user: 请从给定的汇编指令推导出C源代码：

```asm
<loc_aton>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  mov    %rdi,%r12
  push   %rbp
  mov    %rsi,%rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x28(%rsp)
  xor    %eax,%eax
  lea    0x20(%rsp),%r14
  mov    %rdi,0x20(%rsp)
  movl   $0x0,0x18(%rsp)
  movl   $0x0,0x1c(%rsp)
  call   <strlen@plt>
  lea    0x18(%rsp),%rsi
  mov    %r14,%rdi
  movslq %eax,%rbx
  call   <latlon2ul@plt>
  lea    0x1c(%rsp),%rsi
  mov    %r14,%rdi
  mov    %eax,0x8(%rsp)
  call   <latlon2ul@plt>
  mov    0x1c(%rsp),%ecx
  xor    %r8d,%r8d
  mov    %eax,%r13d
  mov    0x18(%rsp),%eax
  lea    (%rax,%rcx,1),%esi
  cmp    $0x3,%esi
  je     L119
L198:
  mov    0x28(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L53
  add    $0x38,%rsp
  mov    %r8d,%eax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax)
L119:
  cmp    $0x1,%eax
  je     L201
  cmp    $0x1,%ecx
  jne    L401
  cmp    $0x2,%eax
  je     L24
L401:
  xor    %r8d,%r8d
  jmp    L198
  nopl   0x0(%rax)
L201:
  cmp    $0x2,%ecx
  jne    L198
  mov    %r13d,%eax
  mov    0x8(%rsp),%r13d
  mov    %eax,0x8(%rsp)
L24:
  mov    0x20(%rsp),%rax
  movl   $0x1,(%rsp)
  movzbl (%rax),%edi
  cmp    $0x2d,%dil
  jne    L7
  movl   $0xffffffff,(%rsp)
  lea    0x1(%rax),%rcx
  mov    %rcx,0x20(%rsp)
  movzbl 0x1(%rax),%edi
  mov    %rcx,%rax
L7:
  cmp    $0x2b,%dil
  jne    L377
  lea    0x1(%rax),%rcx
  mov    %rcx,0x20(%rsp)
  movzbl 0x1(%rax),%edi
L377:
  xor    %r15d,%r15d
  jmp    L282
  nopl   (%rax)
L384:
  mov    0x20(%rsp),%rax
  lea    (%r15,%r15,4),%esi
  lea    0x1(%rax),%rcx
  mov    %rcx,0x20(%rsp)
  movsbl (%rax),%ecx
  movzbl 0x1(%rax),%edi
  lea    -0x30(%rcx,%rsi,2),%r15d
L282:
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L384
  mov    0x20(%rsp),%rax
  xor    %esi,%esi
  movzbl (%rax),%edi
  cmp    $0x2e,%dil
  je     L323
L200:
  imul   $0x64,%r15d,%ecx
  mov    (%rsp),%r15d
  add    %r12,%rbx
  add    %esi,%ecx
  imul   %ecx,%r15d
  add    $0x989680,%r15d
  jmp    L262
  xchg   %ax,%ax
L6:
  cmp    %rbx,%rax
  jae    L179
  lea    0x1(%rax),%rdx
  mov    %rdx,0x20(%rsp)
  movzbl 0x1(%rax),%edi
L262:
  call   <isspace@plt>
  test   %rax,%rax
  mov    0x20(%rsp),%rax
  je     L6
  jmp    L179
  nopl   0x0(%rax,%rax,1)
L213:
  mov    0x20(%rsp),%rax
  cmp    %rbx,%rax
  jae    L332
  add    $0x1,%rax
  mov    %rax,0x20(%rsp)
L179:
  movzbl (%rax),%edi
  call   <isspace@plt>
  test   %rax,%rax
  jne    L213
  cmp    %rbx,0x20(%rsp)
  jae    L332
  mov    %r14,%rdi
  call   <precsize_aton@plt>
  mov    %rax,%r12
  mov    0x20(%rsp),%rax
  jmp    L269
  nopl   0x0(%rax)
L134:
  cmp    %rbx,%rax
  jae    L320
  add    $0x1,%rax
  mov    %rax,0x20(%rsp)
L269:
  movzbl (%rax),%edi
  call   <isspace@plt>
  test   %rax,%rax
  mov    0x20(%rsp),%rax
  je     L134
  jmp    L320
  nopw   0x0(%rax,%rax,1)
L427:
  mov    0x20(%rsp),%rax
  cmp    %rbx,%rax
  jae    L421
  add    $0x1,%rax
  mov    %rax,0x20(%rsp)
L320:
  movzbl (%rax),%edi
  call   <isspace@plt>
  test   %rax,%rax
  jne    L427
  cmp    %rbx,0x20(%rsp)
  jae    L49
  mov    %r14,%rdi
  call   <precsize_aton@plt>
  mov    %rax,(%rsp)
  mov    0x20(%rsp),%rax
  jmp    L376
  nopw   0x0(%rax,%rax,1)
L92:
  cmp    %rbx,%rax
  jae    L281
  add    $0x1,%rax
  mov    %rax,0x20(%rsp)
L376:
  movzbl (%rax),%edi
  call   <isspace@plt>
  test   %rax,%rax
  mov    0x20(%rsp),%rax
  je     L92
  jmp    L281
  nopw   0x0(%rax,%rax,1)
L115:
  mov    0x20(%rsp),%rax
  cmp    %rbx,%rax
  jae    L400
  add    $0x1,%rax
  mov    %rax,0x20(%rsp)
L281:
  movzbl (%rax),%edi
  call   <isspace@plt>
  test   %rax,%rax
  jne    L115
  mov    (%rsp),%edx
  cmp    %rbx,0x20(%rsp)
  jae    L404
  mov    %r14,%rdi
  call   <precsize_aton@plt>
  mov    (%rsp),%edx
  nopl   (%rax)
L138:
  mov    %edx,0x8(%rbp)
  lea    0x10(%rbp),%r14
  mov    %r13d,%edi
  movl   $0x0,0x0(%rbp)
  mov    %r14,%rsi
  mov    %r12d,0x4(%rbp)
  mov    %eax,0xc(%rbp)
  call   <PUTLONG@plt>
  mov    0x8(%rsp),%edi
  mov    %r14,%rsi
  call   <PUTLONG@plt>
  mov    %r14,%rsi
  mov    %r15d,%edi
  call   <PUTLONG@plt>
  mov    $0x10,%r8d
  jmp    L198
  nopw   0x0(%rax,%rax,1)
L332:
  mov    $0x13,%eax
  mov    $0x16,%edx
  mov    $0x12,%r12d
  jmp    L138
  nopw   0x0(%rax,%rax,1)
L421:
  mov    $0x13,%eax
  mov    $0x16,%edx
  jmp    L138
  nopl   0x0(%rax)
L323:
  lea    0x1(%rax),%rdi
  mov    %esi,0xc(%rsp)
  mov    %rdi,0x20(%rsp)
  movzbl 0x1(%rax),%edi
  call   <isdigit@plt>
  test   %rax,%rax
  mov    0x20(%rsp),%rax
  jne    L35
  movzbl (%rax),%edi
  mov    0xc(%rsp),%esi
  jmp    L200
L400:
  mov    (%rsp),%edx
  mov    $0x13,%eax
  jmp    L138
L35:
  lea    0x1(%rax),%rsi
  mov    %rsi,0x20(%rsp)
  movsbl (%rax),%esi
  movzbl 0x1(%rax),%edi
  lea    -0xf0(%rsi,%rsi,4),%esi
  add    %esi,%esi
  mov    %esi,0xc(%rsp)
  call   <isdigit@plt>
  mov    0xc(%rsp),%esi
  test   %rax,%rax
  mov    0x20(%rsp),%rax
  jne    L38
  movzbl (%rax),%edi
  jmp    L200
L38:
  lea    0x1(%rax),%rdi
  mov    %rdi,0x20(%rsp)
  movsbl (%rax),%edi
  lea    -0x30(%rsi,%rdi,1),%esi
  movzbl 0x1(%rax),%edi
  jmp    L200
L49:
  mov    $0x13,%eax
  mov    $0x16,%edx
  jmp    L138
L404:
  mov    $0x13,%eax
  jmp    L138
L53:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
int loc_aton(const char *ascii, u_char *binary) {
  const char *cp, *maxcp;
  u_char *bcp;
  u_int32_t latit = 0, longit = 0, alt = 0;
  u_int32_t lltemp1 = 0, lltemp2 = 0;
  int altmeters = 0, altfrac = 0, altsign = 1;
  u_int8_t hp = 0x16;
  u_int8_t vp = 0x13;
  u_int8_t siz = 0x12;
  int which1 = 0, which2 = 0;
  cp = ascii;
  maxcp = cp + strlen(ascii);
  lltemp1 = latlon2ul((char **)&cp, &which1);
  lltemp2 = latlon2ul((char **)&cp, &which2);
  switch (which1 + which2) {
  case 3:
    if ((which1 == 1) && (which2 == 2)) {
      latit = lltemp1;
      longit = lltemp2;
    } else if ((which1 == 2) && (which2 == 1)) {
      longit = lltemp1;
      latit = lltemp2;
    } else {
      return (0);
    }
    break;
  default:
    return (0);
  }
  if (*cp == '-') {
    altsign = -1;
    cp++;
  }
  if (*cp == '+')
    cp++;
  while (isdigit((unsigned char)*cp))
    altmeters = altmeters * 10 + (*cp++ - '0');
  if (*cp == '.') {
    cp++;
    if (isdigit((unsigned char)*cp)) {
      altfrac = (*cp++ - '0') * 10;
      if (isdigit((unsigned char)*cp)) {
        altfrac += (*cp++ - '0');
      }
    }
  }
  alt = (10000000 + (altsign * (altmeters * 100 + altfrac)));
  while (!isspace((unsigned char)*cp) && (cp < maxcp))
    cp++;
  while (isspace((unsigned char)*cp) && (cp < maxcp))
    cp++;
  if (cp >= maxcp)
    goto defaults;
  siz = precsize_aton(&cp);
  while (!isspace((unsigned char)*cp) && (cp < maxcp))
    cp++;
  while (isspace((unsigned char)*cp) && (cp < maxcp))
    cp++;
  if (cp >= maxcp)
    goto defaults;
  hp = precsize_aton(&cp);
  while (!isspace((unsigned char)*cp) && (cp < maxcp))
    cp++;
  while (isspace((unsigned char)*cp) && (cp < maxcp))
    cp++;
  if (cp >= maxcp)
    goto defaults;
  vp = precsize_aton(&cp);
defaults:
  bcp = binary;
  *bcp++ = (u_int8_t)0;
  *bcp++ = siz;
  *bcp++ = hp;
  *bcp++ = vp;
  PUTLONG(latit, bcp);
  PUTLONG(longit, bcp);
  PUTLONG(alt, bcp);
  return (16);
}
```