examples/performance-thread/common/arch/x86/ctx.c

/*
 * SPDX-License-Identifier: BSD-3-Clause
 * Copyright 2015 Intel Corporation.
 * Copyright 2012 Hasan Alayli <halayli@gmail.com>
 */

#if defined(__x86_64__)
__asm__ (
".text\n"
".p2align 4,,15\n"
".globl ctx_switch\n"
".globl _ctx_switch\n"
"ctx_switch:\n"
"_ctx_switch:\n"
"   movq %rsp, 0(%rsi)  # save stack_pointer\n"
"   movq %rbp, 8(%rsi)  # save frame_pointer\n"
"   movq (%rsp), %rax   # save insn_pointer\n"
"   movq %rax, 16(%rsi)\n"
"   movq %rbx, 24(%rsi)\n   # save rbx,r12-r15\n"
"   movq 24(%rdi), %rbx\n"
"   movq %r15, 56(%rsi)\n"
"   movq %r14, 48(%rsi)\n"
"   movq 48(%rdi), %r14\n"
"   movq 56(%rdi), %r15\n"
"   movq %r13, 40(%rsi)\n"
"   movq %r12, 32(%rsi)\n"
"   movq 32(%rdi), %r12\n"
"   movq 40(%rdi), %r13\n"
"   movq 0(%rdi), %rsp  # restore stack_pointer\n"
"   movq 16(%rdi), %rax # restore insn_pointer\n"
"   movq 8(%rdi), %rbp  # restore frame_pointer\n"
"   movq %rax, (%rsp)\n"
"   ret\n"
    );
#else
#pragma GCC error "__x86_64__ is not defined"
#endif