-build
        with:
-          key: llvm-build-19-${{ matrix.os }}-v1
+          key: llvm-build-20-${{ matrix.os }}-v2
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -79,7 +80,7 @@ jobs:
          rm -rf llvm-project
          make llvm-source
          # install dependencies
-          HOMEBREW_NO_AUTO_UPDATE=1 brew install cmake ninja
+          HOMEBREW_NO_AUTO_UPDATE=1 brew install ninja
          # build!
          make llvm-build
          find llvm-build -name CMakeFiles -prune -exec rm -r '{}' \;
@@ -130,11 +131,11 @@ jobs:
        run: |
          brew install llvm@${{ matrix.version }}
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Build TinyGo (LLVM ${{ matrix.version }})
        run: go install -tags=llvm${{ matrix.version }}
@@ -31,7 +31,7 @@ jobs:
          sudo rm -rf /usr/local/share/boost
          df -h
      - name: Check out the repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
        with:
          submodules: recursive
      - name: Set up Docker Buildx
@@ -58,7 +58,7 @@ jobs:
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
        with:
          context: .
          push: true
@@ -66,45 +66,3 @@ jobs:
          labels: ${{ steps.meta.outputs.labels }}
          cache-from: type=gha
          cache-to: type=gha,mode=max
-      - name: Trigger Drivers repo build on Github Actions
-        run: |
-          curl -X POST \
-          -H "Authorization: Bearer ${{secrets.GHA_ACCESS_TOKEN}}" \
-          -H "Accept: application/vnd.github.v3+json" \
-          https://api.github.com/repos/tinygo-org/drivers/actions/workflows/build.yml/dispatches \
-          -d '{"ref": "dev"}'
-      - name: Trigger Bluetooth repo build on Github Actions
-        run: |
-          curl -X POST \
-          -H "Authorization: Bearer ${{secrets.GHA_ACCESS_TOKEN}}" \
-          -H "Accept: application/vnd.github.v3+json" \
-          https://api.github.com/repos/tinygo-org/bluetooth/actions/workflows/linux.yml/dispatches \
-          -d '{"ref": "dev"}'
-      - name: Trigger TinyFS repo build on Github Actions
-        run: |
-          curl -X POST \
-          -H "Authorization: Bearer ${{secrets.GHA_ACCESS_TOKEN}}" \
-          -H "Accept: application/vnd.github.v3+json" \
-          https://api.github.com/repos/tinygo-org/tinyfs/actions/workflows/build.yml/dispatches \
-          -d '{"ref": "dev"}'
-      - name: Trigger TinyFont repo build on Github Actions
-        run: |
-          curl -X POST \
-          -H "Authorization: Bearer ${{secrets.GHA_ACCESS_TOKEN}}" \
-          -H "Accept: application/vnd.github.v3+json" \
-          https://api.github.com/repos/tinygo-org/tinyfont/actions/workflows/build.yml/dispatches \
-          -d '{"ref": "dev"}'
-      - name: Trigger TinyDraw repo build on Github Actions
-        run: |
-          curl -X POST \
-          -H "Authorization: Bearer ${{secrets.GHA_ACCESS_TOKEN}}" \
-          -H "Accept: application/vnd.github.v3+json" \
-          https://api.github.com/repos/tinygo-org/tinydraw/actions/workflows/build.yml/dispatches \
-          -d '{"ref": "dev"}'
-      - name: Trigger TinyTerm repo build on Github Actions
-        run: |
-          curl -X POST \
-          -H "Authorization: Bearer ${{secrets.GHA_ACCESS_TOKEN}}" \
-          -H "Accept: application/vnd.github.v3+json" \
-          https://api.github.com/repos/tinygo-org/tinyterm/actions/workflows/build.yml/dispatches \
-          -d '{"ref": "dev"}'
@@ -18,7 +18,7 @@ jobs:
    # statically linked binary.
    runs-on: ubuntu-latest
    container:
-      image: golang:1.24-alpine
+      image: golang:1.25-alpine
    outputs:
      version: ${{ steps.version.outputs.version }}
    steps:
@@ -26,12 +26,12 @@ jobs:
        # tar: needed for actions/cache@v4
        # git+openssh: needed for checkout (I think?)
        # ruby: needed to install fpm
-        run: apk add tar git openssh make g++ ruby-dev
+        run: apk add tar git openssh make g++ ruby-dev mold
      - name: Work around CVE-2022-24765
        # We're not on a multi-user machine, so this is safe.
        run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
        with:
          submodules: true
      - name: Extract TinyGo version
@@ -48,7 +48,7 @@ jobs:
        uses: actions/cache/restore@v4
        id: cache-llvm-source
        with:
-          key: llvm-source-19-linux-alpine-v1
+          key: llvm-source-20-linux-alpine-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
@@ -73,7 +73,7 @@ jobs:
        uses: actions/cache/restore@v4
        id: cache-llvm-build
        with:
-          key: llvm-build-19-linux-alpine-v1
+          key: llvm-build-20-linux-alpine-v1
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -131,13 +131,13 @@ jobs:
    needs: build-linux
    steps:
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
        with:
          submodules: true
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Install wasmtime
        uses: bytecodealliance/actions/wasmtime/setup@v1
@@ -164,7 +164,7 @@ jobs:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
        with:
          submodules: true
      - name: Install apt dependencies
@@ -179,9 +179,9 @@ jobs:
              simavr \
              ninja-build
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Install Node.js
        uses: actions/setup-node@v4
@@ -197,7 +197,7 @@ jobs:
        uses: actions/cache/restore@v4
        id: cache-llvm-source
        with:
-          key: llvm-source-19-linux-asserts-v1
+          key: llvm-source-20-linux-asserts-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
@@ -222,7 +222,7 @@ jobs:
        uses: actions/cache/restore@v4
        id: cache-llvm-build
        with:
-          key: llvm-build-19-linux-asserts-v1
+          key: llvm-build-20-linux-asserts-v1
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -284,7 +284,7 @@ jobs:
    needs: build-linux
    steps:
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
      - name: Get TinyGo version
        id: version
        run: ./.github/workflows/tinygo-extract-version.sh | tee -a "$GITHUB_OUTPUT"
@@ -296,15 +296,15 @@ jobs:
              g++-${{ matrix.toolchain }} \
              libc6-dev-${{ matrix.libc }}-cross
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Restore LLVM source cache
        uses: actions/cache/restore@v4
        id: cache-llvm-source
        with:
-          key: llvm-source-19-linux-v1
+          key: llvm-source-20-linux-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
@@ -329,7 +329,7 @@ jobs:
        uses: actions/cache/restore@v4
        id: cache-llvm-build
        with:
-          key: llvm-build-19-linux-${{ matrix.goarch }}-v3
+          key: llvm-build-20-linux-${{ matrix.goarch }}-v1
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -25,7 +25,7 @@ jobs:
      contents: read
    steps:
      - name: Check out the repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
        with:
          submodules: recursive
      - name: Set up Docker Buildx
@@ -35,8 +35,8 @@ jobs:
        uses: docker/metadata-action@v5
        with:
          images: |
-            tinygo/llvm-19
-            ghcr.io/${{ github.repository_owner }}/llvm-19
+            tinygo/llvm-20
+            ghcr.io/${{ github.repository_owner }}/llvm-20
          tags: |
            type=sha,format=long
            type=raw,value=latest
@@ -52,7 +52,7 @@ jobs:
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
        with:
          target: tinygo-llvm-build
          context: .
@@ -21,7 +21,7 @@ jobs:
        # See: https://github.com/tinygo-org/tinygo/pull/4516#issuecomment-2416363668
        run: sudo apt-get remove llvm-18
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
      - name: Pull musl, bdwgc
        run: |
            git submodule update --init lib/musl lib/bdwgc
@@ -29,7 +29,7 @@ jobs:
        uses: actions/cache/restore@v4
        id: cache-llvm-source
        with:
-          key: llvm-source-19-linux-nix-v1
+          key: llvm-source-20-linux-nix-v1
          path: |
            llvm-project/compiler-rt
      - name: Download LLVM source
@@ -20,7 +20,7 @@ jobs:
        run: |
          echo "$HOME/go/bin" >> $GITHUB_PATH
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
        with:
          fetch-depth: 0 # fetch all history (no sparse checkout)
          submodules: true
@@ -30,7 +30,7 @@ jobs:
        uses: actions/cache@v4
        id: cache-llvm-source
        with:
-          key: llvm-source-19-sizediff-v1
+          key: llvm-source-20-sizediff-v1
          path: |
            llvm-project/compiler-rt
      - name: Download LLVM source
@@ -31,7 +31,7 @@ jobs:
        run: |
          scoop install ninja binaryen
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
        with:
          submodules: true
      - name: Extract TinyGo version
@@ -39,15 +39,15 @@ jobs:
        shell: bash
        run: ./.github/workflows/tinygo-extract-version.sh | tee -a "$GITHUB_OUTPUT"
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Restore cached LLVM source
        uses: actions/cache/restore@v4
        id: cache-llvm-source
        with:
-          key: llvm-source-19-windows-v1
+          key: llvm-source-20-windows-v1
          path: |
            llvm-project/clang/lib/Headers
            llvm-project/clang/include
@@ -72,7 +72,7 @@ jobs:
        uses: actions/cache/restore@v4
        id: cache-llvm-build
        with:
-          key: llvm-build-19-windows-v1
+          key: llvm-build-20-windows-v2
          path: llvm-build
      - name: Build LLVM
        if: steps.cache-llvm-build.outputs.cache-hit != 'true'
@@ -143,11 +143,11 @@ jobs:
        run: |
          scoop install binaryen
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Download TinyGo build
        uses: actions/download-artifact@v4
@@ -173,11 +173,11 @@ jobs:
          maximum-size: 24GB
          disk-root: "C:"
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Download TinyGo build
        uses: actions/download-artifact@v4
@@ -209,11 +209,11 @@ jobs:
        run: |
          scoop install binaryen && scoop install wasmtime@29.0.1
      - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
      - name: Install Go
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
        with:
-          go-version: '1.24'
+          go-version: '1.25.5'
          cache: true
      - name: Download TinyGo build
        uses: actions/download-artifact@v4
@@ -16,13 +16,13 @@
 	url = https://github.com/WebAssembly/wasi-libc
 [submodule "lib/picolibc"]
 	path = lib/picolibc
-	url = https://github.com/keith-packard/picolibc.git
+	url = https://github.com/picolibc/picolibc.git
 [submodule "lib/stm32-svd"]
 	path = lib/stm32-svd
 	url = https://github.com/tinygo-org/stm32-svd
 [submodule "lib/musl"]
 	path = lib/musl
-	url = git://git.musl-libc.org/musl
+	url = https://github.com/tinygo-org/musl-libc.git
 [submodule "lib/binaryen"]
 	path = lib/binaryen
 	url = https://github.com/WebAssembly/binaryen.git
@@ -1,3 +1,156 @@
+0.40.1
+---
+* **machine**
+  - nrf: fix flash writes when SoftDevice is enabled
+* **runtime**
+  - runtime: avoid fixed math/rand sequence on RP2040/RP2350 (#5124)
+  - runtime: add calls to initRand() during run() for all schedulers
+  - runtime: call initRand() before initHeap() during initialization
+  - runtime: use rand_hwrng hardwareRand for RP2040/RP2350 (#5135)
+* **libs**
+  - picolibc: use updated location for git repo
+
+0.40.0
+---
+* **general**
+  - all: add full LLVM 20 support
+  - core: feat: enable //go:linkname pragma for globals
+  - core: feature: Add flag to ignore go compatibility matrix (#5078)
+  - chore: update version for 0.40 development cycle
+* **compiler**
+  - emit an error when the actual arch doesn't match GOARCH
+  - mark string parameters as readonly
+  - use Tarjan's SCC algorithm to detect loops for defer
+  - lower "large stack" limit to 16kb
+* **core**
+  - shrink bdwgc library
+  - Fix linker errors for runtime.vgetrandom and crypto/internal/sysrand.fatal
+  - fix: add TryLock to sync.RWMutex
+  - fix: correct linter issues exposed by the fix in #4679
+  - fix: don't hardcode success return state
+  - fix: expand RTT debugger compatibility
+  - internal/task (threads): save stack bounds instead of scanning under a lock
+  - internal/task: create detached threads and fix error handling
+  - interp: better errors when debugging interp
+  - transform (gc): create stack slots in callers of external functions
+  - internal/task: prevent semaphore resource leak for threads scheduler
+* **machine**
+  - cortexm: optimize code size for the HardFault_Handler
+  - fe310: add I2C pins for the HiFive1b
+  - clarify WriteAt semantics of BlockDevice
+  - fix deprecated AsmFull comment (#5005)
+  - make sure DMA buffers do not escape unnecessarily
+  - only enable USB-CDC when needed
+  - use larger SPI MAXCNT on nrf52833 and nrf52840
+  - fix: update m.queuedBytes when clamping output to avoid corrupting sentBytes
+  - fix: use int64 in ReadTemperature to avoid overflow
+  - fix(rp2): disable DBGPAUSE on startup
+  - fix(rp2): possible integer overflow while computing factors for SPI baudrate
+  - fix(rp2): reset spinlocks at startup
+  - fix(rp2): switch spinlock busy loop to wfe
+  - fix(rp2): use side-effect-free spinlocks
+  - nrf: add ADC_VDDH which is an ADC pin for VDDH
+  - nrf: don't block SPI transfer
+  - nrf: don't set PSELN, it's ignored in single ended mode anyway
+  - nrf: fix typo in ADC configuration
+  - nrf: refactor SoftDevice enabled check
+  - nrf: rename pwmPin to adcPin
+  - nrf: support flash operations while the SoftDevice is enabled
+  - rp2040: allow writing to the UART inside interrupts
+  - machine,nrf528: stop the bus only once on I2C bus error and ensures the first error is returned
+* **net**
+  - update submodule to latest commits
+* **runtime**
+  - (avr): fix infinite longjmp loop if stack is aligned to 256 bytes
+  - (gc_blocks.go): clear full size of allocation
+  - (gc_blocks.go): make sweep branchless
+  - (gc_blocks.go): simplify scanning logic
+  - (gc_blocks.go): use a linked stack to scan marked objects
+  - (gc_blocks.go): use best-fit allocation
+  - (gc_boehm.go): fix world already stopped check
+  - (wasm): scan the system stack
+  - fix sleep duration for long sleeps
+  - remove copied code for nrf52840
+  - src/syscall: update src buffer after write
+  - wasm: fix C realloc and optimize it a bit
+* **targets**
+  - add xiao-esp32s3 board target
+  - Add ESP32-S3 support (#5091)
+  - Added Gopher ARCADE board
+  - Create "pico2-ice" target board (#5062)
+* **build/test**
+  - Add testing.T.Context() and testing.B.Context()
+  - create separate go.mod file for testing dependencies for wasm tests that use Chromium headless browser to avoid use of older incompatible version.
+  - go back to normal scheduler instead of tasks scheduler for macos CI
+  - update CI to use Go 1.25.5
+  - update macOS GH actions builds to handle sunset of macOS 13
+  - use task scheduler on macOS builds to avoid test race condition lockups
+  - update all CI builds to use latest stable Go release. Also update some of the actions to their latest releases.
+  - update GH actions builds to use Go 1.25.4
+  - uninstall cmake before install
+  - fix: point the submodule for musl-lib to a mirror in the TinyGo GitHub org
+  - fix: remove macOS 15 from CI build matrix (conflicts with macOS 14 build)
+  - fix: separate host expected bytes from device intended bytes
+  - fix/typo: makeESPFirmwareImage
+  - make: GNUmakefile: shrink TinyGo binaries on Linux
+  - move the directory list into a variable
+  - several improvements to the macOS GH actions build
+  - Fix for #4678: top-level 'make lint' wasn't working
+  - fix: increase the timeout for chromedp to connect to the headless browser used for running the wasm tests.
+  - testdata: some more packages for the test corpus
+
+0.39.0
+---
+* **general**
+  - all: add Go 1.25 support
+  - net: update to latest tinygo net package
+  - docs: clarify build verification step for macOS users
+  - Add flag to skip Renesas SVD builds
+* **build**
+  - Makefile: install missing dlmalloc files
+  - flash: add -o flag support to save built binary (Fixes #4937) (#4942)
+  - fix: update version of clang to 17 to accommodate latest Go 1.25 docker base image
+* **ci**
+  - chore: update all CI builds to test Go 1.25 release
+  - fix: disable test-newest since CircleCI seems unable to download due to rate-limits on Dockerhub
+  - ci: rename some jobs to avoid churn on every Go/LLVM version bump
+  - ci: make the goroutines test less racy
+  - tests: de-flake goroutines test
+* **compiler**
+  - compiler: implement internal/abi.Escape
+* **main**
+  - main: show the compiler error (if any) for `tinygo test -c`
+  - chore: correct GOOS=js name in error messages for WASM
+* **machine**
+  - machine: add international keys
+  - machine: remove some unnecessary "// peripherals:" comments
+  - machine: add I2C pin comments
+  - machine: standardize I2C errors with "i2c:" prefix
+  - machine: make I2C usable in the simulator
+  - fix: add SPI and I2C to teensy 4.1 (#4943)
+  - `rp2`: use the correct channel mask for rp2350 ADC; hold lock during read (#4938)
+  - `rp2`: disable digital input for analog inputs
+* **runtime**
+  - runtime: ensure time.Sleep(d) sleeps at least d
+  - runtime: stub out weak pointer support
+  - runtime: implement dummy AddCleanup
+  - runtime: enable multi-core scheduler for rp2350
+  - `internal/task`: use -stack-size flag when starting a new thread
+  - `internal/task`: add SA_RESTART flag to GC interrupts
+  - `internal/task`: a few small correctness fixes
+  - `internal/gclayout`: make gclayout values constants
+  - darwin: add threading support and use it by default
+* **standard library**
+  - `sync`: implement sync.Swap
+  - `reflect`: implement Method.IsExported
+* **testing**
+  - testing: stub out testing.B.Loop
+* **targets**
+  - `stm32`: add support for the STM32L031G6U6
+  - add metro-rp2350 board definition (#4989)
+  - `rp2040/rp2350`: set the default stack size to 8k for rp2040/rp2350 based boards where this was not already the case
+
+
 0.38.0
 ---
 * **general**
@@ -1,8 +1,8 @@
 # tinygo-llvm stage obtains the llvm source for TinyGo
-FROM golang:1.24 AS tinygo-llvm
+FROM golang:1.25 AS tinygo-llvm

 RUN apt-get update && \
-    apt-get install -y apt-utils make cmake clang-15 ninja-build && \
+    apt-get install -y apt-utils make cmake clang-17 ninja-build && \
    rm -rf \
        /var/lib/apt/lists/* \
        /var/log/* \
@@ -33,7 +33,7 @@ RUN cd /tinygo/ && \

 # tinygo-compiler copies the compiler build over to a base Go container (without
 # all the build tools etc).
-FROM golang:1.24 AS tinygo-compiler
+FROM golang:1.25 AS tinygo-compiler

 # Copy tinygo build.
 COPY --from=tinygo-compiler-build /tinygo/build/release/tinygo /tinygo
@@ -79,6 +79,26 @@ ifeq (1, $(STATIC))
    BINARYEN_OPTION += -DCMAKE_CXX_FLAGS="-static" -DCMAKE_C_FLAGS="-static"
 endif

+# Optimize the binary size for Linux.
+# These flags may work on other platforms, but have only been tested on Linux.
+ifeq ($(uname),Linux)
+    HAS_MOLD := $(shell command -v ld.mold 2> /dev/null)
+    HAS_LLD := $(shell command -v ld.lld 2> /dev/null)
+    LLVM_CFLAGS := -ffunction-sections -fdata-sections -fvisibility=hidden
+    LLVM_LDFLAGS := -Wl,--gc-sections
+    ifneq ($(HAS_MOLD),)
+        # Mold might be slightly faster.
+        LLVM_LDFLAGS += -fuse-ld=mold -Wl,--icf=all
+    else ifneq ($(HAS_LLD),)
+        # LLD is more commonly available.
+        LLVM_LDFLAGS += -fuse-ld=lld -Wl,--icf=all
+    endif
+    LLVM_OPTION += \
+        -DCMAKE_C_FLAGS="$(LLVM_CFLAGS)" \
+        -DCMAKE_CXX_FLAGS="$(LLVM_CFLAGS)"
+    CGO_LDFLAGS += $(LLVM_LDFLAGS)
+endif
+
 # Cross compiling support.
 ifneq ($(CROSS),)
    CC = $(CROSS)-gcc
@@ -243,7 +263,7 @@ gen-device-renesas: build/gen-device-svd
 	GO111MODULE=off $(GO) fmt ./src/device/renesas

 $(LLVM_PROJECTDIR)/llvm:
-	git clone -b xtensa_release_19.1.2 --depth=1 https://github.com/espressif/llvm-project $(LLVM_PROJECTDIR)
+	git clone -b tinygo_20.x --depth=1 https://github.com/tinygo-org/llvm-project $(LLVM_PROJECTDIR)
 llvm-source: $(LLVM_PROJECTDIR)/llvm ## Get LLVM sources

 # Configure LLVM.
@@ -460,11 +480,16 @@ TEST_PACKAGES_HOST := $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_WINDOWS)
 TEST_IOFS := false
 endif

+TEST_SKIP_FLAG := -skip='TestExtraMethods|TestParseAndBytesRoundTrip/P256/Generic'
+TEST_ADDITIONAL_FLAGS ?=
+
 # Test known-working standard library packages.
 # TODO: parallelize, and only show failing tests (no implied -v flag).
 .PHONY: tinygo-test
 tinygo-test:
-	$(TINYGO) test $(TEST_PACKAGES_HOST) $(TEST_PACKAGES_SLOW)
+	@# TestExtraMethods: used by many crypto packages and uses reflect.Type.Method which is not implemented.
+	@# TestParseAndBytesRoundTrip/P256/Generic: relies on t.Skip() which is not implemented
+	$(TINYGO) test $(TEST_ADDITIONAL_FLAGS) $(TEST_SKIP_FLAG) $(TEST_PACKAGES_HOST) $(TEST_PACKAGES_SLOW)
 	@# io/fs requires os.ReadDir, not yet supported on windows or wasi. It also
 	@# requires a large stack-size. Hence, io/fs is only run conditionally.
 	@# For more details, see the comments on issue #3143.
@@ -472,7 +497,7 @@ ifeq ($(TEST_IOFS),true)
 	$(TINYGO) test -stack-size=6MB io/fs
 endif
 tinygo-test-fast:
-	$(TINYGO) test $(TEST_PACKAGES_HOST)
+	$(TINYGO) test $(TEST_SKIP_FLAG) $(TEST_PACKAGES_HOST)
 tinygo-bench:
 	$(TINYGO) test -bench . $(TEST_PACKAGES_HOST) $(TEST_PACKAGES_SLOW)
 tinygo-bench-fast:
@@ -480,18 +505,18 @@ tinygo-bench-fast:

 # Same thing, except for wasi rather than the current platform.
 tinygo-test-wasm:
-	$(TINYGO) test -target wasm $(TEST_PACKAGES_WASM)
+	$(TINYGO) test -target wasm $(TEST_SKIP_FLAG) $(TEST_PACKAGES_WASM)
 tinygo-test-wasi:
-	$(TINYGO) test -target wasip1 $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW) ./tests/runtime_wasi
+	$(TINYGO) test -target wasip1 $(TEST_SKIP_FLAG) $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW) ./tests/runtime_wasi
 tinygo-test-wasip1:
-	GOOS=wasip1 GOARCH=wasm $(TINYGO) test $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW) ./tests/runtime_wasi
+	GOOS=wasip1 GOARCH=wasm $(TINYGO) test $(TEST_SKIP_FLAG) $(TEST_PACKAGES_FAST) $(TEST_PACKAGES_SLOW) ./tests/runtime_wasi
 tinygo-test-wasip1-fast:
-	$(TINYGO) test -target=wasip1 $(TEST_PACKAGES_FAST) ./tests/runtime_wasi
+	$(TINYGO) test -target=wasip1 $(TEST_SKIP_FLAG) $(TEST_PACKAGES_FAST) ./tests/runtime_wasi

 tinygo-test-wasip2-slow:
-	$(TINYGO) test -target=wasip2 $(TEST_PACKAGES_SLOW)
+	$(TINYGO) test -target=wasip2 $(TEST_SKIP_FLAG) $(TEST_PACKAGES_SLOW)
 tinygo-test-wasip2-fast:
-	$(TINYGO) test -target=wasip2 $(TEST_PACKAGES_FAST) ./tests/runtime_wasi
+	$(TINYGO) test -target=wasip2 $(TEST_SKIP_FLAG) $(TEST_PACKAGES_FAST) ./tests/runtime_wasi

 tinygo-test-wasip2-sum-slow:
 	TINYGO=$(TINYGO) \
@@ -517,7 +542,7 @@ tinygo-bench-wasip2-fast:

 # Run tests on riscv-qemu since that one provides a large amount of memory.
 tinygo-test-baremetal:
-	$(TINYGO) test -target riscv-qemu $(TEST_PACKAGES_BAREMETAL)
+	$(TINYGO) test -target riscv-qemu $(TEST_SKIP_FLAG) $(TEST_PACKAGES_BAREMETAL)

 # Test external packages in a large corpus.
 test-corpus:
@@ -597,6 +622,8 @@ smoketest: testchdir
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=feather-rp2040      examples/device-id
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=pico2-ice           examples/blinky1
+	@$(MD5SUM) test.hex
 	# test simulated boards on play.tinygo.org
 ifneq ($(WASM), 0)
 	GOOS=js GOARCH=wasm $(TINYGO) build -size short -o test.wasm -tags=arduino              examples/blinky1
@@ -771,6 +798,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=gopher-badge      examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=gopher-arcade      examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=ae-rp2040           examples/echo
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=thumby              examples/echo
@@ -781,6 +810,8 @@ endif
 	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=pico-plus2          examples/blinky1
 	@$(MD5SUM) test.hex
+	$(TINYGO) build -size short -o test.hex -target=metro-rp2350        examples/blinky1
+	@$(MD5SUM) test.hex
 	$(TINYGO) build -size short -o test.hex -target=waveshare-rp2040-tiny examples/echo
 	@$(MD5SUM) test.hex
 	# test pwm
@@ -884,6 +915,8 @@ ifneq ($(XTENSA), 0)
 	@$(MD5SUM) test.bin
 	$(TINYGO) build -size short -o test.bin -target mch2022             examples/machinetest
 	@$(MD5SUM) test.bin
+	$(TINYGO) build -size short -o test.bin -target=xiao-esp32s3   		examples/blinky1
+	@$(MD5SUM) test.bin
 endif
 	$(TINYGO) build -size short -o test.bin -target=esp-c3-32s-kit      examples/blinky1
 	@$(MD5SUM) test.bin
@@ -945,7 +978,7 @@ endif


 wasmtest:
-	$(GO) test ./tests/wasm
+	cd ./tests/wasm && $(GO) test .

 build/release: tinygo gen-device $(if $(filter 1,$(USE_SYSTEM_BINARYEN)),,binaryen)
 	@mkdir -p build/release/tinygo/bin
@@ -1092,6 +1125,7 @@ endif
 tools:
 	cd internal/tools && go generate -tags tools ./

+LINTDIRS=src/os/ src/reflect/
 .PHONY: lint
 lint: tools ## Lint source tree
 	revive -version
@@ -1099,7 +1133,10 @@ lint: tools ## Lint source tree
 	# revive.toml isn't flexible enough to filter out just one kind of error from a checker, so do it with grep here.
 	# Can't use grep with friendly formatter.  Plain output isn't too bad, though.
 	# Use 'grep .' to get rid of stray blank line
-	revive -config revive.toml compiler/... src/{os,reflect}/*.go | grep -v "should have comment or be unexported" | grep '.' | awk '{print}; END {exit NR>0}'
+	revive -config revive.toml compiler/... $$( find $(LINTDIRS) -type f -name '*.go' ) \
+		| grep -v "should have comment or be unexported" \
+		| grep '.' \
+		| awk '{print}; END {exit NR>0}'

 SPELLDIRSCMD=find . -depth 1 -type d  | egrep -wv '.git|lib|llvm|src'; find src -depth 1 | egrep -wv 'device|internal|net|vendor'; find src/internal -depth 1 -type d | egrep -wv src/internal/wasi
 .PHONY: spell
@@ -30,7 +30,10 @@ var BoehmGC = Library{
 			// Use a minimal environment.
 			"-DNO_MSGBOX_ON_ERROR", // don't call MessageBoxA on Windows
 			"-DDONT_USE_ATEXIT",
-			"-DNO_GETENV",
+			"-DNO_GETENV",          // smaller binary, more predictable configuration
+			"-DNO_CLOCK",           // don't use system clock
+			"-DNO_DEBUGGING",       // reduce code size
+			"-DGC_NO_FINALIZATION", // finalization is not used at the moment

 			// Special flag to work around the lack of __data_start in ld.lld.
 			// TODO: try to fix this in LLVM/lld directly so we don't have to
@@ -39,6 +42,8 @@ var BoehmGC = Library{

 			// Do not scan the stack. We have our own mechanism to do this.
 			"-DSTACK_NOT_SCANNED",
+			"-DNO_PROC_STAT",  // we scan the stack manually (don't read /proc/self/stat on Linux)
+			"-DSTACKBOTTOM=0", // dummy value, we scan the stack manually

 			// Assertions can be enabled while debugging GC issues.
 			//"-DGC_ASSERTIONS",
@@ -63,7 +68,6 @@ var BoehmGC = Library{
 			"blacklst.c",
 			"dbg_mlc.c",
 			"dyn_load.c",
-			"finalize.c",
 			"headers.c",
 			"mach_dep.c",
 			"malloc.c",
@@ -71,7 +75,6 @@ var BoehmGC = Library{
 			"mark_rts.c",
 			"misc.c",
 			"new_hblk.c",
-			"obj_map.c",
 			"os_dep.c",
 			"reclaim.c",
 		}
@@ -1042,11 +1042,11 @@ func Build(pkgName, outpath, tmpdir string, config *compileopts.Config) (BuildRe
 		if err != nil {
 			return result, err
 		}
-	case "esp32", "esp32-img", "esp32c3", "esp8266":
+	case "esp32", "esp32-img", "esp32c3", "esp32s3", "esp8266":
 		// Special format for the ESP family of chips (parsed by the ROM
 		// bootloader).
 		result.Binary = filepath.Join(tmpdir, "main"+outext)
-		err := makeESPFirmareImage(result.Executable, result.Binary, outputBinaryFormat)
+		err := makeESPFirmwareImage(result.Executable, result.Binary, outputBinaryFormat)
 		if err != nil {
 			return result, err
 		}
@@ -28,6 +28,7 @@ func TestClangAttributes(t *testing.T) {
 		"cortex-m4",
 		"cortex-m7",
 		"esp32c3",
+		"esp32s3",
 		"fe310",
 		"gameboy-advance",
 		"k210",
@@ -144,8 +144,6 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
            .Default(llvm::DebugCompressionType::None);
  }

-  Opts.RelaxELFRelocations = !Args.hasArg(OPT_mrelax_relocations_no);
-  Opts.SSE2AVX = Args.hasArg(OPT_msse2avx);
  if (auto *DwarfFormatArg = Args.getLastArg(OPT_gdwarf64, OPT_gdwarf32))
    Opts.Dwarf64 = DwarfFormatArg->getOption().matches(OPT_gdwarf64);
  Opts.DwarfVersion = getLastArgIntValue(Args, OPT_dwarf_version_EQ, 2, Diags);
@@ -236,6 +234,9 @@ bool AssemblerInvocation::CreateFromArgs(AssemblerInvocation &Opts,
  Opts.EmitCompactUnwindNonCanonical =
      Args.hasArg(OPT_femit_compact_unwind_non_canonical);
  Opts.Crel = Args.hasArg(OPT_crel);
+  Opts.ImplicitMapsyms = Args.hasArg(OPT_mmapsyms_implicit);
+  Opts.X86RelaxRelocations = !Args.hasArg(OPT_mrelax_relocations_no);
+  Opts.X86Sse2Avx = Args.hasArg(OPT_msse2avx);

  Opts.AsSecureLogFile = Args.getLastArgValue(OPT_as_secure_log_file);

@@ -294,8 +295,9 @@ static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
  MCOptions.EmitCompactUnwindNonCanonical = Opts.EmitCompactUnwindNonCanonical;
  MCOptions.MCSaveTempLabels = Opts.SaveTemporaryLabels;
  MCOptions.Crel = Opts.Crel;
-  MCOptions.X86RelaxRelocations = Opts.RelaxELFRelocations;
-  MCOptions.X86Sse2Avx = Opts.SSE2AVX;
+  MCOptions.ImplicitMapSyms = Opts.ImplicitMapsyms;
+  MCOptions.X86RelaxRelocations = Opts.X86RelaxRelocations;
+  MCOptions.X86Sse2Avx = Opts.X86Sse2Avx;
  MCOptions.CompressDebugSections = Opts.CompressDebugSections;
  MCOptions.AsSecureLogFile = Opts.AsSecureLogFile;

@@ -343,10 +345,6 @@ static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
  // MCObjectFileInfo needs a MCContext reference in order to initialize itself.
  std::unique_ptr<MCObjectFileInfo> MOFI(
      TheTarget->createMCObjectFileInfo(Ctx, PIC));
-  if (Opts.DarwinTargetVariantTriple)
-    MOFI->setDarwinTargetVariantTriple(*Opts.DarwinTargetVariantTriple);
-  if (!Opts.DarwinTargetVariantSDKVersion.empty())
-    MOFI->setDarwinTargetVariantSDKVersion(Opts.DarwinTargetVariantSDKVersion);
  Ctx.setObjectFileInfo(MOFI.get());

  if (Opts.GenDwarfForAssembly)
@@ -428,6 +426,13 @@ static bool ExecuteAssemblerImpl(AssemblerInvocation &Opts,
    Str.reset(TheTarget->createMCObjectStreamer(
        T, Ctx, std::move(MAB), std::move(OW), std::move(CE), *STI));
    Str.get()->initSections(Opts.NoExecStack, *STI);
+    if (T.isOSBinFormatMachO() && T.isOSDarwin()) {
+      Triple *TVT = Opts.DarwinTargetVariantTriple
+                        ? &*Opts.DarwinTargetVariantTriple
+                        : nullptr;
+      Str->emitVersionForTarget(T, VersionTuple(), TVT,
+                                Opts.DarwinTargetVariantSDKVersion);
+    }
  }

  // When -fembed-bitcode is passed to clang_as, a 1-byte marker
@@ -45,10 +45,6 @@ struct AssemblerInvocation {
  LLVM_PREFERRED_TYPE(bool)
  unsigned GenDwarfForAssembly : 1;
  LLVM_PREFERRED_TYPE(bool)
-  unsigned RelaxELFRelocations : 1;
-  LLVM_PREFERRED_TYPE(bool)
-  unsigned SSE2AVX : 1;
-  LLVM_PREFERRED_TYPE(bool)
  unsigned Dwarf64 : 1;
  unsigned DwarfVersion;
  std::string DwarfDebugFlags;
@@ -117,6 +113,13 @@ struct AssemblerInvocation {

  LLVM_PREFERRED_TYPE(bool)
  unsigned Crel : 1;
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned ImplicitMapsyms : 1;
+
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned X86RelaxRelocations : 1;
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned X86Sse2Avx : 1;

  /// The name of the relocation model to use.
  std::string RelocationModel;
@@ -148,7 +151,6 @@ public:
    ShowInst = 0;
    ShowEncoding = 0;
    RelaxAll = 0;
-    SSE2AVX = 0;
    NoExecStack = 0;
    FatalWarnings = 0;
    NoWarn = 0;
@@ -160,6 +162,9 @@ public:
    EmitDwarfUnwind = EmitDwarfUnwindType::Default;
    EmitCompactUnwindNonCanonical = false;
    Crel = false;
+    ImplicitMapsyms = 0;
+    X86RelaxRelocations = 0;
+    X86Sse2Avx = 0;
  }

  static bool CreateFromArgs(AssemblerInvocation &Res,
@@ -60,7 +60,7 @@ bool tinygo_clang_driver(int argc, char **argv) {
 			}

 			// Create the actual diagnostics engine.
-			Clang->createDiagnostics();
+			Clang->createDiagnostics(*llvm::vfs::getRealFileSystem());
 			if (!Clang->hasDiagnostics()) {
 				return false;
 			}
@@ -26,17 +26,20 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {

 	// Version range supported by TinyGo.
 	const minorMin = 19
-	const minorMax = 24
+	const minorMax = 25

 	// Check that we support this Go toolchain version.
 	gorootMajor, gorootMinor, err := goenv.GetGorootVersion()
 	if err != nil {
 		return nil, err
 	}
-	if gorootMajor != 1 || gorootMinor < minorMin || gorootMinor > minorMax {
-		// Note: when this gets updated, also update the Go compatibility matrix:
-		// https://github.com/tinygo-org/tinygo-site/blob/dev/content/docs/reference/go-compat-matrix.md
-		return nil, fmt.Errorf("requires go version 1.%d through 1.%d, got go%d.%d", minorMin, minorMax, gorootMajor, gorootMinor)
+
+	if options.GoCompatibility {
+		if gorootMajor != 1 || gorootMinor < minorMin || gorootMinor > minorMax {
+			// Note: when this gets updated, also update the Go compatibility matrix:
+			// https://github.com/tinygo-org/tinygo-site/blob/dev/content/docs/reference/go-compat-matrix.md
+			return nil, fmt.Errorf("requires go version 1.%d through 1.%d, got go%d.%d", minorMin, minorMax, gorootMajor, gorootMinor)
+		}
 	}

 	// Check that the Go toolchain version isn't too new, if we haven't been
@@ -23,7 +23,7 @@ type espImageSegment struct {
 	data []byte
 }

-// makeESPFirmareImage converts an input ELF file to an image file for an ESP32 or
+// makeESPFirmwareImage converts an input ELF file to an image file for an ESP32 or
 // ESP8266 chip. This is a special purpose image format just for the ESP chip
 // family, and is parsed by the on-chip mask ROM bootloader.
 //
@@ -31,7 +31,7 @@ type espImageSegment struct {
 // https://github.com/espressif/esptool/wiki/Firmware-Image-Format
 // https://github.com/espressif/esp-idf/blob/8fbb63c2a701c22ccf4ce249f43aded73e134a34/components/bootloader_support/include/esp_image_format.h#L58
 // https://github.com/espressif/esptool/blob/master/esptool.py
-func makeESPFirmareImage(infile, outfile, format string) error {
+func makeESPFirmwareImage(infile, outfile, format string) error {
 	inf, err := elf.Open(infile)
 	if err != nil {
 		return err
@@ -100,11 +100,12 @@ func makeESPFirmareImage(infile, outfile, format string) error {
 	chip_id := map[string]uint16{
 		"esp32":   0x0000,
 		"esp32c3": 0x0005,
+		"esp32s3": 0x0009,
 	}[chip]

 	// Image header.
 	switch chip {
-	case "esp32", "esp32c3":
+	case "esp32", "esp32c3", "esp32s3":
 		// Header format:
 		// https://github.com/espressif/esp-idf/blob/v4.3/components/bootloader_support/include/esp_app_format.h#L71
 		// Note: not adding a SHA256 hash as the binary is modified by
@@ -42,9 +42,9 @@ func TestBinarySize(t *testing.T) {
 	// This is a small number of very diverse targets that we want to test.
 	tests := []sizeTest{
 		// microcontrollers
-		{"hifive1b", "examples/echo", 4556, 280, 0, 2264},
-		{"microbit", "examples/serial", 2920, 388, 8, 2272},
-		{"wioterminal", "examples/pininterrupt", 7379, 1489, 116, 6912},
+		{"hifive1b", "examples/echo", 3668, 280, 0, 2244},
+		{"microbit", "examples/serial", 2694, 342, 8, 2248},
+		{"wioterminal", "examples/pininterrupt", 6833, 1491, 120, 6888},

 		// TODO: also check wasm. Right now this is difficult, because
 		// wasm binaries are run through wasm-opt and therefore the
@@ -226,7 +226,7 @@ func (c *Config) StackSize() uint64 {

 // MaxStackAlloc returns the size of the maximum allocation to put on the stack vs heap.
 func (c *Config) MaxStackAlloc() uint64 {
-	if c.StackSize() > 32*1024 {
+	if c.StackSize() >= 16*1024 {
 		return 1024
 	}

@@ -59,6 +59,7 @@ type Options struct {
 	WITPackage      string // pass through to wasm-tools component embed invocation
 	WITWorld        string // pass through to wasm-tools component embed -w option
 	ExtLDFlags      []string
+	GoCompatibility bool // enable to check for Go version compatibility
 }

 // Verify performs a validation on the given options, raising an error if options are not valid.
@@ -245,7 +245,7 @@ func (b *builder) createRuntimeAssert(assert llvm.Value, blockPrefix, assertFunc
 	// current insert position.
 	faultBlock := b.ctx.AddBasicBlock(b.llvmFn, blockPrefix+".throw")
 	nextBlock := b.insertBasicBlock(blockPrefix + ".next")
-	b.blockExits[b.currentBlock] = nextBlock // adjust outgoing block for phi nodes
+	b.currentBlockInfo.exit = nextBlock // adjust outgoing block for phi nodes

 	// Now branch to the out-of-bounds or the regular block.
 	b.CreateCondBr(assert, faultBlock, nextBlock)
@@ -32,6 +32,9 @@ const (
 	// Whether this is a full or partial Go parameter (int, slice, etc).
 	// The extra context parameter is not a Go parameter.
 	paramIsGoParam = 1 << iota
+
+	// Whether this is a readonly parameter (for example, a string pointer).
+	paramIsReadonly
 )

 // createRuntimeCallCommon creates a runtime call. Use createRuntimeCall or
@@ -167,6 +170,7 @@ func (c *compilerContext) flattenAggregateType(t llvm.Type, name string, goType
 				continue
 			}
 			suffix := strconv.Itoa(i)
+			isString := false
 			if goType != nil {
 				// Try to come up with a good suffix for this struct field,
 				// depending on which Go type it's based on.
@@ -183,12 +187,16 @@ func (c *compilerContext) flattenAggregateType(t llvm.Type, name string, goType
 						suffix = []string{"r", "i"}[i]
 					case types.String:
 						suffix = []string{"data", "len"}[i]
+						isString = true
 					}
 				case *types.Signature:
 					suffix = []string{"context", "funcptr"}[i]
 				}
 			}
 			subInfos := c.flattenAggregateType(subfield, name+"."+suffix, extractSubfield(goType, i))
+			if isString {
+				subInfos[0].flags |= paramIsReadonly
+			}
 			paramInfos = append(paramInfos, subInfos...)
 		}
 		return paramInfos
@@ -152,10 +152,12 @@ type builder struct {
 	llvmFnType        llvm.Type
 	llvmFn            llvm.Value
 	info              functionInfo
-	locals            map[ssa.Value]llvm.Value            // local variables
-	blockEntries      map[*ssa.BasicBlock]llvm.BasicBlock // a *ssa.BasicBlock may be split up
-	blockExits        map[*ssa.BasicBlock]llvm.BasicBlock // these are the exit blocks
+	locals            map[ssa.Value]llvm.Value // local variables
+	blockInfo         []blockInfo
 	currentBlock      *ssa.BasicBlock
+	currentBlockInfo  *blockInfo
+	tarjanStack       []uint
+	tarjanIndex       uint
 	phis              []phiNode
 	deferPtr          llvm.Value
 	deferFrame        llvm.Value
@@ -187,11 +189,22 @@ func newBuilder(c *compilerContext, irbuilder llvm.Builder, f *ssa.Function) *bu
 		info:            c.getFunctionInfo(f),
 		locals:          make(map[ssa.Value]llvm.Value),
 		dilocals:        make(map[*types.Var]llvm.Metadata),
-		blockEntries:    make(map[*ssa.BasicBlock]llvm.BasicBlock),
-		blockExits:      make(map[*ssa.BasicBlock]llvm.BasicBlock),
 	}
 }

+type blockInfo struct {
+	// entry is the LLVM basic block corresponding to the start of this *ssa.Block.
+	entry llvm.BasicBlock
+
+	// exit is the LLVM basic block corresponding to the end of this *ssa.Block.
+	// It will be different than entry if any of the block's instructions contain internal branches.
+	exit llvm.BasicBlock
+
+	// tarjan holds state for applying Tarjan's strongly connected components algorithm to the CFG.
+	// This is used by defer.go to determine whether to stack- or heap-allocate defer data.
+	tarjan tarjanNode
+}
+
 type deferBuiltin struct {
 	callName string
 	pos      token.Pos
@@ -1220,14 +1233,29 @@ func (b *builder) createFunctionStart(intrinsic bool) {
 		// intrinsic (like an atomic operation). Create the entry block
 		// manually.
 		entryBlock = b.ctx.AddBasicBlock(b.llvmFn, "entry")
-	} else {
-		for _, block := range b.fn.DomPreorder() {
-			llvmBlock := b.ctx.AddBasicBlock(b.llvmFn, block.Comment)
-			b.blockEntries[block] = llvmBlock
-			b.blockExits[block] = llvmBlock
+		// Intrinsics may create internal branches (e.g. nil checks).
+		// They will attempt to access b.currentBlockInfo to update the exit block.
+		// Create some fake block info for them to access.
+		blockInfo := []blockInfo{
+			{
+				entry: entryBlock,
+				exit:  entryBlock,
+			},
 		}
+		b.blockInfo = blockInfo
+		b.currentBlockInfo = &blockInfo[0]
+	} else {
+		blocks := b.fn.Blocks
+		blockInfo := make([]blockInfo, len(blocks))
+		for _, block := range b.fn.DomPreorder() {
+			info := &blockInfo[block.Index]
+			llvmBlock := b.ctx.AddBasicBlock(b.llvmFn, block.Comment)
+			info.entry = llvmBlock
+			info.exit = llvmBlock
+		}
+		b.blockInfo = blockInfo
 		// Normal functions have an entry block.
-		entryBlock = b.blockEntries[b.fn.Blocks[0]]
+		entryBlock = blockInfo[0].entry
 	}
 	b.SetInsertPointAtEnd(entryBlock)

@@ -1323,8 +1351,9 @@ func (b *builder) createFunction() {
 		if b.DumpSSA {
 			fmt.Printf("%d: %s:\n", block.Index, block.Comment)
 		}
-		b.SetInsertPointAtEnd(b.blockEntries[block])
 		b.currentBlock = block
+		b.currentBlockInfo = &b.blockInfo[block.Index]
+		b.SetInsertPointAtEnd(b.currentBlockInfo.entry)
 		for _, instr := range block.Instrs {
 			if instr, ok := instr.(*ssa.DebugRef); ok {
 				if !b.Debug {
@@ -1384,7 +1413,7 @@ func (b *builder) createFunction() {
 		block := phi.ssa.Block()
 		for i, edge := range phi.ssa.Edges {
 			llvmVal := b.getValue(edge, getPos(phi.ssa))
-			llvmBlock := b.blockExits[block.Preds[i]]
+			llvmBlock := b.blockInfo[block.Preds[i].Index].exit
 			phi.llvm.AddIncoming([]llvm.Value{llvmVal}, []llvm.BasicBlock{llvmBlock})
 		}
 	}
@@ -1498,11 +1527,11 @@ func (b *builder) createInstruction(instr ssa.Instruction) {
 	case *ssa.If:
 		cond := b.getValue(instr.Cond, getPos(instr))
 		block := instr.Block()
-		blockThen := b.blockEntries[block.Succs[0]]
-		blockElse := b.blockEntries[block.Succs[1]]
+		blockThen := b.blockInfo[block.Succs[0].Index].entry
+		blockElse := b.blockInfo[block.Succs[1].Index].entry
 		b.CreateCondBr(cond, blockThen, blockElse)
 	case *ssa.Jump:
-		blockJump := b.blockEntries[instr.Block().Succs[0]]
+		blockJump := b.blockInfo[instr.Block().Succs[0].Index].entry
 		b.CreateBr(blockJump)
 	case *ssa.MapUpdate:
 		m := b.getValue(instr.Map, getPos(instr))
@@ -1570,7 +1599,8 @@ func (b *builder) createBuiltin(argTypes []types.Type, argValues []llvm.Value, c
 		elemsLen := b.CreateExtractValue(elems, 1, "append.elemsLen")
 		elemType := b.getLLVMType(argTypes[0].Underlying().(*types.Slice).Elem())
 		elemSize := llvm.ConstInt(b.uintptrType, b.targetData.TypeAllocSize(elemType), false)
-		result := b.createRuntimeCall("sliceAppend", []llvm.Value{srcBuf, elemsBuf, srcLen, srcCap, elemsLen, elemSize}, "append.new")
+		elemLayout := b.createObjectLayout(elemType, pos)
+		result := b.createRuntimeCall("sliceAppend", []llvm.Value{srcBuf, elemsBuf, srcLen, srcCap, elemsLen, elemSize, elemLayout}, "append.new")
 		newPtr := b.CreateExtractValue(result, 0, "append.newPtr")
 		newLen := b.CreateExtractValue(result, 1, "append.newLen")
 		newCap := b.CreateExtractValue(result, 2, "append.newCap")
@@ -100,7 +100,7 @@ func (b *builder) createLandingPad() {

 	// Continue at the 'recover' block, which returns to the parent in an
 	// appropriate way.
-	b.CreateBr(b.blockEntries[b.fn.Recover])
+	b.CreateBr(b.blockInfo[b.fn.Recover.Index].entry)
 }

 // Create a checkpoint (similar to setjmp). This emits inline assembly that
@@ -234,41 +234,108 @@ func (b *builder) createInvokeCheckpoint() {
 	continueBB := b.insertBasicBlock("")
 	b.CreateCondBr(isZero, continueBB, b.landingpad)
 	b.SetInsertPointAtEnd(continueBB)
-	b.blockExits[b.currentBlock] = continueBB
+	b.currentBlockInfo.exit = continueBB
 }

-// isInLoop checks if there is a path from a basic block to itself.
-func isInLoop(start *ssa.BasicBlock) bool {
-	// Use a breadth-first search to scan backwards through the block graph.
-	queue := []*ssa.BasicBlock{start}
-	checked := map[*ssa.BasicBlock]struct{}{}
+// isInLoop checks if there is a path from the current block to itself.
+// Use Tarjan's strongly connected components algorithm to search for cycles.
+// A one-node SCC is a cycle iff there is an edge from the node to itself.
+// A multi-node SCC is always a cycle.
+// https://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm
+func (b *builder) isInLoop() bool {
+	if b.currentBlockInfo.tarjan.lowLink == 0 {
+		b.strongConnect(b.currentBlock)
+	}
+	return b.currentBlockInfo.tarjan.cyclic
+}

-	for len(queue) > 0 {
-		// pop a block off of the queue
-		block := queue[len(queue)-1]
-		queue = queue[:len(queue)-1]
+func (b *builder) strongConnect(block *ssa.BasicBlock) {
+	// Assign a new index.
+	// Indices start from 1 so that 0 can be used as a sentinel.
+	assignedIndex := b.tarjanIndex + 1
+	b.tarjanIndex = assignedIndex

-		// Search through predecessors.
-		// Searching backwards means that this is pretty fast when the block is close to the start of the function.
-		// Defers are often placed near the start of the function.
-		for _, pred := range block.Preds {
-			if pred == start {
-				// cycle found
-				return true
-			}
+	// Apply the new index.
+	blockIndex := block.Index
+	node := &b.blockInfo[blockIndex].tarjan
+	node.lowLink = assignedIndex

-			if _, ok := checked[pred]; ok {
-				// block already checked
-				continue
-			}
+	// Push the node onto the stack.
+	node.onStack = true
+	b.tarjanStack = append(b.tarjanStack, uint(blockIndex))

-			// add to queue and checked map
-			queue = append(queue, pred)
-			checked[pred] = struct{}{}
+	// Process the successors.
+	for _, successor := range block.Succs {
+		// Look up the successor's state.
+		successorIndex := successor.Index
+		if successorIndex == blockIndex {
+			// Handle a self-cycle specially.
+			node.cyclic = true
+			continue
+		}
+		successorNode := &b.blockInfo[successorIndex].tarjan
+
+		switch {
+		case successorNode.lowLink == 0:
+			// This node has not yet been visisted.
+			b.strongConnect(successor)
+
+		case !successorNode.onStack:
+			// This node has been visited, but is in a different SCC.
+			// Ignore it, and do not update lowLink.
+			continue
+		}
+
+		// Update the lowLink index.
+		// This always uses the min-of-lowlink instead of using index in the on-stack case.
+		// This is done for two reasons:
+		// 1. The lowLink update can be shared between the new-node and on-stack cases.
+		// 2. The assigned index does not need to be saved - it is only needed for root node detection.
+		if successorNode.lowLink < node.lowLink {
+			node.lowLink = successorNode.lowLink
 		}
 	}

-	return false
+	if node.lowLink == assignedIndex {
+		// This is a root node.
+		// Pop the SCC off the stack.
+		stack := b.tarjanStack
+		top := stack[len(stack)-1]
+		stack = stack[:len(stack)-1]
+		blocks := b.blockInfo
+		topNode := &blocks[top].tarjan
+		topNode.onStack = false
+
+		if top != uint(blockIndex) {
+			// The root node is not the only node in the SCC.
+			// Mark all nodes in this SCC as cyclic.
+			topNode.cyclic = true
+			for top != uint(blockIndex) {
+				top = stack[len(stack)-1]
+				stack = stack[:len(stack)-1]
+				topNode = &blocks[top].tarjan
+				topNode.onStack = false
+				topNode.cyclic = true
+			}
+		}
+
+		b.tarjanStack = stack
+	}
+}
+
+// tarjanNode holds per-block state for isInLoop and strongConnect.
+type tarjanNode struct {
+	// lowLink is the index of the first visited node that is reachable from this block.
+	// The lowLink indices are assigned by the SCC search, and do not correspond to b.Index.
+	// A lowLink of 0 is used as a sentinel to mark a node which has not yet been visited.
+	lowLink uint
+
+	// onStack tracks whether this node is currently on the SCC search stack.
+	onStack bool
+
+	// cyclic indicates whether this block is in a loop.
+	// If lowLink is 0, strongConnect must be called before reading this field.
+	cyclic bool
 }

 // createDefer emits a single defer instruction, to be run when this function
@@ -410,7 +477,10 @@ func (b *builder) createDefer(instr *ssa.Defer) {

 	// Put this struct in an allocation.
 	var alloca llvm.Value
-	if !isInLoop(instr.Block()) {
+	if instr.Block() != b.currentBlock {
+		panic("block mismatch")
+	}
+	if !b.isInLoop() {
 		// This can safely use a stack allocation.
 		alloca = llvmutil.CreateEntryBlockAlloca(b.Builder, deferredCallType, "defer.alloca")
 	} else {
@@ -38,10 +38,10 @@ func (b *builder) createInlineAsm(args []ssa.Value) (llvm.Value, error) {
 // provided immediately. For example:
 //
 //	arm.AsmFull(
-//	    "str {value}, {result}",
+//	    "str {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 func (b *builder) createInlineAsmFull(instr *ssa.CallCommon) (llvm.Value, error) {
 	asmString := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
@@ -737,7 +737,7 @@ func (b *builder) createTypeAssert(expr *ssa.TypeAssert) llvm.Value {
 	prevBlock := b.GetInsertBlock()
 	okBlock := b.insertBasicBlock("typeassert.ok")
 	nextBlock := b.insertBasicBlock("typeassert.next")
-	b.blockExits[b.currentBlock] = nextBlock // adjust outgoing block for phi nodes
+	b.currentBlockInfo.exit = nextBlock // adjust outgoing block for phi nodes
 	b.CreateCondBr(commaOk, okBlock, nextBlock)

 	// Retrieve the value from the interface if the type assert was
@@ -27,6 +27,8 @@ func (b *builder) defineIntrinsicFunction() {
 		b.createStackSaveImpl()
 	case name == "runtime.KeepAlive":
 		b.createKeepAliveImpl()
+	case name == "machine.keepAliveNoEscape":
+		b.createMachineKeepAliveImpl()
 	case strings.HasPrefix(name, "runtime/volatile.Load"):
 		b.createVolatileLoad()
 	case strings.HasPrefix(name, "runtime/volatile.Store"):
@@ -121,6 +123,43 @@ func (b *builder) createKeepAliveImpl() {
 	b.CreateRetVoid()
 }

+// createAbiEscapeImpl implements the generic internal/abi.Escape function. It
+// currently only supports pointer types.
+func (b *builder) createAbiEscapeImpl() {
+	b.createFunctionStart(true)
+
+	// The first parameter is assumed to be a pointer. This is checked at the
+	// call site of createAbiEscapeImpl.
+	pointerValue := b.getValue(b.fn.Params[0], getPos(b.fn))
+
+	// Create an equivalent of the following C code, which is basically just a
+	// nop but ensures the pointerValue is kept alive:
+	//
+	//     __asm__ __volatile__("" : : "r"(pointerValue))
+	//
+	// It should be portable to basically everything as the "r" register type
+	// exists basically everywhere.
+	asmType := llvm.FunctionType(b.dataPtrType, []llvm.Type{b.dataPtrType}, false)
+	asmFn := llvm.InlineAsm(asmType, "", "=r,0", true, false, 0, false)
+	result := b.createCall(asmType, asmFn, []llvm.Value{pointerValue}, "")
+
+	b.CreateRet(result)
+}
+
+// Implement machine.keepAliveNoEscape, which makes sure the compiler keeps the
+// pointer parameter alive until this point (for GC).
+func (b *builder) createMachineKeepAliveImpl() {
+	b.createFunctionStart(true)
+	pointerValue := b.getValue(b.fn.Params[0], getPos(b.fn))
+
+	// See createKeepAliveImpl for details.
+	asmType := llvm.FunctionType(b.ctx.VoidType(), []llvm.Type{b.dataPtrType}, false)
+	asmFn := llvm.InlineAsm(asmType, "", "r", true, false, 0, false)
+	b.createCall(asmType, asmFn, []llvm.Value{pointerValue}, "")
+
+	b.CreateRetVoid()
+}
+
 var mathToLLVMMapping = map[string]string{
 	"math.Ceil":  "llvm.ceil.f64",
 	"math.Exp":   "llvm.exp.f64",
@@ -218,7 +218,7 @@ func Version() int {
 	return major
 }

-// Return the byte order for the given target triple. Most targets are little
+// ByteOrder returns the byte order for the given target triple. Most targets are little
 // endian, but for example MIPS can be big-endian.
 func ByteOrder(target string) binary.ByteOrder {
 	if strings.HasPrefix(target, "mips-") {
@@ -250,6 +250,9 @@ func (b *builder) createMapIteratorNext(rangeVal ssa.Value, llvmRangeVal, it llv
 func hashmapIsBinaryKey(keyType types.Type) bool {
 	switch keyType := keyType.Underlying().(type) {
 	case *types.Basic:
+		// TODO: unsafe.Pointer is also a binary key, but to support that we
+		// need to fix an issue with interp first (see
+		// https://github.com/tinygo-org/tinygo/pull/4898).
 		return keyType.Info()&(types.IsBoolean|types.IsInteger) != 0
 	case *types.Pointer:
 		return true
@@ -142,6 +142,11 @@ func (c *compilerContext) getFunction(fn *ssa.Function) (llvm.Type, llvm.Value)
 			nocapture := c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0)
 			llvmFn.AddAttributeAtIndex(i+1, nocapture)
 		}
+		if paramInfo.flags&paramIsReadonly != 0 && paramInfo.llvmType.TypeKind() == llvm.PointerTypeKind {
+			// Readonly pointer parameters (like strings) benefit from being marked as readonly.
+			readonly := c.ctx.CreateEnumAttribute(llvm.AttributeKindID("readonly"), 0)
+			llvmFn.AddAttributeAtIndex(i+1, readonly)
+		}
 	}

 	// Set a number of function or parameter attributes, depending on the
@@ -154,6 +159,8 @@ func (c *compilerContext) getFunction(fn *ssa.Function) (llvm.Type, llvm.Value)
 		llvmFn.AddFunctionAttr(c.ctx.CreateEnumAttribute(llvm.AttributeKindID("noreturn"), 0))
 	case "internal/abi.NoEscape":
 		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
+	case "machine.keepAliveNoEscape", "machine.unsafeNoEscape":
+		llvmFn.AddAttributeAtIndex(1, c.ctx.CreateEnumAttribute(llvm.AttributeKindID("nocapture"), 0))
 	case "runtime.alloc":
 		// Tell the optimizer that runtime.alloc is an allocator, meaning that it
 		// returns values that are never null and never alias to an existing value.
@@ -253,6 +260,23 @@ func (c *compilerContext) maybeCreateSyntheticFunction(fn *ssa.Function, llvmFn
 	// The exception is the package initializer, which does appear in the
 	// *ssa.Package members and so shouldn't be created here.
 	if fn.Synthetic != "" && fn.Synthetic != "package initializer" && fn.Synthetic != "generic function" && fn.Synthetic != "range-over-func yield" {
+		if origin := fn.Origin(); origin != nil && origin.RelString(nil) == "internal/abi.Escape" {
+			// This is a special implementation or internal/abi.Escape, which
+			// can only really be implemented in the compiler.
+			// For simplicity we'll only implement pointer parameters for now.
+			if _, ok := fn.Params[0].Type().Underlying().(*types.Pointer); ok {
+				irbuilder := c.ctx.NewBuilder()
+				defer irbuilder.Dispose()
+				b := newBuilder(c, irbuilder, fn)
+				b.createAbiEscapeImpl()
+				llvmFn.SetLinkage(llvm.LinkOnceODRLinkage)
+				llvmFn.SetUnnamedAddr(true)
+			}
+			// If the parameter is not of a pointer type, it will be left
+			// unimplemented. This will result in a linker error if the function
+			// is really called, making it clear it needs to be implemented.
+			return
+		}
 		if len(fn.Blocks) == 0 {
 			c.addError(fn.Pos(), "missing function body")
 			return
@@ -613,7 +637,7 @@ func (c *compilerContext) addStandardAttributes(llvmFn llvm.Value) {
 // linkName is equal to .RelString(nil) on a global and extern is false, but for
 // some symbols this is different (due to //go:extern for example).
 type globalInfo struct {
-	linkName string // go:extern
+	linkName string // go:extern, go:linkname
 	extern   bool   // go:extern
 	align    int    // go:align
 	section  string // go:section
@@ -698,14 +722,14 @@ func (c *compilerContext) getGlobalInfo(g *ssa.Global) globalInfo {
 	// Check for //go: pragmas, which may change the link name (among others).
 	doc := c.astComments[info.linkName]
 	if doc != nil {
-		info.parsePragmas(doc)
+		info.parsePragmas(doc, c, g)
 	}
 	return info
 }

 // Parse //go: pragma comments from the source. In particular, it parses the
-// //go:extern pragma on globals.
-func (info *globalInfo) parsePragmas(doc *ast.CommentGroup) {
+// //go:extern and //go:linkname pragmas on globals.
+func (info *globalInfo) parsePragmas(doc *ast.CommentGroup, c *compilerContext, g *ssa.Global) {
 	for _, comment := range doc.List {
 		if !strings.HasPrefix(comment.Text, "//go:") {
 			continue
@@ -726,6 +750,17 @@ func (info *globalInfo) parsePragmas(doc *ast.CommentGroup) {
 			if len(parts) == 2 {
 				info.section = parts[1]
 			}
+		case "//go:linkname":
+			if len(parts) != 3 || parts[1] != g.Name() {
+				continue
+			}
+			// Only enable go:linkname when the package imports "unsafe".
+			// This is a slightly looser requirement than what gc uses: gc
+			// requires the file to import "unsafe", not the package as a
+			// whole.
+			if hasUnsafeImport(g.Pkg.Pkg) {
+				info.linkName = parts[2]
+			}
 		}
 	}
 }
@@ -74,6 +74,14 @@ func (b *builder) createRawSyscall(call *ssa.CallCommon) (llvm.Value, error) {
 		return b.CreateCall(fnType, target, args, ""), nil

 	case b.GOARCH == "arm" && b.GOOS == "linux":
+		if arch := b.archFamily(); arch != "arm" {
+			// Some targets pretend to be linux/arm for compatibility but aren't
+			// actually such a system. Make sure we emit an error instead of
+			// creating inline assembly that will fail to compile.
+			// See: https://github.com/tinygo-org/tinygo/issues/4959
+			return llvm.Value{}, b.makeError(call.Pos(), "system calls are not supported: target emulates a linux/arm system on "+arch)
+		}
+
 		// Implement the EABI system call convention for Linux.
 		// Source: syscall(2) man page.
 		args := []llvm.Value{}
@@ -1,6 +1,6 @@
 ; ModuleID = 'basic.go'
 source_filename = "basic.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %main.kv = type { float, i32, i32, i32 }
@@ -206,7 +206,7 @@ entry:
  ret void
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'channel.go'
 source_filename = "channel.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime.channelOp = type { ptr, ptr, i32, ptr }
@@ -82,11 +82,11 @@ entry:
  store i32 1, ptr %select.send.value, align 4
  call void @llvm.lifetime.start.p0(i64 16, ptr nonnull %select.states.alloca)
  store ptr %ch1, ptr %select.states.alloca, align 4
-  %select.states.alloca.repack1 = getelementptr inbounds i8, ptr %select.states.alloca, i32 4
+  %select.states.alloca.repack1 = getelementptr inbounds nuw i8, ptr %select.states.alloca, i32 4
  store ptr %select.send.value, ptr %select.states.alloca.repack1, align 4
-  %0 = getelementptr inbounds i8, ptr %select.states.alloca, i32 8
+  %0 = getelementptr inbounds nuw i8, ptr %select.states.alloca, i32 8
  store ptr %ch2, ptr %0, align 4
-  %.repack3 = getelementptr inbounds i8, ptr %select.states.alloca, i32 12
+  %.repack3 = getelementptr inbounds nuw i8, ptr %select.states.alloca, i32 12
  store ptr null, ptr %.repack3, align 4
  %select.result = call { i32, i1 } @runtime.chanSelect(ptr undef, ptr nonnull %select.states.alloca, i32 2, i32 2, ptr null, i32 0, i32 0, ptr undef) #4
  call void @llvm.lifetime.end.p0(i64 16, ptr nonnull %select.states.alloca)
@@ -107,8 +107,8 @@ select.body:                                      ; preds = %select.next

 declare { i32, i1 } @runtime.chanSelect(ptr, ptr, i32, i32, ptr, i32, i32, ptr) #1

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 attributes #4 = { nounwind }
@@ -27,7 +27,7 @@ entry:
  %0 = call ptr @llvm.stacksave.p0()
  call void @runtime.setupDeferFrame(ptr nonnull %deferframe.buf, ptr %0, ptr undef) #4
  store i32 0, ptr %defer.alloca, align 4
-  %defer.alloca.repack15 = getelementptr inbounds i8, ptr %defer.alloca, i32 4
+  %defer.alloca.repack15 = getelementptr inbounds nuw i8, ptr %defer.alloca, i32 4
  store ptr null, ptr %defer.alloca.repack15, align 4
  store ptr %defer.alloca, ptr %deferPtr, align 4
  %setjmp = call i32 asm "\0Amovs r0, #0\0Amov r2, pc\0Astr r2, [r1, #4]", "={r0},{r1},~{r1},~{r2},~{r3},~{r4},~{r5},~{r6},~{r7},~{r8},~{r9},~{r10},~{r11},~{r12},~{lr},~{q0},~{q1},~{q2},~{q3},~{q4},~{q5},~{q6},~{q7},~{q8},~{q9},~{q10},~{q11},~{q12},~{q13},~{q14},~{q15},~{cpsr},~{memory}"(ptr nonnull %deferframe.buf) #5
@@ -51,7 +51,7 @@ rundefers.loophead:                               ; preds = %3, %rundefers.block
  br i1 %stackIsNil, label %rundefers.end, label %rundefers.loop

 rundefers.loop:                                   ; preds = %rundefers.loophead
-  %stack.next.gep = getelementptr inbounds i8, ptr %2, i32 4
+  %stack.next.gep = getelementptr inbounds nuw i8, ptr %2, i32 4
  %stack.next = load ptr, ptr %stack.next.gep, align 4
  store ptr %stack.next, ptr %deferPtr, align 4
  %callback = load i32, ptr %2, align 4
@@ -87,7 +87,7 @@ rundefers.loophead6:                              ; preds = %5, %lpad
  br i1 %stackIsNil7, label %rundefers.end3, label %rundefers.loop5

 rundefers.loop5:                                  ; preds = %rundefers.loophead6
-  %stack.next.gep8 = getelementptr inbounds i8, ptr %4, i32 4
+  %stack.next.gep8 = getelementptr inbounds nuw i8, ptr %4, i32 4
  %stack.next9 = load ptr, ptr %stack.next.gep8, align 4
  store ptr %stack.next9, ptr %deferPtr, align 4
  %callback11 = load i32, ptr %4, align 4
@@ -144,11 +144,11 @@ entry:
  %0 = call ptr @llvm.stacksave.p0()
  call void @runtime.setupDeferFrame(ptr nonnull %deferframe.buf, ptr %0, ptr undef) #4
  store i32 0, ptr %defer.alloca, align 4
-  %defer.alloca.repack22 = getelementptr inbounds i8, ptr %defer.alloca, i32 4
+  %defer.alloca.repack22 = getelementptr inbounds nuw i8, ptr %defer.alloca, i32 4
  store ptr null, ptr %defer.alloca.repack22, align 4
  store ptr %defer.alloca, ptr %deferPtr, align 4
  store i32 1, ptr %defer.alloca2, align 4
-  %defer.alloca2.repack23 = getelementptr inbounds i8, ptr %defer.alloca2, i32 4
+  %defer.alloca2.repack23 = getelementptr inbounds nuw i8, ptr %defer.alloca2, i32 4
  store ptr %defer.alloca, ptr %defer.alloca2.repack23, align 4
  store ptr %defer.alloca2, ptr %deferPtr, align 4
  %setjmp = call i32 asm "\0Amovs r0, #0\0Amov r2, pc\0Astr r2, [r1, #4]", "={r0},{r1},~{r1},~{r2},~{r3},~{r4},~{r5},~{r6},~{r7},~{r8},~{r9},~{r10},~{r11},~{r12},~{lr},~{q0},~{q1},~{q2},~{q3},~{q4},~{q5},~{q6},~{q7},~{q8},~{q9},~{q10},~{q11},~{q12},~{q13},~{q14},~{q15},~{cpsr},~{memory}"(ptr nonnull %deferframe.buf) #5
@@ -172,7 +172,7 @@ rundefers.loophead:                               ; preds = %4, %3, %rundefers.b
  br i1 %stackIsNil, label %rundefers.end, label %rundefers.loop

 rundefers.loop:                                   ; preds = %rundefers.loophead
-  %stack.next.gep = getelementptr inbounds i8, ptr %2, i32 4
+  %stack.next.gep = getelementptr inbounds nuw i8, ptr %2, i32 4
  %stack.next = load ptr, ptr %stack.next.gep, align 4
  store ptr %stack.next, ptr %deferPtr, align 4
  %callback = load i32, ptr %2, align 4
@@ -218,7 +218,7 @@ rundefers.loophead10:                             ; preds = %7, %6, %lpad
  br i1 %stackIsNil11, label %rundefers.end7, label %rundefers.loop9

 rundefers.loop9:                                  ; preds = %rundefers.loophead10
-  %stack.next.gep12 = getelementptr inbounds i8, ptr %5, i32 4
+  %stack.next.gep12 = getelementptr inbounds nuw i8, ptr %5, i32 4
  %stack.next13 = load ptr, ptr %stack.next.gep12, align 4
  store ptr %stack.next13, ptr %deferPtr, align 4
  %callback15 = load i32, ptr %5, align 4
@@ -270,6 +270,241 @@ entry:
  ret void
 }

+; Function Attrs: nounwind
+define hidden void @main.deferInfiniteLoop(ptr %context) unnamed_addr #1 {
+entry:
+  %deferPtr = alloca ptr, align 4
+  store ptr null, ptr %deferPtr, align 4
+  %deferframe.buf = alloca %runtime.deferFrame, align 4
+  %0 = call ptr @llvm.stacksave.p0()
+  call void @runtime.setupDeferFrame(ptr nonnull %deferframe.buf, ptr %0, ptr undef) #4
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %defer.next = load ptr, ptr %deferPtr, align 4
+  %defer.alloc.call = call dereferenceable(12) ptr @runtime.alloc(i32 12, ptr null, ptr undef) #4
+  store i32 0, ptr %defer.alloc.call, align 4
+  %defer.alloc.call.repack1 = getelementptr inbounds nuw i8, ptr %defer.alloc.call, i32 4
+  store ptr %defer.next, ptr %defer.alloc.call.repack1, align 4
+  %defer.alloc.call.repack3 = getelementptr inbounds nuw i8, ptr %defer.alloc.call, i32 8
+  store i32 8, ptr %defer.alloc.call.repack3, align 4
+  store ptr %defer.alloc.call, ptr %deferPtr, align 4
+  br label %for.body
+
+recover:                                          ; preds = %rundefers.end
+  ret void
+
+lpad:                                             ; No predecessors!
+  br label %rundefers.loophead
+
+rundefers.loophead:                               ; preds = %rundefers.callback0, %lpad
+  br i1 poison, label %rundefers.end, label %rundefers.loop
+
+rundefers.loop:                                   ; preds = %rundefers.loophead
+  switch i32 poison, label %rundefers.default [
+    i32 0, label %rundefers.callback0
+  ]
+
+rundefers.callback0:                              ; preds = %rundefers.loop
+  br label %rundefers.loophead
+
+rundefers.default:                                ; preds = %rundefers.loop
+  unreachable
+
+rundefers.end:                                    ; preds = %rundefers.loophead
+  br label %recover
+}
+
+; Function Attrs: nounwind
+define hidden void @main.deferLoop(ptr %context) unnamed_addr #1 {
+entry:
+  %deferPtr = alloca ptr, align 4
+  store ptr null, ptr %deferPtr, align 4
+  %deferframe.buf = alloca %runtime.deferFrame, align 4
+  %0 = call ptr @llvm.stacksave.p0()
+  call void @runtime.setupDeferFrame(ptr nonnull %deferframe.buf, ptr %0, ptr undef) #4
+  br label %for.loop
+
+for.loop:                                         ; preds = %for.body, %entry
+  %1 = phi i32 [ 0, %entry ], [ %3, %for.body ]
+  %2 = icmp slt i32 %1, 10
+  br i1 %2, label %for.body, label %for.done
+
+for.body:                                         ; preds = %for.loop
+  %defer.next = load ptr, ptr %deferPtr, align 4
+  %defer.alloc.call = call dereferenceable(12) ptr @runtime.alloc(i32 12, ptr null, ptr undef) #4
+  store i32 0, ptr %defer.alloc.call, align 4
+  %defer.alloc.call.repack13 = getelementptr inbounds nuw i8, ptr %defer.alloc.call, i32 4
+  store ptr %defer.next, ptr %defer.alloc.call.repack13, align 4
+  %defer.alloc.call.repack15 = getelementptr inbounds nuw i8, ptr %defer.alloc.call, i32 8
+  store i32 %1, ptr %defer.alloc.call.repack15, align 4
+  store ptr %defer.alloc.call, ptr %deferPtr, align 4
+  %3 = add i32 %1, 1
+  br label %for.loop
+
+for.done:                                         ; preds = %for.loop
+  br label %rundefers.block
+
+rundefers.after:                                  ; preds = %rundefers.end
+  call void @runtime.destroyDeferFrame(ptr nonnull %deferframe.buf, ptr undef) #4
+  ret void
+
+rundefers.block:                                  ; preds = %for.done
+  br label %rundefers.loophead
+
+rundefers.loophead:                               ; preds = %rundefers.callback0, %rundefers.block
+  %4 = load ptr, ptr %deferPtr, align 4
+  %stackIsNil = icmp eq ptr %4, null
+  br i1 %stackIsNil, label %rundefers.end, label %rundefers.loop
+
+rundefers.loop:                                   ; preds = %rundefers.loophead
+  %stack.next.gep = getelementptr inbounds nuw i8, ptr %4, i32 4
+  %stack.next = load ptr, ptr %stack.next.gep, align 4
+  store ptr %stack.next, ptr %deferPtr, align 4
+  %callback = load i32, ptr %4, align 4
+  switch i32 %callback, label %rundefers.default [
+    i32 0, label %rundefers.callback0
+  ]
+
+rundefers.callback0:                              ; preds = %rundefers.loop
+  %gep = getelementptr inbounds nuw i8, ptr %4, i32 8
+  %param = load i32, ptr %gep, align 4
+  call void @runtime.printlock(ptr undef) #4
+  call void @runtime.printint32(i32 %param, ptr undef) #4
+  call void @runtime.printunlock(ptr undef) #4
+  br label %rundefers.loophead
+
+rundefers.default:                                ; preds = %rundefers.loop
+  unreachable
+
+rundefers.end:                                    ; preds = %rundefers.loophead
+  br label %rundefers.after
+
+recover:                                          ; preds = %rundefers.end1
+  ret void
+
+lpad:                                             ; No predecessors!
+  br label %rundefers.loophead4
+
+rundefers.loophead4:                              ; preds = %rundefers.callback010, %lpad
+  br i1 poison, label %rundefers.end1, label %rundefers.loop3
+
+rundefers.loop3:                                  ; preds = %rundefers.loophead4
+  switch i32 poison, label %rundefers.default2 [
+    i32 0, label %rundefers.callback010
+  ]
+
+rundefers.callback010:                            ; preds = %rundefers.loop3
+  br label %rundefers.loophead4
+
+rundefers.default2:                               ; preds = %rundefers.loop3
+  unreachable
+
+rundefers.end1:                                   ; preds = %rundefers.loophead4
+  br label %recover
+}
+
+; Function Attrs: nounwind
+define hidden void @main.deferBetweenLoops(ptr %context) unnamed_addr #1 {
+entry:
+  %defer.alloca = alloca { i32, ptr, i32 }, align 4
+  %deferPtr = alloca ptr, align 4
+  store ptr null, ptr %deferPtr, align 4
+  %deferframe.buf = alloca %runtime.deferFrame, align 4
+  %0 = call ptr @llvm.stacksave.p0()
+  call void @runtime.setupDeferFrame(ptr nonnull %deferframe.buf, ptr %0, ptr undef) #4
+  br label %for.loop
+
+for.loop:                                         ; preds = %for.body, %entry
+  %1 = phi i32 [ 0, %entry ], [ %3, %for.body ]
+  %2 = icmp slt i32 %1, 10
+  br i1 %2, label %for.body, label %for.done
+
+for.body:                                         ; preds = %for.loop
+  %3 = add i32 %1, 1
+  br label %for.loop
+
+for.done:                                         ; preds = %for.loop
+  %defer.next = load ptr, ptr %deferPtr, align 4
+  store i32 0, ptr %defer.alloca, align 4
+  %defer.alloca.repack16 = getelementptr inbounds nuw i8, ptr %defer.alloca, i32 4
+  store ptr %defer.next, ptr %defer.alloca.repack16, align 4
+  %defer.alloca.repack18 = getelementptr inbounds nuw i8, ptr %defer.alloca, i32 8
+  store i32 1, ptr %defer.alloca.repack18, align 4
+  store ptr %defer.alloca, ptr %deferPtr, align 4
+  br label %for.loop1
+
+for.loop1:                                        ; preds = %for.body2, %for.done
+  %4 = phi i32 [ 0, %for.done ], [ %6, %for.body2 ]
+  %5 = icmp slt i32 %4, 10
+  br i1 %5, label %for.body2, label %for.done3
+
+for.body2:                                        ; preds = %for.loop1
+  %6 = add i32 %4, 1
+  br label %for.loop1
+
+for.done3:                                        ; preds = %for.loop1
+  br label %rundefers.block
+
+rundefers.after:                                  ; preds = %rundefers.end
+  call void @runtime.destroyDeferFrame(ptr nonnull %deferframe.buf, ptr undef) #4
+  ret void
+
+rundefers.block:                                  ; preds = %for.done3
+  br label %rundefers.loophead
+
+rundefers.loophead:                               ; preds = %rundefers.callback0, %rundefers.block
+  %7 = load ptr, ptr %deferPtr, align 4
+  %stackIsNil = icmp eq ptr %7, null
+  br i1 %stackIsNil, label %rundefers.end, label %rundefers.loop
+
+rundefers.loop:                                   ; preds = %rundefers.loophead
+  %stack.next.gep = getelementptr inbounds nuw i8, ptr %7, i32 4
+  %stack.next = load ptr, ptr %stack.next.gep, align 4
+  store ptr %stack.next, ptr %deferPtr, align 4
+  %callback = load i32, ptr %7, align 4
+  switch i32 %callback, label %rundefers.default [
+    i32 0, label %rundefers.callback0
+  ]
+
+rundefers.callback0:                              ; preds = %rundefers.loop
+  %gep = getelementptr inbounds nuw i8, ptr %7, i32 8
+  %param = load i32, ptr %gep, align 4
+  call void @runtime.printlock(ptr undef) #4
+  call void @runtime.printint32(i32 %param, ptr undef) #4
+  call void @runtime.printunlock(ptr undef) #4
+  br label %rundefers.loophead
+
+rundefers.default:                                ; preds = %rundefers.loop
+  unreachable
+
+rundefers.end:                                    ; preds = %rundefers.loophead
+  br label %rundefers.after
+
+recover:                                          ; preds = %rundefers.end4
+  ret void
+
+lpad:                                             ; No predecessors!
+  br label %rundefers.loophead7
+
+rundefers.loophead7:                              ; preds = %rundefers.callback013, %lpad
+  br i1 poison, label %rundefers.end4, label %rundefers.loop6
+
+rundefers.loop6:                                  ; preds = %rundefers.loophead7
+  switch i32 poison, label %rundefers.default5 [
+    i32 0, label %rundefers.callback013
+  ]
+
+rundefers.callback013:                            ; preds = %rundefers.loop6
+  br label %rundefers.loophead7
+
+rundefers.default5:                               ; preds = %rundefers.loop6
+  unreachable
+
+rundefers.end4:                                   ; preds = %rundefers.loophead7
+  br label %recover
+}
+
 attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+armv7-m,+hwdiv,+soft-float,+thumb-mode,-aes,-bf16,-cdecp0,-cdecp1,-cdecp2,-cdecp3,-cdecp4,-cdecp5,-cdecp6,-cdecp7,-crc,-crypto,-d32,-dotprod,-dsp,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-hwdiv-arm,-i8mm,-lob,-mve,-mve.fp,-neon,-pacbti,-ras,-sb,-sha2,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" }
 attributes #1 = { nounwind "target-features"="+armv7-m,+hwdiv,+soft-float,+thumb-mode,-aes,-bf16,-cdecp0,-cdecp1,-cdecp2,-cdecp3,-cdecp4,-cdecp5,-cdecp6,-cdecp7,-crc,-crypto,-d32,-dotprod,-dsp,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-hwdiv-arm,-i8mm,-lob,-mve,-mve.fp,-neon,-pacbti,-ras,-sb,-sha2,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" }
 attributes #2 = { "target-features"="+armv7-m,+hwdiv,+soft-float,+thumb-mode,-aes,-bf16,-cdecp0,-cdecp1,-cdecp2,-cdecp3,-cdecp4,-cdecp5,-cdecp6,-cdecp7,-crc,-crypto,-d32,-dotprod,-dsp,-fp-armv8,-fp-armv8d16,-fp-armv8d16sp,-fp-armv8sp,-fp16,-fp16fml,-fp64,-fpregs,-fullfp16,-hwdiv-arm,-i8mm,-lob,-mve,-mve.fp,-neon,-pacbti,-ras,-sb,-sha2,-vfp2,-vfp2sp,-vfp3,-vfp3d16,-vfp3d16sp,-vfp3sp,-vfp4,-vfp4d16,-vfp4d16sp,-vfp4sp" }
@@ -18,3 +18,23 @@ func deferMultiple() {
 	}()
 	external()
 }
+
+func deferInfiniteLoop() {
+	for {
+		defer print(8)
+	}
+}
+
+func deferLoop() {
+	for i := 0; i < 10; i++ {
+		defer print(i)
+	}
+}
+
+func deferBetweenLoops() {
+	for i := 0; i < 10; i++ {
+	}
+	defer print(1)
+	for i := 0; i < 10; i++ {
+	}
+}
@@ -1,6 +1,6 @@
 ; ModuleID = 'float.go'
 source_filename = "float.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 ; Function Attrs: allockind("alloc,zeroed") allocsize(0)
@@ -93,6 +93,6 @@ entry:
  ret i8 %0
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
@@ -1,6 +1,6 @@
 ; ModuleID = 'func.go'
 source_filename = "func.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 ; Function Attrs: allockind("alloc,zeroed") allocsize(0)
@@ -44,7 +44,7 @@ entry:
  ret void
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'gc.go'
 source_filename = "gc.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime._interface = type { ptr, ptr }
@@ -105,18 +105,18 @@ entry:
  %makeslice = call align 1 dereferenceable(5) ptr @runtime.alloc(i32 5, ptr nonnull inttoptr (i32 3 to ptr), ptr undef) #3
  call void @runtime.trackPointer(ptr nonnull %makeslice, ptr nonnull %stackalloc, ptr undef) #3
  store ptr %makeslice, ptr @main.slice1, align 4
-  store i32 5, ptr getelementptr inbounds (i8, ptr @main.slice1, i32 4), align 4
-  store i32 5, ptr getelementptr inbounds (i8, ptr @main.slice1, i32 8), align 4
+  store i32 5, ptr getelementptr inbounds nuw (i8, ptr @main.slice1, i32 4), align 4
+  store i32 5, ptr getelementptr inbounds nuw (i8, ptr @main.slice1, i32 8), align 4
  %makeslice1 = call align 4 dereferenceable(20) ptr @runtime.alloc(i32 20, ptr nonnull inttoptr (i32 67 to ptr), ptr undef) #3
  call void @runtime.trackPointer(ptr nonnull %makeslice1, ptr nonnull %stackalloc, ptr undef) #3
  store ptr %makeslice1, ptr @main.slice2, align 4
-  store i32 5, ptr getelementptr inbounds (i8, ptr @main.slice2, i32 4), align 4
-  store i32 5, ptr getelementptr inbounds (i8, ptr @main.slice2, i32 8), align 4
+  store i32 5, ptr getelementptr inbounds nuw (i8, ptr @main.slice2, i32 4), align 4
+  store i32 5, ptr getelementptr inbounds nuw (i8, ptr @main.slice2, i32 8), align 4
  %makeslice3 = call align 4 dereferenceable(60) ptr @runtime.alloc(i32 60, ptr nonnull inttoptr (i32 71 to ptr), ptr undef) #3
  call void @runtime.trackPointer(ptr nonnull %makeslice3, ptr nonnull %stackalloc, ptr undef) #3
  store ptr %makeslice3, ptr @main.slice3, align 4
-  store i32 5, ptr getelementptr inbounds (i8, ptr @main.slice3, i32 4), align 4
-  store i32 5, ptr getelementptr inbounds (i8, ptr @main.slice3, i32 8), align 4
+  store i32 5, ptr getelementptr inbounds nuw (i8, ptr @main.slice3, i32 4), align 4
+  store i32 5, ptr getelementptr inbounds nuw (i8, ptr @main.slice3, i32 8), align 4
  ret void
 }

@@ -127,7 +127,7 @@ entry:
  %0 = call align 8 dereferenceable(16) ptr @runtime.alloc(i32 16, ptr null, ptr undef) #3
  call void @runtime.trackPointer(ptr nonnull %0, ptr nonnull %stackalloc, ptr undef) #3
  store double %v.r, ptr %0, align 8
-  %.repack1 = getelementptr inbounds i8, ptr %0, i32 8
+  %.repack1 = getelementptr inbounds nuw i8, ptr %0, i32 8
  store double %v.i, ptr %.repack1, align 8
  %1 = insertvalue %runtime._interface { ptr @"reflect/types.type:basic:complex128", ptr undef }, ptr %0, 1
  call void @runtime.trackPointer(ptr nonnull @"reflect/types.type:basic:complex128", ptr nonnull %stackalloc, ptr undef) #3
@@ -135,7 +135,7 @@ entry:
  ret %runtime._interface %1
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'go1.20.go'
 source_filename = "go1.20.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime._string = type { ptr, i32 }
@@ -50,14 +50,14 @@ unsafe.String.throw:                              ; preds = %entry
 declare void @runtime.unsafeSlicePanic(ptr) #1

 ; Function Attrs: nounwind
-define hidden ptr @main.unsafeStringData(ptr %s.data, i32 %s.len, ptr %context) unnamed_addr #2 {
+define hidden ptr @main.unsafeStringData(ptr readonly %s.data, i32 %s.len, ptr %context) unnamed_addr #2 {
 entry:
  %stackalloc = alloca i8, align 1
  call void @runtime.trackPointer(ptr %s.data, ptr nonnull %stackalloc, ptr undef) #3
  ret ptr %s.data
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'go1.21.go'
 source_filename = "go1.21.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime._string = type { ptr, i32 }
@@ -77,7 +77,7 @@ entry:
 }

 ; Function Attrs: nounwind
-define hidden %runtime._string @main.minString(ptr %a.data, i32 %a.len, ptr %b.data, i32 %b.len, ptr %context) unnamed_addr #2 {
+define hidden %runtime._string @main.minString(ptr readonly %a.data, i32 %a.len, ptr readonly %b.data, i32 %b.len, ptr %context) unnamed_addr #2 {
 entry:
  %0 = insertvalue %runtime._string zeroinitializer, ptr %a.data, 0
  %1 = insertvalue %runtime._string %0, i32 %a.len, 1
@@ -86,12 +86,12 @@ entry:
  %stackalloc = alloca i8, align 1
  %4 = call i1 @runtime.stringLess(ptr %a.data, i32 %a.len, ptr %b.data, i32 %b.len, ptr undef) #5
  %5 = select i1 %4, %runtime._string %1, %runtime._string %3
-  %6 = extractvalue %runtime._string %5, 0
+  %6 = select i1 %4, ptr %a.data, ptr %b.data
  call void @runtime.trackPointer(ptr %6, ptr nonnull %stackalloc, ptr undef) #5
  ret %runtime._string %5
 }

-declare i1 @runtime.stringLess(ptr, i32, ptr, i32, ptr) #1
+declare i1 @runtime.stringLess(ptr readonly, i32, ptr readonly, i32, ptr) #1

 ; Function Attrs: nounwind
 define hidden i32 @main.maxInt(i32 %a, i32 %b, ptr %context) unnamed_addr #2 {
@@ -116,7 +116,7 @@ entry:
 }

 ; Function Attrs: nounwind
-define hidden %runtime._string @main.maxString(ptr %a.data, i32 %a.len, ptr %b.data, i32 %b.len, ptr %context) unnamed_addr #2 {
+define hidden %runtime._string @main.maxString(ptr readonly %a.data, i32 %a.len, ptr readonly %b.data, i32 %b.len, ptr %context) unnamed_addr #2 {
 entry:
  %0 = insertvalue %runtime._string zeroinitializer, ptr %a.data, 0
  %1 = insertvalue %runtime._string %0, i32 %a.len, 1
@@ -125,7 +125,7 @@ entry:
  %stackalloc = alloca i8, align 1
  %4 = call i1 @runtime.stringLess(ptr %b.data, i32 %b.len, ptr %a.data, i32 %a.len, ptr undef) #5
  %5 = select i1 %4, %runtime._string %1, %runtime._string %3
-  %6 = extractvalue %runtime._string %5, 0
+  %6 = select i1 %4, ptr %a.data, ptr %b.data
  call void @runtime.trackPointer(ptr %6, ptr nonnull %stackalloc, ptr undef) #5
  ret %runtime._string %5
 }
@@ -171,9 +171,9 @@ declare i32 @llvm.smax.i32(i32, i32) #4
 ; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
 declare i32 @llvm.umax.i32(i32, i32) #4

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nocallback nofree nounwind willreturn memory(argmem: write) }
 attributes #4 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
 attributes #5 = { nounwind }
@@ -65,7 +65,7 @@ entry:
  store i32 3, ptr %n, align 4
  %0 = call align 4 dereferenceable(8) ptr @runtime.alloc(i32 8, ptr null, ptr undef) #9
  store i32 5, ptr %0, align 4
-  %1 = getelementptr inbounds i8, ptr %0, i32 4
+  %1 = getelementptr inbounds nuw i8, ptr %0, i32 4
  store ptr %n, ptr %1, align 4
  %stacksize = call i32 @"internal/task.getGoroutineStackSize"(i32 ptrtoint (ptr @"main.closureFunctionGoroutine$1$gowrapper" to i32), ptr undef) #9
  call void @"internal/task.start"(i32 ptrtoint (ptr @"main.closureFunctionGoroutine$1$gowrapper" to i32), ptr nonnull %0, i32 %stacksize, ptr undef) #9
@@ -87,7 +87,7 @@ entry:
 define linkonce_odr void @"main.closureFunctionGoroutine$1$gowrapper"(ptr %0) unnamed_addr #5 {
 entry:
  %1 = load i32, ptr %0, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 4
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 4
  %3 = load ptr, ptr %2, align 4
  call void @"main.closureFunctionGoroutine$1"(i32 %1, ptr %3)
  ret void
@@ -104,9 +104,9 @@ define hidden void @main.funcGoroutine(ptr %fn.context, ptr %fn.funcptr, ptr %co
 entry:
  %0 = call align 4 dereferenceable(12) ptr @runtime.alloc(i32 12, ptr null, ptr undef) #9
  store i32 5, ptr %0, align 4
-  %1 = getelementptr inbounds i8, ptr %0, i32 4
+  %1 = getelementptr inbounds nuw i8, ptr %0, i32 4
  store ptr %fn.context, ptr %1, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 8
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 8
  store ptr %fn.funcptr, ptr %2, align 4
  %stacksize = call i32 @"internal/task.getGoroutineStackSize"(i32 ptrtoint (ptr @main.funcGoroutine.gowrapper to i32), ptr undef) #9
  call void @"internal/task.start"(i32 ptrtoint (ptr @main.funcGoroutine.gowrapper to i32), ptr nonnull %0, i32 %stacksize, ptr undef) #9
@@ -117,9 +117,9 @@ entry:
 define linkonce_odr void @main.funcGoroutine.gowrapper(ptr %0) unnamed_addr #6 {
 entry:
  %1 = load i32, ptr %0, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 4
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 4
  %3 = load ptr, ptr %2, align 4
-  %4 = getelementptr inbounds i8, ptr %0, i32 8
+  %4 = getelementptr inbounds nuw i8, ptr %0, i32 8
  %5 = load ptr, ptr %4, align 4
  call void %5(i32 %1, ptr %3) #9
  ret void
@@ -154,11 +154,11 @@ define hidden void @main.startInterfaceMethod(ptr %itf.typecode, ptr %itf.value,
 entry:
  %0 = call align 4 dereferenceable(16) ptr @runtime.alloc(i32 16, ptr null, ptr undef) #9
  store ptr %itf.value, ptr %0, align 4
-  %1 = getelementptr inbounds i8, ptr %0, i32 4
+  %1 = getelementptr inbounds nuw i8, ptr %0, i32 4
  store ptr @"main$string", ptr %1, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 8
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 8
  store i32 4, ptr %2, align 4
-  %3 = getelementptr inbounds i8, ptr %0, i32 12
+  %3 = getelementptr inbounds nuw i8, ptr %0, i32 12
  store ptr %itf.typecode, ptr %3, align 4
  %stacksize = call i32 @"internal/task.getGoroutineStackSize"(i32 ptrtoint (ptr @"interface:{Print:func:{basic:string}{}}.Print$invoke$gowrapper" to i32), ptr undef) #9
  call void @"internal/task.start"(i32 ptrtoint (ptr @"interface:{Print:func:{basic:string}{}}.Print$invoke$gowrapper" to i32), ptr nonnull %0, i32 %stacksize, ptr undef) #9
@@ -171,11 +171,11 @@ declare void @"interface:{Print:func:{basic:string}{}}.Print$invoke"(ptr, ptr, i
 define linkonce_odr void @"interface:{Print:func:{basic:string}{}}.Print$invoke$gowrapper"(ptr %0) unnamed_addr #8 {
 entry:
  %1 = load ptr, ptr %0, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 4
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 4
  %3 = load ptr, ptr %2, align 4
-  %4 = getelementptr inbounds i8, ptr %0, i32 8
+  %4 = getelementptr inbounds nuw i8, ptr %0, i32 8
  %5 = load i32, ptr %4, align 4
-  %6 = getelementptr inbounds i8, ptr %0, i32 12
+  %6 = getelementptr inbounds nuw i8, ptr %0, i32 12
  %7 = load ptr, ptr %6, align 4
  call void @"interface:{Print:func:{basic:string}{}}.Print$invoke"(ptr %1, ptr %3, i32 %5, ptr %7, ptr undef) #9
  ret void
@@ -1,6 +1,6 @@
 ; ModuleID = 'goroutine.go'
 source_filename = "goroutine.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

@"main$string" = internal unnamed_addr constant [4 x i8] c"test", align 1
@@ -72,7 +72,7 @@ entry:
  %0 = call align 4 dereferenceable(8) ptr @runtime.alloc(i32 8, ptr null, ptr undef) #9
  call void @runtime.trackPointer(ptr nonnull %0, ptr nonnull %stackalloc, ptr undef) #9
  store i32 5, ptr %0, align 4
-  %1 = getelementptr inbounds i8, ptr %0, i32 4
+  %1 = getelementptr inbounds nuw i8, ptr %0, i32 4
  store ptr %n, ptr %1, align 4
  call void @"internal/task.start"(i32 ptrtoint (ptr @"main.closureFunctionGoroutine$1$gowrapper" to i32), ptr nonnull %0, i32 65536, ptr undef) #9
  %2 = load i32, ptr %n, align 4
@@ -93,7 +93,7 @@ entry:
 define linkonce_odr void @"main.closureFunctionGoroutine$1$gowrapper"(ptr %0) unnamed_addr #5 {
 entry:
  %1 = load i32, ptr %0, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 4
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 4
  %3 = load ptr, ptr %2, align 4
  call void @"main.closureFunctionGoroutine$1"(i32 %1, ptr %3)
  call void @runtime.deadlock(ptr undef) #9
@@ -113,9 +113,9 @@ entry:
  %0 = call align 4 dereferenceable(12) ptr @runtime.alloc(i32 12, ptr null, ptr undef) #9
  call void @runtime.trackPointer(ptr nonnull %0, ptr nonnull %stackalloc, ptr undef) #9
  store i32 5, ptr %0, align 4
-  %1 = getelementptr inbounds i8, ptr %0, i32 4
+  %1 = getelementptr inbounds nuw i8, ptr %0, i32 4
  store ptr %fn.context, ptr %1, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 8
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 8
  store ptr %fn.funcptr, ptr %2, align 4
  call void @"internal/task.start"(i32 ptrtoint (ptr @main.funcGoroutine.gowrapper to i32), ptr nonnull %0, i32 65536, ptr undef) #9
  ret void
@@ -125,9 +125,9 @@ entry:
 define linkonce_odr void @main.funcGoroutine.gowrapper(ptr %0) unnamed_addr #6 {
 entry:
  %1 = load i32, ptr %0, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 4
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 4
  %3 = load ptr, ptr %2, align 4
-  %4 = getelementptr inbounds i8, ptr %0, i32 8
+  %4 = getelementptr inbounds nuw i8, ptr %0, i32 8
  %5 = load ptr, ptr %4, align 4
  call void %5(i32 %1, ptr %3) #9
  call void @runtime.deadlock(ptr undef) #9
@@ -165,11 +165,11 @@ entry:
  %0 = call align 4 dereferenceable(16) ptr @runtime.alloc(i32 16, ptr null, ptr undef) #9
  call void @runtime.trackPointer(ptr nonnull %0, ptr nonnull %stackalloc, ptr undef) #9
  store ptr %itf.value, ptr %0, align 4
-  %1 = getelementptr inbounds i8, ptr %0, i32 4
+  %1 = getelementptr inbounds nuw i8, ptr %0, i32 4
  store ptr @"main$string", ptr %1, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 8
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 8
  store i32 4, ptr %2, align 4
-  %3 = getelementptr inbounds i8, ptr %0, i32 12
+  %3 = getelementptr inbounds nuw i8, ptr %0, i32 12
  store ptr %itf.typecode, ptr %3, align 4
  call void @"internal/task.start"(i32 ptrtoint (ptr @"interface:{Print:func:{basic:string}{}}.Print$invoke$gowrapper" to i32), ptr nonnull %0, i32 65536, ptr undef) #9
  ret void
@@ -181,24 +181,24 @@ declare void @"interface:{Print:func:{basic:string}{}}.Print$invoke"(ptr, ptr, i
 define linkonce_odr void @"interface:{Print:func:{basic:string}{}}.Print$invoke$gowrapper"(ptr %0) unnamed_addr #8 {
 entry:
  %1 = load ptr, ptr %0, align 4
-  %2 = getelementptr inbounds i8, ptr %0, i32 4
+  %2 = getelementptr inbounds nuw i8, ptr %0, i32 4
  %3 = load ptr, ptr %2, align 4
-  %4 = getelementptr inbounds i8, ptr %0, i32 8
+  %4 = getelementptr inbounds nuw i8, ptr %0, i32 8
  %5 = load i32, ptr %4, align 4
-  %6 = getelementptr inbounds i8, ptr %0, i32 12
+  %6 = getelementptr inbounds nuw i8, ptr %0, i32 12
  %7 = load ptr, ptr %6, align 4
  call void @"interface:{Print:func:{basic:string}{}}.Print$invoke"(ptr %1, ptr %3, i32 %5, ptr %7, ptr undef) #9
  call void @runtime.deadlock(ptr undef) #9
  unreachable
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #3 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="main.regularFunction" }
-attributes #4 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="main.inlineFunctionGoroutine$1" }
-attributes #5 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="main.closureFunctionGoroutine$1" }
-attributes #6 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper" }
-attributes #7 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="reflect/methods.Print(string)" "tinygo-methods"="reflect/methods.Print(string)" }
-attributes #8 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="interface:{Print:func:{basic:string}{}}.Print$invoke" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #3 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="main.regularFunction" }
+attributes #4 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="main.inlineFunctionGoroutine$1" }
+attributes #5 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="main.closureFunctionGoroutine$1" }
+attributes #6 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper" }
+attributes #7 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="reflect/methods.Print(string)" "tinygo-methods"="reflect/methods.Print(string)" }
+attributes #8 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-gowrapper"="interface:{Print:func:{basic:string}{}}.Print$invoke" }
 attributes #9 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'interface.go'
 source_filename = "interface.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime._interface = type { ptr, ptr }
@@ -130,11 +130,11 @@ entry:

 declare %runtime._string @"interface:{Error:func:{}{basic:string}}.Error$invoke"(ptr, ptr, ptr) #6

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #3 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.Error() string" }
-attributes #4 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.String() string" }
-attributes #5 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="main.$methods.foo(int) uint8" "tinygo-methods"="reflect/methods.String() string; main.$methods.foo(int) uint8" }
-attributes #6 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="reflect/methods.Error() string" "tinygo-methods"="reflect/methods.Error() string" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #3 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.Error() string" }
+attributes #4 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-methods"="reflect/methods.String() string" }
+attributes #5 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="main.$methods.foo(int) uint8" "tinygo-methods"="reflect/methods.String() string; main.$methods.foo(int) uint8" }
+attributes #6 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "tinygo-invoke"="reflect/methods.Error() string" "tinygo-methods"="reflect/methods.Error() string" }
 attributes #7 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'pointer.go'
 source_filename = "pointer.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 ; Function Attrs: allockind("alloc,zeroed") allocsize(0)
@@ -44,7 +44,7 @@ entry:
  ret ptr %x
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'pragma.go'
 source_filename = "pragma.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

@extern_global = external global [0 x i8], align 1
@@ -93,13 +93,13 @@ entry:
  ret void
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #3 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-export-name"="extern_func" }
-attributes #4 = { inlinehint nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #5 = { noinline nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #6 = { noinline nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-export-name"="exportedFunctionInSection" }
-attributes #7 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-import-module"="modulename" "wasm-import-name"="import1" }
-attributes #8 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-import-module"="foobar" "wasm-import-name"="imported" }
-attributes #9 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-export-name"="exported" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #3 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-export-name"="extern_func" }
+attributes #4 = { inlinehint nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #5 = { noinline nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #6 = { noinline nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-export-name"="exportedFunctionInSection" }
+attributes #7 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-import-module"="modulename" "wasm-import-name"="import1" }
+attributes #8 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-import-module"="foobar" "wasm-import-name"="imported" }
+attributes #9 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" "wasm-export-name"="exported" }
@@ -1,6 +1,6 @@
 ; ModuleID = 'slice.go'
 source_filename = "slice.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 ; Function Attrs: allockind("alloc,zeroed") allocsize(0)
@@ -51,11 +51,11 @@ entry:
  %varargs = call align 4 dereferenceable(12) ptr @runtime.alloc(i32 12, ptr nonnull inttoptr (i32 3 to ptr), ptr undef) #3
  call void @runtime.trackPointer(ptr nonnull %varargs, ptr nonnull %stackalloc, ptr undef) #3
  store i32 1, ptr %varargs, align 4
-  %0 = getelementptr inbounds i8, ptr %varargs, i32 4
+  %0 = getelementptr inbounds nuw i8, ptr %varargs, i32 4
  store i32 2, ptr %0, align 4
-  %1 = getelementptr inbounds i8, ptr %varargs, i32 8
+  %1 = getelementptr inbounds nuw i8, ptr %varargs, i32 8
  store i32 3, ptr %1, align 4
-  %append.new = call { ptr, i32, i32 } @runtime.sliceAppend(ptr %ints.data, ptr nonnull %varargs, i32 %ints.len, i32 %ints.cap, i32 3, i32 4, ptr undef) #3
+  %append.new = call { ptr, i32, i32 } @runtime.sliceAppend(ptr %ints.data, ptr nonnull %varargs, i32 %ints.len, i32 %ints.cap, i32 3, i32 4, ptr nonnull inttoptr (i32 3 to ptr), ptr undef) #3
  %append.newPtr = extractvalue { ptr, i32, i32 } %append.new, 0
  %append.newLen = extractvalue { ptr, i32, i32 } %append.new, 1
  %append.newCap = extractvalue { ptr, i32, i32 } %append.new, 2
@@ -66,13 +66,13 @@ entry:
  ret { ptr, i32, i32 } %4
 }

-declare { ptr, i32, i32 } @runtime.sliceAppend(ptr, ptr nocapture readonly, i32, i32, i32, i32, ptr) #1
+declare { ptr, i32, i32 } @runtime.sliceAppend(ptr, ptr nocapture readonly, i32, i32, i32, i32, ptr, ptr) #1

 ; Function Attrs: nounwind
 define hidden { ptr, i32, i32 } @main.sliceAppendSlice(ptr %ints.data, i32 %ints.len, i32 %ints.cap, ptr %added.data, i32 %added.len, i32 %added.cap, ptr %context) unnamed_addr #2 {
 entry:
  %stackalloc = alloca i8, align 1
-  %append.new = call { ptr, i32, i32 } @runtime.sliceAppend(ptr %ints.data, ptr %added.data, i32 %ints.len, i32 %ints.cap, i32 %added.len, i32 4, ptr undef) #3
+  %append.new = call { ptr, i32, i32 } @runtime.sliceAppend(ptr %ints.data, ptr %added.data, i32 %ints.len, i32 %ints.cap, i32 %added.len, i32 4, ptr nonnull inttoptr (i32 3 to ptr), ptr undef) #3
  %append.newPtr = extractvalue { ptr, i32, i32 } %append.new, 0
  %append.newLen = extractvalue { ptr, i32, i32 } %append.new, 1
  %append.newCap = extractvalue { ptr, i32, i32 } %append.new, 2
@@ -322,7 +322,7 @@ unsafe.Slice.throw:                               ; preds = %entry
  unreachable
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'string.go'
 source_filename = "string.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %runtime._string = type { ptr, i32 }
@@ -31,13 +31,13 @@ entry:
 }

 ; Function Attrs: nounwind
-define hidden i32 @main.stringLen(ptr %s.data, i32 %s.len, ptr %context) unnamed_addr #2 {
+define hidden i32 @main.stringLen(ptr readonly %s.data, i32 %s.len, ptr %context) unnamed_addr #2 {
 entry:
  ret i32 %s.len
 }

 ; Function Attrs: nounwind
-define hidden i8 @main.stringIndex(ptr %s.data, i32 %s.len, i32 %index, ptr %context) unnamed_addr #2 {
+define hidden i8 @main.stringIndex(ptr readonly %s.data, i32 %s.len, i32 %index, ptr %context) unnamed_addr #2 {
 entry:
  %.not = icmp ult i32 %index, %s.len
  br i1 %.not, label %lookup.next, label %lookup.throw
@@ -55,16 +55,16 @@ lookup.throw:                                     ; preds = %entry
 declare void @runtime.lookupPanic(ptr) #1

 ; Function Attrs: nounwind
-define hidden i1 @main.stringCompareEqual(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
+define hidden i1 @main.stringCompareEqual(ptr readonly %s1.data, i32 %s1.len, ptr readonly %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
 entry:
  %0 = call i1 @runtime.stringEqual(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr undef) #3
  ret i1 %0
 }

-declare i1 @runtime.stringEqual(ptr, i32, ptr, i32, ptr) #1
+declare i1 @runtime.stringEqual(ptr readonly, i32, ptr readonly, i32, ptr) #1

 ; Function Attrs: nounwind
-define hidden i1 @main.stringCompareUnequal(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
+define hidden i1 @main.stringCompareUnequal(ptr readonly %s1.data, i32 %s1.len, ptr readonly %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
 entry:
  %0 = call i1 @runtime.stringEqual(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr undef) #3
  %1 = xor i1 %0, true
@@ -72,23 +72,23 @@ entry:
 }

 ; Function Attrs: nounwind
-define hidden i1 @main.stringCompareLarger(ptr %s1.data, i32 %s1.len, ptr %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
+define hidden i1 @main.stringCompareLarger(ptr readonly %s1.data, i32 %s1.len, ptr readonly %s2.data, i32 %s2.len, ptr %context) unnamed_addr #2 {
 entry:
  %0 = call i1 @runtime.stringLess(ptr %s2.data, i32 %s2.len, ptr %s1.data, i32 %s1.len, ptr undef) #3
  ret i1 %0
 }

-declare i1 @runtime.stringLess(ptr, i32, ptr, i32, ptr) #1
+declare i1 @runtime.stringLess(ptr readonly, i32, ptr readonly, i32, ptr) #1

 ; Function Attrs: nounwind
-define hidden i8 @main.stringLookup(ptr %s.data, i32 %s.len, i8 %x, ptr %context) unnamed_addr #2 {
+define hidden i8 @main.stringLookup(ptr readonly %s.data, i32 %s.len, i8 %x, ptr %context) unnamed_addr #2 {
 entry:
  %0 = zext i8 %x to i32
-  %.not = icmp ult i32 %0, %s.len
+  %.not = icmp ugt i32 %s.len, %0
  br i1 %.not, label %lookup.next, label %lookup.throw

 lookup.next:                                      ; preds = %entry
-  %1 = getelementptr inbounds i8, ptr %s.data, i32 %0
+  %1 = getelementptr inbounds nuw i8, ptr %s.data, i32 %0
  %2 = load i8, ptr %1, align 1
  ret i8 %2

@@ -97,7 +97,7 @@ lookup.throw:                                     ; preds = %entry
  unreachable
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #3 = { nounwind }
@@ -1,6 +1,6 @@
 ; ModuleID = 'zeromap.go'
 source_filename = "zeromap.go"
-target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-i128:128-n32:64-S128-ni:1:10:20"
 target triple = "wasm32-unknown-wasi"

 %main.hasPadding = type { i1, i32, i1 }
@@ -27,9 +27,9 @@ entry:
  call void @llvm.lifetime.start.p0(i64 4, ptr nonnull %hashmap.value)
  call void @llvm.lifetime.start.p0(i64 12, ptr nonnull %hashmap.key)
  store %main.hasPadding %2, ptr %hashmap.key, align 4
-  %3 = getelementptr inbounds i8, ptr %hashmap.key, i32 1
+  %3 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 1
  call void @runtime.memzero(ptr nonnull %3, i32 3, ptr undef) #5
-  %4 = getelementptr inbounds i8, ptr %hashmap.key, i32 9
+  %4 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 9
  call void @runtime.memzero(ptr nonnull %4, i32 3, ptr undef) #5
  %5 = call i1 @runtime.hashmapBinaryGet(ptr %m, ptr nonnull %hashmap.key, ptr nonnull %hashmap.value, i32 4, ptr undef) #5
  call void @llvm.lifetime.end.p0(i64 12, ptr nonnull %hashmap.key)
@@ -60,9 +60,9 @@ entry:
  store i32 5, ptr %hashmap.value, align 4
  call void @llvm.lifetime.start.p0(i64 12, ptr nonnull %hashmap.key)
  store %main.hasPadding %2, ptr %hashmap.key, align 4
-  %3 = getelementptr inbounds i8, ptr %hashmap.key, i32 1
+  %3 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 1
  call void @runtime.memzero(ptr nonnull %3, i32 3, ptr undef) #5
-  %4 = getelementptr inbounds i8, ptr %hashmap.key, i32 9
+  %4 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 9
  call void @runtime.memzero(ptr nonnull %4, i32 3, ptr undef) #5
  call void @runtime.hashmapBinarySet(ptr %m, ptr nonnull %hashmap.key, ptr nonnull %hashmap.value, ptr undef) #5
  call void @llvm.lifetime.end.p0(i64 12, ptr nonnull %hashmap.key)
@@ -81,16 +81,16 @@ entry:
  call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %hashmap.key)
  %s.elt = extractvalue [2 x %main.hasPadding] %s, 0
  store %main.hasPadding %s.elt, ptr %hashmap.key, align 4
-  %hashmap.key.repack1 = getelementptr inbounds i8, ptr %hashmap.key, i32 12
+  %hashmap.key.repack1 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 12
  %s.elt2 = extractvalue [2 x %main.hasPadding] %s, 1
  store %main.hasPadding %s.elt2, ptr %hashmap.key.repack1, align 4
-  %0 = getelementptr inbounds i8, ptr %hashmap.key, i32 1
+  %0 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 1
  call void @runtime.memzero(ptr nonnull %0, i32 3, ptr undef) #5
-  %1 = getelementptr inbounds i8, ptr %hashmap.key, i32 9
+  %1 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 9
  call void @runtime.memzero(ptr nonnull %1, i32 3, ptr undef) #5
-  %2 = getelementptr inbounds i8, ptr %hashmap.key, i32 13
+  %2 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 13
  call void @runtime.memzero(ptr nonnull %2, i32 3, ptr undef) #5
-  %3 = getelementptr inbounds i8, ptr %hashmap.key, i32 21
+  %3 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 21
  call void @runtime.memzero(ptr nonnull %3, i32 3, ptr undef) #5
  %4 = call i1 @runtime.hashmapBinaryGet(ptr %m, ptr nonnull %hashmap.key, ptr nonnull %hashmap.value, i32 4, ptr undef) #5
  call void @llvm.lifetime.end.p0(i64 24, ptr nonnull %hashmap.key)
@@ -109,16 +109,16 @@ entry:
  call void @llvm.lifetime.start.p0(i64 24, ptr nonnull %hashmap.key)
  %s.elt = extractvalue [2 x %main.hasPadding] %s, 0
  store %main.hasPadding %s.elt, ptr %hashmap.key, align 4
-  %hashmap.key.repack1 = getelementptr inbounds i8, ptr %hashmap.key, i32 12
+  %hashmap.key.repack1 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 12
  %s.elt2 = extractvalue [2 x %main.hasPadding] %s, 1
  store %main.hasPadding %s.elt2, ptr %hashmap.key.repack1, align 4
-  %0 = getelementptr inbounds i8, ptr %hashmap.key, i32 1
+  %0 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 1
  call void @runtime.memzero(ptr nonnull %0, i32 3, ptr undef) #5
-  %1 = getelementptr inbounds i8, ptr %hashmap.key, i32 9
+  %1 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 9
  call void @runtime.memzero(ptr nonnull %1, i32 3, ptr undef) #5
-  %2 = getelementptr inbounds i8, ptr %hashmap.key, i32 13
+  %2 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 13
  call void @runtime.memzero(ptr nonnull %2, i32 3, ptr undef) #5
-  %3 = getelementptr inbounds i8, ptr %hashmap.key, i32 21
+  %3 = getelementptr inbounds nuw i8, ptr %hashmap.key, i32 21
  call void @runtime.memzero(ptr nonnull %3, i32 3, ptr undef) #5
  call void @runtime.hashmapBinarySet(ptr %m, ptr nonnull %hashmap.key, ptr nonnull %hashmap.value, ptr undef) #5
  call void @llvm.lifetime.end.p0(i64 24, ptr nonnull %hashmap.key)
@@ -132,9 +132,9 @@ entry:
  ret void
 }

-attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #1 = { "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #2 = { nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
-attributes #3 = { noinline nounwind "target-features"="+bulk-memory,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #0 = { allockind("alloc,zeroed") allocsize(0) "alloc-family"="runtime.alloc" "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #1 = { "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #2 = { nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
+attributes #3 = { noinline nounwind "target-features"="+bulk-memory,+bulk-memory-opt,+call-indirect-overlong,+mutable-globals,+nontrapping-fptoint,+sign-ext,-multivalue,-reference-types" }
 attributes #4 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
 attributes #5 = { nounwind }
@@ -5,8 +5,6 @@ go 1.22.0
 require (
 	github.com/aykevl/go-wasm v0.0.2-0.20250317121156-42b86c494139
 	github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2
-	github.com/chromedp/cdproto v0.0.0-20220113222801-0725d94bb6ee
-	github.com/chromedp/chromedp v0.7.6
 	github.com/gofrs/flock v0.8.1
 	github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf
 	github.com/inhies/go-bytesize v0.0.0-20220417184213-4913239db9cf
@@ -24,13 +22,7 @@ require (
 )

 require (
-	github.com/chromedp/sysutil v1.0.0 // indirect
 	github.com/creack/goselect v0.1.2 // indirect
-	github.com/gobwas/httphead v0.1.0 // indirect
-	github.com/gobwas/pool v0.2.1 // indirect
-	github.com/gobwas/ws v1.1.0 // indirect
-	github.com/josharian/intern v1.0.0 // indirect
-	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/stretchr/testify v1.8.4 // indirect
 	golang.org/x/text v0.22.0 // indirect
@@ -2,33 +2,16 @@ github.com/aykevl/go-wasm v0.0.2-0.20250317121156-42b86c494139 h1:2O/WuAt8J5id3k
 github.com/aykevl/go-wasm v0.0.2-0.20250317121156-42b86c494139/go.mod h1:7sXyiaA0WtSogCu67R2252fQpVmJMh9JWJ9ddtGkpWw=
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2 h1:oMCHnXa6CCCafdPDbMh/lWRhRByN0VFLvv+g+ayx1SI=
 github.com/blakesmith/ar v0.0.0-20150311145944-8bd4349a67f2/go.mod h1:PkYb9DJNAwrSvRx5DYA+gUcOIgTGVMNkfSCbZM8cWpI=
-github.com/chromedp/cdproto v0.0.0-20211126220118-81fa0469ad77/go.mod h1:At5TxYYdxkbQL0TSefRjhLE3Q0lgvqKKMSFUglJ7i1U=
-github.com/chromedp/cdproto v0.0.0-20220113222801-0725d94bb6ee h1:+SFdIVfQpG0s0DHYzou0kgfE0n0ZjKPwbiRJsXrZegU=
-github.com/chromedp/cdproto v0.0.0-20220113222801-0725d94bb6ee/go.mod h1:At5TxYYdxkbQL0TSefRjhLE3Q0lgvqKKMSFUglJ7i1U=
-github.com/chromedp/chromedp v0.7.6 h1:2juGaktzjwULlsn+DnvIZXFUckEp5xs+GOBroaea+jA=
-github.com/chromedp/chromedp v0.7.6/go.mod h1:ayT4YU/MGAALNfOg9gNrpGSAdnU51PMx+FCeuT1iXzo=
-github.com/chromedp/sysutil v1.0.0 h1:+ZxhTpfpZlmchB58ih/LBHX52ky7w2VhQVKQMucy3Ic=
-github.com/chromedp/sysutil v1.0.0/go.mod h1:kgWmDdq8fTzXYcKIBqIYvRRTnYb9aNS9moAV0xufSww=
 github.com/creack/goselect v0.1.2 h1:2DNy14+JPjRBgPzAd1thbQp4BSIihxcBf0IXhQXDRa0=
 github.com/creack/goselect v0.1.2/go.mod h1:a/NhLweNvqIYMuxcMOuWY516Cimucms3DglDzQP3hKY=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/gobwas/httphead v0.1.0 h1:exrUm0f4YX0L7EBwZHuCF4GDp8aJfVeBrlLQrs6NqWU=
-github.com/gobwas/httphead v0.1.0/go.mod h1:O/RXo79gxV8G+RqlR/otEwx4Q36zl9rqC5u12GKvMCM=
-github.com/gobwas/pool v0.2.1 h1:xfeeEhW7pwmX8nuLVlqbzVc7udMDrwetjEv+TZIz1og=
-github.com/gobwas/pool v0.2.1/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
-github.com/gobwas/ws v1.1.0 h1:7RFti/xnNkMJnrK7D1yQ/iCIB5OrrY/54/H930kIbHA=
-github.com/gobwas/ws v1.1.0/go.mod h1:nzvNcVha5eUziGrbxFCo6qFIojQHjJV5cLYIbezhfL0=
 github.com/gofrs/flock v0.8.1 h1:+gYjHKf32LDeiEEFhQaotPbLuUXjY5ZqxKgXy7n59aw=
 github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
 github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf h1:7+FW5aGwISbqUtkfmIpZJGRgNFg2ioYPvFaUxdqpDsg=
 github.com/google/shlex v0.0.0-20181106134648-c34317bd91bf/go.mod h1:RpwtwJQFrIEPstU94h88MWPXP2ektJZ8cZ0YntAmXiE=
 github.com/inhies/go-bytesize v0.0.0-20220417184213-4913239db9cf h1:FtEj8sfIcaaBfAKrE1Cwb61YDtYq9JxChK1c7AKce7s=
 github.com/inhies/go-bytesize v0.0.0-20220417184213-4913239db9cf/go.mod h1:yrqSXGoD/4EKfF26AOGzscPOgTTJcyAwM2rpixWT+t4=
-github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
-github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
-github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
-github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
 github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892 h1:6J+qramlHVLmiBOgRiBOnQkno8uprqG6YFFQTt6uYIw=
 github.com/marcinbor85/gohex v0.0.0-20200531091804-343a4b548892/go.mod h1:Pb6XcsXyropB9LNHhnqaknG/vEwYztLkQzVCHv8sQ3M=
 github.com/mattn/go-colorable v0.1.4/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
@@ -42,8 +25,6 @@ github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D
 github.com/mattn/go-runewidth v0.0.7/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
 github.com/mattn/go-tty v0.0.4 h1:NVikla9X8MN0SQAqCYzpGyXv0jY7MNl3HOWD2dkle7E=
 github.com/mattn/go-tty v0.0.4/go.mod h1:u5GGXBtZU6RQoKV8gY5W6UhMudbR5vXnUe7j3pxse28=
-github.com/orisano/pixelmatch v0.0.0-20210112091706-4fa4c7ba91d5 h1:1SoBaSPudixRecmlHXb/GxmaD3fLMtHIDN13QujwQuc=
-github.com/orisano/pixelmatch v0.0.0-20210112091706-4fa4c7ba91d5/go.mod h1:nZgzbfBr3hhjoZnS66nKrHmduYNpc34ny7RK4z5/HM0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sigurn/crc16 v0.0.0-20211026045750-20ab5afb07e3 h1:aQKxg3+2p+IFXXg97McgDGT5zcMrQoi0EICZs8Pgchs=
@@ -63,8 +44,6 @@ golang.org/x/sync v0.11.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201207223542-d4d67f95c62d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20211124211545-fe61309f8881/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.30.0 h1:QjkSwP/36a20jFYWkSue1YwXzLmsV5Gfq7Eiy72C1uc=
@@ -10,7 +10,7 @@ import (

 // Version of TinyGo.
 // Update this value before release of new version of software.
-const version = "0.39.0-dev"
+const version = "0.40.1"

 // Return TinyGo version, either in the form 0.30.0 or as a development version
 // (like 0.30.0-dev-abcd012).
@@ -577,7 +577,7 @@ func (r *runner) run(fn *function, params []value, parentMem *memoryView, indent
 						// runtime instead of at compile time. But we need to
 						// revert any changes made by the call first.
 						if r.debug {
-							fmt.Fprintln(os.Stderr, indent+"!! revert because of error:", callErr.Err)
+							fmt.Fprintln(os.Stderr, indent+"!! revert because of error:", callErr.Error())
 						}
 						callMem.revert()
 						err := r.runAtRuntime(fn, inst, locals, &mem, indent)
@@ -10,7 +10,7 @@ target triple = "x86_64--linux"
@main.exposedValue2 = local_unnamed_addr global i16 0
@main.insertedValue = local_unnamed_addr global { i8, i32, { float, { i64, i16 } } } zeroinitializer
@main.gepArray = local_unnamed_addr global [8 x i8] zeroinitializer
-@main.negativeGEP = global ptr getelementptr inbounds (i8, ptr @main.negativeGEP, i64 2)
+@main.negativeGEP = global ptr getelementptr inbounds nuw (i8, ptr @main.negativeGEP, i64 2)

 declare void @runtime.printint64(i64) unnamed_addr

@@ -5,7 +5,7 @@ target triple = "x86_64--linux"
@ptrToIntResult = local_unnamed_addr global i8 2
@pointerTagResult = local_unnamed_addr global i64 2
@someArray = internal global { i16, i8, i8 } zeroinitializer
-@someArrayPointer = local_unnamed_addr global ptr getelementptr inbounds (i8, ptr @someArray, i64 2)
+@someArrayPointer = local_unnamed_addr global ptr getelementptr inbounds nuw (i8, ptr @someArray, i64 2)

 define void @runtime.initAll() local_unnamed_addr {
  ret void
@@ -291,7 +291,8 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 	})

 	if testConfig.CompileOnly {
-		return true, nil
+		// Return the compiler error, if there is one.
+		return true, err
 	}

 	importPath := strings.TrimSuffix(result.ImportPath, ".test")
@@ -339,8 +340,17 @@ func dirsToModuleRootAbs(maindir, modroot string) []string {
 	return dirs
 }

+// validateOutputFormat checks if the output file extension matches the expected format
+func validateOutputFormat(outpath, expectedExt string) error {
+	actualExt := filepath.Ext(outpath)
+	if actualExt != expectedExt {
+		return fmt.Errorf("output format %s does not match target format %s", actualExt, expectedExt)
+	}
+	return nil
+}
+
 // Flash builds and flashes the built binary to the given serial port.
-func Flash(pkgName, port string, options *compileopts.Options) error {
+func Flash(pkgName, port, outpath string, options *compileopts.Options) error {
 	config, err := builder.NewConfig(options)
 	if err != nil {
 		return err
@@ -389,13 +399,24 @@ func Flash(pkgName, port string, options *compileopts.Options) error {
 	if !options.Work {
 		defer os.RemoveAll(tmpdir)
 	}
-
+	// Validate output format before building
+	if outpath != "" {
+		if err := validateOutputFormat(outpath, fileExt); err != nil {
+			return err
+		}
+	}
 	// Build the binary.
 	result, err := builder.Build(pkgName, fileExt, tmpdir, config)
 	if err != nil {
 		return err
 	}

+	// Save output file if specified (after build, before flashing)
+	if outpath != "" {
+		if err := copyFile(result.Binary, outpath); err != nil {
+			return fmt.Errorf("failed to save output file: %v", err)
+		}
+	}
 	// do we need port reset to put MCU into bootloader mode?
 	if config.Target.PortReset == "true" && flashMethod != "openocd" {
 		port, err := getDefaultPort(port, config.Target.SerialPort)
@@ -1297,6 +1318,11 @@ extension at all.`
 			(https://tinygo.org/docs/reference/microcontrollers/).
 			Examples: "arduino-nano", "d1mini", "xiao".

+	-o={filename}:
+			Save the built binary to the specified output file. The file
+			format must match the target's expected format (e.g., .hex,
+			.uf2). Both flashing and saving will be performed.
+
 	-monitor: 
 			Start the serial monitor (see below) immediately after
 			flashing. However, some microcontrollers need a split second
@@ -1609,6 +1635,7 @@ func main() {
 	cpuprofile := flag.String("cpuprofile", "", "cpuprofile output")
 	monitor := flag.Bool("monitor", false, "enable serial monitor")
 	baudrate := flag.Int("baudrate", 115200, "baudrate of serial monitor")
+	gocompatibility := flag.Bool("go-compatibility", true, "enable to check for Go versions compatibility, you can also configure this by setting the TINYGO_GOCOMPATIBILITY environment variable")

 	// Internal flags, that are only intended for TinyGo development.
 	printIR := flag.Bool("internal-printir", false, "print LLVM IR")
@@ -1627,7 +1654,7 @@ func main() {
 		flag.BoolVar(&flagTest, "test", false, "supply -test flag to go list")
 	}
 	var outpath string
-	if command == "help" || command == "build" || command == "test" {
+	if command == "help" || command == "build" || command == "test" || command == "flash" {
 		flag.StringVar(&outpath, "o", "", "output filename")
 	}

@@ -1686,6 +1713,16 @@ func main() {
 		ocdCommands = strings.Split(*ocdCommandsString, ",")
 	}

+	val, ok := os.LookupEnv("TINYGO_GOCOMPATIBILITY")
+	if ok {
+		b, err := strconv.ParseBool(val)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "could not parse TINYGO_GOCOMPATIBILITY value %q: %v\n", val, err)
+			os.Exit(1)
+		}
+		*gocompatibility = b
+	}
+
 	options := &compileopts.Options{
 		GOOS:            goenv.Get("GOOS"),
 		GOARCH:          goenv.Get("GOARCH"),
@@ -1722,6 +1759,7 @@ func main() {
 		Timeout:         *timeout,
 		WITPackage:      witPackage,
 		WITWorld:        witWorld,
+		GoCompatibility: *gocompatibility,
 	}
 	if *printCommands {
 		options.PrintCommands = printCommand
@@ -1778,7 +1816,7 @@ func main() {
 	case "flash", "gdb", "lldb":
 		pkgName := filepath.ToSlash(flag.Arg(0))
 		if command == "flash" {
-			err := Flash(pkgName, *port, options)
+			err := Flash(pkgName, *port, outpath, options)
 			printBuildOutput(err, *flagJSON)
 		} else {
 			if !options.Debug {
@@ -1864,6 +1902,7 @@ func main() {
 						wd = ""
 					}
 					diagnostics.CreateDiagnostics(err).WriteTo(os.Stderr, wd)
+					os.Exit(1)
 				}
 				if !passed {
 					select {
@@ -35,8 +35,8 @@ func Monitor(executable, port string, config *compileopts.Config) error {
 		// Use the RTT interface, which is documented (in part) here:
 		// https://wiki.segger.com/RTT

-		// Try to find the "machine.rttSerialInstance" symbol, which is the RTT
-		// control block.
+		// Try to find the "_SEGGER_RTT" symbol (machine.rttSerialInstance)
+		// symbol, which is the RTT control block.
 		file, err := elf.Open(executable)
 		if err != nil {
 			return fmt.Errorf("could not open ELF file to determine RTT control block: %w", err)
@@ -48,7 +48,7 @@ func Monitor(executable, port string, config *compileopts.Config) error {
 		}
 		var address uint64
 		for _, symbol := range symbols {
-			if symbol.Name == "machine.rttSerialInstance" {
+			if symbol.Name == "_SEGGER_RTT" {
 				address = symbol.Value
 				break
 			}
@@ -63,6 +63,10 @@ func SecCertificateCopyData(cert CFRef) ([]byte, error) {
 	return nil, errors.New("not implemented")
 }

+func SecTrustCopyCertificateChain(trustObj CFRef) (CFRef, error) {
+	return 0, errors.New("not implemented")
+}
+
 func SecTrustEvaluateWithError(trustObj CFRef) (int, error) {
 	return 0, errors.New("not implemented")
 }
@@ -48,10 +48,10 @@ func Asm(asm string)
 // recognizes template values in the form {name}, like so:
 //
 //	arm.AsmFull(
-//	    "str {value}, {result}",
+//	    "str {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 //
 // You can use {} in the asm string (which expands to a register) to set the
@@ -1,29 +1,6 @@
 .syntax unified
 .cfi_sections .debug_frame

-.section .text.HardFault_Handler
-.global  HardFault_Handler
-.type    HardFault_Handler, %function
-HardFault_Handler:
-    .cfi_startproc
-    // Put the old stack pointer in the first argument, for easy debugging. This
-    // is especially useful on Cortex-M0, which supports far fewer debug
-    // facilities.
-    mov r0, sp
-
-    // Load the default stack pointer from address 0 so that we can call normal
-    // functions again that expect a working stack. However, it will corrupt the
-    // old stack so the function below must not attempt to recover from this
-    // fault.
-    movs r3, #0
-    ldr r3, [r3]
-    mov sp, r3
-
-    // Continue handling this error in Go.
-    bl handleHardFault
-    .cfi_endproc
-.size HardFault_Handler, .-HardFault_Handler
-
 // This is a convenience function for semihosting support.
 // At some point, this should be replaced by inline assembly.
 .section .text.SemihostingCall
@@ -10,10 +10,10 @@ func Asm(asm string)
 // recognizes template values in the form {name}, like so:
 //
 //	arm.AsmFull(
-//	    "str {value}, {result}",
+//	    "str {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 //
 // You can use {} in the asm string (which expands to a register) to set the
@@ -10,10 +10,10 @@ func Asm(asm string)
 // recognizes template values in the form {name}, like so:
 //
 //	arm.AsmFull(
-//	    "str {value}, {result}",
+//	    "str {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 //
 // You can use {} in the asm string (which expands to a register) to set the
@@ -10,10 +10,10 @@ func Asm(asm string)
 // recognizes template values in the form {name}, like so:
 //
 //	arm.AsmFull(
-//	    "st {value}, {result}",
+//	    "st {value}, [{result}]",
 //	    map[string]interface{}{
-//	        "value":  1
-//	        "result": &dest,
+//	        "value":  1,
+//	        "result": uintptr(unsafe.Pointer(&dest)),
 //	    })
 //
 // You can use {} in the asm string (which expands to a register) to set the
@@ -8,3 +8,10 @@ import "unsafe"
 func NoEscape(p unsafe.Pointer) unsafe.Pointer {
 	return p
 }
+
+func Escape[T any](x T) T {
+	// This function is either implemented in the compiler, or left undefined
+	// for some variation of T. The body of this function should not be compiled
+	// as-is.
+	panic("internal/abi.Escape: unreachable (implemented in the compiler)")
+}
@@ -1745,7 +1745,7 @@ func memzero(ptr unsafe.Pointer, size uintptr)
 func alloc(size uintptr, layout unsafe.Pointer) unsafe.Pointer

 //go:linkname sliceAppend runtime.sliceAppend
-func sliceAppend(srcBuf, elemsBuf unsafe.Pointer, srcLen, srcCap, elemsLen uintptr, elemSize uintptr) (unsafe.Pointer, uintptr, uintptr)
+func sliceAppend(srcBuf, elemsBuf unsafe.Pointer, srcLen, srcCap, elemsLen uintptr, elemSize uintptr, layout unsafe.Pointer) (unsafe.Pointer, uintptr, uintptr)

 //go:linkname sliceCopy runtime.sliceCopy
 func sliceCopy(dst, src unsafe.Pointer, dstLen, srcLen uintptr, elemSize uintptr) int
@@ -1810,7 +1810,7 @@ func buflen(v Value) (unsafe.Pointer, uintptr) {
 }

 //go:linkname sliceGrow runtime.sliceGrow
-func sliceGrow(buf unsafe.Pointer, oldLen, oldCap, newCap, elemSize uintptr) (unsafe.Pointer, uintptr, uintptr)
+func sliceGrow(buf unsafe.Pointer, oldLen, oldCap, newCap, elemSize uintptr, layout unsafe.Pointer) (unsafe.Pointer, uintptr, uintptr)

 // extend slice to hold n new elements
 func extendSlice(v Value, n int) sliceHeader {
@@ -1823,7 +1823,10 @@ func extendSlice(v Value, n int) sliceHeader {
 		old = *(*sliceHeader)(v.value)
 	}

-	nbuf, nlen, ncap := sliceGrow(old.data, old.len, old.cap, old.len+uintptr(n), v.typecode.elem().Size())
+	elem := v.typecode.elem()
+	elemSize := elem.Size()
+	elemLayout := elem.gcLayout()
+	nbuf, nlen, ncap := sliceGrow(old.data, old.len, old.cap, old.len+uintptr(n), elemSize, elemLayout)

 	return sliceHeader{
 		data: nbuf,
@@ -1862,8 +1865,10 @@ func AppendSlice(s, t Value) Value {
 	}
 	sSlice := (*sliceHeader)(s.value)
 	tSlice := (*sliceHeader)(t.value)
-	elemSize := s.typecode.elem().Size()
-	ptr, len, cap := sliceAppend(sSlice.data, tSlice.data, sSlice.len, sSlice.cap, tSlice.len, elemSize)
+	elem := s.typecode.elem()
+	elemSize := elem.Size()
+	elemLayout := elem.gcLayout()
+	ptr, len, cap := sliceAppend(sSlice.data, tSlice.data, sSlice.len, sSlice.cap, tSlice.len, elemSize, elemLayout)
 	result := &sliceHeader{
 		data: ptr,
 		len:  len,
@@ -108,6 +108,10 @@ func (*stackState) unwind()
 func (t *Task) Resume() {
 	// The current task must be saved and restored because this can nest on WASM with JS.
 	prevTask := currentTask
+	if prevTask == nil {
+		// Save the system stack pointer.
+		saveStackPointer()
+	}
 	t.gcData.swap()
 	currentTask = t
 	if !t.state.launched {
@@ -123,6 +127,9 @@ func (t *Task) Resume() {
 	}
 }

+//go:linkname saveStackPointer runtime.saveStackPointer
+func saveStackPointer()
+
 //export tinygo_rewind
 func (*state) rewind()

@@ -1,4 +1,4 @@
-//go:build scheduler.tasks && esp32
+//go:build scheduler.tasks && (esp32 || esp32s3)

 package task

@@ -58,6 +58,7 @@ void tinygo_task_init(void *mainTask, pthread_t *thread, int *numCPU, void *cont
    // Using pthread_kill, we can still send the signal to a specific thread.
    struct sigaction act = { 0 };
    act.sa_handler = tinygo_task_gc_pause;
+    act.sa_flags = SA_RESTART;
    sigaction(taskPauseSignal, &act, NULL);

    // Obtain the number of CPUs available on program start (for NumCPU).
@@ -100,7 +101,7 @@ static void* start_wrapper(void *arg) {
 };

 // Start a new goroutine in an OS thread.
-int tinygo_task_start(uintptr_t fn, void *args, void *task, pthread_t *thread, uintptr_t *stackTop, void *context) {
+int tinygo_task_start(uintptr_t fn, void *args, void *task, pthread_t *thread, uintptr_t *stackTop, uintptr_t stackSize, void *context) {
    // Sanity check. Should get optimized away.
    if (sizeof(pthread_t) != sizeof(void*)) {
        __builtin_trap();
@@ -117,13 +118,23 @@ int tinygo_task_start(uintptr_t fn, void *args, void *task, pthread_t *thread, u
    #else
    sem_init(&state.startlock, 0, 0);
    #endif
-    int result = pthread_create(thread, NULL, &start_wrapper, &state);
+    pthread_attr_t attrs;
+    pthread_attr_init(&attrs);
+	pthread_attr_setdetachstate(&attrs, PTHREAD_CREATE_DETACHED);
+    pthread_attr_setstacksize(&attrs, stackSize);
+    int result = pthread_create(thread, &attrs, &start_wrapper, &state);
+    pthread_attr_destroy(&attrs);
+	if (result != 0) {
+		return result;
+	}

    // Wait until the thread has been created and read all state_pass variables.
    #if __APPLE__
    dispatch_semaphore_wait(state.startlock, DISPATCH_TIME_FOREVER);
+    dispatch_release(state.startlock);
    #else
    sem_wait(&state.startlock);
+    sem_destroy(&state.startlock);
    #endif

    return result;
@@ -23,16 +23,15 @@ type state struct {
 	// is needed to be able to scan the stack.
 	stackTop uintptr

+	// Lowest address of the stack.
+	// This is populated when the thread is stopped by the GC.
+	stackBottom uintptr
+
 	// Next task in the activeTasks queue.
 	QueueNext *Task

 	// Semaphore to pause/resume the thread atomically.
 	pauseSem Semaphore
-
-	// Semaphore used for stack scanning.
-	// We can't reuse pauseSem here since the thread might have been paused for
-	// other reasons (for example, because it was waiting on a channel).
-	gcSem Semaphore
 }

 // Goroutine counter, starting at 0 for the main goroutine.
@@ -96,6 +95,9 @@ func (t *Task) Resume() {
 	t.state.pauseSem.Post()
 }

+// otherGoroutines is the total number of live goroutines minus one.
+var otherGoroutines uint32
+
 // Start a new OS thread.
 func start(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	t := &Task{}
@@ -109,12 +111,13 @@ func start(fn uintptr, args unsafe.Pointer, stackSize uintptr) {
 	// and the stop-the-world GC won't see threads that haven't started yet or
 	// are not fully started yet.
 	activeTaskLock.Lock()
-	errCode := tinygo_task_start(fn, args, t, &t.state.thread, &t.state.stackTop)
+	errCode := tinygo_task_start(fn, args, t, &t.state.thread, &t.state.stackTop, stackSize)
 	if errCode != 0 {
 		runtimePanic("could not start thread")
 	}
 	t.state.QueueNext = activeTasks
 	activeTasks = t
+	otherGoroutines++
 	activeTaskLock.Unlock()
 }

@@ -135,6 +138,7 @@ func taskExited(t *Task) {
 			break
 		}
 	}
+	otherGoroutines--
 	activeTaskLock.Unlock()

 	// Sanity check.
@@ -143,9 +147,42 @@ func taskExited(t *Task) {
 	}
 }

-// Futex to wait on until all tasks have finished scanning the stack.
-// This is basically a sync.WaitGroup.
-var scanDoneFutex Futex
+// scanWaitGroup is used to wait on until all threads have finished the current state transition.
+var scanWaitGroup waitGroup
+
+type waitGroup struct {
+	f Futex
+}
+
+func initWaitGroup(n uint32) waitGroup {
+	var wg waitGroup
+	wg.f.Store(n)
+	return wg
+}
+
+func (wg *waitGroup) done() {
+	if wg.f.Add(^uint32(0)) == 0 {
+		wg.f.WakeAll()
+	}
+}
+
+func (wg *waitGroup) wait() {
+	for {
+		val := wg.f.Load()
+		if val == 0 {
+			return
+		}
+		wg.f.Wait(val)
+	}
+}
+
+// gcState is used to track and notify threads when the GC is stopping/resuming.
+var gcState Futex
+
+const (
+	gcStateResumed = iota
+	gcStateStopped
+)

 // GC scan phase. Because we need to stop the world while scanning, this kinda
 // needs to be done in the tasks package.
@@ -155,65 +192,71 @@ var scanDoneFutex Futex
 func GCStopWorldAndScan() {
 	current := Current()

-	// Don't allow new goroutines to be started while pausing/resuming threads
-	// in the stop-the-world phase.
-	activeTaskLock.Lock()
+	// NOTE: This does not need to be atomic.
+	if gcState.Load() == gcStateResumed {
+		// Don't allow new goroutines to be started while pausing/resuming threads
+		// in the stop-the-world phase.
+		activeTaskLock.Lock()

-	// Pause all other threads.
-	numOtherThreads := uint32(0)
-	for t := activeTasks; t != nil; t = t.state.QueueNext {
-		if t != current {
-			numOtherThreads++
-			tinygo_task_send_gc_signal(t.state.thread)
+		// Wait for threads to finish resuming.
+		scanWaitGroup.wait()
+
+		// Change the gc state to stopped.
+		// NOTE: This does not need to be atomic.
+		gcState.Store(gcStateStopped)
+
+		// Set the number of threads to wait for.
+		scanWaitGroup = initWaitGroup(otherGoroutines)
+
+		// Pause all other threads.
+		for t := activeTasks; t != nil; t = t.state.QueueNext {
+			if t != current {
+				tinygo_task_send_gc_signal(t.state.thread)
+			}
 		}
+
+		// Wait for the threads to finish stopping.
+		scanWaitGroup.wait()
 	}

-	// Store the number of threads to wait for in the futex.
-	// This is the equivalent of doing an initial wg.Add(numOtherThreads).
-	scanDoneFutex.Store(numOtherThreads)
+	// Scan other thread stacks.
+	for t := activeTasks; t != nil; t = t.state.QueueNext {
+		if t != current {
+			markRoots(t.state.stackBottom, t.state.stackTop)
+		}
+	}

 	// Scan the current stack, and all current registers.
 	scanCurrentStack()

-	// Wake each paused thread for the first time so it will scan the stack.
-	for t := activeTasks; t != nil; t = t.state.QueueNext {
-		if t != current {
-			t.state.gcSem.Post()
-		}
-	}
-
-	// Wait until all threads have finished scanning their stack.
-	// This is the equivalent of wg.Wait()
-	for {
-		val := scanDoneFutex.Load()
-		if val == 0 {
-			break
-		}
-		scanDoneFutex.Wait(val)
-	}
-
 	// Scan all globals (implemented in the runtime).
 	gcScanGlobals()
 }

 // After the GC is done scanning, resume all other threads.
-//
-// This must only be called after a GCStopWorldAndScan call.
 func GCResumeWorld() {
-	current := Current()
-
-	// Wake each paused thread for the second time, so they will resume normal
-	// operation.
-	for t := activeTasks; t != nil; t = t.state.QueueNext {
-		if t != current {
-			t.state.gcSem.Post()
-		}
+	// NOTE: This does not need to be atomic.
+	if gcState.Load() == gcStateResumed {
+		// This is already resumed.
+		return
 	}

+	// Set the wait group to track resume progress.
+	scanWaitGroup = initWaitGroup(otherGoroutines)
+
+	// Set the state to resumed.
+	gcState.Store(gcStateResumed)
+
+	// Wake all of the stopped threads.
+	gcState.WakeAll()
+
 	// Allow goroutines to start and exit again.
 	activeTaskLock.Unlock()
 }

+//go:linkname markRoots runtime.markRoots
+func markRoots(start, end uintptr)
+
 // Scan globals, implemented in the runtime package.
 func gcScanGlobals()

@@ -221,34 +264,27 @@ var stackScanLock PMutex

 //export tinygo_task_gc_pause
 func tingyo_task_gc_pause(sig int32) {
-	// Wait until we get the signal to start scanning the stack.
-	Current().state.gcSem.Wait()
+	// Write the entrty stack pointer to the state.
+	Current().state.stackBottom = uintptr(stacksave())

-	// Scan the thread stack.
-	// Only scan a single thread stack at a time, because the GC marking phase
-	// doesn't support parallelism.
-	// TODO: it may be possible to call markRoots directly (without saving
-	// registers) since we are in a signal handler that already saved a bunch of
-	// registers. This is an optimization left for a future time.
-	stackScanLock.Lock()
-	scanCurrentStack()
-	stackScanLock.Unlock()
+	// Notify the GC that we are stopped.
+	scanWaitGroup.done()

-	// Equivalent of wg.Done(): subtract one from the futex and if the result is
-	// 0 (meaning we were the last in the waitgroup), wake the waiting thread.
-	n := uint32(1)
-	if scanDoneFutex.Add(-n) == 0 {
-		scanDoneFutex.Wake()
+	// Wait for the GC to resume.
+	for gcState.Load() == gcStateStopped {
+		gcState.Wait(gcStateStopped)
 	}

-	// Wait until we get the signal we can resume normally (after the mark phase
-	// has finished).
-	Current().state.gcSem.Wait()
+	// Notify the GC that we have resumed.
+	scanWaitGroup.done()
 }

 //go:export tinygo_scanCurrentStack
 func scanCurrentStack()

+//go:linkname stacksave runtime.stacksave
+func stacksave() unsafe.Pointer
+
 // Return the highest address of the current stack.
 func StackTop() uintptr {
 	return Current().state.stackTop
@@ -266,7 +302,7 @@ func tinygo_task_init(t *Task, thread *threadID, numCPU *int32)
 // Here same as for tinygo_task_init.
 //
 //go:linkname tinygo_task_start tinygo_task_start
-func tinygo_task_start(fn uintptr, args unsafe.Pointer, t *Task, thread *threadID, stackTop *uintptr) int32
+func tinygo_task_start(fn uintptr, args unsafe.Pointer, t *Task, thread *threadID, stackTop *uintptr, stackSize uintptr) int32

 // Pause the thread by sending it a signal.
 //
@@ -15,8 +15,8 @@ const (
 	P09 Pin = 9
 	P10 Pin = 10
 	P11 Pin = 11
-	P12 Pin = 12
-	P13 Pin = 13
+	P12 Pin = 12 // peripherals: I2C0 SDA
+	P13 Pin = 13 // peripherals: I2C0 SCL
 	P14 Pin = 14
 	P15 Pin = 15
 	P16 Pin = 16
@@ -0,0 +1,22 @@
+//go:build gopher_arcade
+
+package machine
+
+// Return the current CPU frequency in hertz.
+func CPUFrequency() uint32 {
+	return 8000000
+}
+
+const (
+	P5 Pin = PB0
+	P6 Pin = PB1
+	P7 Pin = PB2
+	P2 Pin = PB3
+	P3 Pin = PB4
+	P1 Pin = PB5
+
+	LED          = P1
+	BUTTON_LEFT  = P7
+	BUTTON_RIGHT = P5
+	SPEAKER      = P6
+)
@@ -0,0 +1,183 @@
+//go:build metro_rp2350
+
+package machine
+
+// GPIO pins
+const (
+	GP0  Pin = GPIO0
+	GP1  Pin = GPIO1
+	GP2  Pin = GPIO2
+	GP3  Pin = GPIO3
+	GP4  Pin = GPIO4
+	GP5  Pin = GPIO5
+	GP6  Pin = GPIO6
+	GP7  Pin = GPIO7
+	GP8  Pin = GPIO8
+	GP9  Pin = GPIO9
+	GP10 Pin = GPIO10
+	GP11 Pin = GPIO11
+	GP12 Pin = GPIO12
+	GP13 Pin = GPIO13
+	GP14 Pin = GPIO14
+	GP15 Pin = GPIO15
+	GP16 Pin = GPIO16
+	GP17 Pin = GPIO17
+	GP18 Pin = GPIO18
+	GP19 Pin = GPIO19
+	GP20 Pin = GPIO20
+	GP21 Pin = GPIO21
+	GP22 Pin = GPIO22
+	GP23 Pin = GPIO23
+	GP24 Pin = GPIO24
+	GP25 Pin = GPIO25
+	GP26 Pin = GPIO26
+	GP27 Pin = GPIO27
+	GP28 Pin = GPIO28
+	GP29 Pin = GPIO29
+	GP30 Pin = GPIO30
+	GP31 Pin = GPIO31
+	GP32 Pin = GPIO32
+	GP33 Pin = GPIO33
+	GP34 Pin = GPIO34
+	GP35 Pin = GPIO35
+	GP36 Pin = GPIO36
+	GP37 Pin = GPIO37
+	GP38 Pin = GPIO38
+	GP39 Pin = GPIO39
+	GP40 Pin = GPIO40
+	GP41 Pin = GPIO41
+	GP42 Pin = GPIO42
+	GP43 Pin = GPIO43
+	GP44 Pin = GPIO44
+	GP45 Pin = GPIO45
+	GP46 Pin = GPIO46
+
+	// Boot button
+	BUTTON Pin = GPIO24
+
+	// Onboard LED
+	LED Pin = GPIO23
+
+	// Onboard NeoPixel
+	NEOPIXEL Pin = GPIO25
+	WS2812   Pin = GPIO25
+
+	// Onboard crystal oscillator frequency, in MHz.
+	xoscFreq = 12 // MHz
+)
+
+// Arduino-header digital pins
+const (
+	RX  Pin = GPIO1
+	TX  Pin = GPIO0
+	D2  Pin = GPIO2
+	D3  Pin = GPIO3
+	D4  Pin = GPIO4
+	D5  Pin = GPIO5
+	D6  Pin = GPIO6
+	D7  Pin = GPIO7
+	D8  Pin = GPIO8
+	D9  Pin = GPIO9
+	D10 Pin = GPIO10
+	D11 Pin = GPIO11
+	D22 Pin = GPIO22
+	D23 Pin = GPIO23
+)
+
+// Arduino-header analog pins
+const (
+	A0 Pin = GPIO41
+	A1 Pin = GPIO42
+	A2 Pin = GPIO43
+	A3 Pin = GPIO44
+	A4 Pin = GPIO45
+	A5 Pin = GPIO46
+)
+
+// I2C Default pins on Raspberry Pico.
+const (
+	I2C0_SDA_PIN = GP20
+	I2C0_SCL_PIN = GP21
+
+	I2C1_SDA_PIN = GP2
+	I2C1_SCL_PIN = GP3
+)
+
+// SPI default pins
+const (
+	// Default Serial Clock Bus 0 for SPI communications
+	SPI0_SCK_PIN = GPIO18
+	// Default Serial Out Bus 0 for SPI communications
+	SPI0_SDO_PIN = GPIO19 // Tx
+	// Default Serial In Bus 0 for SPI communications
+	SPI0_SDI_PIN = GPIO16 // Rx
+
+	// Default Serial Clock Bus 1 for SPI communications
+	SPI1_SCK_PIN = GPIO30
+	// Default Serial Out Bus 1 for SPI communications
+	SPI1_SDO_PIN = GPIO31 // Tx
+	// Default Serial In Bus 1 for SPI communications
+	SPI1_SDI_PIN = GPIO28 // Rx
+
+	// SPI header pins
+	MOSI Pin = SPI1_SDO_PIN
+	MISO Pin = SPI1_SDI_PIN
+	SCK  Pin = SPI1_SCK_PIN
+)
+
+// SD card reader pins
+const (
+	SD_SCK         = GPIO34
+	SD_MOSI        = GPIO35
+	SD_MISO        = GPIO36
+	SDIO_DATA1     = GPIO37
+	SDIO_DATA2     = GPIO38
+	SD_CS          = GPIO39
+	SD_CARD_DETECT = GPIO40
+)
+
+// HSTX pins
+const (
+	CKN Pin = GPIO15
+	CKP Pin = GPIO14
+	D0N Pin = GPIO19
+	D0P Pin = GPIO18
+	D1N Pin = GPIO17
+	D1P Pin = GPIO16
+	D2N Pin = GPIO13
+	D2P Pin = GPIO12
+	D26 Pin = GPIO26
+	D27 Pin = GPIO27
+	SCL Pin = GPIO21
+	SDA Pin = GPIO20
+)
+
+// USB host header pins
+const (
+	USB_HOST_DATA_PLUS  Pin = GPIO32
+	USB_HOST_DATA_MINUS Pin = GPIO33
+	USB_HOST_5V_POWER   Pin = GPIO29
+)
+
+// UART pins
+const (
+	UART0_TX_PIN = GPIO0
+	UART0_RX_PIN = GPIO1
+	UART1_TX_PIN = GPIO8
+	UART1_RX_PIN = GPIO9
+	UART_TX_PIN  = UART0_TX_PIN
+	UART_RX_PIN  = UART0_RX_PIN
+)
+
+var DefaultUART = UART0
+
+// USB identifiers
+const (
+	usb_STRING_PRODUCT      = "Metro RP2350"
+	usb_STRING_MANUFACTURER = "Adafruit"
+)
+
+var (
+	usb_VID uint16 = 0x239A
+	usb_PID uint16 = 0x814E
+)
@@ -0,0 +1,173 @@
+//go:build pico2_ice
+
+// Most of the info is from
+// https://pico2-ice.tinyvision.ai/md_pinout.html although
+// (2025-09-07) RP4 appears twice in that pinout - the schematic is
+// more clear. Consistent with other RPi boards, we use GPn instead of
+// RPn to reference the RPi connected pins.
+
+package machine
+
+// GPIO pins
+const (
+	GP0  = GPIO0
+	GP1  = GPIO1
+	GP2  = GPIO2
+	GP3  = GPIO3
+	GP4  = GPIO4
+	GP5  = GPIO5
+	GP6  = GPIO6
+	GP7  = GPIO7
+	GP8  = GPIO8
+	GP9  = GPIO9
+	GP10 = GPIO10
+	GP11 = GPIO11
+	GP12 = GPIO12
+	GP13 = GPIO13
+	GP14 = GPIO14
+	GP15 = GPIO15
+	GP16 = GPIO16
+	GP17 = GPIO17
+	GP18 = GPIO18
+	GP19 = GPIO19
+	GP20 = GPIO20
+	GP21 = GPIO21
+	GP22 = GPIO22
+	GP23 = GPIO23
+	GP24 = GPIO24
+	GP25 = GPIO25
+	GP26 = GPIO26
+	GP27 = GPIO27
+	GP28 = GPIO28
+	GP29 = GPIO29
+	GP30 = GPIO30
+	GP31 = GPIO31
+	GP32 = GPIO32
+	GP33 = GPIO33
+	GP34 = GPIO34
+	GP35 = GPIO35
+	GP36 = GPIO36
+	GP37 = GPIO37
+	GP38 = GPIO38
+	GP39 = GPIO39
+	GP40 = GPIO40
+	GP41 = GPIO41
+	GP42 = GPIO42
+	GP43 = GPIO43
+	GP44 = GPIO44
+	GP45 = GPIO45
+	GP46 = GPIO46
+	GP47 = GPIO47
+
+	// RPi pins shared with ICE. The ICE number is what appears on
+	// the board silkscreen.
+	ICE9  = GP28
+	ICE11 = GP29
+	ICE14 = GP7
+	ICE15 = GP6
+	ICE16 = GP5
+	ICE17 = GP4
+	ICE18 = GP27
+	ICE19 = GP23
+	ICE20 = GP22
+	ICE21 = GP26
+	ICE23 = GP25
+	ICE25 = GP30
+	ICE26 = GP24
+	ICE27 = GP20
+
+	// FPGA Clock pin.
+	ICE35_G0 = GP21
+
+	// Silkscreen & Pinout names
+	ICE_SSN = ICE16
+	ICE_SO  = ICE14
+	ICE_SI  = ICE17
+	ICE_CK  = ICE15
+	SD      = GP2
+	SC      = GP3
+
+	FPGA_RSTN = GP31
+	A3        = GP32
+	A1        = GP33
+	A4        = GP34
+	A2        = GP35
+	B3        = GP36
+	B1        = GP37
+	B4        = GP38
+	B2        = GP39
+	N0        = GP40 // On the board these are labeled "~0"
+	N1        = GP41
+	N2        = GP42
+	N3        = GP43
+	N4        = GP44
+	N5        = GP45
+	N6        = GP46
+
+	// Functions from Schematic.
+	ICE_DONE = GP40
+	USB_BOOT = GP42
+
+	// Button
+	SW1     = GP42
+	BOOTSEL = GP42
+
+	// Tricolor LEDs
+	LED_RED   = GP1
+	LED_GREEN = GP0
+	LED_BLUE  = GP9
+
+	// Onboard LED
+	LED = LED_GREEN
+
+	// Onboard crystal oscillator frequency, in MHz.
+	xoscFreq = 12 // MHz
+)
+
+// This board does not define default i2c pins.
+const (
+	I2C0_SDA_PIN = NoPin
+	I2C0_SCL_PIN = NoPin
+	I2C1_SDA_PIN = NoPin
+	I2C1_SCL_PIN = NoPin
+)
+
+// SPI default pins
+const (
+	// Default Serial Clock Bus 0 for SPI communications
+	SPI0_SCK_PIN = GPIO18
+	// Default Serial Out Bus 0 for SPI communications
+	SPI0_SDO_PIN = GPIO19 // Tx
+	// Default Serial In Bus 0 for SPI communications
+	SPI0_SDI_PIN = GPIO16 // Rx
+
+	// Default Serial Clock Bus 1 for SPI communications
+	SPI1_SCK_PIN = GPIO10
+	// Default Serial Out Bus 1 for SPI communications
+	SPI1_SDO_PIN = GPIO11 // Tx
+	// Default Serial In Bus 1 for SPI communications
+	SPI1_SDI_PIN = GPIO12 // Rx
+)
+
+// UART pins
+const (
+	UART0_TX_PIN = GPIO0
+	UART0_RX_PIN = GPIO1
+	UART1_TX_PIN = GPIO8
+	UART1_RX_PIN = GPIO9
+	UART_TX_PIN  = UART0_TX_PIN
+	UART_RX_PIN  = UART0_RX_PIN
+)
+
+var DefaultUART = UART0
+
+// USB identifiers
+const (
+	usb_STRING_PRODUCT      = "Pico2"
+	usb_STRING_MANUFACTURER = "Raspberry Pi"
+)
+
+var (
+	usb_VID uint16 = 0x2E8A
+	usb_PID uint16 = 0x000A
+)
@@ -0,0 +1,58 @@
+//go:build xiao_esp32s3
+
+// This file contains the pin mappings for the Seeed XIAO ESP32S3 boards.
+//
+// Seeed Studio XIAO ESP32S3 is an IoT mini development board based on
+// the Espressif ESP32-S3 WiFi/Bluetooth dual-mode chip.
+//
+// - https://www.seeedstudio.com/XIAO-ESP32S3-p-5627.html
+// - https://wiki.seeedstudio.com/xiao_esp32s3_getting_started/
+
+package machine
+
+// Digital Pins
+const (
+	D0  = GPIO1
+	D1  = GPIO2
+	D2  = GPIO3
+	D3  = GPIO4
+	D4  = GPIO5
+	D5  = GPIO6
+	D6  = GPIO43
+	D7  = GPIO44
+	D8  = GPIO7
+	D9  = GPIO8
+	D10 = GPIO9
+)
+
+// Analog pins
+const (
+	A0 = GPIO1
+	A1 = GPIO2
+	A2 = GPIO3
+	A3 = GPIO4
+)
+
+// UART pins
+const (
+	UART_RX_PIN = GPIO44
+	UART_TX_PIN = GPIO43
+)
+
+// I2C pins
+const (
+	SDA_PIN = GPIO5
+	SCL_PIN = GPIO6
+)
+
+// SPI pins
+const (
+	SPI_SCK_PIN = GPIO7
+	SPI_SDI_PIN = GPIO9
+	SPI_SDO_PIN = GPIO8
+)
+
+// Onboard LEDs
+const (
+	LED = GPIO21
+)
@@ -43,6 +43,11 @@ type BlockDevice interface {
 	io.ReaderAt

 	// WriteAt writes the given number of bytes to the block device.
+	//
+	// This interface directly writes data to the underlying block device.
+	// Different kinds of devices have different requirements: most can only
+	// write data after the page has been erased, and many can only write data
+	// with specific alignment (such as 4-byte alignment).
 	io.WriterAt

 	// Size returns the number of bytes in this block device.
@@ -1,6 +1,9 @@
 package machine

-import "errors"
+import (
+	"errors"
+	"unsafe"
+)

 var (
 	ErrTimeoutRNG         = errors.New("machine: RNG Timeout")
@@ -62,3 +65,30 @@ func (p Pin) Low() {
 type ADC struct {
 	Pin Pin
 }
+
+// Convert the pointer to a uintptr, to be used for memory I/O (DMA for
+// example). It also means the pointer is "gone" as far as the compiler is
+// concerned, and a GC cycle might deallocate the object. To prevent this from
+// happening, also call keepAliveNoEscape at a point after the address isn't
+// accessed anymore by the hardware.
+// The only exception is if the pointer is accessed later in a volatile way
+// (volatile read/write), which also forces the value to stay alive until that
+// point.
+//
+// This function is treated specially by the compiler to mark the 'ptr'
+// parameter as not escaping.
+//
+// TODO: this function should eventually be replaced with the proposed ptrtoaddr
+// instruction in LLVM. See:
+// https://discourse.llvm.org/t/clarifiying-the-semantics-of-ptrtoint/83987/10
+// https://github.com/llvm/llvm-project/pull/139357
+func unsafeNoEscape(ptr unsafe.Pointer) uintptr {
+	return uintptr(ptr)
+}
+
+// Make sure the given pointer stays alive until this point. This is similar to
+// runtime.KeepAlive, with the difference that it won't let the pointer escape.
+// This is typically used together with unsafeNoEscape.
+//
+// This is a compiler intrinsic.
+func keepAliveNoEscape(ptr unsafe.Pointer)
@@ -337,7 +337,7 @@ func handleUSBSetAddress(setup usb.Setup) bool {

 // SendUSBInPacket sends a packet for USB (interrupt in / bulk in).
 func SendUSBInPacket(ep uint32, data []byte) bool {
-	sendUSBPacket(ep, data, 0)
+	sendUSBPacket(ep, data)

 	// clear transfer complete flag
 	setEPINTFLAG(ep, sam.USB_DEVICE_EPINTFLAG_TRCPT1)
@@ -351,27 +351,28 @@ func SendUSBInPacket(ep uint32, data []byte) bool {
 // Prevent file size increases: https://github.com/tinygo-org/tinygo/pull/998
 //
 //go:noinline
-func sendUSBPacket(ep uint32, data []byte, maxsize uint16) {
-	l := uint16(len(data))
-	if 0 < maxsize && maxsize < l {
-		l = maxsize
+func sendUSBPacket(ep uint32, data []byte) {
+	// Select the corresponding buffer.
+	buffer := udd_ep_control_cache_buffer[:]
+	if ep != 0 {
+		buffer = udd_ep_in_cache_buffer[ep][:]
 	}

-	// Set endpoint address for sending data
-	if ep == 0 {
-		copy(udd_ep_control_cache_buffer[:], data[:l])
-		usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_control_cache_buffer))))
-	} else {
-		copy(udd_ep_in_cache_buffer[ep][:], data[:l])
-		usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
-	}
+	// Copy the packet to the buffer.
+	copy(buffer[:len(data)], data)
+
+	// Select the corresponding endpoint descriptor.
+	endpoint := &usbEndpointDescriptors[ep].DeviceDescBank[1]
+
+	// Set the endpoint address.
+	endpoint.ADDR.Set(uint32(uintptr(unsafe.Pointer(unsafe.SliceData(buffer)))))

 	// clear multi-packet size which is total bytes already sent
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
+	endpoint.PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)

 	// set byte count, which is total number of bytes to be sent
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits((uint32(l) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask) << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
+	endpoint.PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
+	endpoint.PCKSIZE.SetBits((uint32(len(data)) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask) << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
 }

 func ReceiveUSBControlPacket() ([cdcLineInfoSize]byte, error) {
@@ -340,7 +340,7 @@ func handleUSBSetAddress(setup usb.Setup) bool {

 // SendUSBInPacket sends a packet for USB (interrupt in / bulk in).
 func SendUSBInPacket(ep uint32, data []byte) bool {
-	sendUSBPacket(ep, data, 0)
+	sendUSBPacket(ep, data)

 	// clear transfer complete flag
 	setEPINTFLAG(ep, sam.USB_DEVICE_ENDPOINT_EPINTFLAG_TRCPT1)
@@ -354,27 +354,28 @@ func SendUSBInPacket(ep uint32, data []byte) bool {
 // Prevent file size increases: https://github.com/tinygo-org/tinygo/pull/998
 //
 //go:noinline
-func sendUSBPacket(ep uint32, data []byte, maxsize uint16) {
-	l := uint16(len(data))
-	if 0 < maxsize && maxsize < l {
-		l = maxsize
+func sendUSBPacket(ep uint32, data []byte) {
+	// Select the corresponding buffer.
+	buffer := udd_ep_control_cache_buffer[:]
+	if ep != 0 {
+		buffer = udd_ep_in_cache_buffer[ep][:]
 	}

-	// Set endpoint address for sending data
-	if ep == 0 {
-		copy(udd_ep_control_cache_buffer[:], data[:l])
-		usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_control_cache_buffer))))
-	} else {
-		copy(udd_ep_in_cache_buffer[ep][:], data[:l])
-		usbEndpointDescriptors[ep].DeviceDescBank[1].ADDR.Set(uint32(uintptr(unsafe.Pointer(&udd_ep_in_cache_buffer[ep]))))
-	}
+	// Copy the packet to the buffer.
+	copy(buffer[:len(data)], data)
+
+	// Select the corresponding endpoint descriptor.
+	endpoint := &usbEndpointDescriptors[ep].DeviceDescBank[1]
+
+	// Set the endpoint address.
+	endpoint.ADDR.Set(uint32(uintptr(unsafe.Pointer(unsafe.SliceData(buffer)))))

 	// clear multi-packet size which is total bytes already sent
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)
+	endpoint.PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Mask << usb_DEVICE_PCKSIZE_MULTI_PACKET_SIZE_Pos)

 	// set byte count, which is total number of bytes to be sent
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
-	usbEndpointDescriptors[ep].DeviceDescBank[1].PCKSIZE.SetBits((uint32(l) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask) << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
+	endpoint.PCKSIZE.ClearBits(usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
+	endpoint.PCKSIZE.SetBits((uint32(len(data)) & usb_DEVICE_PCKSIZE_BYTE_COUNT_Mask) << usb_DEVICE_PCKSIZE_BYTE_COUNT_Pos)
 }

 func ReceiveUSBControlPacket() ([cdcLineInfoSize]byte, error) {
@@ -519,6 +519,10 @@ type Serialer interface {
 	RTS() bool
 }

+func initUSB() {
+	// nothing to do here
+}
+
 // USB Serial/JTAG Controller
 // See esp32-c3_technical_reference_manual_en.pdf
 // pg. 736
@@ -0,0 +1,312 @@
+//go:build esp32s3
+
+package machine
+
+import (
+	"device/esp"
+	"errors"
+	"runtime/volatile"
+	"unsafe"
+)
+
+const deviceName = esp.Device
+
+const xtalClock = 40_000000       // 40MHz
+const apbClock = 80_000000        // 80MHz
+const cryptoPWMClock = 160_000000 // 160MHz
+
+// GetCPUFrequency returns the current CPU frequency of the chip.
+func GetCPUFrequency() (uint32, error) {
+	switch esp.SYSTEM.GetSYSCLK_CONF_SOC_CLK_SEL() {
+	case 0:
+		return xtalClock / (esp.SYSTEM.GetSYSCLK_CONF_PRE_DIV_CNT() + 1), nil
+	case 1:
+		switch esp.SYSTEM.GetCPU_PER_CONF_CPUPERIOD_SEL() {
+		case 0:
+			return 80e6, nil
+		case 1:
+			return 160e6, nil
+		case 2:
+			// If esp.SYSTEM.GetCPU_PER_CONF_PLL_FREQ_SEL() == 1, this is undefined
+			return 240e6, nil
+		}
+	case 2:
+		//RC Fast Clock
+		return (175e5) / (esp.SYSTEM.GetSYSCLK_CONF_PRE_DIV_CNT() + 1), nil
+	}
+	return 0, errors.New("machine: Unable to determine current cpu frequency")
+}
+
+// SetCPUFrequency sets the frequency of the CPU to one of several targets
+func SetCPUFrequency(frequency uint32) error {
+	// Always assume we are on PLL. Lower frequencies can be set with a different
+	// clock source, but this will change the behavior of APB clock and Crypto PWM
+	// clock
+	//esp.SYSTEM.SetSYSCLK_CONF_SOC_CLK_SEL(1)
+
+	switch frequency {
+	case 80_000000:
+		esp.SYSTEM.SetCPU_PER_CONF_CPUPERIOD_SEL(0)
+		esp.SYSTEM.SetCPU_PER_CONF_PLL_FREQ_SEL(0) // Reduce PLL freq when possible
+		return nil
+	case 160_000000:
+		esp.SYSTEM.SetCPU_PER_CONF_CPUPERIOD_SEL(1)
+		esp.SYSTEM.SetCPU_PER_CONF_PLL_FREQ_SEL(0)
+		return nil
+	case 240_000000:
+		esp.SYSTEM.SetCPU_PER_CONF_PLL_FREQ_SEL(1) // Increase PLL freq when needed
+		esp.SYSTEM.SetCPU_PER_CONF_CPUPERIOD_SEL(2)
+		return nil
+	}
+	return errors.New("machine: Unsupported CPU frequency selected. Supported: 80, 160, 240 MHz")
+}
+
+var (
+	ErrInvalidSPIBus = errors.New("machine: invalid SPI bus")
+)
+
+const (
+	PinOutput PinMode = iota
+	PinInput
+	PinInputPullup
+	PinInputPulldown
+)
+
+// Hardware pin numbers
+const (
+	GPIO0  Pin = 0
+	GPIO1  Pin = 1
+	GPIO2  Pin = 2
+	GPIO3  Pin = 3
+	GPIO4  Pin = 4
+	GPIO5  Pin = 5
+	GPIO6  Pin = 6
+	GPIO7  Pin = 7
+	GPIO8  Pin = 8
+	GPIO9  Pin = 9
+	GPIO10 Pin = 10
+	GPIO11 Pin = 11
+	GPIO12 Pin = 12
+	GPIO13 Pin = 13
+	GPIO14 Pin = 14
+	GPIO15 Pin = 15
+	GPIO16 Pin = 16
+	GPIO17 Pin = 17
+	GPIO18 Pin = 18
+	GPIO19 Pin = 19
+	GPIO20 Pin = 20
+	GPIO21 Pin = 21
+	GPIO26 Pin = 26
+	GPIO27 Pin = 27
+	GPIO28 Pin = 28
+	GPIO29 Pin = 29
+	GPIO30 Pin = 30
+	GPIO31 Pin = 31
+	GPIO32 Pin = 32
+	GPIO33 Pin = 33
+	GPIO34 Pin = 34
+	GPIO35 Pin = 35
+	GPIO36 Pin = 36
+	GPIO37 Pin = 37
+	GPIO38 Pin = 38
+	GPIO39 Pin = 39
+	GPIO40 Pin = 40
+	GPIO41 Pin = 41
+	GPIO42 Pin = 42
+	GPIO43 Pin = 43
+	GPIO44 Pin = 44
+	GPIO45 Pin = 45
+	GPIO46 Pin = 46
+	GPIO47 Pin = 47
+	GPIO48 Pin = 48
+)
+
+// Configure this pin with the given configuration.
+func (p Pin) Configure(config PinConfig) {
+	// Output function 256 is a special value reserved for use as a regular GPIO
+	// pin. Peripherals (SPI etc) can set a custom output function by calling
+	// lowercase configure() instead with a signal name.
+	p.configure(config, 256)
+}
+
+// configure is the same as Configure, but allows for setting a specific input
+// or output signal.
+// Signals are always routed through the GPIO matrix for simplicity. Output
+// signals are configured in FUNCx_OUT_SEL_CFG which selects a particular signal
+// to output on a given pin. Input signals are configured in FUNCy_IN_SEL_CFG,
+// which sets the pin to use for a particular input signal.
+func (p Pin) configure(config PinConfig, signal uint32) {
+	if p == NoPin {
+		// This simplifies pin configuration in peripherals such as SPI.
+		return
+	}
+
+	ioConfig := uint32(0)
+
+	// MCU_SEL: Function 1 is always GPIO
+	ioConfig |= (1 << esp.IO_MUX_GPIO_MCU_SEL_Pos)
+
+	// FUN_IE: Make this pin an input pin (always set for GPIO operation)
+	ioConfig |= esp.IO_MUX_GPIO_FUN_IE
+
+	// DRV: Set drive strength to 20 mA as a default. Pins 17 and 18 are special
+	var drive uint32
+	if p == GPIO17 || p == GPIO18 {
+		drive = 1 // 20 mA
+	} else {
+		drive = 2 // 20 mA
+	}
+	ioConfig |= (drive << esp.IO_MUX_GPIO_FUN_DRV_Pos)
+
+	// WPU/WPD: Select pull mode.
+	if config.Mode == PinInputPullup {
+		ioConfig |= esp.IO_MUX_GPIO_FUN_WPU
+	} else if config.Mode == PinInputPulldown {
+		ioConfig |= esp.IO_MUX_GPIO_FUN_WPD
+	}
+
+	// Set configuration
+	ioRegister := p.ioMuxReg()
+	ioRegister.Set(ioConfig)
+
+	switch config.Mode {
+	case PinOutput:
+		// Set the 'output enable' bit.
+		if p < 32 {
+			esp.GPIO.ENABLE_W1TS.Set(1 << p)
+		} else {
+			esp.GPIO.ENABLE1_W1TS.Set(1 << (p - 32))
+		}
+		// Set the signal to read the output value from. It can be a peripheral
+		// output signal, or the special value 256 which indicates regular GPIO
+		// usage.
+		p.outFunc().Set(signal)
+	case PinInput, PinInputPullup, PinInputPulldown:
+		// Clear the 'output enable' bit.
+		if p < 32 {
+			esp.GPIO.ENABLE_W1TC.Set(1 << p)
+		} else {
+			esp.GPIO.ENABLE1_W1TC.Set(1 << (p - 32))
+		}
+		if signal != 256 {
+			// Signal is a peripheral function (not a simple GPIO). Connect this
+			// signal to the pin.
+			// Note that outFunc and inFunc work in the opposite direction.
+			// outFunc configures a pin to use a given output signal, while
+			// inFunc specifies a pin to use to read the signal from.
+			inFunc(signal).Set(esp.GPIO_FUNC_IN_SEL_CFG_SEL | uint32(p)<<esp.GPIO_FUNC_IN_SEL_CFG_IN_SEL_Pos)
+		}
+	}
+}
+
+// ioMuxReg returns the IO_MUX_n_REG register used for configuring the io mux for
+// this pin
+func (p Pin) ioMuxReg() *volatile.Register32 {
+	return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(&esp.IO_MUX.GPIO0), uintptr(p)*4))
+}
+
+// outFunc returns the FUNCx_OUT_SEL_CFG register used for configuring the
+// output function selection.
+func (p Pin) outFunc() *volatile.Register32 {
+	return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(&esp.GPIO.FUNC0_OUT_SEL_CFG), uintptr(p)*4))
+}
+
+// inFunc returns the FUNCy_IN_SEL_CFG register used for configuring the input
+// function selection.
+func inFunc(signal uint32) *volatile.Register32 {
+	return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(&esp.GPIO.FUNC0_IN_SEL_CFG), uintptr(signal)*4))
+}
+
+// Set the pin to high or low.
+// Warning: only use this on an output pin!
+func (p Pin) Set(value bool) {
+	if value {
+		reg, mask := p.portMaskSet()
+		reg.Set(mask)
+	} else {
+		reg, mask := p.portMaskClear()
+		reg.Set(mask)
+	}
+}
+
+// Return the register and mask to enable a given GPIO pin. This can be used to
+// implement bit-banged drivers.
+//
+// Warning: only use this on an output pin!
+func (p Pin) PortMaskSet() (*uint32, uint32) {
+	reg, mask := p.portMaskSet()
+	return &reg.Reg, mask
+}
+
+// Return the register and mask to disable a given GPIO pin. This can be used to
+// implement bit-banged drivers.
+//
+// Warning: only use this on an output pin!
+func (p Pin) PortMaskClear() (*uint32, uint32) {
+	reg, mask := p.portMaskClear()
+	return &reg.Reg, mask
+}
+
+func (p Pin) portMaskSet() (*volatile.Register32, uint32) {
+	if p < 32 {
+		return &esp.GPIO.OUT_W1TS, 1 << p
+	} else {
+		return &esp.GPIO.OUT1_W1TS, 1 << (p - 32)
+	}
+}
+
+func (p Pin) portMaskClear() (*volatile.Register32, uint32) {
+	if p < 32 {
+		return &esp.GPIO.OUT_W1TC, 1 << p
+	} else {
+		return &esp.GPIO.OUT1_W1TC, 1 << (p - 32)
+	}
+}
+
+// Get returns the current value of a GPIO pin when the pin is configured as an
+// input or as an output.
+func (p Pin) Get() bool {
+	if p < 32 {
+		return esp.GPIO.IN.Get()&(1<<p) != 0
+	} else {
+		return esp.GPIO.IN1.Get()&(1<<(p-32)) != 0
+	}
+}
+
+var DefaultUART = UART0
+
+var (
+	UART0  = &_UART0
+	_UART0 = UART{Bus: esp.UART0, Buffer: NewRingBuffer()}
+	UART1  = &_UART1
+	_UART1 = UART{Bus: esp.UART1, Buffer: NewRingBuffer()}
+	UART2  = &_UART2
+	_UART2 = UART{Bus: esp.UART2, Buffer: NewRingBuffer()}
+)
+
+type UART struct {
+	Bus    *esp.UART_Type
+	Buffer *RingBuffer
+}
+
+func (uart *UART) Configure(config UARTConfig) {
+	if config.BaudRate == 0 {
+		config.BaudRate = 115200
+	}
+	// Crystal clock source is selected by default
+	uart.Bus.CLKDIV.Set(xtalClock / config.BaudRate)
+}
+
+func (uart *UART) writeByte(b byte) error {
+	for (uart.Bus.STATUS.Get()>>16)&0xff >= 128 {
+		// Read UART_TXFIFO_CNT from the status register, which indicates how
+		// many bytes there are in the transmit buffer. Wait until there are
+		// less than 128 bytes in this buffer (the default buffer size).
+	}
+	uart.Bus.FIFO.Set(uint32(b))
+	return nil
+}
+
+func (uart *UART) flush() {}
+
+// TODO: SPI
@@ -3,7 +3,9 @@
 package machine

 import (
+	"device/arm"
 	"device/nrf"
+	"errors"
 	"internal/binary"
 	"runtime/interrupt"
 	"unsafe"
@@ -380,6 +382,10 @@ func (f flashBlockDevice) ReadAt(p []byte, off int64) (n int, err error) {
 // If the length of p is not long enough it will be padded with 0xFF bytes.
 // This method assumes that the destination is already erased.
 func (f flashBlockDevice) WriteAt(p []byte, off int64) (n int, err error) {
+	if len(p) == 0 {
+		return 0, nil // nothing to do (and it would fail in sd_flash_write)
+	}
+
 	if FlashDataStart()+uintptr(off)+uintptr(len(p)) > FlashDataEnd() {
 		return 0, errFlashCannotWritePastEOF
 	}
@@ -387,6 +393,35 @@ func (f flashBlockDevice) WriteAt(p []byte, off int64) (n int, err error) {
 	address := FlashDataStart() + uintptr(off)
 	padded := flashPad(p, int(f.WriteBlockSize()))

+	// When the SoftDevice is enabled, access to the flash is restricted and
+	// must go through the SoftDevice API.
+	if isSoftDeviceEnabled() {
+		// Call sd_flash_write, which is SVC_SOC_BASE + 9 in all the
+		// SoftDevices I've checked.
+		// Documentation:
+		// https://docs.nordicsemi.com/bundle/s140_v6.0.0_api/page/group_n_r_f_s_o_c_f_u_n_c_t_i_o_n_s.html
+		numberOfWords := len(padded) / 4 // flash access goes in 32-bit words
+		result := arm.SVCall3(0x20+9, address, &padded[0], uint32(numberOfWords))
+		if result != 0 {
+			// Could not queue flash operation? Not sure when this can
+			// happen.
+			return 0, flashError
+		}
+
+		// Wait until the SoftDevice is finished.
+		flashStatus = flashStatusBusy
+		for flashStatus == flashStatusBusy {
+			handleSoftDeviceEvents()
+		}
+
+		// Check whether the operation was successful.
+		if flashStatus != flashStatusOk {
+			flashStatus = flashStatusOk
+			return 0, flashError
+		}
+		return len(p), nil
+	}
+
 	waitWhileFlashBusy()

 	nrf.NVMC.SetCONFIG_WEN(nrf.NVMC_CONFIG_WEN_Wen)
@@ -428,6 +463,40 @@ func (f flashBlockDevice) EraseBlockSize() int64 {
 // supports this. The start and len parameters are in block numbers, use
 // EraseBlockSize to map addresses to blocks.
 func (f flashBlockDevice) EraseBlocks(start, len int64) error {
+	// When the SoftDevice is enabled, access to the flash is restricted and
+	// must go through the SoftDevice API.
+	if isSoftDeviceEnabled() {
+		for i := range uint32(len) {
+			flashPage := uint32(FlashDataStart())/eraseBlockSizeValue + uint32(start) + i
+
+			// Call sd_flash_page_erase, which is SVC_SOC_BASE + 8 in all the
+			// SoftDevices I've checked.
+			// Documentation:
+			// https://docs.nordicsemi.com/bundle/s140_v6.0.0_api/page/group_n_r_f_s_o_c_f_u_n_c_t_i_o_n_s.html#ga9c93dd94a138ad8b5ed3693ea38ffb3e
+			result := arm.SVCall1(0x20+8, flashPage)
+			if result != 0 {
+				// Could not queue flash operation? Not sure when this can
+				// happen.
+				return flashError
+			}
+
+			// Wait until the SoftDevice is finished.
+			flashStatus = flashStatusBusy
+			for flashStatus == flashStatusBusy {
+				handleSoftDeviceEvents()
+			}
+
+			// Check whether the operation was successful.
+			if flashStatus != flashStatusOk {
+				flashStatus = flashStatusOk
+				return flashError
+			}
+		}
+		return nil
+	}
+
+	// SoftDevice is not used or enabled. Use NVIC directly.
+
 	address := FlashDataStart() + uintptr(start*f.EraseBlockSize())
 	waitWhileFlashBusy()

@@ -447,3 +516,52 @@ func waitWhileFlashBusy() {
 	for nrf.NVMC.GetREADY() != nrf.NVMC_READY_READY_Ready {
 	}
 }
+
+var flashError = errors.New("machine: flash operation failed")
+
+const (
+	flashStatusOk = iota
+	flashStatusError
+	flashStatusBusy
+)
+
+var flashStatus uint8 = flashStatusOk
+
+var sdEvent uint32
+
+// Process all queued SoftDevice events. May only be called when the SoftDevice is enabled.
+//
+// Normally these are handled in the same interrupt where Bluetooth events are
+// handled. But in TinyGo, that's complicated. One option would be to put it in
+// the tinygo.org/x/bluetooth package, but that would cause a circular
+// dependency between the machine and the bluetooth package. Another would be to
+// put it here, but let the bluetooth package call handleSoftDeviceEvents, but
+// that relies on updating the bluetooth package at the same time. As a
+// compromise, these events are handled directly where they are expected (here
+// in the machine package). This works in practice since there are only very few
+// of such events (at the moment, only flash-related ones which is in the
+// machine package anyway).
+func handleSoftDeviceEvents() {
+	for {
+		var result uintptr
+		if nrf.Device == "nrf52" || nrf.Device == "nrf52840" || nrf.Device == "nrf52833" {
+			// sd_evt_get: SOC_SVC_BASE_NOT_AVAILABLE + 31
+			result = arm.SVCall1(0x2C+31, &sdEvent)
+		} else {
+			return // TODO: nrf51 etc
+		}
+		if result != 0 {
+			// Some error occured. The only possible error is
+			// NRF_ERROR_NOT_FOUND, which means there are no more events.
+			return
+		}
+
+		// The following events are the same numbers in all SoftDevices I've checked.
+		switch sdEvent {
+		case 2: // NRF_EVT_FLASH_OPERATION_SUCCESS
+			flashStatus = flashStatusOk
+		case 3: // NRF_EVT_FLASH_OPERATION_ERROR
+			flashStatus = flashStatusError
+		}
+	}
+}
@@ -69,3 +69,5 @@ const eraseBlockSizeValue = 4096
 func eraseBlockSize() int64 {
 	return eraseBlockSizeValue
 }
+
+const spiMaxBufferSize = 255 // from the datasheet: TXD.MAXCNT and RXD.MAXCNT
@@ -90,3 +90,5 @@ const eraseBlockSizeValue = 4096
 func eraseBlockSize() int64 {
 	return eraseBlockSizeValue
 }
+
+const spiMaxBufferSize = 0xffff // from the datasheet: TXD.MAXCNT and RXD.MAXCNT
@@ -108,3 +108,9 @@ const eraseBlockSizeValue = 4096
 func eraseBlockSize() int64 {
 	return eraseBlockSizeValue
 }
+
+const spiMaxBufferSize = 0xffff // from the datasheet: TXD.MAXCNT and RXD.MAXCNT
+
+// ADC instance for the VDDH input pin. This pin is typically connected to USB
+// input voltage (~5V) or directly to a battery.
+var ADC_VDDH = ADC{adcVDDHPin}
@@ -256,7 +256,7 @@ func initEndpoint(ep, config uint32) {

 // SendUSBInPacket sends a packet for USBHID (interrupt in / bulk in).
 func SendUSBInPacket(ep uint32, data []byte) bool {
-	sendUSBPacket(ep, data, 0)
+	sendUSBPacket(ep, data)

 	// clear transfer complete flag
 	nrf.USBD.INTENCLR.Set(nrf.USBD_INTENCLR_ENDEPOUT0 << 4)
@@ -267,33 +267,32 @@ func SendUSBInPacket(ep uint32, data []byte) bool {
 // Prevent file size increases: https://github.com/tinygo-org/tinygo/pull/998
 //
 //go:noinline
-func sendUSBPacket(ep uint32, data []byte, maxsize uint16) {
+func sendUSBPacket(ep uint32, data []byte) {
+	// Select the corresponding buffer.
 	count := len(data)
-	if 0 < int(maxsize) && int(maxsize) < count {
-		count = int(maxsize)
-	}
-
+	var buffer []byte
 	if ep == 0 {
-		copy(udd_ep_control_cache_buffer[:], data[:count])
+		buffer = udd_ep_control_cache_buffer[:]
 		if count > usb.EndpointPacketSize {
+			// The packet must be sent in chunks.
 			sendOnEP0DATADONE.offset = usb.EndpointPacketSize
-			sendOnEP0DATADONE.ptr = &udd_ep_control_cache_buffer[sendOnEP0DATADONE.offset]
+			sendOnEP0DATADONE.ptr = &udd_ep_control_cache_buffer[usb.EndpointPacketSize]
 			sendOnEP0DATADONE.count = count - usb.EndpointPacketSize
 			count = usb.EndpointPacketSize
 		}
-		sendViaEPIn(
-			ep,
-			&udd_ep_control_cache_buffer[0],
-			count,
-		)
 	} else {
-		copy(udd_ep_in_cache_buffer[ep][:], data[:count])
-		sendViaEPIn(
-			ep,
-			&udd_ep_in_cache_buffer[ep][0],
-			count,
-		)
+		buffer = udd_ep_in_cache_buffer[ep][:]
 	}
+
+	// Copy the packet to the buffer.
+	copy(buffer[:len(data)], data)
+
+	// Send the first chunk of the packet.
+	sendViaEPIn(
+		ep,
+		&buffer[0],
+		count,
+	)
 }

 func handleEndpointRx(ep uint32) []byte {
@@ -49,7 +49,7 @@ func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) {

 	// Configure for a single shot to perform both write and read (as applicable)
 	if len(w) != 0 {
-		i2c.Bus.TXD.PTR.Set(uint32(uintptr(unsafe.Pointer(&w[0]))))
+		i2c.Bus.TXD.PTR.Set(uint32(unsafeNoEscape(unsafe.Pointer(unsafe.SliceData(w)))))
 		i2c.Bus.TXD.MAXCNT.Set(uint32(len(w)))

 		// If no read, immediately signal stop after TX
@@ -58,7 +58,7 @@ func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) {
 		}
 	}
 	if len(r) != 0 {
-		i2c.Bus.RXD.PTR.Set(uint32(uintptr(unsafe.Pointer(&r[0]))))
+		i2c.Bus.RXD.PTR.Set(uint32(unsafeNoEscape(unsafe.Pointer(unsafe.SliceData(r)))))
 		i2c.Bus.RXD.MAXCNT.Set(uint32(len(r)))

 		// Auto-start Rx after Tx and Stop after Rx
@@ -78,17 +78,22 @@ func (i2c *I2C) Tx(addr uint16, w, r []byte) (err error) {
 		// Allow scheduler to run
 		gosched()

-		// Handle errors by ensuring STOP sent on bus
-		if i2c.Bus.EVENTS_ERROR.Get() != 0 {
+		// Handle first occurrence of error by ensuring STOP sent on bus
+		if err == nil && i2c.Bus.EVENTS_ERROR.Get() != 0 {
+			err = twiCError(i2c.Bus.ERRORSRC.Get())
 			if i2c.Bus.EVENTS_STOPPED.Get() == 0 {
 				// STOP cannot be sent during SUSPEND
 				i2c.Bus.TASKS_RESUME.Set(1)
 				i2c.Bus.TASKS_STOP.Set(1)
 			}
-			err = twiCError(i2c.Bus.ERRORSRC.Get())
 		}
 	}

+	// Make sure the w and r buffers stay alive until this point, so they won't
+	// be garbage collected while the buffers are used by the hardware.
+	keepAliveNoEscape(unsafe.Pointer(unsafe.SliceData(w)))
+	keepAliveNoEscape(unsafe.Pointer(unsafe.SliceData(r)))
+
 	return
 }

@@ -117,7 +122,7 @@ func (i2c *I2C) Listen(addr uint8) error {
 //
 // For request events, the caller MUST call `Reply` to avoid hanging the i2c bus indefinitely.
 func (i2c *I2C) WaitForEvent(buf []byte) (evt I2CTargetEvent, count int, err error) {
-	i2c.BusT.RXD.PTR.Set(uint32(uintptr(unsafe.Pointer(&buf[0]))))
+	i2c.BusT.RXD.PTR.Set(uint32(unsafeNoEscape(unsafe.Pointer(unsafe.SliceData(buf)))))
 	i2c.BusT.RXD.MAXCNT.Set(uint32(len(buf)))

 	i2c.BusT.TASKS_PREPARERX.Set(nrf.TWIS_TASKS_PREPARERX_TASKS_PREPARERX_Trigger)
@@ -134,6 +139,10 @@ func (i2c *I2C) WaitForEvent(buf []byte) (evt I2CTargetEvent, count int, err err
 		}
 	}

+	// Make sure buf stays alive until this point, so it won't be garbage
+	// collected while it is used by the hardware.
+	keepAliveNoEscape(unsafe.Pointer(unsafe.SliceData(buf)))
+
 	count = 0
 	evt = I2CFinish
 	err = nil
@@ -163,7 +172,7 @@ func (i2c *I2C) WaitForEvent(buf []byte) (evt I2CTargetEvent, count int, err err

 // Reply supplies the response data the controller.
 func (i2c *I2C) Reply(buf []byte) error {
-	i2c.BusT.TXD.PTR.Set(uint32(uintptr(unsafe.Pointer(&buf[0]))))
+	i2c.BusT.TXD.PTR.Set(uint32(unsafeNoEscape(unsafe.Pointer(unsafe.SliceData(buf)))))
 	i2c.BusT.TXD.MAXCNT.Set(uint32(len(buf)))

 	i2c.BusT.EVENTS_STOPPED.Set(0)
@@ -180,6 +189,10 @@ func (i2c *I2C) Reply(buf []byte) error {
 		}
 	}

+	// Make sure the buffer stays alive until this point, so it won't be garbage
+	// collected while it is used by the hardware.
+	keepAliveNoEscape(unsafe.Pointer(unsafe.SliceData(buf)))
+
 	i2c.BusT.EVENTS_STOPPED.Set(0)

 	return nil
@@ -12,6 +12,8 @@ func CPUFrequency() uint32 {
 	return 64000000
 }

+var adcVDDHPin = Pin(254) // special pin number for VDDH on the nrf52840
+
 // InitADC initializes the registers needed for ADC.
 func InitADC() {
 	// Enable ADC.
@@ -26,7 +28,7 @@ func InitADC() {
 // Samples can be 1(default), 2, 4, 8, 16, 32, 64, 128, 256 samples
 func (a *ADC) Configure(config ADCConfig) {
 	var configVal uint32 = nrf.SAADC_CH_CONFIG_RESP_Bypass<<nrf.SAADC_CH_CONFIG_RESP_Pos |
-		nrf.SAADC_CH_CONFIG_RESP_Bypass<<nrf.SAADC_CH_CONFIG_RESN_Pos |
+		nrf.SAADC_CH_CONFIG_RESN_Bypass<<nrf.SAADC_CH_CONFIG_RESN_Pos |
 		nrf.SAADC_CH_CONFIG_REFSEL_Internal<<nrf.SAADC_CH_CONFIG_REFSEL_Pos |
 		nrf.SAADC_CH_CONFIG_MODE_SE<<nrf.SAADC_CH_CONFIG_MODE_Pos

@@ -116,36 +118,43 @@ func (a *ADC) Configure(config ADCConfig) {

 // Get returns the current value of an ADC pin in the range 0..0xffff.
 func (a *ADC) Get() uint16 {
-	var pwmPin uint32
+	var adcPin uint32
 	var rawValue volatile.Register16

 	switch a.Pin {
 	case 2:
-		pwmPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput0
+		adcPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput0
 	case 3:
-		pwmPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput1
+		adcPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput1
 	case 4:
-		pwmPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput2
+		adcPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput2
 	case 5:
-		pwmPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput3
+		adcPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput3
 	case 28:
-		pwmPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput4
+		adcPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput4
 	case 29:
-		pwmPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput5
+		adcPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput5
 	case 30:
-		pwmPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput6
+		adcPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput6
 	case 31:
-		pwmPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput7
+		adcPin = nrf.SAADC_CH_PSELP_PSELP_AnalogInput7
+	case adcVDDHPin:
+		if Device == "nrf52840" {
+			adcPin = 0x0D // VDDHDIV5 on the nrf52840
+		} else {
+			return 0
+		}
 	default:
 		return 0
 	}

 	// Set pin to read.
-	nrf.SAADC.CH[0].PSELN.Set(pwmPin)
-	nrf.SAADC.CH[0].PSELP.Set(pwmPin)
+	nrf.SAADC.CH[0].PSELP.Set(adcPin)

 	// Destination for sample result.
-	nrf.SAADC.RESULT.PTR.Set(uint32(uintptr(unsafe.Pointer(&rawValue))))
+	// Note: rawValue doesn't need to be kept alive for the GC, since the
+	// volatile read later will force it to stay alive.
+	nrf.SAADC.RESULT.PTR.Set(uint32(unsafeNoEscape(unsafe.Pointer(&rawValue))))
 	nrf.SAADC.RESULT.MAXCNT.Set(1) // One sample

 	// Start tasks.
@@ -301,20 +310,18 @@ func (spi *SPI) Transfer(w byte) (byte, error) {
 // padded until they fit: if len(w) > len(r) the extra bytes received will be
 // dropped and if len(w) < len(r) extra 0 bytes will be sent.
 func (spi *SPI) Tx(w, r []byte) error {
-	// Unfortunately the hardware (on the nrf52832) only supports up to 255
-	// bytes in the buffers, so if either w or r is longer than that the
-	// transfer needs to be broken up in pieces.
-	// The nrf52840 supports far larger buffers however, which isn't yet
-	// supported.
+	// Unfortunately the hardware (on the nrf52832) only supports a limited
+	// amount of bytes in the buffers (depending on the chip), so if either w or
+	// r is longer than that the transfer needs to be broken up in pieces.
 	for len(r) != 0 || len(w) != 0 {
 		// Prepare the SPI transfer: set the DMA pointers and lengths.
 		// read buffer
 		nr := uint32(len(r))
 		if nr > 0 {
-			if nr > 255 {
-				nr = 255
+			if nr > spiMaxBufferSize {
+				nr = spiMaxBufferSize
 			}
-			spi.Bus.RXD.PTR.Set(uint32(uintptr(unsafe.Pointer(&r[0]))))
+			spi.Bus.RXD.PTR.Set(uint32(unsafeNoEscape(unsafe.Pointer(unsafe.SliceData(r)))))
 			r = r[nr:]
 		}
 		spi.Bus.RXD.MAXCNT.Set(nr)
@@ -322,10 +329,10 @@ func (spi *SPI) Tx(w, r []byte) error {
 		// write buffer
 		nw := uint32(len(w))
 		if nw > 0 {
-			if nw > 255 {
-				nw = 255
+			if nw > spiMaxBufferSize {
+				nw = spiMaxBufferSize
 			}
-			spi.Bus.TXD.PTR.Set(uint32(uintptr(unsafe.Pointer(&w[0]))))
+			spi.Bus.TXD.PTR.Set(uint32(unsafeNoEscape(unsafe.Pointer(unsafe.SliceData(w)))))
 			w = w[nw:]
 		}
 		spi.Bus.TXD.MAXCNT.Set(nw)
@@ -335,10 +342,16 @@ func (spi *SPI) Tx(w, r []byte) error {
 		// finished if the transfer is send-only (a common case).
 		spi.Bus.TASKS_START.Set(1)
 		for spi.Bus.EVENTS_END.Get() == 0 {
+			gosched()
 		}
 		spi.Bus.EVENTS_END.Set(0)
 	}

+	// Make sure the w and r buffers stay alive for the GC until this point,
+	// since they are used by the hardware but not otherwise visible.
+	keepAliveNoEscape(unsafe.Pointer(unsafe.SliceData(r)))
+	keepAliveNoEscape(unsafe.Pointer(unsafe.SliceData(w)))
+
 	return nil
 }

@@ -7,3 +7,7 @@ package machine
 func GetRNG() (ret uint32, err error) {
 	return getRNG()
 }
+
+func isSoftDeviceEnabled() bool {
+	return false
+}
@@ -11,9 +11,8 @@ import (

 // avoid a heap allocation in GetRNG.
 var (
-	softdeviceEnabled uint8
-	bytesAvailable    uint8
-	buf               [4]uint8
+	bytesAvailable uint8
+	buf            [4]uint8

 	errNoSoftDeviceSupport = errors.New("rng: softdevice not supported on this device")
 	errNotEnoughRandomData = errors.New("rng: not enough random data available")
@@ -24,9 +23,7 @@ var (
 func GetRNG() (ret uint32, err error) {
 	// First check whether the SoftDevice is enabled.
 	// sd_rand_application_bytes_available_get cannot be called when the SoftDevice is not enabled.
-	arm.SVCall1(0x12, &softdeviceEnabled) // sd_softdevice_is_enabled
-
-	if softdeviceEnabled == 0 {
+	if !isSoftDeviceEnabled() {
 		return getRNG()
 	}

@@ -57,3 +54,8 @@ func GetRNG() (ret uint32, err error) {

 	return uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24, nil
 }
+
+// This function is defined in the runtime, but we need it too.
+//
+//go:linkname isSoftDeviceEnabled runtime.isSoftDeviceEnabled
+func isSoftDeviceEnabled() bool
@@ -58,6 +58,10 @@ func machineInit() {

 	// Peripheral clocks should now all be running
 	unresetBlockWait(RESETS_RESET_Msk)
+
+	// DBGPAUSE pauses the timer when a debugger is connected. This prevents
+	// sleep functions from ever returning, so disable it.
+	timer.setDbgPause(false)
 }

 //go:linkname ticks runtime.machineTicks
@@ -128,7 +128,7 @@ func handleUSBSetAddress(setup usb.Setup) bool {
 	const ackTimeout = 570

 	rp.USBCTRL_REGS.SIE_STATUS.Set(rp.USBCTRL_REGS_SIE_STATUS_ACK_REC)
-	sendUSBPacket(0, []byte{}, 0)
+	sendUSBPacket(0, []byte{})

 	// Wait for transfer to complete with a timeout.
 	t := timer.timeElapsed()
@@ -131,7 +131,7 @@ func handleUSBSetAddress(setup usb.Setup) bool {
 	const ackTimeout = 570

 	rp.USB.SIE_STATUS.Set(rp.USB_SIE_STATUS_ACK_REC)
-	sendUSBPacket(0, []byte{}, 0)
+	sendUSBPacket(0, []byte{})

 	// Wait for transfer to complete with a timeout.
 	t := timer.timeElapsed()
@@ -124,6 +124,31 @@ const (
 	fnXIP pinFunc = 0
 )

+// validPins confirms that the SPI pin selection is a legitimate one
+// for the the 2040 chip.
+func (spi *SPI) validPins(config SPIConfig) error {
+	var okSDI, okSDO, okSCK bool
+	switch spi.Bus {
+	case rp.SPI0:
+		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
+		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23
+		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22
+	case rp.SPI1:
+		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
+		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
+		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
+	}
+	switch {
+	case !okSDI:
+		return errSPIInvalidSDI
+	case !okSDO:
+		return errSPIInvalidSDO
+	case !okSCK:
+		return errSPIInvalidSCK
+	}
+	return nil
+}
+
 // Configure configures the gpio pin as per mode.
 func (p Pin) Configure(config PinConfig) {
 	if p == NoPin {
@@ -2,6 +2,8 @@

 package machine

+import "device/rp"
+
 // Analog pins on RP2350a.
 const (
 	ADC0 Pin = GPIO26
@@ -12,3 +14,28 @@ const (
 	// fifth ADC channel.
 	thermADC = 30
 )
+
+// validPins confirms that the SPI pin selection is a legitimate one
+// for the the 2350a chip.
+func (spi *SPI) validPins(config SPIConfig) error {
+	var okSDI, okSDO, okSCK bool
+	switch spi.Bus {
+	case rp.SPI0:
+		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
+		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23
+		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22
+	case rp.SPI1:
+		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
+		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
+		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
+	}
+	switch {
+	case !okSDI:
+		return errSPIInvalidSDI
+	case !okSDO:
+		return errSPIInvalidSDO
+	case !okSCK:
+		return errSPIInvalidSCK
+	}
+	return nil
+}
@@ -2,6 +2,8 @@

 package machine

+import "device/rp"
+
 // RP2350B has additional pins.

 const (
@@ -46,3 +48,28 @@ var (
 	PWM10 = getPWMGroup(10)
 	PWM11 = getPWMGroup(11)
 )
+
+// validPins confirms that the SPI pin selection is a legitimate one
+// for the the 2350b chip.
+func (spi *SPI) validPins(config SPIConfig) error {
+	var okSDI, okSDO, okSCK bool
+	switch spi.Bus {
+	case rp.SPI0:
+		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20 || config.SDI == 32 || config.SDI == 36
+		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23 || config.SDO == 35 || config.SDO == 39
+		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22 || config.SCK == 34 || config.SCK == 38
+	case rp.SPI1:
+		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28 || config.SDI == 40 || config.SDI == 44
+		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27 || config.SDO == 31 || config.SDO == 43 || config.SDO == 47
+		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26 || config.SCK == 30 || config.SCK == 42 || config.SCK == 46
+	}
+	switch {
+	case !okSDI:
+		return errSPIInvalidSDI
+	case !okSDO:
+		return errSPIInvalidSDO
+	case !okSCK:
+		return errSPIInvalidSCK
+	}
+	return nil
+}
@@ -100,7 +100,8 @@ func ReadTemperature() (millicelsius int32) {
 	rp.ADC.CS.SetBits(rp.ADC_CS_TS_EN)

 	// T = 27 - (ADC_voltage - 0.706)/0.001721
-	return (27000<<16 - (int32(thermChan.getVoltage())-706<<16)*581) >> 16
+	// 1/0.001721 ≈ 581
+	return int32(((int64(27000) << 16) - ((int64(thermChan.getVoltage()) - (int64(706) << 16)) * 581)) >> 16)
 }

 // waitForReady spins waiting for the ADC peripheral to become ready.
@@ -108,7 +108,7 @@ func (spi *SPI) SetBaudRate(br uint32) error {
 	var prescale, postdiv uint32
 	freq := CPUFrequency()
 	for prescale = 2; prescale < 255; prescale += 2 {
-		if freq < (prescale+2)*256*br {
+		if uint64(freq) < uint64((prescale+2)*256)*uint64(br) {
 			break
 		}
 	}
@@ -165,27 +165,9 @@ func (spi *SPI) Configure(config SPIConfig) error {
 			config.SDI = SPI1_SDI_PIN
 		}
 	}
-	var okSDI, okSDO, okSCK bool
-	switch spi.Bus {
-	case rp.SPI0:
-		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
-		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23
-		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22
-	case rp.SPI1:
-		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
-		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
-		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
+	if err := spi.validPins(config); err != nil {
+		return err
 	}
-
-	switch {
-	case !okSDI:
-		return errSPIInvalidSDI
-	case !okSDO:
-		return errSPIInvalidSDO
-	case !okSCK:
-		return errSPIInvalidSCK
-	}
-
 	if config.Frequency == 0 {
 		config.Frequency = defaultBaud
 	}
@@ -309,7 +291,7 @@ func (spi *SPI) tx(tx []byte) error {
 	//   - set data size to single bytes
 	//   - set the DREQ so that the DMA will fill the SPI FIFO as needed
 	//   - start the transfer
-	ch.READ_ADDR.Set(uint32(uintptr(unsafe.Pointer(&tx[0]))))
+	ch.READ_ADDR.Set(uint32(unsafeNoEscape(unsafe.Pointer(unsafe.SliceData(tx)))))
 	ch.WRITE_ADDR.Set(uint32(uintptr(unsafe.Pointer(&spi.Bus.SSPDR))))
 	ch.TRANS_COUNT.Set(uint32(len(tx)))
 	ch.CTRL_TRIG.Set(rp.DMA_CH0_CTRL_TRIG_INCR_READ |
@@ -328,6 +310,11 @@ func (spi *SPI) tx(tx []byte) error {
 	for ch.CTRL_TRIG.Get()&rp.DMA_CH0_CTRL_TRIG_BUSY != 0 {
 	}

+	// Make sure the read buffer stays alive until this point (in the unlikely
+	// case the tx slice wasn't read after this function returns and a GC cycle
+	// happened inbetween).
+	keepAliveNoEscape(unsafe.Pointer(unsafe.SliceData(tx)))
+
 	// We didn't read any result values, which means the RX FIFO has likely
 	// overflown. We have to clean up this mess now.

--- a/Show More
+++ b/Show More