user: 提供的汇编代码用C语言表示会是什么样子：

```asm
<iterative_merge>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x48,%rsp
  mov    %rdi,%r13
  mov    %rsi,%r14
  mov    %rsi,0x18(%rsp)
  mov    %rsi,%rax
  shr    %rax
  mov    %rax,0x20(%rsp)
  mov    %eax,%edi
  call   <log@plt>
  mov    %eax,%ebx
  mov    $0x2,%edi
  call   <log@plt>
  mov    %eax,%ecx
  mov    %ebx,%eax
  cltd
  idiv   %ecx
  mov    %eax,%edi
  call   <floor@plt>
  mov    %eax,%esi
  mov    $0x2,%edi
  call   <pow@plt>
  mov    %eax,%edx
  lea    (%rax,%rax,1),%ecx
  movslq %ecx,%rcx
  mov    %r14,%rax
  sub    %rcx,%rax
  movslq %edx,%rdx
  cmp    %rdx,%rax
  cmovb  %rdx,%rax
  lea    0x0(,%rax,4),%ebx
  mov    %ebx,%edi
  call   <malloc@plt>
  mov    %rax,%r15
  mov    %ebx,%edx
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <memset@plt>
  cmp    $0x1,%r14
  jbe    L160
  movl   $0x1,0x28(%rsp)
  movq   $0x1,0x10(%rsp)
  mov    %r14d,%eax
  sub    $0x1,%eax
  mov    %eax,0x2c(%rsp)
  lea    0x4(%r15),%rax
  mov    %rax,0x30(%rsp)
  lea    0x4(%r13),%rax
  mov    %rax,0x38(%rsp)
  jmp    L151
L172:
  mov    0x18(%rsp),%rax
  mov    %eax,%ebx
  sub    0x28(%rsp),%ebx
  lea    -0x1(%rbx),%r12d
  mov    0x2c(%rsp),%ebp
  mov    0x10(%rsp),%rdi
  sub    %rdi,%rax
  mov    %rax,%r14
  lea    0x0(,%rax,4),%edx
  lea    0x0(%r13,%rdi,4),%rsi
  mov    %r15,%rdi
  call   <memcpy@plt>
  mov    0x10(%rsp),%eax
  lea    0x0(,%rax,4),%edx
  lea    0x0(%r13,%r14,4),%rdi
  mov    %r13,%rsi
  call   <memmove@plt>
  jmp    L130
L17:
  mov    %r12d,%eax
  mov    0xc(%rsp),%edi
  sub    %edi,%eax
  lea    0x4(,%rax,4),%edx
  movslq %edi,%rax
  lea    0x0(%r13,%rax,4),%rsi
  mov    %r15,%rdi
  call   <memcpy@plt>
  jmp    L201
L72:
  add    $0x1,%edx
  mov    %ecx,-0x4(%r13,%rax,4)
L118:
  mov    %eax,%r14d
  add    $0x1,%rax
  cmp    %r12d,%edx
  jg     L78
  cmp    %ebp,%ebx
  jg     L78
L31:
  movslq %ebx,%rcx
  mov    0x0(%r13,%rcx,4),%esi
  movslq %edx,%rcx
  mov    (%r15,%rcx,4),%ecx
  cmp    %ecx,%esi
  jge    L72
  add    $0x1,%ebx
  mov    %esi,-0x4(%r13,%rax,4)
  jmp    L118
L37:
  mov    $0x0,%edx
L78:
  cmp    %edx,%r12d
  jl     L206
  movslq %edx,%rcx
  lea    (%r15,%rcx,4),%rax
  mov    %edx,%edi
  mov    %r12d,%esi
  sub    %edx,%esi
  lea    (%rsi,%rcx,1),%rdx
  mov    0x30(%rsp),%rsi
  lea    (%rsi,%rdx,4),%rsi
  movslq %r14d,%rdx
  sub    %rcx,%rdx
  lea    0x0(%r13,%rdx,4),%rcx
  sub    %r15,%rcx
L92:
  mov    (%rax),%edx
  mov    %edx,(%rcx,%rax,1)
  add    $0x4,%rax
  cmp    %rsi,%rax
  jne    L92
  lea    0x1(%r14,%r12,1),%r14d
  sub    %edi,%r14d
L206:
  cmp    %ebp,%ebx
  jg     L57
  movslq %ebx,%rdx
  lea    0x0(%r13,%rdx,4),%rax
  mov    %ebp,%edi
  mov    %ebx,%r8d
  sub    %ebx,%ebp
  add    %rdx,%rbp
  mov    0x38(%rsp),%rbx
  lea    (%rbx,%rbp,4),%rsi
  movslq %r14d,%rcx
  sub    %rdx,%rcx
L152:
  mov    (%rax),%edx
  mov    %edx,(%rax,%rcx,4)
  add    $0x4,%rax
  cmp    %rax,%rsi
  jne    L152
  lea    0x1(%rdi),%eax
  mov    %eax,0xc(%rsp)
  sub    %r8d,%eax
  add    %eax,%r14d
L76:
  mov    0xc(%rsp),%eax
  mov    %eax,%ebx
  mov    0x28(%rsp),%edi
  add    %edi,%ebx
  movslq %ebx,%rbx
  add    %edi,%eax
  mov    0x18(%rsp),%rsi
  cmp    %rsi,%rbx
  mov    0x2c(%rsp),%edx
  cmovae %edx,%eax
  mov    %eax,%ebx
  lea    -0x1(%rax),%r12d
  lea    (%r12,%rdi,1),%ebp
  movslq %ebp,%rbp
  lea    (%r12,%rdi,1),%eax
  cmp    %rsi,%rbp
  cmovae %edx,%eax
  mov    %eax,%ebp
  movslq %r14d,%rax
  cmp    %rsi,%rax
  jae    L1
L58:
  mov    0x10(%rsp),%rdi
  cmp    %rdi,0x20(%rsp)
  jae    L17
L201:
  sub    0xc(%rsp),%r12d
  cmp    %ebp,%ebx
  jg     L37
  test   %r12d,%r12d
  js     L37
  add    $0x1,%r14d
  movslq %r14d,%rax
  mov    $0x0,%edx
  jmp    L31
L57:
  mov    %ebx,0xc(%rsp)
  jmp    L76
L1:
  shll   0x28(%rsp)
  mov    0x28(%rsp),%eax
  cltq
  mov    %rax,0x10(%rsp)
  cmp    %rsi,%rax
  jae    L160
L151:
  mov    0x10(%rsp),%rdi
  cmp    %rdi,0x20(%rsp)
  jb     L172
  mov    0x28(%rsp),%ebx
  lea    -0x1(%rbx),%r12d
  lea    (%r12,%rbx,1),%ebp
L130:
  mov    $0x0,%r14d
  movl   $0x0,0xc(%rsp)
  jmp    L58
L160:
  mov    %r15,%rdi
  call   <free@plt>
  add    $0x48,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void iterative_merge(int a[], size_t n) {
  int t = pow(2, floor(log(n / 2) / log(2)));
  int tempsize = (t > n - 2 * t) ? t : n - 2 * t;
  int *temparray = (int *)malloc(tempsize * sizeof(int));
  memset(temparray, 0, tempsize * sizeof(int));
  int l, l_max, r, r_max, incr, i, j, cpy_size;
  incr = 1;
  while (incr < n) {
    if (incr <= n / 2) {
      l = 0;
      r = incr;
      l_max = r - 1;
      r_max = l_max + incr;
    } else {
      l = 0;
      r = n - incr;
      l_max = r - 1;
      r_max = n - 1;
      memcpy(temparray, &a[incr], (n - incr) * sizeof(int));
      memmove(&a[n - incr], &a[0], incr * sizeof(int));
    }
    i = j = 0;
    while (i < n) {
      if (incr <= n / 2) {
        cpy_size = l_max - l + 1;
        memcpy(temparray, &a[l], cpy_size * sizeof(int));
      }
      j = 0;
      while (j <= l_max - l && r <= r_max) {
        if (a[r] < temparray[j]) {
          a[i] = a[r++];
        } else {
          a[i] = temparray[j++];
        }
        ++i;
      }
      while (j <= l_max - l) {
        a[i++] = temparray[j++];
      }
      while (r <= r_max) {
        a[i++] = a[r++];
      }
      l = r;
      r = (r + incr < n) ? r + incr : n - 1;
      l_max = r - 1;
      r_max = (l_max + incr < n) ? l_max + incr : n - 1;
    }
    incr *= 2;
  }
  free(temparray);
  return;
}
```