quest.txt

matklad@nixos [09:31:33] [~/quest] 
-> % cat g.c                                                                                                                  
int a;

int b;

int inc_a() { return a++; }
int inc_b() { return b++; }

int main() {
    inc_a();
    inc_b();
}

matklad@nixos [09:31:44] [~/quest] 
-> % clang -O0 -c g.c                                                                                                          

matklad@nixos [09:31:47] [~/quest] 
-> % objdump -d g.o                                                                                                            
g.o:     file format elf64-x86-64


Disassembly of section .text:

0000000000000000 <inc_a>:
   0:   55                      push   %rbp
   1:   48 89 e5                mov    %rsp,%rbp
   4:   8b 04 25 00 00 00 00    mov    0x0,%eax
   b:   89 c1                   mov    %eax,%ecx
   d:   81 c1 01 00 00 00       add    $0x1,%ecx
  13:   89 0c 25 00 00 00 00    mov    %ecx,0x0
  1a:   5d                      pop    %rbp
  1b:   c3                      retq   
  1c:   0f 1f 40 00             nopl   0x0(%rax)

0000000000000020 <inc_b>:
  20:   55                      push   %rbp
  21:   48 89 e5                mov    %rsp,%rbp
  24:   8b 04 25 00 00 00 00    mov    0x0,%eax
  2b:   89 c1                   mov    %eax,%ecx
  2d:   81 c1 01 00 00 00       add    $0x1,%ecx
  33:   89 0c 25 00 00 00 00    mov    %ecx,0x0
  3a:   5d                      pop    %rbp
  3b:   c3                      retq   
  3c:   0f 1f 40 00             nopl   0x0(%rax)

0000000000000040 <main>:
  40:   55                      push   %rbp
  41:   48 89 e5                mov    %rsp,%rbp
  44:   48 83 ec 10             sub    $0x10,%rsp
  48:   e8 b3 ff ff ff          callq  0 <inc_a>
  4d:   89 45 fc                mov    %eax,-0x4(%rbp)
  50:   e8 cb ff ff ff          callq  20 <inc_b>
  55:   31 c9                   xor    %ecx,%ecx
  57:   89 45 f8                mov    %eax,-0x8(%rbp)
  5a:   89 c8                   mov    %ecx,%eax
  5c:   48 83 c4 10             add    $0x10,%rsp
  60:   5d                      pop    %rbp
  61:   c3                      retq   

Question: how it happened that inc_a and inc_b have exactly the same code?