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https://github.com/tinygo-org/tinygo.git
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Ayke van Laethem
134de98ba5
Instead of referring to an unused global, use a constant value. This is safe even when using `-gc=none` (since no actual memory gets allocated) which wasn't the case before. It should also reduce binary size by a few bytes for most programs.
46 lines
1.2 KiB
Go
46 lines
1.2 KiB
Go
//go:build tinygo.riscv
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package runtime
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import "device/riscv"
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const zeroSizeAllocPtr uintptr = 0xffff_fff0 // should be unused on most RISC-V chips
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const deferExtraRegs = 0
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const callInstSize = 4 // 8 without relaxation, maybe 4 with relaxation
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// RISC-V has a maximum alignment of 16 bytes (both for RV32 and for RV64).
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// Source: https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf
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func align(ptr uintptr) uintptr {
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return (ptr + 15) &^ 15
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}
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func getCurrentStackPointer() uintptr {
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return uintptr(stacksave())
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}
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// The safest thing to do here would just be to disable interrupts for
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// procPin/procUnpin. Note that a global variable is safe in this case, as any
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// access to procPinnedMask will happen with interrupts disabled.
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var procPinnedMask uintptr
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//go:linkname procPin sync/atomic.runtime_procPin
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func procPin() {
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procPinnedMask = riscv.DisableInterrupts()
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}
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//go:linkname procUnpin sync/atomic.runtime_procUnpin
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func procUnpin() {
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riscv.EnableInterrupts(procPinnedMask)
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}
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func waitForEvents() {
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mask := riscv.DisableInterrupts()
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if runqueue := schedulerRunQueue(); runqueue == nil || !runqueue.Empty() {
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riscv.Asm("wfi")
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}
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riscv.EnableInterrupts(mask)
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}
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