mirror of
https://github.com/tinygo-org/tinygo.git
synced 2026-08-13 15:33:40 +00:00
Damian Gryski
34 lines
717 B
Go
34 lines
717 B
Go
package gclayout
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import "unsafe"
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// Internal constants for gc layout
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// See runtime/gc_precise.go
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var (
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NoPtrs unsafe.Pointer
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Pointer unsafe.Pointer
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String unsafe.Pointer
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Slice unsafe.Pointer
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)
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func init() {
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var sizeBits uintptr
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switch unsafe.Sizeof(uintptr(0)) {
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case 8:
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sizeBits = 6
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case 4:
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sizeBits = 5
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case 2:
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sizeBits = 4
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}
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var sizeShift = sizeBits + 1
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NoPtrs = unsafe.Pointer(uintptr(0b0<<sizeShift) | uintptr(0b1<<1) | uintptr(1))
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Pointer = unsafe.Pointer(uintptr(0b1<<sizeShift) | uintptr(0b1<<1) | uintptr(1))
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String = unsafe.Pointer(uintptr(0b01<<sizeShift) | uintptr(0b10<<1) | uintptr(1))
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Slice = unsafe.Pointer(uintptr(0b001<<sizeShift) | uintptr(0b11<<1) | uintptr(1))
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}
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