user: 请从给定的汇编指令推导出C源代码:

```asm
<test_collapse>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x20,%rsp
  movl   $0x0,-0x1c(%rbp)
  jmp    L495
L458:
  addl   $0x1,-0x1c(%rbp)
L495:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L458
  movl   $0x0,-0x1c(%rbp)
  jmp    L98
L186:
  addl   $0x1,-0x1c(%rbp)
L98:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L186
  movl   $0x0,-0x1c(%rbp)
  jmp    L48
L408:
  addl   $0x1,-0x1c(%rbp)
L48:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L408
  movl   $0x0,-0x1c(%rbp)
  jmp    L214
L250:
  addl   $0x1,-0x1c(%rbp)
L214:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L250
  movl   $0x0,-0x1c(%rbp)
  jmp    L112
L164:
  addl   $0x1,-0x1c(%rbp)
L112:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L164
  movl   $0x0,-0x1c(%rbp)
  jmp    L321
L333:
  addl   $0x1,-0x1c(%rbp)
L321:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L333
  movl   $0x0,-0x1c(%rbp)
  jmp    L52
L448:
  addl   $0x1,-0x1c(%rbp)
L52:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L448
  movl   $0x0,-0x1c(%rbp)
  jmp    L209
L287:
  addl   $0x1,-0x1c(%rbp)
L209:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L287
  movl   $0x0,-0x1c(%rbp)
  jmp    L267
L400:
  addl   $0x1,-0x1c(%rbp)
L267:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L400
  movl   $0x0,-0x1c(%rbp)
  jmp    L129
L65:
  addl   $0x1,-0x1c(%rbp)
L129:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L65
  movl   $0x0,-0x1c(%rbp)
  jmp    L159
L328:
  addl   $0x1,-0x1c(%rbp)
L159:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L328
  movl   $0x0,-0x1c(%rbp)
  jmp    L387
L284:
  addl   $0x1,-0x1c(%rbp)
L387:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L284
  movl   $0x0,-0x18(%rbp)
  jmp    L466
L310:
  movl   $0x0,-0x14(%rbp)
  jmp    L174
L127:
  movl   $0x0,-0x10(%rbp)
  jmp    L492
L364:
  movl   $0x0,-0xc(%rbp)
  jmp    L272
L298:
  mov    $0x0,%eax
  call   <foo@plt>
  addl   $0x1,-0xc(%rbp)
L272:
  cmpl   $0xf,-0xc(%rbp)
  jle    L298
  addl   $0x1,-0x10(%rbp)
L492:
  cmpl   $0xf,-0x10(%rbp)
  jle    L364
  addl   $0x1,-0x14(%rbp)
L174:
  cmpl   $0xf,-0x14(%rbp)
  jle    L127
  addl   $0x1,-0x18(%rbp)
L466:
  cmpl   $0xf,-0x18(%rbp)
  jle    L310
  movl   $0x0,-0x1c(%rbp)
  jmp    L326
L212:
  addl   $0x1,-0x1c(%rbp)
L326:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L212
  movl   $0x0,-0x1c(%rbp)
  jmp    L292
L252:
  addl   $0x1,-0x1c(%rbp)
L292:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L252
  movl   $0x0,-0x1c(%rbp)
  jmp    L278
L375:
  addl   $0x1,-0x1c(%rbp)
L278:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L375
  movl   $0x0,-0x1c(%rbp)
  jmp    L238
L106:
  addl   $0x1,-0x1c(%rbp)
L238:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L106
  movl   $0x0,-0x1c(%rbp)
  jmp    L341
L6:
  addl   $0x1,-0x1c(%rbp)
L341:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L6
  movl   $0x0,-0x1c(%rbp)
  jmp    L2
L280:
  addl   $0x1,-0x1c(%rbp)
L2:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L280
  movl   $0x0,-0x1c(%rbp)
  jmp    L384
L304:
  movl   $0x0,-0x8(%rbp)
  jmp    L188
L120:
  movl   $0x0,-0x4(%rbp)
  jmp    L395
L152:
  mov    -0x8(%rbp),%eax
  add    %eax,-0x1c(%rbp)
  addl   $0x1,-0x4(%rbp)
L395:
  cmpl   $0xf,-0x4(%rbp)
  jle    L152
  addl   $0x1,-0x8(%rbp)
L188:
  cmpl   $0xf,-0x8(%rbp)
  jle    L120
  addl   $0x1,-0x1c(%rbp)
L384:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L304
  nop
  nop
  leave
  ret
```

assistant: ```c
void test_collapse() {
  int i;
#pragma omp parallel
#pragma omp for collapse
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse()
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(,
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(, )
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse 4)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(4
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(4,
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(4, )
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(4)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(4 4)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(4, , 4)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(4)
  for (int i1 = 0; i1 < 16; ++i1)
    for (int i2 = 0; i2 < 16; ++i2)
      for (int i3 = 0; i3 < 16; ++i3)
        for (int i4 = 0; i4 < 16; ++i4)
          foo();
#pragma omp parallel
#pragma omp for collapse(4, 8)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(2.5)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(foo())
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(-5)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(0)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(5 - 5)
  for (i = 0; i < 16; ++i)
    ;
#pragma omp parallel
#pragma omp for collapse(2)
  for (i = 0; i < 16; ++i)
    for (int j = 0; j < 16; ++j)
#pragma omp for reduction(+ : i, j)
      for (int k = 0; k < 16; ++k)
        i += j;
}
```