user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<LU_decomp>:
  endbr64
  test   %edi,%edi
  jle    L115
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  mov    %edi,%r12d
  push   %rbp
  push   %rbx
  cmp    $0x1,%edi
  je     L80
  movslq %esi,%rax
  mov    %rdx,-0x10(%rsp)
  mov    %rdx,%r14
  lea    -0x2(%rdi),%r13d
  lea    0x8(,%rax,8),%rbx
  lea    0x0(,%rax,8),%rbp
  movq   $0x2,-0x30(%rsp)
  lea    (%rdx,%rbp,1),%rax
  mov    %rbx,-0x18(%rsp)
  lea    0x18(%rdx),%r15
  mov    %rax,-0x20(%rsp)
  mov    %rax,-0x38(%rsp)
  mov    $0x8,%eax
  sub    %rdx,%rax
  nopl   0x0(%rax)
L22:
  mov    -0x30(%rsp),%rdi
  mov    -0x38(%rsp),%rsi
  mov    $0x10,%edx
  mov    %r13d,%r9d
  shr    %r9d
  mov    %rsi,%r8
  mov    %edi,%ebx
  mov    %edi,-0x40(%rsp)
  lea    -0x1(%r9),%r9d
  lea    0x0(,%rdi,8),%rcx
  add    $0x1,%r9
  sub    $0x1,%ebx
  sub    %rcx,%rdx
  lea    0x10(%rsi),%rcx
  mov    %r13d,%esi
  shl    $0x4,%r9
  mov    %rdx,-0x48(%rsp)
  shl    $0x3,%rsi
  mov    -0x10(%rsp),%rdx
  mov    %rsi,%r11
  mov    -0x38(%rsp),%rsi
  sub    %rdx,%r11
  sub    %rdx,%r8
  mov    $0x8,%edx
  mov    %r11,-0x50(%rsp)
  mov    %r13d,%r11d
  sub    %rax,%rdx
  and    $0xfffffffe,%r11d
  mov    %rdx,-0x58(%rsp)
  mov    -0x48(%rsp),%rdx
  mov    %r11d,%r10d
  mov    %r11d,-0x3c(%rsp)
  add    %edi,%r10d
  lea    0x8(%rax),%rdi
  add    %rdi,%rdx
  movslq %r10d,%r10
  mov    %rdi,-0x28(%rsp)
  mov    %rdx,-0x48(%rsp)
  shl    $0x3,%r10
  lea    (%r14,%r10,1),%r11
L2:
  movsd  (%rsi),%xmm0
  divsd  -0x18(%r15),%xmm0
  movsd  %xmm0,(%rsi)
  mulsd  -0x10(%r15),%xmm0
  movsd  -0x8(%rcx),%xmm1
  mov    -0x58(%rsp),%rax
  lea    (%rax,%r8,1),%rdx
  subsd  %xmm0,%xmm1
  movsd  %xmm1,-0x8(%rcx)
  cmp    -0x40(%rsp),%r12d
  jle    L93
  mov    -0x48(%rsp),%rax
  lea    (%rax,%rsi,1),%rdi
  lea    0x8(%r8),%rax
  cmp    %rax,%rdi
  mov    -0x50(%rsp),%rax
  setge  %dil
  add    %rcx,%rax
  cmp    %r8,%rax
  setle  %al
  or     %dil,%al
  je     L56
  cmp    $0x1,%r13d
  setne  %dil
  cmp    %r15,%rcx
  setne  %al
  test   %al,%dil
  je     L56
  movsd  (%rsi),%xmm2
  lea    -0x8(%r15),%rdi
  xor    %eax,%eax
  unpcklpd %xmm2,%xmm2
  cs nopw 0x0(%rax,%rax,1)
L38:
  movupd (%rdi,%rax,1),%xmm1
  movupd (%rcx,%rax,1),%xmm0
  mulpd  %xmm2,%xmm1
  subpd  %xmm1,%xmm0
  movups %xmm0,(%rcx,%rax,1)
  add    $0x10,%rax
  cmp    %r9,%rax
  jne    L38
  cmp    %r13d,-0x3c(%rsp)
  je     L93
  movsd  (%rsi),%xmm1
  mulsd  (%r11),%xmm1
  add    %r10,%rdx
  movsd  (%rdx),%xmm0
  subsd  %xmm1,%xmm0
  movsd  %xmm0,(%rdx)
L93:
  add    $0x1,%ebx
  add    %rbp,%rsi
  add    %rbp,%r8
  add    %rbp,%rcx
  cmp    %ebx,%r12d
  jg     L2
  mov    -0x18(%rsp),%rbx
  mov    -0x20(%rsp),%rdi
  sub    $0x1,%r13d
  addq   $0x1,-0x30(%rsp)
  mov    -0x28(%rsp),%rax
  add    %rbx,-0x38(%rsp)
  mov    %rdi,%r14
  add    %rbx,%r15
  cmp    $0xffffffff,%r13d
  je     L80
  lea    (%rdi,%rbp,1),%rbx
  mov    %rbx,-0x20(%rsp)
  jmp    L22
  nopl   0x0(%rax,%rax,1)
L56:
  mov    -0x30(%rsp),%rax
  nopl   (%rax)
L91:
  movsd  (%rsi),%xmm1
  mulsd  (%r14,%rax,8),%xmm1
  movsd  (%rdx,%rax,8),%xmm0
  subsd  %xmm1,%xmm0
  movsd  %xmm0,(%rdx,%rax,8)
  add    $0x1,%rax
  cmp    %eax,%r12d
  jg     L91
  jmp    L93
L80:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L115:
  ret
```

assistant: ```c
void LU_decomp(int const n, int const lda, double *const A) {
  int i, j, k;
  for (k = 0; k < n; k++) {
    double *const Ak = A + k * lda;
    for (i = k + 1; i < n; i++) {
      double *const Ai = A + i * lda;
      Ai[k] /= Ak[k];
      for (j = k + 1; j < n; j++)
        Ai[j] -= Ai[k] * Ak[j];
    }
  }
}
```