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

```asm
<crypto_scrypt_smix_sse2>:
  endbr64
  push   %r15
  mov    %rsi,%rax
  push   %r14
  shl    $0x7,%rax
  push   %r13
  mov    %rsi,%r13
  push   %r12
  mov    %r8,%r12
  push   %rbp
  push   %rbx
  mov    %rdi,%rbx
  sub    $0x58,%rsp
  mov    %rcx,0x10(%rsp)
  lea    (%rax,%r8,1),%rcx
  mov    %rax,0x18(%rsp)
  add    %rcx,%rax
  mov    %rax,0x38(%rsp)
  mov    %rsi,%rax
  add    %rax,%rax
  mov    %edx,0x20(%rsp)
  mov    %rcx,0x30(%rsp)
  mov    %rax,0x8(%rsp)
  je     L25
  mov    %rsi,0x28(%rsp)
  xor    %r14d,%r14d
  nopw   0x0(%rax,%rax,1)
L102:
  mov    %r14,%rcx
  mov    %r14,%rbp
  xor    %r13d,%r13d
  shl    $0x6,%rcx
  shl    $0x4,%rbp
  lea    (%r12,%rcx,1),%r15
  nopl   (%rax)
L13:
  mov    %r13d,%edi
  add    $0x5,%r13d
  add    $0x4,%r15
  and    $0xf,%edi
  add    %rbp,%rdi
  shl    $0x4,%rdi
  add    %rbx,%rdi
  call   <le32dec@plt>
  mov    %eax,-0x4(%r15)
  cmp    $0x50,%r13d
  jne    L13
  add    $0x1,%r14
  cmp    %r14,0x8(%rsp)
  jne    L102
  mov    0x20(%rsp),%eax
  mov    0x28(%rsp),%r13
  test   %eax,%eax
  jle    L52
L84:
  mov    0x20(%rsp),%r14d
  mov    %rbx,0x40(%rsp)
  mov    %r13d,%ebp
  xor    %r10d,%r10d
  mov    0x10(%rsp),%r8
  mov    0x38(%rsp),%r15
  shl    $0x7,%ebp
  sub    $0x1,%r14d
  mov    0x30(%rsp),%rbx
  mov    %r14d,%eax
  mov    %r14d,0x4c(%rsp)
  mov    %r10d,%r14d
  and    $0xfffffffe,%eax
  add    $0x2,%eax
  mov    %eax,0x28(%rsp)
  cs nopw 0x0(%rax,%rax,1)
L100:
  mov    %r8,%rdi
  mov    %ebp,%edx
  mov    %r12,%rsi
  mov    %r8,0x20(%rsp)
  call   <sse2_blkcpy@plt>
  mov    %r13,%rcx
  mov    %r15,%rdx
  mov    %rbx,%rsi
  mov    %r12,%rdi
  call   <sse2_blockmix_salsa8@plt>
  mov    0x20(%rsp),%r8
  mov    %ebp,%edx
  mov    %rbx,%rsi
  add    0x18(%rsp),%r8
  mov    %r8,%rdi
  mov    %r8,0x20(%rsp)
  call   <sse2_blkcpy@plt>
  mov    %r13,%rcx
  mov    %r15,%rdx
  mov    %r12,%rsi
  mov    %rbx,%rdi
  call   <sse2_blockmix_salsa8@plt>
  mov    0x20(%rsp),%r8
  mov    %r14d,%r9d
  add    0x18(%rsp),%r8
  lea    0x2(%r14),%r14d
  cmp    %r14d,0x28(%rsp)
  jne    L100
  mov    0x40(%rsp),%rbx
  mov    %r9d,0x20(%rsp)
  xor    %r8d,%r8d
  mov    0x4c(%rsp),%r14d
  mov    0x38(%rsp),%r15
  mov    %rbx,0x28(%rsp)
  mov    0x30(%rsp),%rbx
  nopl   0x0(%rax)
L54:
  mov    %r13,%rsi
  mov    %r12,%rdi
  mov    %r8d,0x18(%rsp)
  call   <sse2_integerify@plt>
  mov    %ebp,%edx
  mov    %r12,%rdi
  and    %r14d,%eax
  mov    %eax,%esi
  shl    $0x7,%esi
  movslq %esi,%rsi
  imul   %r13,%rsi
  add    0x10(%rsp),%rsi
  call   <sse2_blkxor@plt>
  mov    %r13,%rcx
  mov    %r15,%rdx
  mov    %rbx,%rsi
  mov    %r12,%rdi
  call   <sse2_blockmix_salsa8@plt>
  mov    %r13,%rsi
  mov    %rbx,%rdi
  call   <sse2_integerify@plt>
  mov    %ebp,%edx
  mov    %rbx,%rdi
  and    %r14d,%eax
  mov    %eax,%esi
  shl    $0x7,%esi
  movslq %esi,%rsi
  imul   %r13,%rsi
  add    0x10(%rsp),%rsi
  call   <sse2_blkxor@plt>
  mov    %r13,%rcx
  mov    %r15,%rdx
  mov    %r12,%rsi
  mov    %rbx,%rdi
  call   <sse2_blockmix_salsa8@plt>
  mov    0x18(%rsp),%r8d
  mov    %r8d,%eax
  add    $0x2,%r8d
  cmp    %eax,0x20(%rsp)
  jne    L54
  cmpq   $0x0,0x8(%rsp)
  mov    0x28(%rsp),%rbx
  je     L86
L52:
  xor    %r13d,%r13d
  nop
L38:
  mov    %r13,%rdx
  mov    %r13,%rbp
  xor    %r15d,%r15d
  shl    $0x6,%rdx
  shl    $0x4,%rbp
  lea    (%r12,%rdx,1),%r14
  nopl   (%rax)
L60:
  mov    %r15d,%edi
  mov    (%r14),%esi
  add    $0x5,%r15d
  add    $0x4,%r14
  and    $0xf,%edi
  add    %rbp,%rdi
  shl    $0x4,%rdi
  add    %rbx,%rdi
  call   <le32enc@plt>
  cmp    $0x50,%r15d
  jne    L60
  add    $0x1,%r13
  cmp    0x8(%rsp),%r13
  jne    L38
L86:
  add    $0x58,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L25:
  mov    0x20(%rsp),%edx
  test   %edx,%edx
  jg     L84
  jmp    L86
```

assistant: ```c
void crypto_scrypt_smix_sse2(uint8_t *B, size_t r, uint64_t N, void *V, void *XY) {
  __m128i *X = XY;
  __m128i *Y = (void *)((uintptr_t)(XY) + 128 * r);
  __m128i *Z = (void *)((uintptr_t)(XY) + 256 * r);
  uint32_t *X32 = (void *)X;
  uint64_t i, j;
  size_t k;
  for (k = 0; k < 2 * r; k++) {
    for (i = 0; i < 16; i++) {
      X32[k * 16 + i] = le32dec(&B[(k * 16 + (i * 5 % 16)) * 4]);
    }
  }
  for (i = 0; i < N; i += 2) {
    sse2_blkcpy(((unsigned char *)V) + i * 128 * r, X, 128 * r);
    sse2_blockmix_salsa8(X, Y, Z, r);
    sse2_blkcpy(((unsigned char *)V) + (i + 1) * 128 * r, Y, 128 * r);
    sse2_blockmix_salsa8(Y, X, Z, r);
  }
  for (i = 0; i < N; i += 2) {
    j = sse2_integerify(X, r) & (N - 1);
    sse2_blkxor(X, ((unsigned char *)V) + j * 128 * r, 128 * r);
    sse2_blockmix_salsa8(X, Y, Z, r);
    j = sse2_integerify(Y, r) & (N - 1);
    sse2_blkxor(Y, ((unsigned char *)V) + j * 128 * r, 128 * r);
    sse2_blockmix_salsa8(Y, X, Z, r);
  }
  for (k = 0; k < 2 * r; k++) {
    for (i = 0; i < 16; i++) {
      le32enc(&B[(k * 16 + (i * 5 % 16)) * 4], X32[k * 16 + i]);
    }
  }
}
```