blob: eaa346a143e732b11d896d06458a5386a5c449f7 [file] [log] [blame]
// 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.
/*
* Apple still insists on underscore prefixes for C function names.
*/
#ifdef __APPLE__
#define EXT(s) _##s
#else
#define EXT(s) s
#endif
/*
* void crosscall_amd64(M *m, G *g, void (*fn)(void))
*
* Calling into the 6c tool chain, where all registers are caller save.
* Called from standard x86-64 ABI, where %rbx, %rbp, %r12-%r15
* are callee-save so they must be saved explicitly.
* The standard x86-64 ABI passes the three arguments m, g, fn
* in %rdi, %rsi, %rdx.
*
* Also need to set %r15 to g and %r14 to m (see ../pkg/runtime/mkasmh.sh)
* during the call.
*/
.globl EXT(crosscall_amd64)
EXT(crosscall_amd64):
pushq %rbx
pushq %rbp
pushq %r12
pushq %r13
pushq %r14
pushq %r15
movq %rdi, %r14 /* m */
movq %rsi, %r15 /* g */
call *%rdx /* fn */
popq %r15
popq %r14
popq %r13
popq %r12
popq %rbp
popq %rbx
ret