user: 请从给定的汇编指令推导出C源代码:

```asm
<gauss>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x78,%rsp
  mov    %rdi,0x30(%rsp)
  mov    %rsi,0x68(%rsp)
  mov    %edx,%r14d
  mov    %edx,0x28(%rsp)
  mov    %ecx,%ebx
  mov    %ecx,0x10(%rsp)
  mov    %r8d,%r15d
  movslq %ecx,%rax
  mov    %rax,0x60(%rsp)
  lea    0x0(,%rcx,4),%edi
  call   <malloc@plt>
  mov    %rax,0x50(%rsp)
  test   %r14d,%r14d
  jle    L81
  lea    -0x1(%rbx),%ebx
  mov    %ebx,0x58(%rsp)
  test   %ebx,%ebx
  jle    L369
  mov    %ebx,0x2c(%rsp)
  mov    $0x0,%r13d
  movq   $0x0,0x20(%rsp)
  mov    $0x0,%edi
  movl   $0x0,0x4c(%rsp)
  lea    -0x2(%r14),%eax
  mov    %eax,0x5c(%rsp)
  jmp    L71
L51:
  mov    0x4c(%rsp),%ebx
  cmp    %ebx,0x28(%rsp)
  jle    L222
L182:
  mov    0x60(%rsp),%rax
  lea    -0x4(,%rax,4),%rcx
  movslq 0x4c(%rsp),%rax
  mov    0x30(%rsp),%rsi
  mov    0x28(%rsp),%edi
L295:
  mov    (%rsi,%rax,8),%rdx
  cmpl   $0x0,(%rdx,%rcx,1)
  jne    L190
  add    $0x1,%rax
  cmp    %eax,%edi
  jg     L295
L222:
  mov    0x4c(%rsp),%eax
  test   %eax,%eax
  jle    L27
  mov    0x60(%rsp),%rbx
  lea    -0x4(,%rbx,4),%rsi
  mov    %eax,%ecx
  mov    $0x0,%eax
  mov    0x30(%rsp),%rdi
  mov    0x68(%rsp),%r8
L236:
  mov    (%rdi,%rax,8),%rdx
  mov    (%rdx,%rsi,1),%edx
  mov    %edx,(%r8,%rax,4)
  add    $0x1,%rax
  cmp    %rcx,%rax
  jne    L236
  mov    0x58(%rsp),%ebx
  cmp    %ebx,0x4c(%rsp)
  jge    L196
L166:
  movslq 0x4c(%rsp),%rax
  mov    0x58(%rsp),%edx
  mov    0x68(%rsp),%rcx
L14:
  movl   $0x0,(%rcx,%rax,4)
  add    $0x1,%rax
  cmp    %eax,%edx
  jg     L14
L125:
  mov    0x4c(%rsp),%edi
  sub    $0x1,%edi
  js     L44
L167:
  movslq %edi,%rax
  mov    0x68(%rsp),%r11
  lea    (%r11,%rax,4),%rcx
  mov    0x30(%rsp),%rbx
  lea    (%rbx,%rax,8),%rsi
  mov    0x50(%rsp),%r8
  sub    %r11,%r8
  mov    0x58(%rsp),%ebx
  lea    -0x2(%rbx),%r9d
  jmp    L278
L369:
  movl   $0x0,0x4c(%rsp)
  jmp    L182
L190:
  mov    0x50(%rsp),%rdi
  call   <free@plt>
  mov    $0x0,%eax
  jmp    L153
L27:
  mov    0x10(%rsp),%eax
  sub    $0x1,%eax
  mov    %eax,0x58(%rsp)
  cmp    %eax,0x4c(%rsp)
  jl     L166
  jmp    L125
L103:
  mov    (%rcx),%eax
  cltd
  idiv   %r15d
  lea    (%rdx,%r15,1),%eax
  cltd
  idiv   %r15d
  mov    %edx,(%rcx)
  sub    $0x4,%rcx
  sub    $0x8,%rsi
  sub    $0x1,%edi
  js     L44
L278:
  mov    (%r8,%rcx,1),%edx
  lea    0x1(%rdx),%eax
  cmp    %ebx,%eax
  jge    L103
  cltq
  shl    $0x2,%rax
  mov    %r9d,%r10d
  sub    %edx,%r10d
  movslq %edx,%rdx
  lea    0x2(%r10,%rdx,1),%r10
  shl    $0x2,%r10
L184:
  mov    (%rsi),%rdx
  mov    (%rdx,%rax,1),%edx
  imul   (%r11,%rax,1),%edx
  sub    %edx,(%rcx)
  add    $0x4,%rax
  cmp    %rax,%r10
  jne    L184
  jmp    L103
L196:
  mov    0x4c(%rsp),%edi
  sub    $0x1,%edi
  jmp    L167
L299:
  mov    0x40(%rsp),%eax
  add    $0x1,%eax
  jmp    L50
L343:
  cmp    $0xffffffff,%edx
  je     L299
  mov    0x20(%rsp),%rsi
  mov    %esi,0x14(%rsp)
  cmp    %esi,0x10(%rsp)
  jle    L124
  movslq %edx,%rdx
  mov    0x30(%rsp),%rax
  lea    (%rax,%rdx,8),%rcx
  mov    0x2c(%rsp),%eax
  lea    0x1(%rsi,%rax,1),%r10
  shl    $0x2,%r10
  mov    %r13,%rax
L129:
  mov    %rax,%rdx
  add    (%rbx),%rdx
  mov    (%rdx),%esi
  mov    (%rcx),%r9
  mov    (%r9,%rax,1),%r9d
  mov    %r9d,(%rdx)
  mov    (%rcx),%rdx
  mov    %esi,(%rdx,%rax,1)
  add    $0x4,%rax
  cmp    %r10,%rax
  jne    L129
L124:
  lea    0x1(%rdi),%eax
  mov    %eax,0x44(%rsp)
  cmp    %eax,0x28(%rsp)
  jle    L91
  mov    0x30(%rsp),%rcx
  lea    0x8(%rcx,%r8,1),%r14
  mov    0x5c(%rsp),%eax
  sub    %edi,%eax
  add    0x38(%rsp),%rax
  lea    0x10(%rcx,%rax,8),%rax
  mov    %rax,0x18(%rsp)
  mov    0x2c(%rsp),%eax
  mov    0x20(%rsp),%rdi
  lea    0x1(%rdi,%rax,1),%r12
  shl    $0x2,%r12
  mov    %r13,0x8(%rsp)
L318:
  mov    %r14,%rbp
  mov    (%r14),%rax
  mov    0x8(%rsp),%rdi
  mov    (%rax,%rdi,1),%r13d
  neg    %r13d
  mov    (%rbx),%rax
  mov    (%rax,%rdi,1),%edi
  mov    %r15d,%esi
  call   <invMod@plt>
  imul   %r13d,%eax
  cltd
  idiv   %r15d
  mov    %edx,%edi
  mov    0x14(%rsp),%esi
  cmp    %esi,0x10(%rsp)
  jle    L376
  mov    0x8(%rsp),%rcx
L75:
  mov    %rcx,%rsi
  add    0x0(%rbp),%rsi
  mov    (%rbx),%rax
  mov    %edi,%edx
  imul   (%rax,%rcx,1),%edx
  mov    %edx,%eax
  add    (%rsi),%eax
  cltd
  idiv   %r15d
  mov    %edx,(%rsi)
  add    $0x4,%rcx
  cmp    %r12,%rcx
  jne    L75
L376:
  add    $0x8,%r14
  cmp    0x18(%rsp),%r14
  jne    L318
  mov    0x8(%rsp),%r13
L91:
  mov    (%rbx),%rax
  mov    (%rax,%r13,1),%edi
  mov    %r15d,%esi
  call   <invMod@plt>
  mov    %eax,%edi
  mov    0x14(%rsp),%ecx
  cmp    %ecx,0x10(%rsp)
  jle    L92
  mov    0x2c(%rsp),%eax
  mov    0x20(%rsp),%rcx
  lea    0x1(%rcx,%rax,1),%r8
  shl    $0x2,%r8
  mov    %r13,%rcx
L9:
  mov    %rcx,%rsi
  add    (%rbx),%rsi
  mov    %edi,%eax
  imul   (%rsi),%eax
  cltd
  idiv   %r15d
  mov    %edx,(%rsi)
  add    $0x4,%rcx
  cmp    %r8,%rcx
  jne    L9
L92:
  mov    0x50(%rsp),%rax
  mov    0x38(%rsp),%rbx
  mov    0x48(%rsp),%edi
  mov    %edi,(%rax,%rbx,4)
  addl   $0x1,0x4c(%rsp)
  mov    0x40(%rsp),%eax
  add    $0x1,%eax
  mov    0x44(%rsp),%edi
  cmp    %edi,0x28(%rsp)
  jle    L51
  mov    0x44(%rsp),%edi
L50:
  addq   $0x1,0x20(%rsp)
  add    $0x4,%r13
  subl   $0x1,0x2c(%rsp)
  cmp    0x58(%rsp),%eax
  jge    L51
L71:
  mov    0x20(%rsp),%rax
  mov    %eax,0x40(%rsp)
  mov    %eax,0x48(%rsp)
  cmp    %edi,0x28(%rsp)
  jle    L51
  movslq %edi,%rax
  mov    %rax,0x38(%rsp)
  lea    0x0(,%rax,8),%r8
  mov    0x30(%rsp),%rax
  lea    (%rax,%r8,1),%rbx
  mov    %rbx,%rcx
  mov    %edi,%eax
  mov    $0xffffffff,%edx
  mov    0x28(%rsp),%r9d
L150:
  mov    (%rcx),%rsi
  cmpl   $0x0,(%rsi,%r13,1)
  cmovne %eax,%edx
  add    $0x1,%eax
  add    $0x8,%rcx
  test   %edx,%edx
  jns    L343
  cmp    %eax,%r9d
  jg     L150
  jmp    L343
L81:
  mov    0x10(%rsp),%eax
  sub    $0x1,%eax
  mov    %eax,0x58(%rsp)
  movl   $0x0,0x4c(%rsp)
  test   %eax,%eax
  jg     L166
L44:
  mov    0x50(%rsp),%rdi
  call   <free@plt>
  mov    $0x1,%eax
L153:
  add    $0x78,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
int gauss(int **a, int *x, int m, int n, int q) {
  int rank = 0, i, j, k, l, *pivot = (int *)malloc(sizeof(int) * n);
  for (i = 0, j = 0; i < m && j < n - 1; ++j) {
    int p = -1, tmp = 0;
    for (k = i; p < 0 && k < m; ++k) {
      if (a[k][j] != 0)
        p = k;
    }
    if (p == -1)
      continue;
    for (k = j; k < n; ++k)
      tmp = a[i][k], a[i][k] = a[p][k], a[p][k] = tmp;
    for (k = i + 1; k < m; ++k) {
      tmp = -a[k][j] * invMod(a[i][j], q) % q;
      for (l = j; l < n; ++l)
        a[k][l] = (a[k][l] + tmp * a[i][l]) % q;
    }
    tmp = invMod(a[i][j], q);
    for (k = j; k < n; ++k)
      a[i][k] = a[i][k] * tmp % q;
    pivot[i++] = j, rank++;
  }
  for (i = rank; i < m; ++i)
    if (a[i][n - 1] != 0) {
      free(pivot);
      return 0;
    }
  for (i = 0; i < rank; ++i)
    x[i] = a[i][n - 1];
  for (i = rank; i < n - 1; ++i)
    x[i] = 0;
  for (i = rank - 1; i >= 0; --i) {
    for (j = pivot[i] + 1; j < n - 1; ++j)
      x[i] -= a[i][j] * x[j];
    x[i] -= x[i] / q * q, x[i] = (x[i] + q) % q;
  }
  free(pivot);
  return 1;
}
```