user: Demonstrate the C code that generates the assembly output below:

```asm
<test_collapse>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x20,%rsp
  movl   $0x0,-0x1c(%rbp)
  jmp    L412
L38:
  addl   $0x1,-0x1c(%rbp)
L412:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L38
  movl   $0x0,-0x1c(%rbp)
  jmp    L383
L444:
  addl   $0x1,-0x1c(%rbp)
L383:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L444
  movl   $0x0,-0x1c(%rbp)
  jmp    L42
L411:
  addl   $0x1,-0x1c(%rbp)
L42:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L411
  movl   $0x0,-0x1c(%rbp)
  jmp    L445
L430:
  addl   $0x1,-0x1c(%rbp)
L445:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L430
  movl   $0x0,-0x1c(%rbp)
  jmp    L499
L230:
  addl   $0x1,-0x1c(%rbp)
L499:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L230
  movl   $0x0,-0x1c(%rbp)
  jmp    L332
L93:
  addl   $0x1,-0x1c(%rbp)
L332:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L93
  movl   $0x0,-0x1c(%rbp)
  jmp    L188
L264:
  addl   $0x1,-0x1c(%rbp)
L188:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L264
  movl   $0x0,-0x1c(%rbp)
  jmp    L134
L315:
  addl   $0x1,-0x1c(%rbp)
L134:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L315
  movl   $0x0,-0x1c(%rbp)
  jmp    L348
L347:
  addl   $0x1,-0x1c(%rbp)
L348:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L347
  movl   $0x0,-0x1c(%rbp)
  jmp    L146
L390:
  addl   $0x1,-0x1c(%rbp)
L146:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L390
  movl   $0x0,-0x1c(%rbp)
  jmp    L346
L429:
  addl   $0x1,-0x1c(%rbp)
L346:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L429
  movl   $0x0,-0x1c(%rbp)
  jmp    L256
L273:
  addl   $0x1,-0x1c(%rbp)
L256:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L273
  movl   $0x0,-0x18(%rbp)
  jmp    L343
L322:
  movl   $0x0,-0x14(%rbp)
  jmp    L306
L378:
  movl   $0x0,-0x10(%rbp)
  jmp    L40
L272:
  movl   $0x0,-0xc(%rbp)
  jmp    L147
L407:
  mov    $0x0,%eax
  call   <foo@plt>
  addl   $0x1,-0xc(%rbp)
L147:
  cmpl   $0xf,-0xc(%rbp)
  jle    L407
  addl   $0x1,-0x10(%rbp)
L40:
  cmpl   $0xf,-0x10(%rbp)
  jle    L272
  addl   $0x1,-0x14(%rbp)
L306:
  cmpl   $0xf,-0x14(%rbp)
  jle    L378
  addl   $0x1,-0x18(%rbp)
L343:
  cmpl   $0xf,-0x18(%rbp)
  jle    L322
  movl   $0x0,-0x1c(%rbp)
  jmp    L21
L358:
  addl   $0x1,-0x1c(%rbp)
L21:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L358
  movl   $0x0,-0x1c(%rbp)
  jmp    L172
L218:
  addl   $0x1,-0x1c(%rbp)
L172:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L218
  movl   $0x0,-0x1c(%rbp)
  jmp    L336
L103:
  addl   $0x1,-0x1c(%rbp)
L336:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L103
  movl   $0x0,-0x1c(%rbp)
  jmp    L380
L300:
  addl   $0x1,-0x1c(%rbp)
L380:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L300
  movl   $0x0,-0x1c(%rbp)
  jmp    L58
L7:
  addl   $0x1,-0x1c(%rbp)
L58:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L7
  movl   $0x0,-0x1c(%rbp)
  jmp    L359
L431:
  addl   $0x1,-0x1c(%rbp)
L359:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L431
  movl   $0x0,-0x1c(%rbp)
  jmp    L205
L460:
  movl   $0x0,-0x8(%rbp)
  jmp    L191
L265:
  movl   $0x0,-0x4(%rbp)
  jmp    L53
L267:
  mov    -0x8(%rbp),%eax
  add    %eax,-0x1c(%rbp)
  addl   $0x1,-0x4(%rbp)
L53:
  cmpl   $0xf,-0x4(%rbp)
  jle    L267
  addl   $0x1,-0x8(%rbp)
L191:
  cmpl   $0xf,-0x8(%rbp)
  jle    L265
  addl   $0x1,-0x1c(%rbp)
L205:
  cmpl   $0xf,-0x1c(%rbp)
  jle    L460
  nop
  nop
  leave
  ret
```

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