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

```asm
<gca_heap_pushup>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x68,%rsp
  mov    %rdi,-0x58(%rbp)
  mov    %rsi,-0x60(%rbp)
  mov    %rdx,-0x68(%rbp)
  mov    %rcx,-0x70(%rbp)
  mov    %r8,-0x78(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x28(%rbp)
  xor    %eax,%eax
  mov    %rsp,%rax
  mov    %rax,%rbx
  mov    -0x68(%rbp),%rax
  mov    %rax,%rdx
  sub    $0x1,%rdx
  mov    %rdx,-0x48(%rbp)
  mov    %rax,%r12
  mov    $0x0,%r13d
  mov    %rax,%r10
  mov    $0x0,%r11d
  mov    $0x10,%edx
  sub    $0x1,%rdx
  add    %rdx,%rax
  mov    $0x10,%esi
  mov    $0x0,%edx
  div    %rsi
  imul   $0x10,%rax,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffff000,%rcx
  mov    %rsp,%rdx
  sub    %rcx,%rdx
L58:
  cmp    %rdx,%rsp
  je     L40
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L58
L40:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L48
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L48:
  mov    %rsp,%rax
  add    $0x0,%rax
  mov    %rax,-0x40(%rbp)
  mov    -0x58(%rbp),%rax
  mov    %rax,-0x38(%rbp)
  mov    -0x60(%rbp),%rax
  sub    $0x1,%rax
  imul   -0x68(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x38(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x68(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <memcpy@plt>
  mov    -0x60(%rbp),%rax
  sub    $0x1,%rax
  mov    %rax,-0x50(%rbp)
  jmp    L52
L63:
  mov    -0x50(%rbp),%rax
  sub    $0x1,%rax
  shr    %rax
  mov    %rax,-0x30(%rbp)
  mov    -0x68(%rbp),%rax
  imul   -0x30(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x38(%rbp),%rax
  lea    (%rdx,%rax,1),%rdi
  mov    -0x78(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  mov    -0x70(%rbp),%rcx
  mov    %rax,%rsi
  call   *%rcx
  test   %eax,%eax
  jns    L55
  mov    -0x68(%rbp),%rax
  imul   -0x30(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x38(%rbp),%rax
  lea    (%rdx,%rax,1),%rsi
  mov    -0x68(%rbp),%rax
  imul   -0x50(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x38(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x68(%rbp),%rax
  mov    %rax,%rdx
  mov    %rcx,%rdi
  call   <memcpy@plt>
  mov    -0x30(%rbp),%rax
  mov    %rax,-0x50(%rbp)
L52:
  cmpq   $0x0,-0x50(%rbp)
  jne    L63
  jmp    L26
L55:
  nop
L26:
  mov    -0x68(%rbp),%rax
  imul   -0x50(%rbp),%rax
  mov    %rax,%rdx
  mov    -0x38(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x68(%rbp),%rdx
  mov    -0x40(%rbp),%rax
  mov    %rax,%rsi
  mov    %rcx,%rdi
  call   <memcpy@plt>
  mov    %rbx,%rsp
  nop
  mov    -0x28(%rbp),%rax
  sub    %fs:0x28,%rax
  je     L33
  call   <__stack_chk_fail@plt>
L33:
  lea    -0x18(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %rbp
  ret
```

assistant: ```c
void gca_heap_pushup(void *heap, size_t nel, size_t es, int (*compar)(const void *_a, const void *_b, void *_arg), void *arg) {
  size_t chi, pi;
  char tmp[es], *b = (char *)heap;
  memcpy(tmp, b + es * (nel - 1), es);
  for (chi = nel - 1; chi > 0; chi = pi) {
    pi = (((chi)-1) / 2);
    if (compar(b + es * pi, tmp, arg) >= 0)
      break;
    memcpy(b + es * chi, b + es * pi, es);
  }
  memcpy(b + es * chi, tmp, es);
}
```