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Diffstat (limited to 'src/libcgo/amd64.S')
| -rw-r--r-- | src/libcgo/amd64.S | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/libcgo/amd64.S b/src/libcgo/amd64.S new file mode 100644 index 000000000..eaa346a14 --- /dev/null +++ b/src/libcgo/amd64.S @@ -0,0 +1,45 @@ +// 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 |