user: What would the C source look like for the assembly code provided here?

```asm
<backSubstitution>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x50,%rsp
  mov    %edi,-0x34(%rbp)
  mov    %rsi,-0x40(%rbp)
  mov    %rdx,-0x48(%rbp)
  mov    -0x34(%rbp),%eax
  mov    %eax,%edi
  call   <zeros@plt>
  mov    %rax,-0x10(%rbp)
  movl   $0x0,-0x24(%rbp)
  jmp    L1
L39:
  mov    -0x24(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x20(%rbp)
  jmp    L86
L2:
  mov    -0x34(%rbp),%eax
  imul   -0x20(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x24(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x34(%rbp),%eax
  imul   -0x24(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x24(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  divsd  %xmm1,%xmm0
  movsd  %xmm0,-0x8(%rbp)
  mov    -0x24(%rbp),%eax
  mov    %eax,-0x1c(%rbp)
  jmp    L99
L79:
  mov    -0x34(%rbp),%eax
  imul   -0x20(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x1c(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x34(%rbp),%eax
  imul   -0x24(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x1c(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  mulsd  -0x8(%rbp),%xmm1
  mov    -0x34(%rbp),%eax
  imul   -0x20(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x1c(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  subsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x1c(%rbp)
L99:
  mov    -0x1c(%rbp),%eax
  cmp    -0x34(%rbp),%eax
  jl     L79
  mov    -0x20(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x24(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  mulsd  -0x8(%rbp),%xmm1
  mov    -0x20(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  subsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x20(%rbp)
L86:
  mov    -0x20(%rbp),%eax
  cmp    -0x34(%rbp),%eax
  jl     L2
  addl   $0x1,-0x24(%rbp)
L1:
  mov    -0x34(%rbp),%eax
  sub    $0x1,%eax
  cmp    %eax,-0x24(%rbp)
  jl     L39
  mov    -0x34(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    -0x8(%rax),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x34(%rbp),%eax
  sub    $0x1,%eax
  imul   -0x34(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x34(%rbp),%eax
  cltq
  add    %rdx,%rax
  shl    $0x3,%rax
  lea    -0x8(%rax),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  mov    -0x34(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    -0x8(%rax),%rdx
  mov    -0x10(%rbp),%rax
  add    %rdx,%rax
  divsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  mov    -0x34(%rbp),%eax
  sub    $0x2,%eax
  mov    %eax,-0x24(%rbp)
  jmp    L87
L90:
  mov    -0x24(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x18(%rbp)
  mov    -0x24(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,-0x20(%rbp)
  jmp    L19
L84:
  mov    -0x34(%rbp),%eax
  imul   -0x24(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x20(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%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
  mulsd  %xmm0,%xmm1
  movsd  -0x18(%rbp),%xmm0
  subsd  %xmm1,%xmm0
  movsd  %xmm0,-0x18(%rbp)
  addl   $0x1,-0x20(%rbp)
L19:
  mov    -0x20(%rbp),%eax
  cmp    -0x34(%rbp),%eax
  jl     L84
  mov    -0x34(%rbp),%eax
  imul   -0x24(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x24(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x40(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm1
  mov    -0x24(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x10(%rbp),%rax
  add    %rdx,%rax
  movsd  -0x18(%rbp),%xmm0
  divsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  subl   $0x1,-0x24(%rbp)
L87:
  cmpl   $0x0,-0x24(%rbp)
  jns    L90
  mov    -0x10(%rbp),%rax
  leave
  ret
```

assistant: ```c
double *backSubstitution(int n, double *matrix, double b[]) {
  int i, j, k;
  double aux, temp;
  double *x = zeros(n);
  for (i = 0; i < (n - 1); i++) {
    for (j = (i + 1); j < n; j++) {
      aux = *(matrix + n * j + i) / *(matrix + n * i + i);
      for (k = i; k < n; k++) {
        *(matrix + n * j + k) -= (aux * (*(matrix + n * i + k)));
      }
      b[j] -= (aux * b[i]);
    }
  }
  x[n - 1] = b[n - 1] / *(matrix + n * (n - 1) + n - 1);
  for (i = (n - 2); i >= 0; i--) {
    temp = b[i];
    for (j = (i + 1); j < n; j++) {
      temp -= (*(matrix + n * i + j) * x[j]);
    }
    x[i] = temp / *(matrix + n * i + i);
  }
  return x;
}
```