user: 下面的汇编指令对应的C源代码是什么：

```asm
<CINTdmat_transpose>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rdi,%r12
  mov    %rsi,-0x8(%rsp)
  mov    %edx,%ebp
  mov    %ecx,-0x18(%rsp)
  cmp    $0x3,%ecx
  jle    L158
  mov    %ecx,%edi
  movslq %edx,%r13
  lea    0x0(,%r13,8),%r15
  lea    0x0(,%rdx,4),%ebx
  movslq %ebx,%rbx
  shl    $0x3,%rbx
  mov    %rsi,%rcx
  mov    %rsi,%r11
  lea    0x0(%r13,%r13,2),%rax
  lea    (%r12,%rax,8),%rsi
  lea    -0x4(%rdi),%eax
  shr    $0x2,%eax
  mov    %eax,-0x14(%rsp)
  mov    %eax,%eax
  mov    %rax,-0x10(%rsp)
  shl    $0x5,%rax
  lea    0x20(%rcx,%rax,1),%r14
  shl    $0x4,%r13
  movslq %edi,%r9
  shl    $0x3,%r9
  mov    %r12,%rcx
  mov    %edx,%r10d
L23:
  lea    (%r15,%rcx,1),%rdi
  lea    (%rcx,%r13,1),%r8
  test   %ebp,%ebp
  jle    L0
  mov    %r11,%rdx
  mov    $0x0,%eax
L155:
  movsd  (%rdx),%xmm0
  movsd  %xmm0,(%rcx,%rax,8)
  movsd  0x8(%rdx),%xmm0
  movsd  %xmm0,(%rdi,%rax,8)
  movsd  0x10(%rdx),%xmm0
  movsd  %xmm0,(%r8,%rax,8)
  movsd  0x18(%rdx),%xmm0
  movsd  %xmm0,(%rsi,%rax,8)
  add    $0x1,%rax
  add    %r9,%rdx
  cmp    %r10,%rax
  jne    L155
L0:
  add    %rbx,%rcx
  add    $0x20,%r11
  add    %rbx,%rsi
  cmp    %r14,%r11
  jne    L23
  mov    -0x10(%rsp),%rax
  add    $0x1,%rax
  imul   %rbx,%rax
  add    %rax,%r12
  mov    -0x14(%rsp),%eax
  lea    0x4(,%rax,4),%eax
L9:
  mov    -0x18(%rsp),%edx
  sub    %eax,%edx
  cmp    $0x2,%edx
  je     L106
  cmp    $0x3,%edx
  je     L37
  cmp    $0x1,%edx
  je     L130
L42:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L158:
  mov    $0x0,%eax
  jmp    L9
L130:
  test   %ebp,%ebp
  jle    L42
  movslq -0x18(%rsp),%rcx
  shl    $0x3,%rcx
  cltq
  mov    -0x8(%rsp),%rbx
  lea    (%rbx,%rax,8),%rdx
  mov    %r12,%rax
  mov    %ebp,%ebp
  lea    (%r12,%rbp,8),%rsi
L8:
  movsd  (%rdx),%xmm0
  movsd  %xmm0,(%rax)
  add    %rcx,%rdx
  add    $0x8,%rax
  cmp    %rsi,%rax
  jne    L8
  jmp    L42
L106:
  movslq %ebp,%rdi
  test   %ebp,%ebp
  jle    L42
  movslq -0x18(%rsp),%rcx
  shl    $0x3,%rcx
  cltq
  mov    -0x8(%rsp),%rbx
  lea    (%rbx,%rax,8),%rdx
  mov    %r12,%rax
  mov    %ebp,%ebp
  lea    (%r12,%rbp,8),%rsi
L55:
  movsd  (%rdx),%xmm0
  movsd  %xmm0,(%rax)
  movsd  0x8(%rdx),%xmm0
  movsd  %xmm0,(%rax,%rdi,8)
  add    %rcx,%rdx
  add    $0x8,%rax
  cmp    %rsi,%rax
  jne    L55
  jmp    L42
L37:
  movslq %ebp,%rsi
  shl    $0x3,%rsi
  lea    (%r12,%rsi,1),%rdi
  test   %ebp,%ebp
  jle    L42
  movslq -0x18(%rsp),%rcx
  shl    $0x3,%rcx
  cltq
  mov    -0x8(%rsp),%rbx
  lea    (%rbx,%rax,8),%rdx
  mov    %ebp,%ebp
  add    %rdi,%rsi
  mov    $0x0,%eax
L18:
  movsd  (%rdx),%xmm0
  movsd  %xmm0,(%r12,%rax,8)
  movsd  0x8(%rdx),%xmm0
  movsd  %xmm0,(%rdi,%rax,8)
  movsd  0x10(%rdx),%xmm0
  movsd  %xmm0,(%rsi,%rax,8)
  add    $0x1,%rax
  add    %rcx,%rdx
  cmp    %rbp,%rax
  jne    L18
  jmp    L42
```

assistant: ```c
void CINTdmat_transpose(double *a_t, const double *a, const int m, const int n) {
  int i, j, k;
  double *pa1, *pa2, *pa3;
  for (j = 0; j < n - 3; j += 4) {
    pa1 = a_t + m;
    pa2 = pa1 + m;
    pa3 = pa2 + m;
    for (i = 0, k = j; i < m; i++, k += n) {
      a_t[i] = a[k + 0];
      pa1[i] = a[k + 1];
      pa2[i] = a[k + 2];
      pa3[i] = a[k + 3];
    }
    a_t += m * 4;
  }
  switch (n - j) {
  case 1:
    for (i = 0, k = j; i < m; i++, k += n) {
      a_t[i] = a[k];
    }
    break;
  case 2:
    pa1 = a_t + m;
    for (i = 0, k = j; i < m; i++, k += n) {
      a_t[i] = a[k + 0];
      pa1[i] = a[k + 1];
    }
    break;
  case 3:
    pa1 = a_t + m;
    pa2 = pa1 + m;
    for (i = 0, k = j; i < m; i++, k += n) {
      a_t[i] = a[k + 0];
      pa1[i] = a[k + 1];
      pa2[i] = a[k + 2];
    }
    break;
  }
}
```