user: 请显示与下面列出的汇编代码相匹配的C语言实现：

```asm
<atof>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x20,%rsp
  mov    %rdi,-0x18(%rbp)
  jmp    L20
L64:
  addq   $0x1,-0x18(%rbp)
L20:
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isspace@plt>
  test   %rax,%rax
  jne    L64
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2d,%al
  jne    L148
  movb   $0x1,-0x9(%rbp)
  addq   $0x1,-0x18(%rbp)
  jmp    L70
L148:
  movb   $0x0,-0x9(%rbp)
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2b,%al
  jne    L70
  addq   $0x1,-0x18(%rbp)
L70:
  pxor   %xmm0,%xmm0
  movss  %xmm0,-0x8(%rbp)
  jmp    L122
L30:
  pxor   %xmm1,%xmm1
  cvtss2sd -0x8(%rbp),%xmm1
  movsd  D16(%rip),%xmm0
  mulsd  %xmm0,%xmm1
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  sub    $0x30,%eax
  pxor   %xmm0,%xmm0
  cvtsi2sd %eax,%xmm0
  addsd  %xmm1,%xmm0
  cvtsd2ss %xmm0,%xmm0
  movss  %xmm0,-0x8(%rbp)
  addq   $0x1,-0x18(%rbp)
L122:
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L30
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x2e,%al
  jne    L2
  addq   $0x1,-0x18(%rbp)
  movss  D38(%rip),%xmm0
  movss  %xmm0,-0x4(%rbp)
  jmp    L117
L0:
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  sub    $0x30,%eax
  pxor   %xmm0,%xmm0
  cvtsi2ss %eax,%xmm0
  mulss  -0x4(%rbp),%xmm0
  movss  -0x8(%rbp),%xmm1
  addss  %xmm1,%xmm0
  movss  %xmm0,-0x8(%rbp)
  pxor   %xmm1,%xmm1
  cvtss2sd -0x4(%rbp),%xmm1
  movsd  D27(%rip),%xmm0
  mulsd  %xmm1,%xmm0
  cvtsd2ss %xmm0,%xmm0
  movss  %xmm0,-0x4(%rbp)
  addq   $0x1,-0x18(%rbp)
L117:
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <isdigit@plt>
  test   %rax,%rax
  jne    L0
L2:
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  movsbl %al,%eax
  mov    %eax,%edi
  call   <toupper@plt>
  cmp    $0x45,%al
  jne    L46
  addq   $0x1,-0x18(%rbp)
  mov    -0x18(%rbp),%rax
  mov    %rax,%rdi
  call   <atoi@plt>
  mov    %al,-0xa(%rbp)
  jmp    L147
L110:
  cmpb   $0x0,-0xa(%rbp)
  jns    L124
  pxor   %xmm1,%xmm1
  cvtss2sd -0x8(%rbp),%xmm1
  movsd  D27(%rip),%xmm0
  mulsd  %xmm1,%xmm0
  cvtsd2ss %xmm0,%xmm0
  movss  %xmm0,-0x8(%rbp)
  movzbl -0xa(%rbp),%eax
  add    $0x1,%eax
  mov    %al,-0xa(%rbp)
  jmp    L147
L124:
  movss  -0x8(%rbp),%xmm1
  movss  D54(%rip),%xmm0
  mulss  %xmm1,%xmm0
  movss  %xmm0,-0x8(%rbp)
  movzbl -0xa(%rbp),%eax
  sub    $0x1,%eax
  mov    %al,-0xa(%rbp)
L147:
  cmpb   $0x0,-0xa(%rbp)
  jne    L110
L46:
  cmpb   $0x0,-0x9(%rbp)
  je     L83
  pxor   %xmm0,%xmm0
  cvtss2sd -0x8(%rbp),%xmm0
  cvtsd2ss %xmm0,%xmm0
  movss  D41(%rip),%xmm1
  xorps  %xmm1,%xmm0
  movss  %xmm0,-0x8(%rbp)
L83:
  movss  -0x8(%rbp),%xmm0
  leave
  ret
```

tool_calls: name: extract_symbolic_data
arguments: data_label: D16
type: f64
name: extract_symbolic_data
arguments: data_label: D38
type: f32
name: extract_symbolic_data
arguments: data_label: D27
type: byte[8]
name: extract_symbolic_data
arguments: data_label: D54
type: byte[4]
name: extract_symbolic_data
arguments: data_label: D41
type: byte[4]

tool: D16: 10

tool: D38: 0.1

tool: {"D27": [0x9a,0x99,0x99,0x99,0x99,0x99,0xb9,0x3f]}

tool: {"D54": [0x00,0x00,0x20,0x41]}

tool: {"D41": [0x00,0x00,0x00,0x80]}

assistant: ```c
float atof(char *s) {
  float value, fraction;
  signed char iexp;
  char sign;
  while (isspace(*s))
    s++;
  if (*s == '-') {
    sign = 1;
    s++;
  } else {
    sign = 0;
    if (*s == '+')
      s++;
  }
  for (value = 0.0; isdigit(*s); s++) {
    value = 10.0 * value + (*s - '0');
  }
  if (*s == '.') {
    s++;
    for (fraction = 0.1; isdigit(*s); s++) {
      value += (*s - '0') * fraction;
      fraction *= 0.1;
    }
  }
  if (toupper(*s) == 'E') {
    s++;
    iexp = (signed char)atoi(s);
    {
      while (iexp != 0) {
        if (iexp < 0) {
          value *= 0.1;
          iexp++;
        } else {
          value *= 10.0;
          iexp--;
        }
      }
    }
  }
  if (sign)
    value *= -1.0;
  return (value);
}
```