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

```asm
<Gauss_elimination>:
  endbr64
  push   %r15
  lea    0x1(%rdi),%eax
  mov    %edi,%r15d
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0xb8,%rsp
  mov    %eax,0x28(%rsp)
  cltq
  mov    %rax,0x78(%rsp)
  lea    -0x1(%rdi),%eax
  mov    %rsi,0x50(%rsp)
  mov    %rdx,0xa8(%rsp)
  mov    %eax,0x80(%rsp)
  test   %eax,%eax
  jle    L300
  test   %edi,%edi
  js     L230
  mov    0x78(%rsp),%rax
  mov    0x28(%rsp),%ebx
  mov    %rsi,%r14
  movslq %edi,%rdi
  mov    %rdi,0xa0(%rsp)
  lea    0x8(,%rdi,8),%rdi
  xor    %r9d,%r9d
  mov    %r14,%r10
  lea    0x0(,%rax,8),%rbp
  mov    %r14,0x40(%rsp)
  lea    0x8(%rbp),%rax
  mov    %rbp,0x38(%rsp)
  mov    %rax,0x88(%rsp)
  mov    %ebx,%eax
  shr    %eax
  mov    %rdi,0x98(%rsp)
  lea    -0x1(%rax),%esi
  mov    %ebx,%eax
  mov    %ebx,0x30(%rsp)
  lea    -0x8(%r14),%rbx
  and    $0xfffffffe,%eax
  add    $0x1,%rsi
  mov    %rbx,0x70(%rsp)
  mov    %r9,%rbx
  mov    %eax,0x94(%rsp)
  shl    $0x4,%rsi
  movslq %eax,%r13
  movq   $0x8,0x48(%rsp)
  mov    %r13,%rdx
  mov    %r15d,0x18(%rsp)
  mov    %rsi,%r15
  nopw   0x0(%rax,%rax,1)
L328:
  lea    0x1(%rbx),%edi
  mov    %ebx,0x90(%rsp)
  mov    %ebx,0x84(%rsp)
  mov    %edi,0x2c(%rsp)
  cmp    %edi,0x18(%rsp)
  jle    L210
  mov    0x38(%rsp),%rsi
  movslq %ebx,%r13
  mov    %r10,0x60(%rsp)
  mov    %ebx,%r12d
  mov    %rdx,0x68(%rsp)
  mov    %r13,%rax
  mov    %rbx,%r13
  lea    (%r14,%rsi,1),%r8
  mov    %r15,0x58(%rsp)
  mov    %rax,%rbx
  mov    %edi,%r15d
  mov    %r14,0x20(%rsp)
  mov    %r8,%r14
  nopl   0x0(%rax)
L278:
  movsd  (%r14,%r13,8),%xmm0
  call   <fabs@plt>
  movslq %r12d,%rcx
  imul   %rbp,%rcx
  add    0x20(%rsp),%rcx
  mov    %rax,0x8(%rsp)
  movsd  (%rcx,%rbx,8),%xmm0
  mov    %rcx,0x10(%rsp)
  call   <fabs@plt>
  mov    0x10(%rsp),%rcx
  cmp    %rax,0x8(%rsp)
  cmovg  %r15d,%r12d
  cmovg  %r14,%rcx
  add    $0x1,%r15d
  add    %rbp,%r14
  cmp    %r15d,0x18(%rsp)
  jne    L278
  mov    %r15d,%edi
  mov    0x60(%rsp),%r10
  mov    0x58(%rsp),%r15
  mov    %r13,%rbx
  mov    0x20(%rsp),%r14
  mov    0x68(%rsp),%rdx
  cmp    %r13d,%r12d
  jne    L357
L260:
  mov    0x70(%rsp),%rdi
  mov    0x48(%rsp),%r12
  mov    %rbx,0x8(%rsp)
  mov    0x38(%rsp),%r8
  mov    0x2c(%rsp),%r11d
  mov    0x98(%rsp),%rsi
  mov    0x94(%rsp),%ebx
  add    %r12,%rdi
  mov    0x40(%rsp),%r9
  mov    0x18(%rsp),%r13d
  nopl   0x0(%rax,%rax,1)
L284:
  movsd  (%r10,%r8,1),%xmm0
  lea    (%r14,%r8,1),%rcx
  movapd %xmm0,%xmm2
  divsd  (%r9),%xmm2
  cmp    %r12,%r8
  je     L136
  movapd %xmm2,%xmm3
  xor    %eax,%eax
  unpcklpd %xmm3,%xmm3
  cs nopw 0x0(%rax,%rax,1)
L229:
  movupd (%rdi,%rax,1),%xmm1
  movupd (%rcx,%rax,1),%xmm0
  mulpd  %xmm3,%xmm1
  subpd  %xmm1,%xmm0
  movups %xmm0,(%rcx,%rax,1)
  add    $0x10,%rax
  cmp    %r15,%rax
  jne    L229
  cmp    0x28(%rsp),%ebx
  je     L343
  mulsd  (%rdi,%rdx,8),%xmm2
  movsd  (%rcx,%rdx,8),%xmm1
  subsd  %xmm2,%xmm1
  movsd  %xmm1,(%rcx,%rdx,8)
L343:
  add    $0x1,%r11d
  add    %rbp,%r8
  cmp    %r11d,%r13d
  jg     L284
  mov    0x8(%rsp),%rbx
L210:
  subl   $0x1,0x30(%rsp)
  mov    0x30(%rsp),%eax
  add    $0x1,%rbx
  add    $0x8,%r10
  mov    0x88(%rsp),%rsi
  add    %rbp,0x38(%rsp)
  add    %rsi,0x40(%rsp)
  add    %rbp,0x48(%rsp)
  cmp    $0x2,%eax
  jne    L328
  mov    0x18(%rsp),%r15d
  mov    0x2c(%rsp),%ebx
  cmp    %ebx,0x80(%rsp)
  jle    L185
L88:
  movslq 0x2c(%rsp),%rax
  mov    0x78(%rsp),%rdi
  mov    0x50(%rsp),%rdx
  lea    0x0(,%rdi,8),%r13
  mov    %rax,%rbx
  mov    %rax,0x18(%rsp)
  imul   %r13,%rbx
  lea    0x8(%r13),%rcx
  lea    (%rdx,%rax,8),%r9
  mov    %rcx,0x68(%rsp)
  mov    %r9,%rbp
  mov    %rbx,%rsi
  mov    %rax,%rbx
  imul   %rcx,%rax
  add    %rdx,%rsi
  add    %rdx,%rax
  mov    %rax,0x20(%rsp)
  mov    %rdi,%rax
  imul   %rbx,%rax
  mov    0x28(%rsp),%ebx
  lea    0x8(,%rax,8),%rax
  mov    %rax,0x30(%rsp)
  mov    %ebx,%eax
  and    $0xfffffffe,%ebx
  shr    %eax
  movslq %ebx,%r14
  mov    %ebx,0x10(%rsp)
  mov    %r15d,%ebx
  lea    -0x1(%rax),%r8d
  mov    %r15d,%eax
  mov    %r14,%rcx
  mov    %rsi,%r14
  lea    0x8(,%rax,8),%rax
  add    $0x1,%r8
  mov    %rax,0x70(%rsp)
  shl    $0x4,%r8
  mov    %r8,%r15
  cs nopw 0x0(%rax,%rax,1)
L254:
  mov    0x2c(%rsp),%edx
  mov    %edx,%r12d
  add    $0x1,%edx
  mov    %edx,0x2c(%rsp)
  cmp    %edx,%ebx
  jle    L245
  mov    0x50(%rsp),%rsi
  movslq %edx,%rax
  mov    %r14,0x48(%rsp)
  mov    %rax,0x38(%rsp)
  imul   0x78(%rsp),%rax
  add    0x18(%rsp),%rax
  mov    %rcx,0x60(%rsp)
  lea    (%rsi,%rax,8),%rdi
  movslq %r12d,%rax
  mov    %r15,0x40(%rsp)
  mov    %edx,%r15d
  lea    (%rsi,%rax,8),%rax
  mov    %rbp,0x58(%rsp)
  mov    %rdi,%rbp
  mov    %rax,0x8(%rsp)
  nopl   0x0(%rax,%rax,1)
L340:
  movsd  0x0(%rbp),%xmm0
  call   <fabs@plt>
  mov    0x8(%rsp),%rsi
  mov    %rax,%r14
  movslq %r12d,%rax
  imul   %r13,%rax
  movsd  (%rsi,%rax,1),%xmm0
  call   <fabs@plt>
  cmp    %r14,%rax
  cmovl  %r15d,%r12d
  add    $0x1,%r15d
  add    %r13,%rbp
  cmp    %ebx,%r15d
  jne    L340
  mov    0x38(%rsp),%rdi
  mov    0x40(%rsp),%r15
  mov    0x48(%rsp),%r14
  mov    0x58(%rsp),%rbp
  imul   %r13,%rdi
  mov    0x60(%rsp),%rcx
  mov    0x2c(%rsp),%r11d
  mov    0x70(%rsp),%rsi
  mov    0x20(%rsp),%r8
  mov    0x30(%rsp),%r10
  mov    0x50(%rsp),%r9
  mov    0x28(%rsp),%r12d
  nopl   0x0(%rax)
L255:
  movsd  0x0(%rbp,%rdi,1),%xmm0
  lea    (%r9,%rdi,1),%rdx
  movapd %xmm0,%xmm2
  divsd  (%r8),%xmm2
  test   %ebx,%ebx
  je     L12
  cmp    %r10,%rdi
  je     L12
  movapd %xmm2,%xmm3
  xor    %eax,%eax
  unpcklpd %xmm3,%xmm3
  cs nopw 0x0(%rax,%rax,1)
L342:
  movupd (%r14,%rax,1),%xmm1
  movupd (%rdx,%rax,1),%xmm0
  mulpd  %xmm3,%xmm1
  subpd  %xmm1,%xmm0
  movups %xmm0,(%rdx,%rax,1)
  add    $0x10,%rax
  cmp    %rax,%r15
  jne    L342
  cmp    %r12d,0x10(%rsp)
  je     L42
  mulsd  (%r14,%rcx,8),%xmm2
  movsd  (%rdx,%rcx,8),%xmm1
  subsd  %xmm2,%xmm1
  movsd  %xmm1,(%rdx,%rcx,8)
L42:
  add    $0x1,%r11d
  add    %r13,%rdi
  cmp    %r11d,%ebx
  jg     L255
L245:
  mov    0x68(%rsp),%rsi
  addq   $0x1,0x18(%rsp)
  add    %r13,%r14
  add    $0x8,%rbp
  add    %rsi,0x20(%rsp)
  mov    0x2c(%rsp),%esi
  add    %r13,0x30(%rsp)
  cmp    %esi,0x80(%rsp)
  jg     L254
  mov    %ebx,%r15d
L185:
  movslq 0x80(%rsp),%rcx
  mov    0x78(%rsp),%rax
  mov    0x50(%rsp),%rbx
  imul   %rcx,%rax
  lea    (%rbx,%rax,8),%rdx
  mov    0xa0(%rsp),%rbx
  movsd  (%rdx,%rbx,8),%xmm0
  lea    0x0(,%rbx,8),%rax
  divsd  (%rdx,%rcx,8),%xmm0
  mov    0xa8(%rsp),%rbx
  mov    %r15d,%ecx
  movsd  %xmm0,-0x8(%rbx,%rax,1)
  sub    $0x2,%ecx
  js     L249
  movslq %ecx,%rcx
  lea    0x10(%rax),%r8
  add    $0x8,%rax
  mov    0x78(%rsp),%r9
  imul   %rcx,%r8
  mov    %rbx,%rdi
  mov    0x50(%rsp),%rbx
  mov    0x80(%rsp),%esi
  imul   %rcx,%rax
  not    %r9
  mov    0xa0(%rsp),%r11
  pxor   %xmm2,%xmm2
  shl    $0x3,%r9
  add    %rbx,%r8
  lea    0x8(%r9),%r10
  add    %rax,%rbx
  mov    %rbx,%rdx
  nopl   0x0(%rax)
L209:
  cmp    %esi,%r15d
  jle    L326
  movslq %esi,%rax
  movapd %xmm2,%xmm1
L117:
  cmp    %ecx,%eax
  je     L312
  movsd  (%rdi,%rax,8),%xmm0
  mulsd  (%rdx,%rax,8),%xmm0
  addsd  %xmm0,%xmm1
L312:
  add    $0x1,%rax
  cmp    %eax,%r15d
  jg     L117
L129:
  movsd  (%rdx,%r11,8),%xmm0
  sub    $0x1,%esi
  add    %r10,%rdx
  subsd  %xmm1,%xmm0
  divsd  (%r8),%xmm0
  movsd  %xmm0,(%rdi,%rcx,8)
  sub    $0x1,%rcx
  add    %r9,%r8
  test   %ecx,%ecx
  jns    L209
L249:
  add    $0xb8,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopw   0x0(%rax,%rax,1)
L136:
  xor    %eax,%eax
  nopw   0x0(%rax,%rax,1)
L193:
  movsd  (%rdi,%rax,1),%xmm1
  movsd  (%rcx,%rax,1),%xmm0
  mulsd  %xmm2,%xmm1
  subsd  %xmm1,%xmm0
  movsd  %xmm0,(%rcx,%rax,1)
  add    $0x8,%rax
  cmp    %rsi,%rax
  jne    L193
  jmp    L343
  nopl   (%rax)
L12:
  xor    %eax,%eax
  nopw   0x0(%rax,%rax,1)
L264:
  movsd  (%r14,%rax,1),%xmm1
  movsd  (%rdx,%rax,1),%xmm0
  mulsd  %xmm2,%xmm1
  subsd  %xmm1,%xmm0
  movsd  %xmm0,(%rdx,%rax,1)
  add    $0x8,%rax
  cmp    %rax,%rsi
  jne    L264
  jmp    L42
L357:
  mov    0x40(%rsp),%r9
  lea    0x0(,%rbx,8),%r11
  mov    0x70(%rsp),%rax
  lea    (%rcx,%r11,1),%r8
  lea    0x10(%rcx,%r11,1),%r11
  add    0x48(%rsp),%rax
  cmp    %r11,%r9
  lea    0x10(%r9),%r11
  setae  %sil
  cmp    %r11,%r8
  setae  %r11b
  or     %sil,%r11b
  je     L218
  mov    0x18(%rsp),%r11d
  sub    0x90(%rsp),%r11d
  cmp    $0x1,%r11d
  jbe    L218
  mov    0x30(%rsp),%r11d
  xor    %edi,%edi
  mov    %r9,%rsi
  shr    %r11d
  shl    $0x4,%r11
  nopl   0x0(%rax)
L344:
  movupd (%rsi,%rdi,1),%xmm0
  movupd (%r8,%rdi,1),%xmm4
  movups %xmm4,(%rsi,%rdi,1)
  movups %xmm0,(%r8,%rdi,1)
  add    $0x10,%rdi
  cmp    %r11,%rdi
  jne    L344
  mov    0x30(%rsp),%esi
  mov    0x84(%rsp),%edi
  mov    %esi,%r8d
  and    $0xfffffffe,%r8d
  add    %r8d,%edi
  cmp    %esi,%r8d
  je     L22
  movslq %edi,%rdi
  movsd  (%rax,%rdi,8),%xmm0
  movsd  (%rcx,%rdi,8),%xmm1
  movsd  %xmm1,(%rax,%rdi,8)
  movsd  %xmm0,(%rcx,%rdi,8)
L22:
  mov    0x2c(%rsp),%esi
  cmp    %esi,0x18(%rsp)
  jg     L260
  jmp    L210
  nopl   0x0(%rax)
L230:
  movslq %edi,%rax
  movl   $0x0,0x2c(%rsp)
  mov    %rax,0xa0(%rsp)
  jmp    L88
L326:
  movapd %xmm2,%xmm1
  jmp    L129
L218:
  mov    %rbx,%r8
L77:
  movsd  (%rax,%r8,8),%xmm0
  movsd  (%rcx,%r8,8),%xmm1
  movsd  %xmm1,(%rax,%r8,8)
  movsd  %xmm0,(%rcx,%r8,8)
  add    $0x1,%r8
  cmp    %r8d,%edi
  jge    L77
  jmp    L22
L300:
  movslq %edi,%rax
  mov    %rax,0xa0(%rsp)
  jmp    L185
```

assistant: ```c
void Gauss_elimination(int n, double (*a)[n + 1], double *x) {
  int i, j, k;
  double temp, s, l;
  for (i = 0; i < n - 1; i++) {
    k = i;
    for (j = i + 1; j < n; j++) {
      if (fabs(a[j][i]) > fabs(a[k][i]))
        k = j;
    }
    if (k != i)
      for (j = i; j <= n; j++) {
        temp = a[i][j];
        a[i][j] = a[k][j];
        a[k][j] = temp;
      }
    for (j = i + 1; j < n; j++) {
      l = a[j][i] / a[i][i];
      for (k = 0; k < n + 1; k++)
        a[j][k] = a[j][k] - a[i][k] * l;
    }
  }
  x[n - 1] = a[n - 1][n] / a[n - 1][n - 1];
  for (i = n - 2; i >= 0; i--) {
    s = 0.0;
    for (j = i; j < n; j++) {
      if (j == i)
        continue;
      s += a[i][j] * x[j];
    }
    x[i] = (a[i][n] - s) / a[i][i];
  }
}
```