Text file src/pkg/runtime/cgo/gcc_amd64.S

     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

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