user: 请从给定的汇编指令推导出C源代码：

```asm
<main>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x70,%rsp
  mov    %edi,-0x64(%rbp)
  mov    %rsi,-0x70(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x8(%rbp)
  xor    %eax,%eax
  movl   $0x32,-0x58(%rbp)
  movl   $0x1,-0x54(%rbp)
  cmpl   $0x1,-0x64(%rbp)
  jle    L26
  mov    -0x70(%rbp),%rax
  add    $0x8,%rax
  mov    (%rax),%rax
  mov    %rax,%rdi
  call   <atoi@plt>
  mov    %eax,-0x58(%rbp)
  cmpl   $0x0,-0x58(%rbp)
  jns    L26
  movl   $0x32,-0x58(%rbp)
L26:
  cmpl   $0x2,-0x64(%rbp)
  jle    L133
  mov    -0x70(%rbp),%rax
  add    $0x10,%rax
  mov    (%rax),%rax
  mov    %rax,%rdi
  call   <atoi@plt>
  mov    %eax,-0x54(%rbp)
  cmpl   $0x0,-0x54(%rbp)
  jns    L133
  movl   $0x1,-0x54(%rbp)
L133:
  mov    -0x54(%rbp),%eax
  cmp    -0x58(%rbp),%eax
  jl     L153
  pxor   %xmm3,%xmm3
  cvtsi2sdl -0x58(%rbp),%xmm3
  movq   %xmm3,%rax
  mov    -0x54(%rbp),%edx
  mov    %edx,%esi
  movq   %rax,%xmm0
  lea    D46(%rip),%rax
  mov    %rax,%rdi
  mov    $0x1,%eax
  call   <printf@plt>
  mov    $0x1,%edi
  call   <exit@plt>
L153:
  mov    -0x58(%rbp),%eax
  imul   %eax,%eax
  mov    $0x8,%esi
  mov    %eax,%edi
  call   <calloc@plt>
  mov    %rax,-0x50(%rbp)
  mov    -0x58(%rbp),%eax
  mov    $0x8,%esi
  mov    %eax,%edi
  call   <calloc@plt>
  mov    %rax,-0x48(%rbp)
  mov    -0x58(%rbp),%eax
  mov    $0x8,%esi
  mov    %eax,%edi
  call   <calloc@plt>
  mov    %rax,-0x40(%rbp)
  movl   $0x0,-0x60(%rbp)
  jmp    L93
L135:
  mov    -0x54(%rbp),%eax
  lea    (%rax,%rax,1),%ecx
  mov    -0x60(%rbp),%eax
  imul   -0x58(%rbp),%eax
  mov    %eax,%edx
  mov    -0x60(%rbp),%eax
  add    %edx,%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  pxor   %xmm0,%xmm0
  cvtsi2sd %ecx,%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x60(%rbp)
L93:
  mov    -0x60(%rbp),%eax
  cmp    -0x58(%rbp),%eax
  jl     L135
  movl   $0x0,-0x60(%rbp)
  jmp    L131
L88:
  movl   $0x0,-0x5c(%rbp)
  jmp    L85
L150:
  mov    -0x60(%rbp),%eax
  cmp    -0x5c(%rbp),%eax
  je     L105
  mov    -0x60(%rbp),%eax
  sub    -0x5c(%rbp),%eax
  mov    %eax,%edx
  neg    %edx
  cmovns %edx,%eax
  cmp    %eax,-0x54(%rbp)
  jl     L105
  mov    -0x60(%rbp),%eax
  imul   -0x58(%rbp),%eax
  mov    %eax,%edx
  mov    -0x5c(%rbp),%eax
  add    %edx,%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  movsd  D5(%rip),%xmm0
  movsd  %xmm0,(%rax)
L105:
  addl   $0x1,-0x5c(%rbp)
L85:
  mov    -0x5c(%rbp),%eax
  cmp    -0x58(%rbp),%eax
  jl     L150
  addl   $0x1,-0x60(%rbp)
L131:
  mov    -0x60(%rbp),%eax
  cmp    -0x58(%rbp),%eax
  jl     L88
  movl   $0x0,-0x60(%rbp)
  jmp    L126
L156:
  mov    -0x60(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movsd  D3(%rip),%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x60(%rbp)
L126:
  mov    -0x60(%rbp),%eax
  cmp    -0x58(%rbp),%eax
  jl     L156
  lea    -0x30(%rbp),%rax
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <gettimeofday@plt>
  mov    -0x40(%rbp),%rdi
  mov    -0x48(%rbp),%rcx
  mov    -0x50(%rbp),%rdx
  mov    -0x54(%rbp),%esi
  mov    -0x58(%rbp),%eax
  mov    %rdi,%r8
  mov    %eax,%edi
  call   <matvec@plt>
  lea    -0x20(%rbp),%rax
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <gettimeofday@plt>
  movsd  -0x20(%rbp),%xmm0
  movsd  -0x30(%rbp),%xmm2
  movapd %xmm0,%xmm1
  subsd  %xmm2,%xmm1
  movsd  -0x18(%rbp),%xmm0
  movsd  -0x28(%rbp),%xmm2
  subsd  %xmm2,%xmm0
  movsd  D13(%rip),%xmm2
  divsd  %xmm2,%xmm0
  addsd  %xmm1,%xmm0
  movsd  %xmm0,-0x38(%rbp)
  mov    -0x38(%rbp),%rax
  movq   %rax,%xmm0
  lea    D48(%rip),%rax
  mov    %rax,%rdi
  mov    $0x1,%eax
  call   <printf@plt>
  mov    -0x50(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  mov    -0x48(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  mov    -0x40(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  mov    $0x0,%eax
  mov    -0x8(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L65
  call   <__stack_chk_fail@plt>
L65:
  leave
  ret
```

tool_calls: name: extract_symbolic_data
arguments: data_label: D46
data_type: string
name: extract_symbolic_data
arguments: data_label: D5
data_type: byte[8]
name: extract_symbolic_data
arguments: data_label: D3
data_type: f64
name: extract_symbolic_data
arguments: data_label: D13
data_type: byte[8]
name: extract_symbolic_data
arguments: data_label: D48
data_type: string

tool: D46: Error: ancho de banda excesivo, N=%d, b=%d


tool: {"D5": [0x00,0x00,0x00,0x00,0x00,0x00,0xf0,0xbf]}

tool: D3: 1

tool: {"D13": [0x00,0x00,0x00,0x00,0x80,0x84,0x2e,0x41]}

tool: D48: TIME TAKEN : %f seconds


assistant: ```c
int main(int argc, char **argv) {
  int i, j, N = 50, b = 1;
  double *A, *v, *w;
  if (argc > 1) {
    if ((N = atoi(argv[1])) < 0)
      N = 50;
  }
  if (argc > 2) {
    if ((b = atoi(argv[2])) < 0)
      b = 1;
  }
  if (b >= N) {
    printf("Error: ancho de banda excesivo, N=%d, b=%d\n", N, b);
    exit(1);
  }
  A = (double *)calloc(N * N, sizeof(double));
  v = (double *)calloc(N, sizeof(double));
  w = (double *)calloc(N, sizeof(double));
  for (i = 0; i < N; i++)
    A[i * N + i] = 2 * b;
  for (i = 0; i < N; i++) {
    for (j = 0; j < N; j++) {
      if (i != j && abs(i - j) <= b)
        A[i * N + j] = -1.0;
    }
  }
  for (i = 0; i < N; i++)
    v[i] = 1.0;
  struct timeval t1, t2;
  double elapsedTime;
  gettimeofday(&t1, NULL);
  matvec(N, b, A, v, w);
  gettimeofday(&t2, NULL);
  elapsedTime = (t2.tv_sec - t1.tv_sec) + ((t2.tv_usec - t1.tv_usec) / (1000.0 * 1000.0));
  printf("TIME TAKEN : %f seconds\n", elapsedTime);
  free(A);
  free(v);
  free(w);
  return 0;
}
```