user: What is the c source code of the assembly code below?

```asm
<sweep>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  mov    %r9,%r13
  push   %r12
  mov    %esi,%r12d
  push   %rbp
  mov    %edi,%ebp
  push   %rbx
  sub    $0x48,%rsp
  mov    0x88(%rsp),%ebx
  mov    %rdx,0x38(%rsp)
  mov    %r8d,0x2c(%rsp)
  mov    0x80(%rsp),%r14
  movsd  %xmm0,0x18(%rsp)
  movsd  %xmm1,0x30(%rsp)
  test   %ebx,%ebx
  je     L31
  mov    %edi,%eax
  cltd
  idiv   %ebx
  mov    %eax,0x24(%rsp)
L7:
  mov    %r12d,%eax
  cltd
  idiv   %ebx
  mov    %eax,0xc(%rsp)
  lea    0x1(%rcx),%eax
  mov    %eax,0x28(%rsp)
  cmp    0x2c(%rsp),%eax
  jg     L99
  mov    %ebx,0x88(%rsp)
  nopw   0x0(%rax,%rax,1)
L38:
  mov    0x24(%rsp),%eax
  test   %eax,%eax
  jle    L68
  mov    0xc(%rsp),%esi
  test   %esi,%esi
  jle    L68
  xor    %r15d,%r15d
  nopl   0x0(%rax,%rax,1)
L80:
  xor    %ebx,%ebx
  mov    %r14,0x80(%rsp)
  mov    %ebx,%r14d
  mov    0x80(%rsp),%rbx
  nopl   (%rax)
L60:
  sub    $0x8,%rsp
  mov    %r13,%r8
  mov    %r14d,%ecx
  mov    %ebp,%edi
  mov    0x90(%rsp),%eax
  mov    %rbx,%r9
  mov    %r15d,%edx
  mov    %r12d,%esi
  add    $0x1,%r14d
  push   %rax
  call   <copy_block@plt>
  pop    %rdi
  pop    %r8
  cmp    %r14d,0xc(%rsp)
  jne    L60
  mov    %rbx,%r14
  add    $0x1,%r15d
  cmp    0x24(%rsp),%r15d
  jne    L80
  mov    %r12d,0x20(%rsp)
  movsd  0x30(%rsp),%xmm1
  xor    %r15d,%r15d
  mov    0x38(%rsp),%rbx
  nopl   0x0(%rax)
L17:
  xor    %eax,%eax
  mov    %r15d,%r12d
  mov    %eax,%r15d
L93:
  mov    0x88(%rsp),%eax
  mov    %r14,%rcx
  mov    %r13,%rdx
  mov    %r15d,%esi
  mov    %ebp,%r9d
  mov    %rbx,%r8
  mov    %r12d,%edi
  add    $0x1,%r15d
  push   %rax
  mov    0x28(%rsp),%eax
  push   %rax
  movsd  0x28(%rsp),%xmm0
  movsd  %xmm1,0x20(%rsp)
  call   <compute_estimate@plt>
  pop    %rdx
  pop    %rcx
  cmp    %r15d,0xc(%rsp)
  movsd  0x10(%rsp),%xmm1
  jne    L93
  mov    %r12d,%r15d
  add    $0x1,%r15d
  cmp    0x24(%rsp),%r15d
  jne    L17
  mov    0x20(%rsp),%r12d
L68:
  addl   $0x1,0x28(%rsp)
  mov    0x28(%rsp),%eax
  cmp    %eax,0x2c(%rsp)
  jge    L38
L99:
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L31:
  movl   $0x1,0x24(%rsp)
  mov    %edi,%ebx
  jmp    L7
```

assistant: ```c
void sweep(int nx, int ny, double dx, double dy, double *f_, int itold, int itnew, double *u_, double *unew_, int block_size) {
  int it;
  int block_x, block_y;
  if (block_size == 0)
    block_size = nx;
  int max_blocks_x = (nx / block_size);
  int max_blocks_y = (ny / block_size);
#pragma omp parallel shared(u_, unew_, f_, max_blocks_x, max_blocks_y, nx, ny, dx, dy, itold, itnew, block_size) private(it, block_x, block_y)
  {
#pragma omp single
    {
      for (it = itold + 1; it <= itnew; it++) {
        for (block_x = 0; block_x < max_blocks_x; block_x++) {
          for (block_y = 0; block_y < max_blocks_y; block_y++) {
#pragma omp task shared(u_, unew_, nx, ny, block_size) firstprivate(block_x, block_y)
            copy_block(nx, ny, block_x, block_y, u_, unew_, block_size);
          }
        }
#pragma omp taskwait
        for (block_x = 0; block_x < max_blocks_x; block_x++) {
          for (block_y = 0; block_y < max_blocks_y; block_y++) {
#pragma omp task default(none) shared(u_, unew_, f_, dx, dy, nx, ny, block_size) firstprivate(block_x, block_y)
            compute_estimate(block_x, block_y, u_, unew_, f_, dx, dy, nx, ny, block_size);
          }
        }
#pragma omp taskwait
      }
    }
  }
}
```