最近想了解一下c是如何编译为汇编语言的
首先写了一个相当简单的c

#include "stdio.h" int main(){    int a = 1;    int b = 2;    int c = a + b;    int d = 3 + 4;    printf("%d %d",c,d);    return 0;}

使用gcc -S编译为汇编语言:

 .file "hello.c" .text .section .rodata.LC0: .string "%d %d" .text .globl main .type main, @functionmain:.LFB0: .cfi_startproc pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset 6, -16 movq %rsp, %rbp .cfi_def_cfa_register 6 subq $16, %rsp movl $1, -16(%rbp) movl $2, -12(%rbp) movl -16(%rbp), %edx movl -12(%rbp), %eax addl %edx, %eax movl %eax, -8(%rbp) movl $7, -4(%rbp) movl -4(%rbp), %edx movl -8(%rbp), %eax movl %eax, %esi leaq .LC0(%rip), %rdi movl $0, %eax call printf@PLT movl $0, %eax leave .cfi_def_cfa 7, 8 ret .cfi_endproc.LFE0: .size main, .-main .ident "GCC: (GNU) 9.1.0" .section .note.GNU-stack,"",@progbits

以”点”做为前缀的指令都是用来指导汇编器的命令。
精简一下差不多这样: