user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<pca>:
  endbr64
  push   %r15
  mov    %r8,%r15
  push   %r14
  movslq %esi,%r14
  push   %r13
  lea    0x0(,%r14,4),%rax
  mov    %rdx,%r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %rcx,%rbx
  sub    $0x38,%rsp
  mov    %edi,0x14(%rsp)
  mov    %rax,%rdi
  mov    %esi,(%rsp)
  mov    %rax,0x20(%rsp)
  call   <malloc@plt>
  lea    0x0(,%r14,8),%r11
  mov    %r11,%rdi
  mov    %r11,0x8(%rsp)
  mov    %rax,%r12
  call   <malloc@plt>
  mov    %rax,%rbp
  test   %r12,%r12
  je     L550
  test   %rax,%rax
  mov    0x8(%rsp),%r11
  mov    0x14(%rsp),%r10d
  je     L196
  mov    (%rsp),%esi
  mov    %r10d,%edi
  xor    %eax,%eax
  mov    %rbx,%r8
  mov    %r15,%rcx
  mov    %r13,%rdx
  mov    %r11,0x18(%rsp)
  mov    %r10d,0x8(%rsp)
  call   <svd@plt>
  mov    0x8(%rsp),%r10d
  mov    0x18(%rsp),%r11
  test   %eax,%eax
  mov    %eax,0x14(%rsp)
  jne    L186
  cmp    %r10d,(%rsp)
  jle    L440
  test   %r10d,%r10d
  jle    L292
  mov    %r10d,%r8d
  lea    -0x1(%r10),%eax
  xor    %esi,%esi
  shl    $0x3,%r8
  lea    0x8(%rbx,%rax,8),%rdi
  nopl   0x0(%rax,%rax,1)
L48:
  movsd  (%r15,%rsi,1),%xmm1
  mov    %rbx,%rax
  nopl   0x0(%rax)
L296:
  mov    (%rax),%rdx
  add    $0x8,%rax
  add    %rsi,%rdx
  movsd  (%rdx),%xmm0
  mulsd  %xmm1,%xmm0
  movsd  %xmm0,(%rdx)
  cmp    %rdi,%rax
  jne    L296
  add    $0x8,%rsi
  cmp    %r8,%rsi
  jne    L48
L292:
  mov    %r10d,%edi
  mov    %r12,%rdx
  mov    %r15,%rsi
  xor    %eax,%eax
  mov    %r10d,0x8(%rsp)
  call   <sort@plt>
  mov    0x8(%rsp),%r10d
  mov    %r10d,%r8d
  shr    $0x1f,%r8d
  add    %r10d,%r8d
  sar    %r8d
  cmp    $0x1,%r10d
  jle    L233
  movslq %r10d,%rdi
  mov    %r8d,%edx
  lea    -0x1(%r10),%eax
  shl    $0x2,%rdi
  shl    $0x2,%rdx
  mov    %rdi,%rsi
  sub    %rdx,%rsi
  cmp    %rdx,%rsi
  jl     L344
  cmp    $0x3,%r10d
  jle    L344
  cmp    $0x7,%r10d
  jle    L242
  mov    %r8d,%r11d
  lea    -0x10(%r12,%rdi,1),%rdx
  mov    %r12,%rsi
  shr    $0x2,%r11d
  sub    $0x1,%r11d
  mov    %r11,%rcx
  mov    %rdx,%r11
  shl    $0x4,%rcx
  sub    %rcx,%r11
  sub    $0x10,%r11
  xchg   %ax,%ax
L6:
  movdqu (%rsi),%xmm0
  movdqu (%rdx),%xmm3
  sub    $0x10,%rdx
  add    $0x10,%rsi
  pshufd $0x1b,%xmm3,%xmm1
  pshufd $0x1b,%xmm0,%xmm0
  movups %xmm1,-0x10(%rsi)
  movups %xmm0,0x10(%rdx)
  cmp    %r11,%rdx
  jne    L6
  mov    %r8d,%esi
  and    $0xfffffffc,%esi
  mov    %esi,%edx
  cmp    %r8d,%esi
  je     L233
L549:
  mov    %r8d,%ecx
  sub    %esi,%ecx
  cmp    $0x1,%ecx
  je     L425
  shl    $0x2,%rsi
  mov    %r12,%r11
  sub    %rsi,%r11
  lea    (%r12,%rsi,1),%r8
  lea    -0x8(%r11,%rdi,1),%rsi
  movq   (%r8),%xmm0
  movq   (%rsi),%xmm1
  pshufd $0xe1,%xmm0,%xmm0
  pshufd $0xe1,%xmm1,%xmm1
  movq   %xmm1,(%r8)
  movq   %xmm0,(%rsi)
  mov    %ecx,%esi
  and    $0xfffffffe,%esi
  add    %esi,%edx
  cmp    %ecx,%esi
  je     L233
L425:
  sub    %edx,%eax
  movslq %edx,%rsi
  cltq
  lea    (%r12,%rsi,4),%rsi
  lea    (%r12,%rax,4),%rax
  mov    (%rsi),%edi
  mov    (%rax),%edx
  mov    %edx,(%rsi)
  mov    %edi,(%rax)
L233:
  mov    (%rsp),%eax
  test   %eax,%eax
  jle    L166
  lea    0x0(,%r14,8),%r9
  xor    %edx,%edx
  movslq %r10d,%rsi
  nopl   0x0(%rax,%rax,1)
L188:
  xor    %eax,%eax
  test   %r10d,%r10d
  jle    L436
  nop
L310:
  movslq (%r12,%rax,4),%rcx
  mov    0x0(%r13,%rcx,8),%rcx
  movsd  (%rcx,%rdx,1),%xmm0
  movsd  %xmm0,0x0(%rbp,%rax,8)
  add    $0x1,%rax
  cmp    %rax,%rsi
  jne    L310
  xor    %eax,%eax
  nop
L300:
  mov    0x0(%r13,%rax,8),%rcx
  movsd  0x0(%rbp,%rax,8),%xmm0
  add    $0x1,%rax
  movsd  %xmm0,(%rcx,%rdx,1)
  cmp    %rax,%rsi
  jne    L300
L436:
  add    $0x8,%rdx
  cmp    %rdx,%r9
  jne    L188
L166:
  test   %r10d,%r10d
  jle    L186
  lea    -0x1(%r10),%eax
  mov    %r10d,%r14d
  mov    %r15,(%rsp)
  mov    %rbx,%r15
  lea    0x8(%rbx,%rax,8),%rax
  lea    0x0(,%r14,8),%r13
  mov    %rax,%rbx
  nopl   0x0(%rax)
L127:
  mov    (%r15),%rdi
  xor    %eax,%eax
  nopl   (%rax)
L307:
  movslq (%r12,%rax,4),%rdx
  movsd  (%rdi,%rdx,8),%xmm0
  movsd  %xmm0,0x0(%rbp,%rax,8)
  add    $0x1,%rax
  cmp    %r14,%rax
  jne    L307
  mov    %r13,%rdx
  mov    %rbp,%rsi
  add    $0x8,%r15
  call   <memcpy@plt>
  cmp    %rbx,%r15
  jne    L127
  mov    (%rsp),%r15
  xor    %eax,%eax
  nopw   0x0(%rax,%rax,1)
L82:
  movslq (%r12,%rax,4),%rdx
  movsd  (%r15,%rdx,8),%xmm0
  movsd  %xmm0,0x0(%rbp,%rax,8)
  add    $0x1,%rax
  cmp    %r14,%rax
  jne    L82
  mov    %r13,%rdx
  mov    %rbp,%rsi
  mov    %r15,%rdi
  call   <memcpy@plt>
L186:
  mov    %r12,%rdi
  call   <free@plt>
  mov    %rbp,%rdi
  call   <free@plt>
L528:
  mov    0x14(%rsp),%eax
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopw   0x0(%rax,%rax,1)
L440:
  mov    (%rsp),%ecx
  test   %ecx,%ecx
  jle    L230
  test   %r10d,%r10d
  jle    L230
  lea    -0x1(%r10),%eax
  xor    %esi,%esi
  lea    0x8(%r13,%rax,8),%rdi
  nopw   0x0(%rax,%rax,1)
L217:
  movsd  (%r15,%rsi,1),%xmm1
  mov    %r13,%rax
  nopl   0x0(%rax)
L444:
  mov    (%rax),%rdx
  add    $0x8,%rax
  add    %rsi,%rdx
  movsd  (%rdx),%xmm0
  mulsd  %xmm1,%xmm0
  movsd  %xmm0,(%rdx)
  cmp    %rdi,%rax
  jne    L444
  add    $0x8,%rsi
  cmp    %rsi,%r11
  jne    L217
L230:
  mov    (%rsp),%edi
  xor    %eax,%eax
  mov    %r12,%rdx
  mov    %r15,%rsi
  mov    %r10d,0x8(%rsp)
  call   <sort@plt>
  mov    (%rsp),%eax
  mov    0x8(%rsp),%r10d
  mov    %eax,%edi
  shr    $0x1f,%edi
  add    %eax,%edi
  sar    %edi
  cmp    $0x1,%eax
  jle    L26
  mov    0x20(%rsp),%rcx
  mov    %eax,%r9d
  lea    -0x1(%rax),%edx
  mov    %edi,%eax
  shl    $0x2,%rax
  mov    %rcx,%rsi
  sub    %rax,%rsi
  cmp    %rsi,%rax
  setle  %al
  test   %rcx,%rcx
  setle  %sil
  or     %sil,%al
  je     L537
  cmp    $0x3,%r9d
  jle    L537
  cmp    $0x7,%r9d
  jle    L515
  mov    %edi,%r8d
  lea    -0x10(%r12,%rcx,1),%rax
  mov    %r12,%rsi
  shr    $0x2,%r8d
  sub    $0x1,%r8d
  mov    %r8,%r11
  mov    %rax,%r8
  shl    $0x4,%r11
  sub    %r11,%r8
  sub    $0x10,%r8
  nopl   0x0(%rax,%rax,1)
L551:
  movdqu (%rsi),%xmm0
  movdqu (%rax),%xmm2
  sub    $0x10,%rax
  add    $0x10,%rsi
  pshufd $0x1b,%xmm2,%xmm1
  pshufd $0x1b,%xmm0,%xmm0
  movups %xmm1,-0x10(%rsi)
  movups %xmm0,0x10(%rax)
  cmp    %rax,%r8
  jne    L551
  mov    %edi,%eax
  and    $0xfffffffc,%eax
  mov    %eax,%esi
  cmp    %edi,%eax
  je     L26
L389:
  sub    %eax,%edi
  cmp    $0x1,%edi
  je     L372
  lea    0x0(,%rax,4),%r11
  mov    0x20(%rsp),%rax
  lea    (%r12,%r11,1),%r8
  sub    $0x8,%rax
  movq   (%r8),%xmm0
  sub    %r11,%rax
  add    %r12,%rax
  pshufd $0xe1,%xmm0,%xmm0
  movq   (%rax),%xmm1
  pshufd $0xe1,%xmm1,%xmm1
  movq   %xmm1,(%r8)
  movq   %xmm0,(%rax)
  mov    %edi,%eax
  and    $0xfffffffe,%eax
  add    %eax,%esi
  cmp    %edi,%eax
  je     L26
L372:
  sub    %esi,%edx
  movslq %esi,%rax
  movslq %edx,%rdx
  lea    (%r12,%rax,4),%rax
  lea    (%r12,%rdx,4),%rdx
  mov    (%rax),%edi
  mov    (%rdx),%esi
  mov    %esi,(%rax)
  mov    %edi,(%rdx)
L26:
  test   %r10d,%r10d
  jle    L379
  lea    -0x1(%r10),%eax
  mov    %r13,%r8
  mov    %rbx,0x18(%rsp)
  lea    0x8(%r13,%rax,8),%rax
  mov    %r15,0x20(%rsp)
  mov    %rbp,%r15
  mov    %rax,0x8(%rsp)
  mov    (%rsp),%eax
  mov    %r14,0x28(%rsp)
  mov    %r12,%r14
  mov    %r8,%r12
  lea    -0x1(%rax),%r13d
  mov    %eax,%ebx
  lea    0x8(,%r13,8),%rdi
  mov    %rdi,%rbp
  nopl   0x0(%rax)
L469:
  test   %ebx,%ebx
  jle    L446
  mov    (%r12),%rdi
  xor    %eax,%eax
  nopw   0x0(%rax,%rax,1)
L521:
  movslq (%r14,%rax,4),%rdx
  movsd  (%rdi,%rdx,8),%xmm0
  mov    %rax,%rdx
  movsd  %xmm0,(%r15,%rax,8)
  add    $0x1,%rax
  cmp    %r13,%rdx
  jne    L521
  mov    %rbp,%rdx
  mov    %r15,%rsi
  call   <memcpy@plt>
L446:
  add    $0x8,%r12
  cmp    0x8(%rsp),%r12
  jne    L469
  mov    %r14,%r12
  mov    %r15,%rbp
  mov    0x18(%rsp),%rbx
  mov    0x20(%rsp),%r15
  mov    0x28(%rsp),%r14
L379:
  mov    (%rsp),%edx
  test   %edx,%edx
  jle    L186
  lea    0x0(,%r14,8),%r8
  xor    %edx,%edx
  nopl   0x0(%rax,%rax,1)
L293:
  xor    %eax,%eax
  nopw   0x0(%rax,%rax,1)
L140:
  movslq (%r12,%rax,4),%rcx
  mov    (%rbx,%rcx,8),%rcx
  movsd  (%rcx,%rdx,1),%xmm0
  movsd  %xmm0,0x0(%rbp,%rax,8)
  add    $0x1,%rax
  cmp    %rax,%r14
  jne    L140
  xor    %eax,%eax
  cs nopw 0x0(%rax,%rax,1)
L49:
  mov    (%rbx,%rax,8),%rcx
  movsd  0x0(%rbp,%rax,8),%xmm0
  add    $0x1,%rax
  movsd  %xmm0,(%rcx,%rdx,1)
  cmp    %rax,%r14
  jne    L49
  add    $0x8,%rdx
  cmp    %rdx,%r8
  jne    L293
  xor    %eax,%eax
  nopl   0x0(%rax,%rax,1)
L419:
  movslq (%r12,%rax,4),%rdx
  movsd  (%r15,%rdx,8),%xmm0
  movsd  %xmm0,0x0(%rbp,%rax,8)
  add    $0x1,%rax
  cmp    %rax,%r14
  jne    L419
  mov    %r8,%rdx
  mov    %rbp,%rsi
  mov    %r15,%rdi
  call   <memcpy@plt>
  jmp    L186
L344:
  cltq
  lea    (%r12,%rax,4),%rdx
  xor    %eax,%eax
  nopl   0x0(%rax)
L50:
  mov    (%rdx),%esi
  mov    (%r12,%rax,4),%ecx
  sub    $0x4,%rdx
  mov    %esi,(%r12,%rax,4)
  add    $0x1,%rax
  mov    %ecx,0x4(%rdx)
  cmp    %eax,%r8d
  jg     L50
  jmp    L233
L537:
  movslq %edx,%rdx
  xor    %eax,%eax
  lea    (%r12,%rdx,4),%rdx
  nopl   0x0(%rax,%rax,1)
L458:
  mov    (%rdx),%esi
  mov    (%r12,%rax,4),%ecx
  sub    $0x4,%rdx
  mov    %esi,(%r12,%rax,4)
  add    $0x1,%rax
  mov    %ecx,0x4(%rdx)
  cmp    %eax,%edi
  jg     L458
  jmp    L26
L515:
  xor    %esi,%esi
  xor    %eax,%eax
  jmp    L389
L242:
  xor    %edx,%edx
  xor    %esi,%esi
  jmp    L549
L196:
  test   %r12,%r12
  je     L550
  mov    %r12,%rdi
  call   <free@plt>
L550:
  test   %rbp,%rbp
  je     L388
  mov    %rbp,%rdi
  call   <free@plt>
  movl   $0xffffffff,0x14(%rsp)
  jmp    L528
L388:
  movl   $0xffffffff,0x14(%rsp)
  jmp    L528
```

assistant: ```c
int pca(int nrows, int ncolumns, double **u, double **v, double *w) {
  int i;
  int j;
  int error;
  int *index = malloc(ncolumns * sizeof(int));
  double *temp = malloc(ncolumns * sizeof(double));
  if (!index || !temp) {
    if (index)
      free(index);
    if (temp)
      free(temp);
    return -1;
  }
  error = svd(nrows, ncolumns, u, w, v);
  if (error == 0) {
    if (nrows >= ncolumns) {
      for (j = 0; j < ncolumns; j++) {
        const double s = w[j];
        for (i = 0; i < nrows; i++)
          u[i][j] *= s;
      }
      sort(ncolumns, w, index);
      for (i = 0; i < ncolumns / 2; i++) {
        j = index[i];
        index[i] = index[ncolumns - 1 - i];
        index[ncolumns - 1 - i] = j;
      }
      for (i = 0; i < nrows; i++) {
        for (j = 0; j < ncolumns; j++)
          temp[j] = u[i][index[j]];
        for (j = 0; j < ncolumns; j++)
          u[i][j] = temp[j];
      }
      for (i = 0; i < ncolumns; i++) {
        for (j = 0; j < ncolumns; j++)
          temp[j] = v[index[j]][i];
        for (j = 0; j < ncolumns; j++)
          v[j][i] = temp[j];
      }
      for (i = 0; i < ncolumns; i++)
        temp[i] = w[index[i]];
      for (i = 0; i < ncolumns; i++)
        w[i] = temp[i];
    } else {
      for (j = 0; j < nrows; j++) {
        const double s = w[j];
        for (i = 0; i < nrows; i++)
          v[i][j] *= s;
      }
      sort(nrows, w, index);
      for (i = 0; i < nrows / 2; i++) {
        j = index[i];
        index[i] = index[nrows - 1 - i];
        index[nrows - 1 - i] = j;
      }
      for (j = 0; j < ncolumns; j++) {
        for (i = 0; i < nrows; i++)
          temp[i] = u[index[i]][j];
        for (i = 0; i < nrows; i++)
          u[i][j] = temp[i];
      }
      for (j = 0; j < nrows; j++) {
        for (i = 0; i < nrows; i++)
          temp[i] = v[j][index[i]];
        for (i = 0; i < nrows; i++)
          v[j][i] = temp[i];
      }
      for (i = 0; i < nrows; i++)
        temp[i] = w[index[i]];
      for (i = 0; i < nrows; i++)
        w[i] = temp[i];
    }
  }
  free(index);
  free(temp);
  return error;
}
```