compiler/runtime: add element layout to sliceAppend

Attach the memory layout of the element type to newly created slices via append when using the precise collector.

compiler/compiler.go

@@ -1599,7 +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")

compiler/testdata/slice.ll

@@ -55,7 +55,7 @@ entry:
   store i32 2, ptr %0, align 4
   %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

src/internal/reflectlite/value.go

@@ -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,

src/runtime/slice.go

@@ -3,19 +3,18 @@ package runtime
 // This file implements compiler builtins for slices: append() and copy().
 
 import (
-	"internal/gclayout"
 	"math/bits"
 	"unsafe"
 )
 
 // Builtin append(src, elements...) function: append elements to src and return
 // the modified (possibly expanded) slice.
-func sliceAppend(srcBuf, elemsBuf unsafe.Pointer, srcLen, srcCap, elemsLen, elemSize uintptr) (unsafe.Pointer, uintptr, uintptr) {
+func sliceAppend(srcBuf, elemsBuf unsafe.Pointer, srcLen, srcCap, elemsLen, elemSize uintptr, layout unsafe.Pointer) (unsafe.Pointer, uintptr, uintptr) {
 	newLen := srcLen + elemsLen
 	if elemsLen > 0 {
 		// Allocate a new slice with capacity for elemsLen more elements, if necessary;
 		// otherwise, reuse the passed slice.
-		srcBuf, _, srcCap = sliceGrow(srcBuf, srcLen, srcCap, newLen, elemSize)
+		srcBuf, _, srcCap = sliceGrow(srcBuf, srcLen, srcCap, newLen, elemSize, layout)
 
 		// Append the new elements in-place.
 		memmove(unsafe.Add(srcBuf, srcLen*elemSize), elemsBuf, elemsLen*elemSize)
@@ -36,7 +35,7 @@ func sliceCopy(dst, src unsafe.Pointer, dstLen, srcLen uintptr, elemSize uintptr
 }
 
 // sliceGrow returns a new slice with space for at least newCap elements
-func sliceGrow(oldBuf unsafe.Pointer, oldLen, oldCap, newCap, elemSize uintptr) (unsafe.Pointer, uintptr, uintptr) {
+func sliceGrow(oldBuf unsafe.Pointer, oldLen, oldCap, newCap, elemSize uintptr, layout unsafe.Pointer) (unsafe.Pointer, uintptr, uintptr) {
 	if oldCap >= newCap {
 		// No need to grow, return the input slice.
 		return oldBuf, oldLen, oldCap
@@ -48,12 +47,6 @@ func sliceGrow(oldBuf unsafe.Pointer, oldLen, oldCap, newCap, elemSize uintptr)
 	// memory allocators, this causes some difficult to debug issues.
 	newCap = 1 << bits.Len(uint(newCap))
 
-	var layout unsafe.Pointer
-	// less type info here; can only go off element size
-	if elemSize < unsafe.Sizeof(uintptr(0)) {
-		layout = gclayout.NoPtrs.AsPtr()
-	}
-
 	buf := alloc(newCap*elemSize, layout)
 	if oldLen > 0 {
 		// copy any data to new slice