user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<variance>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r13
  push   %r12
  mov    %rdi,%r12
  push   %rbx
  mov    %rsi,%rbx
  sub    $0xe8,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,-0x28(%rbp)
  xor    %eax,%eax
  call   <strlen@plt>
  mov    %rsp,%rcx
  add    $0xf,%rax
  mov    %rax,%rdx
  and    $0xfffffffffffff000,%rax
  sub    %rax,%rcx
  and    $0xfffffffffffffff0,%rdx
  cmp    %rcx,%rsp
  je     L25
L100:
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  cmp    %rcx,%rsp
  jne    L100
L25:
  and    $0xfff,%edx
  sub    %rdx,%rsp
  test   %rdx,%rdx
  jne    L55
L120:
  mov    %r12,%rsi
  mov    %rsp,%rdi
  lea    D11(%rip),%r13
  call   <strcpy@plt>
  mov    %r12,%rdi
  mov    %rbx,%rsi
  call   <mean@plt>
  mov    %r13,%rsi
  mov    %rsp,%rdi
  movsd  %xmm0,-0x100(%rbp)
  call   <strtok@plt>
  mov    %rax,%r12
  test   %rax,%rax
  jne    L89
  jmp    L32
  xchg   %ax,%ax
L68:
  mov    %r13,%rsi
  xor    %edi,%edi
  call   <strtok@plt>
  mov    %rax,%r12
  test   %rax,%rax
  je     L32
L89:
  mov    %rbx,%rdi
  call   <strlen@plt>
  mov    %rbx,%rsi
  mov    %r12,%rdi
  mov    %rax,%rdx
  call   <strncmp@plt>
  test   %rax,%rax
  jne    L68
  lea    -0xf0(%rbp),%r13
  mov    %r12,%rsi
  mov    %r13,%rdi
  call   <strcpy@plt>
L154:
  xor    %r12d,%r12d
  xor    %ebx,%ebx
  jmp    L53
  nopw   0x0(%rax,%rax,1)
L4:
  movsbl 0x0(%r13,%r12,1),%edi
  call   <isdigit@plt>
  test   %rax,%rax
  movzbl 0x0(%r13,%r12,1),%eax
  jne    L66
  mov    %eax,%edx
  and    $0xfffffffd,%edx
  cmp    $0x2c,%dl
  jne    L2
L66:
  movslq %ebx,%rdx
  add    $0x1,%ebx
  mov    %al,-0xf0(%rbp,%rdx,1)
L2:
  add    $0x1,%r12
L53:
  mov    %r13,%rdi
  call   <strlen@plt>
  cmp    %r12,%rax
  ja     L4
  movslq %ebx,%rbx
  mov    %r13,%rdi
  movb   $0x0,-0xf0(%rbp,%rbx,1)
  lea    D1(%rip),%rbx
  mov    %rbx,%rsi
  call   <strtok@plt>
  mov    %rax,%rdi
  test   %rax,%rax
  je     L82
  pxor   %xmm3,%xmm3
  movsd  %xmm3,-0xf8(%rbp)
  nopl   0x0(%rax,%rax,1)
L67:
  call   <atof@plt>
  pxor   %xmm0,%xmm0
  mov    $0x2,%esi
  cvtsi2sd %rax,%xmm0
  subsd  -0x100(%rbp),%xmm0
  cvttsd2si %xmm0,%rdi
  call   <pow@plt>
  pxor   %xmm0,%xmm0
  xor    %edi,%edi
  mov    %rbx,%rsi
  cvtsi2sd %rax,%xmm0
  addsd  -0xf8(%rbp),%xmm0
  movsd  %xmm0,-0xf8(%rbp)
  call   <strtok@plt>
  mov    %rax,%rdi
  test   %rax,%rax
  jne    L67
  movsd  -0xf8(%rbp),%xmm0
  divsd  D16(%rip),%xmm0
L167:
  mov    -0x28(%rbp),%rax
  sub    %fs:0x28,%rax
  jne    L65
  lea    -0x18(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %rbp
  ret
  nopw   0x0(%rax,%rax,1)
L32:
  lea    -0xf0(%rbp),%r13
  jmp    L154
  nopl   0x0(%rax)
L55:
  orq    $0x0,-0x8(%rsp,%rdx,1)
  jmp    L120
  nopl   0x0(%rax,%rax,1)
L82:
  pxor   %xmm0,%xmm0
  jmp    L167
L65:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: read_data
arguments: label: D11
datatype: string
name: read_data
arguments: label: D1
datatype: string
name: read_data
arguments: label: D16
datatype: f32[2]

tool: D11: 


tool: D1: ,

tool: {"D16": [0.0,2.625]}

assistant: ```c
double variance(char *str, char *town) {
  char buff[strlen(str)];
  strcpy(buff, str);
  char line[200];
  double rain_mean = mean(str, town);
  char *pch = strtok(buff, "\n");
  while (pch != NULL) {
    if (strncmp(pch, town, strlen(town)) == 0) {
      strcpy(line, pch);
      break;
    }
    pch = strtok(NULL, "\n");
  }
  int cnt = 0;
  for (size_t i = 0; i < strlen(line); ++i) {
    if (isdigit(line[i]) || line[i] == '.' || line[i] == ',')
      line[cnt++] = line[i];
  }
  line[cnt] = '\0';
  double sum = 0;
  pch = strtok(line, ",");
  while (pch != NULL) {
    sum += pow(atof(pch) - rain_mean, 2);
    pch = strtok(NULL, ",");
  }
  return sum / 12;
}
```