1 // Copyright 2009 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 /* 6 * Apple still insists on underscore prefixes for C function names. 7 */ 8 #if defined(__APPLE__) 9 #define EXT(s) _##s 10 #else 11 #define EXT(s) s 12 #endif 13 14 /* 15 * void crosscall_amd64(void (*fn)(void)) 16 * 17 * Calling into the 6c tool chain, where all registers are caller save. 18 * Called from standard x86-64 ABI, where %rbx, %rbp, %r12-%r15 19 * are callee-save so they must be saved explicitly. 20 * The standard x86-64 ABI passes the three arguments m, g, fn 21 * in %rdi, %rsi, %rdx. 22 */ 23 .globl EXT(crosscall_amd64) 24 EXT(crosscall_amd64): 25 pushq %rbx 26 pushq %rbp 27 pushq %r12 28 pushq %r13 29 pushq %r14 30 pushq %r15 31 32 #if defined(_WIN64) 33 call *%rcx /* fn */ 34 #else 35 call *%rdi /* fn */ 36 #endif 37 38 popq %r15 39 popq %r14 40 popq %r13 41 popq %r12 42 popq %rbp 43 popq %rbx 44 ret 45 46 #ifdef __ELF__ 47 .section .note.GNU-stack,"",@progbits 48 #endif 49
