user: 下面的汇编指令对应的C源代码是什么:

```asm
<SHA256_Final>:
  endbr64
  push   %r14
  mov    $0x80000000,%ecx
  push   %r13
  push   %r12
  push   %rbp
  mov    %rsi,%rbp
  push   %rbx
  mov    0x8(%rsi),%edx
  mov    %rdi,%rbx
  mov    (%rsi),%r13
  mov    %edx,%eax
  sar    $0x2,%eax
  movslq %eax,%rdi
  shl    $0x3,%rdi
  lea    0x0(%r13,%rdi,1),%r8
  and    $0x3,%edx
  je     L40
  mov    (%r8),%rsi
  mov    %rsi,%rcx
  or     $0x80,%ch
  cmp    $0x2,%edx
  je     L40
  mov    %rsi,%rcx
  or     $0x80,%cl
  cmp    $0x3,%edx
  jne    L169
L40:
  mov    D6(%rip),%r14
  add    $0x1,%eax
  mov    %rcx,(%r8)
  movslq (%r14),%r12
  lea    -0x1(%r12),%edx
  cmp    %eax,%edx
  jg     L51
  cmp    %eax,%r12d
  jg     L163
L11:
  mov    $0x1,%edx
  mov    %r13,%rsi
  mov    %rbp,%rdi
  call   <sha256_block_host_order@plt>
  movslq (%r14),%r12
  xor    %eax,%eax
L51:
  lea    -0x2(%r12),%edx
  cmp    %eax,%edx
  jle    L122
  lea    -0x3(%r12),%edx
  xor    %esi,%esi
  sub    %eax,%edx
  cltq
  lea    0x8(,%rdx,8),%rdx
  lea    0x0(%r13,%rax,8),%rdi
  call   <memset@plt>
L122:
  mov    0x10(%rbp),%rax
  shl    $0x3,%r12
  mov    $0x1,%edx
  mov    %r13,%rsi
  mov    %rbp,%rdi
  mov    %rax,-0x10(%r13,%r12,1)
  mov    0x18(%rbp),%rax
  mov    %rax,-0x8(%r13,%r12,1)
  call   <sha256_block_host_order@plt>
  mov    0x20(%rbp),%eax
  cmp    $0x80,%eax
  je     L47
  cmp    $0x81,%eax
  je     L22
  xor    %r8d,%r8d
  cmp    $0x80,%eax
  jg     L125
  add    $0x3,%eax
  cmp    $0x6,%eax
  jbe    L81
  mov    0x28(%rbp),%rsi
  xor    %edx,%edx
  nopl   0x0(%rax)
L149:
  mov    %edx,%eax
  mov    (%rsi,%rax,8),%rax
  bswap  %eax
  mov    %eax,(%rbx,%rdx,4)
  mov    0x20(%rbp),%ecx
  add    $0x1,%rdx
  lea    0x3(%rcx),%eax
  test   %ecx,%ecx
  cmovns %ecx,%eax
  sar    $0x2,%eax
  cmp    %edx,%eax
  ja     L149
L81:
  movl   $0x0,0x8(%rbp)
  mov    $0x1,%r8d
L125:
  pop    %rbx
  mov    %r8d,%eax
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
  nopw   0x0(%rax,%rax,1)
L169:
  or     $0x800000,%rsi
  mov    $0x80000000,%ecx
  cmp    $0x1,%edx
  cmove  %rsi,%rcx
  jmp    L40
L163:
  movq   $0x0,0x8(%r13,%rdi,1)
  jmp    L11
  xchg   %ax,%ax
L22:
  mov    0x28(%rbp),%rcx
  xor    %edx,%edx
  cs nopw 0x0(%rax,%rax,1)
L58:
  mov    (%rcx,%rdx,2),%eax
  bswap  %eax
  mov    %eax,(%rbx,%rdx,1)
  add    $0x4,%rdx
  cmp    $0x80,%rdx
  jne    L58
  movl   $0x0,0x8(%rbp)
  mov    $0x1,%r8d
  jmp    L125
  nopl   0x0(%rax)
L47:
  mov    0x28(%rbp),%rcx
  xor    %edx,%edx
  xchg   %ax,%ax
L50:
  mov    (%rcx,%rdx,2),%eax
  bswap  %eax
  mov    %eax,(%rbx,%rdx,1)
  add    $0x4,%rdx
  cmp    $0x80,%rdx
  jne    L50
  movl   $0x0,0x8(%rbp)
  mov    $0x1,%r8d
  jmp    L125
```

assistant: ```c
int SHA256_Final(unsigned char *md, SHA256_CTX *c) {
  register SHA_LONG *p;
  register unsigned long l;
  register int i, j;
  static const unsigned char end[4] = {0x80, 0x00, 0x00, 0x00};
  const unsigned char *cp = end;
  p = c->data;
  i = c->num >> 2;
  j = c->num & 0x03;
  l = (j == 0) ? 0 : p[i];
  {
    switch (j) {
    case 0:
      l = ((unsigned long)(*((cp)++))) << 24;
    case 1:
      l |= ((unsigned long)(*((cp)++))) << 16;
    case 2:
      l |= ((unsigned long)(*((cp)++))) << 8;
    case 3:
      l |= ((unsigned long)(*((cp)++)));
    }
  };
  p[i++] = l;
  if (i > (SHA_LBLOCK - 2)) {
    if (i < SHA_LBLOCK)
      p[i] = 0;
    sha256_block_host_order(c, p, 1);
    i = 0;
  }
  for (; i < (SHA_LBLOCK - 2); i++)
    p[i] = 0;
  p[SHA_LBLOCK - 2] = c->Nh;
  p[SHA_LBLOCK - 1] = c->Nl;
  sha256_block_host_order(c, p, 1);
  do {
    unsigned long ll;
    unsigned int n;
    switch ((c)->md_len) {
    case SHA224_DIGEST_LENGTH:
      for (n = 0; n < SHA224_DIGEST_LENGTH / 4; n++) {
        ll = (c)->h[n];
        ({
          unsigned int r = (ll);
          asm("bswapl %0" : "=r"(r) : "0"(r));
          *((unsigned int *)((md))) = r;
          ((md)) += 4;
          r;
        });
      }
      break;
    case SHA256_DIGEST_LENGTH:
      for (n = 0; n < SHA256_DIGEST_LENGTH / 4; n++) {
        ll = (c)->h[n];
        ({
          unsigned int r = (ll);
          asm("bswapl %0" : "=r"(r) : "0"(r));
          *((unsigned int *)((md))) = r;
          ((md)) += 4;
          r;
        });
      }
      break;
    default:
      if ((c)->md_len > SHA256_DIGEST_LENGTH)
        return 0;
      for (n = 0; n < (c)->md_len / 4; n++) {
        ll = (c)->h[n];
        ({
          unsigned int r = (ll);
          asm("bswapl %0" : "=r"(r) : "0"(r));
          *((unsigned int *)((md))) = r;
          ((md)) += 4;
          r;
        });
      }
      break;
    }
  } while (0);
  c->num = 0;
  return 1;
}
```