user: What is the c source code of the assembly code below:

```asm
<smoother>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x50,%rsp
  mov    %rdi,-0x28(%rbp)
  mov    %rsi,-0x30(%rbp)
  mov    %rdx,-0x38(%rbp)
  mov    %rcx,-0x40(%rbp)
  mov    %r8d,-0x44(%rbp)
  mov    %r9,-0x50(%rbp)
  mov    -0x44(%rbp),%edx
  mov    -0x44(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <mat@plt>
  mov    %rax,-0x18(%rbp)
  mov    -0x44(%rbp),%edx
  mov    -0x44(%rbp),%eax
  mov    %edx,%esi
  mov    %eax,%edi
  call   <mat@plt>
  mov    %rax,-0x10(%rbp)
  mov    -0x44(%rbp),%eax
  mov    $0x1,%esi
  mov    %eax,%edi
  call   <mat@plt>
  mov    %rax,-0x8(%rbp)
  movl   $0xffffffff,-0x1c(%rbp)
  cmpq   $0x0,-0x18(%rbp)
  je     L45
  cmpq   $0x0,-0x10(%rbp)
  je     L45
  cmpq   $0x0,-0x8(%rbp)
  jne    L79
L45:
  mov    -0x1c(%rbp),%eax
  jmp    L53
L79:
  mov    -0x44(%rbp),%ecx
  mov    -0x44(%rbp),%edx
  mov    -0x30(%rbp),%rsi
  mov    -0x18(%rbp),%rax
  mov    %rax,%rdi
  call   <matcpy@plt>
  mov    -0x44(%rbp),%ecx
  mov    -0x44(%rbp),%edx
  mov    -0x40(%rbp),%rsi
  mov    -0x10(%rbp),%rax
  mov    %rax,%rdi
  call   <matcpy@plt>
  mov    -0x44(%rbp),%edx
  mov    -0x18(%rbp),%rax
  mov    %edx,%esi
  mov    %rax,%rdi
  call   <matinv@plt>
  test   %eax,%eax
  jne    L63
  mov    -0x44(%rbp),%edx
  mov    -0x10(%rbp),%rax
  mov    %edx,%esi
  mov    %rax,%rdi
  call   <matinv@plt>
  test   %eax,%eax
  jne    L63
  movl   $0x0,-0x20(%rbp)
  jmp    L39
L24:
  mov    -0x20(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  mov    -0x20(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x10(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x20(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    0x10(%rbp),%rax
  add    %rdx,%rax
  addsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x20(%rbp)
L39:
  mov    -0x44(%rbp),%eax
  imul   %eax,%eax
  cmp    %eax,-0x20(%rbp)
  jl     L24
  mov    -0x44(%rbp),%eax
  mov    %eax,%esi
  mov    0x10(%rbp),%rdi
  call   <matinv@plt>
  mov    %eax,-0x1c(%rbp)
  cmpl   $0x0,-0x1c(%rbp)
  jne    L63
  mov    -0x28(%rbp),%rdi
  mov    -0x18(%rbp),%rsi
  mov    D62(%rip),%rcx
  mov    -0x44(%rbp),%edx
  mov    -0x44(%rbp),%eax
  sub    $0x8,%rsp
  push   -0x8(%rbp)
  pxor   %xmm1,%xmm1
  mov    %rdi,%r9
  mov    %rsi,%r8
  movq   %rcx,%xmm0
  mov    %edx,%ecx
  mov    $0x1,%edx
  mov    %eax,%esi
  lea    D25(%rip),%rax
  mov    %rax,%rdi
  call   <matmul@plt>
  add    $0x10,%rsp
  movsd  D62(%rip),%xmm0
  mov    -0x38(%rbp),%rdi
  mov    -0x10(%rbp),%rsi
  mov    D62(%rip),%rcx
  mov    -0x44(%rbp),%edx
  mov    -0x44(%rbp),%eax
  sub    $0x8,%rsp
  push   -0x8(%rbp)
  movapd %xmm0,%xmm1
  mov    %rdi,%r9
  mov    %rsi,%r8
  movq   %rcx,%xmm0
  mov    %edx,%ecx
  mov    $0x1,%edx
  mov    %eax,%esi
  lea    D25(%rip),%rax
  mov    %rax,%rdi
  call   <matmul@plt>
  add    $0x10,%rsp
  mov    -0x8(%rbp),%rsi
  mov    D62(%rip),%rcx
  mov    -0x44(%rbp),%edx
  mov    -0x44(%rbp),%eax
  sub    $0x8,%rsp
  push   -0x50(%rbp)
  pxor   %xmm1,%xmm1
  mov    %rsi,%r9
  mov    0x10(%rbp),%r8
  movq   %rcx,%xmm0
  mov    %edx,%ecx
  mov    $0x1,%edx
  mov    %eax,%esi
  lea    D25(%rip),%rax
  mov    %rax,%rdi
  call   <matmul@plt>
  add    $0x10,%rsp
L63:
  mov    -0x18(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  mov    -0x10(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  mov    -0x8(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  mov    -0x1c(%rbp),%eax
L53:
  leave
  ret
```

tool_calls: name: read_data
arguments: tag: D62
datatype: f64
name: read_data
arguments: tag: D25
datatype: string

tool: D62: 1

tool: D25: NN

assistant: ```c
extern int smoother(const double *xf, const double *Qf, const double *xb, const double *Qb, int n, double *xs, double *Qs) {
  double *invQf = mat(n, n), *invQb = mat(n, n), *xx = mat(n, 1);
  int i, info = -1;
  if (!invQf || !invQb || !xx) {
    return info;
  }
  matcpy(invQf, Qf, n, n);
  matcpy(invQb, Qb, n, n);
  if (!matinv(invQf, n) && !matinv(invQb, n)) {
    for (i = 0; i < n * n; ++i) {
      Qs[i] = invQf[i] + invQb[i];
    }
    if (!(info = matinv(Qs, n))) {
      matmul("NN", n, 1, n, 1.0, invQf, xf, 0.0, xx);
      matmul("NN", n, 1, n, 1.0, invQb, xb, 1.0, xx);
      matmul("NN", n, 1, n, 1.0, Qs, xx, 0.0, xs);
    }
  }
  free(invQf);
  free(invQb);
  free(xx);
  return info;
}
```