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

```asm
<elimination_step>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %edi,%r12d
  mov    %esi,%ebx
  mov    %esi,0x4(%rsp)
  mov    %rdx,%rbp
  call   <new_matrix@plt>
  mov    %rax,%r15
  mov    %ebx,%esi
  mov    %r12d,%edi
  call   <new_matrix@plt>
  mov    %rax,0x18(%rsp)
  test   %r12d,%r12d
  je     L45
  mov    0x18(%rsp),%rcx
  mov    %rcx,%r14
  mov    %r12d,%eax
  lea    (%rcx,%rax,8),%rdi
  mov    %rdi,0x20(%rsp)
  mov    0x4(%rsp),%r8d
  mov    %r8d,%esi
  jmp    L113
L209:
  mov    (%rcx),%rdx
  movb   $0x0,(%rdx,%rax,1)
  add    $0x1,%rax
  cmp    %rsi,%rax
  jne    L209
L170:
  add    $0x8,%rcx
  cmp    %rdi,%rcx
  je     L51
L113:
  mov    $0x0,%eax
  test   %r8d,%r8d
  jne    L209
  jmp    L170
L51:
  mov    %r12d,%eax
  mov    %rax,0x10(%rsp)
  mov    $0x0,%r13d
  mov    0x4(%rsp),%eax
  mov    %eax,%esi
  mov    %r14,0x28(%rsp)
  mov    %rsi,%r14
  mov    %r12d,0xc(%rsp)
  mov    %eax,%r12d
  jmp    L194
L242:
  add    $0x1,%r13
  cmp    0x10(%rsp),%r13
  je     L106
L194:
  mov    %r13d,0x8(%rsp)
  mov    $0x0,%ebx
  test   %r12d,%r12d
  je     L242
L70:
  mov    %ebx,%edx
  mov    0x0(%rbp,%r13,8),%rax
  movzbl (%rax,%rbx,1),%edi
  test   %edi,%edi
  je     L242
  sub    $0x8,%rsp
  push   %r15
  mov    %rbp,%r9
  mov    %r12d,%r8d
  mov    0x1c(%rsp),%ecx
  mov    0x18(%rsp),%esi
  call   <tag_cell@plt>
  add    $0x1,%rbx
  add    $0x10,%rsp
  cmp    %r14,%rbx
  jne    L70
  jmp    L242
L120:
  add    $0x1,%r13
  cmp    0x10(%rsp),%r13
  je     L247
L97:
  mov    %r13d,0x8(%rsp)
  mov    $0x0,%ebx
  cmpl   $0x0,0x4(%rsp)
  je     L120
L9:
  mov    %ebx,%edx
  mov    0x0(%rbp,%r13,8),%rax
  movzbl (%rax,%rbx,1),%edi
  test   %edi,%edi
  je     L120
  push   %r14
  push   %r15
  mov    %rbp,%r9
  mov    0x14(%rsp),%r8d
  mov    0x1c(%rsp),%ecx
  mov    0x18(%rsp),%esi
  call   <mark_delete@plt>
  add    $0x1,%rbx
  add    $0x10,%rsp
  cmp    %rbx,%r12
  jne    L9
  jmp    L120
L247:
  mov    0x28(%rsp),%r14
  mov    0xc(%rsp),%r12d
  mov    0x4(%rsp),%edi
  mov    %edi,%ecx
  mov    0x20(%rsp),%rsi
  jmp    L122
L106:
  mov    $0x0,%r13d
  mov    0x4(%rsp),%eax
  mov    0x18(%rsp),%r14
  mov    %rax,%r12
  jmp    L97
L112:
  add    $0x1,%rax
  cmp    %rcx,%rax
  je     L115
L210:
  mov    (%r14),%rdx
  cmpb   $0x0,(%rdx,%rax,1)
  je     L112
  mov    0x0(%rbp),%rdx
  movb   $0x0,(%rdx,%rax,1)
  jmp    L112
L115:
  add    $0x8,%rbp
  add    $0x8,%r14
  cmp    %rsi,%r14
  je     L45
L122:
  mov    $0x0,%eax
  test   %edi,%edi
  jne    L210
  jmp    L115
L45:
  mov    %r15,%rsi
  mov    %r12d,%edi
  call   <free_matrix@plt>
  mov    0x18(%rsp),%rax
  add    $0x38,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
unsigned char **elimination_step(const unsigned int width, const unsigned int height, unsigned char **const grid) {
  unsigned int i, j;
  unsigned int cell;
  unsigned char **const tag = new_matrix(width, height);
  unsigned char **const record = new_matrix(width, height);
  for (i = 0; i < width; i++) {
    for (j = 0; j < height; j++) {
      record[i][j] = 0;
    }
  }
  for (i = 0; i < width; i++) {
    for (j = 0; j < height; j++) {
      cell = grid[i][j];
      if (cell) {
        tag_cell(cell, i, j, width, height, grid, tag);
      } else {
        break;
      }
    }
  }
  for (i = 0; i < width; i++) {
    for (j = 0; j < height; j++) {
      cell = grid[i][j];
      if (cell) {
        mark_delete(cell, i, j, width, height, grid, tag, record);
      } else {
        break;
      }
    }
  }
  for (i = 0; i < width; i++) {
    for (j = 0; j < height; j++) {
      if (record[i][j]) {
        grid[i][j] = 0;
      }
    }
  }
  free_matrix(width, tag);
  return record;
}
```