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

```asm
<feistelRound>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x28,%rsp
  mov    %rdi,%r15
  mov    %rsi,%rbp
  mov    %rdx,%r14
  mov    %rcx,(%rsp)
  mov    %r8,0x18(%rsp)
  mov    %r9,0x8(%rsp)
  mov    $0x80,%edi
  call   <malloc@plt>
  mov    %rax,0x10(%rsp)
  mov    $0xc0,%edi
  call   <malloc@plt>
  mov    %rax,%rbx
  mov    $0x80,%edi
  call   <malloc@plt>
  mov    %rax,%r13
  mov    $0x80,%edi
  call   <malloc@plt>
  mov    %rax,%r12
  mov    $0xc0,%edx
  mov    $0x0,%esi
  mov    %rbx,%rdi
  call   <memset@plt>
  mov    $0x80,%edx
  mov    $0x0,%esi
  mov    %r13,%rdi
  call   <memset@plt>
  mov    $0x80,%edx
  mov    $0x0,%esi
  mov    %r12,%rdi
  call   <memset@plt>
  mov    $0x80,%edx
  mov    $0x0,%esi
  mov    0x10(%rsp),%rdi
  call   <memset@plt>
  mov    $0x0,%eax
L48:
  movslq (%r14,%rax,1),%rdx
  mov    -0x4(%rbp,%rdx,4),%edx
  mov    %edx,(%rbx,%rax,1)
  add    $0x4,%rax
  cmp    $0xc0,%rax
  jne    L48
  movslq 0x60(%rsp),%rax
  mov    0x18(%rsp),%rdi
  lea    (%rdi,%rax,8),%rcx
  mov    $0x0,%eax
L3:
  mov    (%rcx),%rdx
  mov    (%rdx,%rax,1),%edx
  xor    %edx,(%rbx,%rax,1)
  add    $0x4,%rax
  cmp    $0xc0,%rax
  jne    L3
  mov    %rbx,%rdx
  mov    $0x0,%eax
L38:
  mov    0x4(%rdx),%esi
  mov    0x8(%rdx),%ecx
  lea    (%rcx,%rsi,2),%esi
  mov    0xc(%rdx),%ecx
  lea    (%rcx,%rsi,2),%esi
  mov    0x10(%rdx),%ecx
  lea    (%rcx,%rsi,2),%ecx
  movslq %ecx,%rcx
  mov    (%rdx),%edi
  mov    0x14(%rdx),%esi
  lea    (%rsi,%rdi,2),%esi
  shl    $0x4,%esi
  movslq %esi,%rsi
  add    %rsi,%rcx
  mov    0x8(%rsp),%rdi
  mov    (%rdi,%rax,2),%rsi
  mov    (%rsi,%rcx,4),%ecx
  mov    %ecx,%esi
  sar    $0x3,%esi
  and    $0x1,%esi
  mov    %esi,0x0(%r13,%rax,4)
  mov    %ecx,%esi
  sar    $0x2,%esi
  and    $0x1,%esi
  mov    %esi,0x4(%r13,%rax,4)
  mov    %ecx,%esi
  sar    %esi
  and    $0x1,%esi
  mov    %esi,0x8(%r13,%rax,4)
  and    $0x1,%ecx
  mov    %ecx,0xc(%r13,%rax,4)
  add    $0x4,%rax
  add    $0x18,%rdx
  cmp    $0x20,%rax
  jne    L38
  mov    %rbx,%rdi
  call   <free@plt>
  mov    $0x0,%eax
L46:
  mov    (%rsp),%rdi
  movslq (%rdi,%rax,1),%rdx
  mov    -0x4(%r13,%rdx,4),%edx
  mov    %edx,(%r12,%rax,1)
  add    $0x4,%rax
  cmp    $0x80,%rax
  jne    L46
  mov    %r13,%rdi
  call   <free@plt>
  mov    $0x80,%edx
  mov    %rbp,%rsi
  mov    0x10(%rsp),%rdi
  call   <memcpy@plt>
  mov    $0x0,%eax
L22:
  mov    (%r15,%rax,1),%edx
  xor    (%r12,%rax,1),%edx
  mov    %edx,0x0(%rbp,%rax,1)
  add    $0x4,%rax
  cmp    $0x80,%rax
  jne    L22
  mov    %r12,%rdi
  call   <free@plt>
  mov    $0x80,%edx
  mov    0x10(%rsp),%rbx
  mov    %rbx,%rsi
  mov    %r15,%rdi
  call   <memcpy@plt>
  mov    %rbx,%rdi
  call   <free@plt>
  add    $0x28,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void feistelRound(int *L_pre, int *R_pre, int *E, int *P, int **subkeys, int **S_box, int round) {
  int i = 0;
  int j = 0;
  int *temp = malloc(sizeof(int) * 32);
  int *expandR = malloc(sizeof(int) * 48);
  int *substitute = malloc(sizeof(int) * 32);
  int *permute = malloc(sizeof(int) * 32);
  memset(expandR, 0, sizeof(int) * 48);
  memset(substitute, 0, sizeof(int) * 32);
  memset(permute, 0, sizeof(int) * 32);
  memset(temp, 0, sizeof(int) * 32);
  for (i = 0; i < 48; i++) {
    (expandR + i)[0] = (R_pre + ((E + i)[0] - 1))[0];
  }
  for (i = 0; i < 48; i++) {
    (expandR + i)[0] = (expandR + i)[0] ^ (subkeys[round] + i)[0];
  }
  for (i = 0; i < 8; i++) {
    int row = (expandR + i * 6)[0] * 2 + (expandR + i * 6 + 5)[0] * 1;
    int col = (expandR + i * 6 + 1)[0] * 2 * 2 * 2 + (expandR + i * 6 + 2)[0] * 2 * 2 + (expandR + i * 6 + 3)[0] * 2 + (expandR + i * 6 + 4)[0] * 1;
    int fourbits = (S_box[i] + row * 16 + col)[0];
    (substitute + j++)[0] = (fourbits >> 3) & 0x1;
    (substitute + j++)[0] = (fourbits >> 2) & 0x1;
    (substitute + j++)[0] = (fourbits >> 1) & 0x1;
    (substitute + j++)[0] = (fourbits)&0x1;
  }
  free(expandR);
  for (i = 0; i < 32; i++) {
    (permute + i)[0] = (substitute + ((P + i)[0] - 1))[0];
  }
  free(substitute);
  memcpy(temp, R_pre, sizeof(int) * 32);
  for (i = 0; i < 32; i++) {
    (R_pre + i)[0] = (L_pre + i)[0] ^ (permute + i)[0];
  }
  free(permute);
  memcpy(L_pre, temp, sizeof(int) * 32);
  free(temp);
}
```