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

```asm
<multiplication>:
  endbr64
  push   %r15
  xor    %r10d,%r10d
  xor    %r11d,%r11d
  xor    %r9d,%r9d
  push   %r14
  xor    %r8d,%r8d
  xor    %edi,%edi
  mov    $0x4,%esi
  push   %r13
  mov    $0x3,%ecx
  mov    $0x2,%edx
  push   %r12
  push   %rbp
  xor    %ebp,%ebp
  push   %rbx
  xor    %ebx,%ebx
  sub    $0x88,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x78(%rsp)
  xor    %eax,%eax
  movl   $0xf4240,0x2c(%rsp)
  mov    $0x1,%eax
  movl   $0x0,0x28(%rsp)
  movl   $0x0,0x24(%rsp)
  movl   $0x0,0x10(%rsp)
  movl   $0x0,0x20(%rsp)
  movl   $0x0,0x1c(%rsp)
  movl   $0x0,0xc(%rsp)
  movl   $0x0,0x18(%rsp)
  movl   $0x0,0x14(%rsp)
  movl   $0x0,0x8(%rsp)
  nopl   0x0(%rax,%rax,1)
L9:
  mov    0x8(%rsp),%r12d
  lea    (%rax,%rax,1),%r13d
  add    %eax,%edi
  add    %edx,%r8d
  lea    0x0(%r13,%rax,1),%r15d
  lea    0x0(,%rax,4),%r14d
  add    %r13d,%edi
  add    %eax,%r12d
  add    %r15d,%edi
  add    %r13d,%r12d
  add    %r14d,%edi
  add    %r15d,%r12d
  movd   %edi,%xmm6
  add    %r14d,%r12d
  mov    %r12d,0x8(%rsp)
  mov    0x14(%rsp),%r12d
  movd   0x8(%rsp),%xmm7
  add    %eax,%r12d
  add    %r13d,%r12d
  add    %r15d,%r12d
  add    %r14d,%r12d
  mov    %r12d,0x14(%rsp)
  movd   %r12d,%xmm2
  mov    0x18(%rsp),%r12d
  punpckldq %xmm2,%xmm7
  add    %eax,%r12d
  add    %r13d,%r12d
  lea    (%rdx,%rdx,1),%r13d
  add    %r15d,%r12d
  add    %r13d,%r8d
  lea    (%r12,%r14,1),%r15d
  mov    0xc(%rsp),%r12d
  lea    0x0(,%rdx,4),%r14d
  mov    %r15d,0x18(%rsp)
  movd   %r15d,%xmm3
  lea    0x0(%r13,%rdx,1),%r15d
  add    %edx,%r12d
  add    %r15d,%r8d
  punpckldq %xmm3,%xmm6
  add    %r13d,%r12d
  add    %r14d,%r8d
  add    %r15d,%r12d
  add    %r14d,%r12d
  mov    %r12d,0xc(%rsp)
  mov    0x1c(%rsp),%r12d
  movd   0xc(%rsp),%xmm5
  add    %edx,%r12d
  add    %r13d,%r12d
  add    %r15d,%r12d
  add    %r14d,%r12d
  mov    %r12d,0x1c(%rsp)
  movd   %r12d,%xmm4
  mov    0x20(%rsp),%r12d
  punpckldq %xmm4,%xmm5
  movd   %r8d,%xmm4
  add    %edx,%r12d
  add    %r13d,%r12d
  mov    0x10(%rsp),%r13d
  add    %r15d,%r12d
  add    %r12d,%r14d
  add    %ecx,%r13d
  lea    (%rcx,%rcx,1),%r12d
  add    %r12d,%r13d
  lea    (%r12,%rcx,1),%r15d
  mov    %r14d,0x20(%rsp)
  add    %esi,%ebx
  movd   %r14d,%xmm1
  add    %r15d,%r13d
  add    %ecx,%r9d
  add    %esi,%r11d
  lea    0x0(,%rcx,4),%r14d
  add    %r12d,%r9d
  add    %esi,%r10d
  add    %esi,%ebp
  add    %r14d,%r13d
  add    %r15d,%r9d
  punpckldq %xmm1,%xmm4
  add    0x8(%rsp),%eax
  mov    %r13d,0x10(%rsp)
  mov    0x24(%rsp),%r13d
  add    %r14d,%r9d
  movd   0x10(%rsp),%xmm3
  movd   %r9d,%xmm2
  add    %ecx,%r13d
  add    %r12d,%r13d
  add    %r15d,%r13d
  add    %r14d,%r13d
  mov    %r13d,0x24(%rsp)
  movd   %r13d,%xmm0
  mov    0x28(%rsp),%r13d
  punpckldq %xmm0,%xmm3
  add    %ecx,%r13d
  add    %r12d,%r13d
  lea    (%rsi,%rsi,1),%r12d
  add    %r15d,%r13d
  add    %r12d,%r11d
  add    %r12d,%ebx
  add    %r12d,%r10d
  lea    0x0(%r13,%r14,1),%r15d
  add    %r12d,%ebp
  lea    (%r12,%rsi,1),%r14d
  mov    %r15d,0x28(%rsp)
  movd   %r15d,%xmm1
  add    %r14d,%r11d
  add    %r14d,%ebx
  mov    0x14(%rsp),%r15d
  add    %r14d,%r10d
  add    %r14d,%ebp
  lea    (%rdi,%rdi,2),%r12d
  lea    0x0(,%rsi,4),%r13d
  mov    0x1c(%rsp),%r14d
  punpckldq %xmm1,%xmm2
  lea    (%rax,%r15,2),%eax
  add    %r13d,%r11d
  add    %r13d,%ebx
  add    %r13d,%r10d
  add    %r13d,%ebp
  add    %r12d,%eax
  add    0xc(%rsp),%edx
  mov    0x18(%rsp),%r15d
  lea    (%rdx,%r14,2),%edx
  mov    0x24(%rsp),%r14d
  lea    (%r8,%r8,2),%r12d
  add    %r11d,%esi
  add    0x10(%rsp),%ecx
  lea    (%rax,%r15,4),%eax
  add    %r12d,%edx
  mov    0x20(%rsp),%r15d
  lea    (%r9,%r9,2),%r12d
  lea    (%rcx,%r14,2),%ecx
  movd   %ebx,%xmm0
  lea    (%rsi,%rbx,2),%esi
  lea    (%rdx,%r15,4),%edx
  add    %r12d,%ecx
  mov    0x28(%rsp),%r15d
  lea    (%r10,%r10,2),%r12d
  movd   %r11d,%xmm1
  movd   %ebp,%xmm8
  add    %r12d,%esi
  punpckldq %xmm0,%xmm1
  lea    (%rcx,%r15,4),%ecx
  subl   $0x1,0x2c(%rsp)
  movd   %r10d,%xmm0
  lea    (%rsi,%rbp,4),%esi
  punpckldq %xmm8,%xmm0
  jne    L9
  movq   %xmm1,0x60(%rsp)
  movq   %xmm0,0x68(%rsp)
  movq   %xmm7,0x30(%rsp)
  movq   %xmm6,0x38(%rsp)
  movq   %xmm5,0x40(%rsp)
  movq   %xmm4,0x48(%rsp)
  movdqa 0x40(%rsp),%xmm0
  paddd  0x30(%rsp),%xmm0
  movq   %xmm3,0x50(%rsp)
  movq   %xmm2,0x58(%rsp)
  paddd  0x50(%rsp),%xmm0
  paddd  0x60(%rsp),%xmm0
  movdqa %xmm0,%xmm1
  psrldq $0x8,%xmm1
  paddd  %xmm1,%xmm0
  movdqa %xmm0,%xmm1
  psrldq $0x4,%xmm1
  paddd  %xmm1,%xmm0
  movd   %xmm0,%eax
  mov    0x78(%rsp),%rdx
  sub    %fs:0x28,%rdx
  jne    L19
  add    $0x88,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L19:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
int multiplication() {
  int mat1[4][4] = {{1, 1, 1, 1}, {2, 2, 2, 2}, {3, 3, 3, 3}, {4, 4, 4, 4}};
  int mat2[4][4] = {{1, 1, 1, 1}, {2, 2, 2, 2}, {3, 3, 3, 3}, {4, 4, 4, 4}};
  int res[4][4];
  int i, j, k;
  for (i = 0; i < 4; i++) {
    for (j = 0; j < 4; j++) {
      res[i][j] = 0;
    }
  }
  int z;
  for (z = 0; z < 1000000; ++z) {
    for (i = 0; i < 4; i++) {
      for (j = 0; j < 4; j++) {
        for (k = 0; k < 4; k++)
          res[i][j] += mat1[i][k] * mat2[k][j];
      }
    }
    for (i = 0; i < 4; i++) {
      for (j = 0; j < 4; j++) {
        for (k = 0; k < 4; k++)
          mat1[i][j] += res[i][k] * mat2[k][j];
      }
    }
  }
  int r = 0;
  for (j = 0; j < 4; j++) {
    for (k = 0; k < 4; k++)
      r += res[j][k];
  }
  return r;
}
```