user: 请将这段汇编代码片段转换成等效的C代码：

```asm
<combine>:
  endbr64
  push   %r15
  push   %r14
  mov    %rdx,%r14
  push   %r13
  sub    %rsi,%r14
  mov    %rsi,%r13
  push   %r12
  lea    0x0(,%r14,8),%r15
  lea    (%rsi,%rdx,1),%r12
  push   %rbp
  shr    %r12
  mov    %rdx,%rbp
  push   %rbx
  mov    %rdi,%rbx
  mov    %r15,%rdi
  sub    $0x18,%rsp
  call   <malloc@plt>
  mov    %rax,%rdi
  cmp    %r12,%r13
  jae    L75
  cmp    %r12,%rbp
  jbe    L75
  mov    %rax,%rsi
  mov    %r13,%rdx
  mov    %r12,%rax
  xor    %ecx,%ecx
  nopl   0x0(%rax,%rax,1)
L127:
  mov    (%rbx,%rdx,8),%r9
  mov    (%rbx,%rax,8),%r8
  add    $0x1,%rcx
  cmp    %r9,%r8
  jbe    L60
  mov    %r9,(%rsi)
  add    $0x1,%rdx
  add    $0x8,%rsi
  cmp    %rax,%rbp
  jbe    L90
  cmp    %rdx,%r12
  ja     L127
  xchg   %ax,%ax
L151:
  cmp    %rax,%rbp
  jbe    L194
  mov    %rbp,%r8
  lea    0x0(,%rcx,8),%r10
  lea    0x8(,%rax,8),%r9
  sub    %rax,%r8
  lea    (%r10,%rdi,1),%rsi
  lea    -0x1(%r8),%r11
  mov    %rsi,%rdx
  cmp    $0x2,%r11
  jbe    L278
  lea    (%rbx,%r9,1),%r11
  cmp    %r11,%rsi
  je     L278
  mov    %r8,%rsi
  mov    %rbx,%r10
  shr    %rsi
  sub    %rdx,%r10
  shl    $0x4,%rsi
  lea    -0x8(%r10,%r9,1),%r9
  add    %rdx,%rsi
  nopl   0x0(%rax)
L268:
  movdqu (%rdx,%r9,1),%xmm1
  add    $0x10,%rdx
  movups %xmm1,-0x10(%rdx)
  cmp    %rdx,%rsi
  jne    L268
  mov    %r8,%rdx
  and    $0xfffffffffffffffe,%rdx
  add    %rdx,%rax
  add    %rdx,%rcx
  cmp    %rdx,%r8
  je     L194
  mov    (%rbx,%rax,8),%rax
  mov    %rax,(%rdi,%rcx,8)
L194:
  test   %r14,%r14
  je     L84
  lea    0x0(,%r13,8),%rdx
  lea    0x8(%rdi),%rsi
  mov    %rdi,%rax
  lea    (%rbx,%rdx,1),%rcx
  cmp    %rsi,%rcx
  je     L158
  lea    -0x1(%r14),%rsi
  cmp    $0x2,%rsi
  jbe    L158
  mov    %r14,%rdx
  sub    %rdi,%rcx
  shr    %rdx
  shl    $0x4,%rdx
  add    %rdi,%rdx
  nopl   0x0(%rax)
L137:
  movdqu (%rax),%xmm2
  movups %xmm2,(%rcx,%rax,1)
  add    $0x10,%rax
  cmp    %rax,%rdx
  jne    L137
  mov    %r14,%rax
  and    $0xfffffffffffffffe,%rax
  and    $0x1,%r14d
  je     L84
  mov    (%rdi,%rax,8),%rdx
  add    %r13,%rax
  mov    %rdx,(%rbx,%rax,8)
L84:
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  jmp    1060 <free@plt>
  nopl   0x0(%rax)
L60:
  mov    %r8,(%rsi)
  add    $0x1,%rax
  add    $0x8,%rsi
  cmp    %rdx,%r12
  jbe    L151
  cmp    %rax,%rbp
  ja     L127
L90:
  cmp    %rdx,%r12
  jbe    L151
  mov    %r12,%r10
  lea    0x0(,%rcx,8),%rsi
  lea    0x8(,%rdx,8),%r9
  sub    %rdx,%r10
  lea    (%rsi,%rdi,1),%r8
  mov    %rsi,0x8(%rsp)
  lea    -0x1(%r10),%r11
  mov    %r8,%rsi
  cmp    $0x2,%r11
  jbe    L102
  lea    (%rbx,%r9,1),%r11
  cmp    %r11,%r8
  je     L102
  mov    %r10,%r8
  mov    %rbx,%r11
  shr    %r8
  sub    %rsi,%r11
  shl    $0x4,%r8
  lea    -0x8(%r11,%r9,1),%r9
  add    %rsi,%r8
  nopl   0x0(%rax,%rax,1)
L133:
  movdqu (%rsi,%r9,1),%xmm0
  add    $0x10,%rsi
  movups %xmm0,-0x10(%rsi)
  cmp    %rsi,%r8
  jne    L133
  mov    %r10,%r8
  and    $0xfffffffffffffffe,%r8
  add    %r8,%rdx
  lea    (%rcx,%r8,1),%rsi
  cmp    %r8,%r10
  je     L243
  mov    (%rbx,%rdx,8),%rdx
  mov    %rdx,(%rdi,%rsi,8)
L243:
  add    %r10,%rcx
  jmp    L151
  cs nopw 0x0(%rax,%rax,1)
L278:
  sub    $0x8,%r9
  mov    %rdi,%rax
  add    %rcx,%rbp
  sub    %r9,%rax
  sub    %rdi,%r9
  sub    %r10,%r9
  lea    (%rax,%rbp,8),%rcx
  lea    (%rbx,%r9,1),%rax
  nopl   0x0(%rax,%rax,1)
L33:
  mov    (%rax,%rsi,1),%rdx
  add    $0x8,%rsi
  mov    %rdx,-0x8(%rsi)
  cmp    %rsi,%rcx
  jne    L33
  jmp    L194
  cs nopw 0x0(%rax,%rax,1)
L158:
  sub    %rdi,%rdx
  add    %rdi,%r15
  add    %rdx,%rbx
  nopl   0x0(%rax)
L144:
  mov    (%rax),%rdx
  mov    %rdx,(%rbx,%rax,1)
  add    $0x8,%rax
  cmp    %rax,%r15
  jne    L144
  jmp    L84
  nopl   (%rax)
L102:
  add    %rcx,%r12
  sub    $0x8,%r9
  lea    (%rdi,%r12,8),%r11
  sub    %r9,%r11
  sub    0x8(%rsp),%r9
  sub    %rdi,%r9
  lea    (%rbx,%r9,1),%rsi
  nopw   0x0(%rax,%rax,1)
L34:
  mov    (%rsi,%r8,1),%rdx
  add    $0x8,%r8
  mov    %rdx,-0x8(%r8)
  cmp    %r8,%r11
  jne    L34
  jmp    L243
  xchg   %ax,%ax
L75:
  mov    %r12,%rax
  mov    %r13,%rdx
  xor    %ecx,%ecx
  jmp    L90
```

assistant: ```c
void combine(unsigned long long int *a, unsigned long long int lower, unsigned long long int upper) {
  unsigned long long int i = 0, j = 0, k = 0, mid = 0;
  mid = (lower + upper) / 2;
  unsigned long long int *result;
  result = (unsigned long long int *)malloc((upper - lower) * sizeof(unsigned long long int));
  for (i = lower, j = mid, k = 0; i < mid && j < upper;) {
    if (*(a + i) < *(a + j))
      *(result + k++) = *(a + i++);
    else
      *(result + k++) = *(a + j++);
  }
  while (i < mid)
    *(result + k++) = *(a + i++);
  while (j < upper)
    *(result + k++) = *(a + j++);
  for (k = 0; k < (upper - lower); k++)
    *(a + lower + k) = *(result + k);
  free(result);
}
```