user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<pftoa>:
  endbr64
  push   %r14
  movd   %xmm0,%ecx
  push   %r13
  shr    $0x17,%ecx
  push   %r12
  sub    $0x7f,%ecx
  push   %rbp
  mov    %rdi,%rbp
  push   %rbx
  sub    $0x10,%rsp
  mov    %fs:0x28,%rdx
  mov    %rdx,0x8(%rsp)
  xor    %edx,%edx
  movd   %xmm0,%edx
  shr    $0x10,%edx
  and    $0x7f,%edx
  cmp    $0x12,%cl
  jg     L34
  cmp    $0xfd,%cl
  jl     L154
  movd   %xmm0,%esi
  movd   %xmm0,%eax
  mov    %rdi,%r12
  xor    %ebx,%ebx
  shr    $0x18,%esi
  test   %sil,%sil
  jns    L42
  movb   $0x2d,(%rdi)
  lea    0x1(%rdi),%r12
  mov    $0x1,%ebx
L42:
  movzbl %dl,%edx
  movzwl %ax,%eax
  movsbl %cl,%r13d
  mov    $0x17,%ecx
  shl    $0x10,%rdx
  sub    %r13d,%ecx
  mov    %r12,%rsi
  lea    0x800000(%rax,%rdx,1),%r14
  mov    $0xa,%edx
  mov    %r14,%rax
  shr    %cl,%rax
  mov    %rax,%rdi
  call   <itoa@plt>
  mov    %rbp,%rdx
  xor    %eax,%eax
  nopl   0x0(%rax,%rax,1)
L109:
  cmpb   $0x0,(%rdx)
  je     L101
  add    $0x1,%eax
  add    $0x1,%rdx
  cmp    $0x8,%eax
  jne    L109
L10:
  mov    $0x14,%ecx
  lea    D8(%rip),%rdx
  add    $0x1,%ebx
  sub    %r13d,%ecx
  shr    %cl,%r14
  and    $0x7,%r14d
  movslq (%rdx,%r14,4),%rax
  add    %rdx,%rax
  notrack jmp *%rax
  nopl   0x0(%rax)
L154:
  mov    $0x30,%eax
  mov    %ax,(%rdi)
L55:
  mov    0x8(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L71
  add    $0x10,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
  nopl   0x0(%rax)
L34:
  movl   $0x666e49,(%rdi)
  jmp    L55
  nopl   0x0(%rax,%rax,1)
L101:
  cmp    $0x5,%eax
  jg     L55
  mov    %rdx,%r12
  mov    %eax,%ebx
  jmp    L10
  nopl   0x0(%rax)
  mov    $0x31,%ecx
  mov    $0x32,%edx
  mov    $0x35,%eax
  nop
L113:
  movb   $0x2e,(%r12)
  mov    %cl,0x5(%rsp)
  mov    %dl,0x6(%rsp)
  lea    0x8(%rsp),%rdx
  mov    %al,0x7(%rsp)
  lea    0x5(%rsp),%rax
L54:
  cmp    $0x6,%ebx
  jg     L189
  movzbl (%rax),%esi
  movslq %ebx,%rcx
  add    $0x1,%ebx
  mov    %sil,0x0(%rbp,%rcx,1)
L189:
  add    $0x1,%rax
  cmp    %rdx,%rax
  jne    L54
  movslq %ebx,%rbx
  movb   $0x0,0x0(%rbp,%rbx,1)
  jmp    L55
  nopl   0x0(%rax)
  mov    $0x32,%ecx
  mov    $0x35,%edx
  mov    $0x30,%eax
  jmp    L113
  nopl   0x0(%rax)
  mov    $0x33,%ecx
  mov    $0x37,%edx
  mov    $0x35,%eax
  jmp    L113
  nopl   0x0(%rax)
  mov    $0x35,%ecx
  mov    $0x30,%edx
  mov    $0x30,%eax
  jmp    L113
  nopl   0x0(%rax)
  mov    $0x36,%ecx
  mov    $0x32,%edx
  mov    $0x35,%eax
  jmp    L113
  nopl   0x0(%rax)
  mov    $0x37,%ecx
  mov    $0x35,%edx
  mov    $0x30,%eax
  jmp    L113
  nopl   0x0(%rax)
  mov    $0x38,%ecx
  mov    $0x37,%edx
  mov    $0x35,%eax
  jmp    L113
L71:
  call   <__stack_chk_fail@plt>
  mov    $0x30,%ecx
  mov    $0x30,%edx
  mov    $0x30,%eax
  jmp    L113
```

assistant: ```c
void pftoa(float value, char *buffer) {
  union {
    float f;
    struct {
      unsigned int mantissa_lo : 16;
      unsigned int mantissa_hi : 7;
      unsigned int exponent : 8;
      unsigned int sign : 1;
    };
  } helper;
  unsigned long mantissa;
  signed char exponent;
  unsigned int int_part;
  char frac_part[3];
  int i, count = 0;
  helper.f = value;
  mantissa = helper.mantissa_lo;
  mantissa += ((unsigned long)helper.mantissa_hi << 16);
  mantissa += 0x00800000;
  exponent = (signed char)helper.exponent - 127;
  if (exponent > 18) {
    buffer[0] = 'I';
    buffer[1] = 'n';
    buffer[2] = 'f';
    buffer[3] = '\0';
    return;
  }
  if (exponent < -3) {
    buffer[0] = '0';
    buffer[1] = '\0';
    return;
  }
  count = 0;
  if (helper.sign) {
    buffer[0] = '-';
    count++;
  }
  int_part = mantissa >> (23 - exponent);
  itoa(int_part, &buffer[count], 10);
  for (i = 0; i < 8; i++)
    if (buffer[i] == '\0') {
      count = i;
      break;
    }
  if (count > 5)
    return;
  buffer[count++] = '.';
  switch (0x7 & (mantissa >> (20 - exponent))) {
  case 0:
    frac_part[0] = '0';
    frac_part[1] = '0';
    frac_part[2] = '0';
    break;
  case 1:
    frac_part[0] = '1';
    frac_part[1] = '2';
    frac_part[2] = '5';
    break;
  case 2:
    frac_part[0] = '2';
    frac_part[1] = '5';
    frac_part[2] = '0';
    break;
  case 3:
    frac_part[0] = '3';
    frac_part[1] = '7';
    frac_part[2] = '5';
    break;
  case 4:
    frac_part[0] = '5';
    frac_part[1] = '0';
    frac_part[2] = '0';
    break;
  case 5:
    frac_part[0] = '6';
    frac_part[1] = '2';
    frac_part[2] = '5';
    break;
  case 6:
    frac_part[0] = '7';
    frac_part[1] = '5';
    frac_part[2] = '0';
    break;
  case 7:
    frac_part[0] = '8';
    frac_part[1] = '7';
    frac_part[2] = '5';
    break;
  }
  for (i = 0; i < 3; i++)
    if (count < 7)
      buffer[count++] = frac_part[i];
  buffer[count] = '\0';
}
```