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Diffstat (limited to 'src/runtime/cgo/asm_386.s')
| -rw-r--r-- | src/runtime/cgo/asm_386.s | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/src/runtime/cgo/asm_386.s b/src/runtime/cgo/asm_386.s new file mode 100644 index 0000000..f9a662a --- /dev/null +++ b/src/runtime/cgo/asm_386.s @@ -0,0 +1,42 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "textflag.h" + +// Set the x_crosscall2_ptr C function pointer variable point to crosscall2. +// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2 +// Use a local trampoline, to avoid taking the address of a dynamically exported +// function. +TEXT ·set_crosscall2(SB),NOSPLIT,$0-0 + MOVL _crosscall2_ptr(SB), AX + MOVL $crosscall2_trampoline<>(SB), BX + MOVL BX, (AX) + RET + +TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0 + JMP crosscall2(SB) + +// Called by C code generated by cmd/cgo. +// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr) +// Saves C callee-saved registers and calls cgocallback with three arguments. +// fn is the PC of a func(a unsafe.Pointer) function. +TEXT crosscall2(SB),NOSPLIT,$28-16 + MOVL BP, 24(SP) + MOVL BX, 20(SP) + MOVL SI, 16(SP) + MOVL DI, 12(SP) + + MOVL ctxt+12(FP), AX + MOVL AX, 8(SP) + MOVL a+4(FP), AX + MOVL AX, 4(SP) + MOVL fn+0(FP), AX + MOVL AX, 0(SP) + CALL runtime·cgocallback(SB) + + MOVL 12(SP), DI + MOVL 16(SP), SI + MOVL 20(SP), BX + MOVL 24(SP), BP + RET |