user: 下面的汇编指令对应的C源代码是什么:

```asm
<fill_blank_frame>:
  endbr64
  push   %r14
  push   %r13
  push   %r12
  mov    %esi,%r12d
  push   %rbp
  mov    %rdi,%rbp
  push   %rbx
  cmp    $0x32595559,%edx
  je     L67
  jle    L27
  cmp    $0x47504a4d,%edx
  je     L24
  cmp    $0x59565955,%edx
  jne    L40
  test   %esi,%esi
  jle    L24
  sub    $0x1,%r12d
  mov    %rdi,%rax
  shr    $0x2,%r12d
  lea    0x4(%rdi,%r12,4),%rdx
  nopl   0x0(%rax,%rax,1)
L75:
  movb   $0xff,(%rax)
  add    $0x4,%rax
  movb   $0x0,-0x3(%rax)
  movb   $0x0,-0x2(%rax)
  movb   $0x0,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L75
L24:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
  nopl   0x0(%rax)
L27:
  cmp    $0x30323449,%edx
  je     L11
  cmp    $0x32315659,%edx
  jne    L40
  lea    0x0(,%rsi,4),%r14d
  movslq %r12d,%r13
  mov    $0x29,%esi
  movslq %r14d,%rbx
  imul   $0x2aaaaaab,%r13,%r13
  mov    %r14d,%eax
  add    %r12d,%r14d
  imul   $0x2aaaaaab,%rbx,%rbx
  sar    $0x1f,%eax
  shr    $0x20,%r13
  shr    $0x20,%rbx
  sub    %eax,%ebx
  mov    %ebx,%edx
  call   <memset@plt>
  mov    %r12d,%eax
  movslq %ebx,%rdi
  mov    $0x6e,%esi
  sar    $0x1f,%eax
  add    %rbp,%rdi
  sub    %eax,%r13d
  mov    %r13d,%edx
  call   <memset@plt>
  movslq %r14d,%rdi
  sar    $0x1f,%r14d
  pop    %rbx
  imul   $0x2aaaaaab,%rdi,%rdi
  mov    %r13d,%edx
  mov    $0xf0,%esi
  shr    $0x20,%rdi
  sub    %r14d,%edi
  movslq %edi,%rdi
  add    %rbp,%rdi
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  jmp    1050 <memset@plt>
L40:
  pop    %rbx
  mov    %r12d,%edx
  mov    %rbp,%rdi
  mov    $0xc0,%esi
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  jmp    1050 <memset@plt>
  nop
L11:
  lea    0x0(,%rsi,4),%r14d
  movslq %r12d,%r13
  mov    $0x29,%esi
  movslq %r14d,%rbx
  imul   $0x2aaaaaab,%r13,%r13
  mov    %r14d,%eax
  add    %r12d,%r14d
  imul   $0x2aaaaaab,%rbx,%rbx
  sar    $0x1f,%eax
  shr    $0x20,%r13
  shr    $0x20,%rbx
  sub    %eax,%ebx
  mov    %ebx,%edx
  call   <memset@plt>
  mov    %r12d,%eax
  movslq %ebx,%rdi
  mov    $0xf0,%esi
  sar    $0x1f,%eax
  add    %rbp,%rdi
  sub    %eax,%r13d
  mov    %r13d,%edx
  call   <memset@plt>
  movslq %r14d,%rdi
  sar    $0x1f,%r14d
  pop    %rbx
  imul   $0x2aaaaaab,%rdi,%rdi
  mov    %r13d,%edx
  mov    $0x6e,%esi
  shr    $0x20,%rdi
  sub    %r14d,%edi
  movslq %edi,%rdi
  add    %rbp,%rdi
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  jmp    1050 <memset@plt>
  nopw   0x0(%rax,%rax,1)
L67:
  test   %esi,%esi
  jle    L24
  sub    $0x1,%r12d
  mov    %rdi,%rax
  shr    $0x2,%r12d
  lea    0x4(%rdi,%r12,4),%rdx
  nopl   0x0(%rax,%rax,1)
L84:
  movb   $0x0,(%rax)
  add    $0x4,%rax
  movb   $0xff,-0x3(%rax)
  movb   $0x0,-0x2(%rax)
  movb   $0x0,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L84
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
```

assistant: ```c
void fill_blank_frame(char *buffer, int len, int fmt) {
  int i;
  switch (fmt) {
  case (('Y') | (('V') << 8) | (('1') << 16) | ((unsigned)('2') << 24)):
    memset(buffer, 41, 4 * len / 6);
    memset(buffer + 4 * len / 6, 110, len / 6);
    memset(buffer + 5 * len / 6, 240, len / 6);
    break;
  case (('I') | (('4') << 8) | (('2') << 16) | ((unsigned)('0') << 24)):
    memset(buffer, 41, 4 * len / 6);
    memset(buffer + 4 * len / 6, 240, len / 6);
    memset(buffer + 5 * len / 6, 110, len / 6);
    break;
  case (('U') | (('Y') << 8) | (('V') << 16) | ((unsigned)('Y') << 24)):
    for (i = 0; i < len; i += 4) {
      buffer[i] = 0xFF;
      buffer[i + 1] = 0;
      buffer[i + 2] = 0;
      buffer[i + 3] = 0;
    }
    break;
  case (('Y') | (('U') << 8) | (('Y') << 16) | ((unsigned)('2') << 24)):
    for (i = 0; i < len; i += 4) {
      buffer[i] = 0;
      buffer[i + 1] = 0xFF;
      buffer[i + 2] = 0;
      buffer[i + 3] = 0;
    }
    break;
  case (('M') | (('J') << 8) | (('P') << 16) | ((unsigned)('G') << 24)):
    break;
  default:
    memset(buffer, 0xC0, len);
  }
}
```