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

```asm
<multiply>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  lea    -0x4000(%rsp),%r11
L104:
  sub    $0x1000,%rsp
  orq    $0x0,(%rsp)
  cmp    %r11,%rsp
  jne    L104
  sub    $0xe78,%rsp
  mov    %rdi,0x20(%rsp)
  mov    %rsi,%r12
  mov    %rdi,%rbx
  mov    %fs:0x28,%rax
  mov    %rax,0x4e68(%rsp)
  xor    %eax,%eax
  call   <strlen@plt>
  mov    %r12,%rdi
  lea    -0x1(%rax),%r14d
  mov    %eax,%ebp
  call   <strlen@plt>
  mov    %r14d,%edx
  mov    %eax,0x3c(%rsp)
  sub    $0x1,%eax
  lea    0x1(%rbx,%rdx,1),%rdx
  mov    %eax,0x38(%rsp)
  mov    %rbx,%rax
  test   %r14d,%r14d
  js     L82
  nopw   0x0(%rax,%rax,1)
L137:
  subb   $0x30,(%rax)
  add    $0x1,%rax
  cmp    %rdx,%rax
  jne    L137
L82:
  mov    0x38(%rsp),%ebx
  mov    %r12,%rax
  mov    %rbx,0x18(%rsp)
  lea    0x1(%r12,%rbx,1),%rdx
  test   %ebx,%ebx
  js     L106
  nopl   (%rax)
L120:
  subb   $0x30,(%rax)
  add    $0x1,%rax
  cmp    %rdx,%rax
  jne    L120
  movslq 0x38(%rsp),%rax
  mov    0x20(%rsp),%rbx
  xor    %r15d,%r15d
  xor    %r13d,%r13d
  mov    %ebp,0x2c(%rsp)
  add    %rax,%r12
  lea    0x2750(%rsp),%rax
  mov    %rax,0x8(%rsp)
  movslq %ebp,%rax
  mov    %r14d,%ebp
  mov    %r12,%r14
  lea    -0x2(%rbx,%rax,1),%rax
  movabs $0x6666666666666667,%rbx
  mov    %rax,0x30(%rsp)
  nopl   (%rax)
L160:
  mov    %r15d,%r12d
  xor    %edx,%edx
  test   %ebp,%ebp
  js     L170
  mov    0x30(%rsp),%r10
  mov    %ebp,%eax
  movsbl (%r14),%r11d
  movslq %ebp,%rsi
  movslq %r13d,%rdi
  add    0x20(%rsp),%rsi
  add    0x8(%rsp),%rdi
  xor    %edx,%edx
  sub    %rax,%r10
  nopl   0x0(%rax)
L50:
  movsbl (%rsi),%ecx
  sub    $0x1,%rsi
  add    $0x1,%rdi
  imul   %r11d,%ecx
  movslq %ecx,%rcx
  add    %rdx,%rcx
  mov    %rcx,%rax
  imul   %rbx
  mov    %rcx,%rax
  sar    $0x3f,%rax
  sar    $0x2,%rdx
  sub    %rax,%rdx
  lea    (%rdx,%rdx,4),%rax
  add    %rax,%rax
  sub    %rax,%rcx
  mov    %cl,-0x1(%rdi)
  cmp    %r10,%rsi
  jne    L50
  add    0x2c(%rsp),%r13d
L170:
  movslq %r13d,%rax
  lea    0x1(%r13),%edi
  xor    %esi,%esi
  sub    $0x1,%r14
  mov    %dl,0x2750(%rsp,%rax,1)
  movslq %edi,%rdi
  lea    0x1(%r15),%rdx
  add    0x8(%rsp),%rdi
  mov    %rdx,0x10(%rsp)
  lea    0x2(%r13,%r12,1),%r13d
  call   <memset@plt>
  cmp    0x18(%rsp),%r15
  je     L47
  mov    0x10(%rsp),%r15
  jmp    L160
  nopl   0x0(%rax,%rax,1)
L47:
  mov    %ebp,%r14d
  mov    0x2c(%rsp),%ebp
L106:
  add    0x38(%rsp),%r14d
  cmp    $0xffffffff,%r14d
  jl     L85
  mov    0x3c(%rsp),%r12d
  lea    0x1(%r14),%r11d
  xor    %edi,%edi
  xor    %r9d,%r9d
  movabs $0x6666666666666667,%rbx
  lea    0x40(%rsp),%r10
  lea    (%r12,%rbp,1),%r8d
  nopw   0x0(%rax,%rax,1)
L62:
  mov    %edi,%r13d
  mov    %ebp,%edx
  xor    %eax,%eax
  xor    %ecx,%ecx
  test   %r12d,%r12d
  jle    L43
  xchg   %ax,%ax
L18:
  cmp    %edi,%edx
  jl     L97
  lea    0x0(%r13,%rcx,1),%esi
  movslq %esi,%rsi
  movsbq 0x2750(%rsp,%rsi,1),%rsi
  add    %rsi,%rax
L97:
  add    $0x1,%edx
  add    %edx,%ecx
  cmp    %edx,%r8d
  jne    L18
  add    %rax,%r9
L43:
  mov    %r9,%rax
  imul   %rbx
  mov    %r9,%rax
  sar    $0x3f,%rax
  sar    $0x2,%rdx
  sub    %rax,%rdx
  lea    (%rdx,%rdx,4),%rax
  add    %rax,%rax
  sub    %rax,%r9
  lea    0x1(%rdi),%rax
  mov    %r9b,(%r10,%rdi,1)
  mov    %rdx,%r9
  cmp    %rdi,%r11
  je     L115
  mov    %rax,%rdi
  jmp    L62
  nopl   0x0(%rax,%rax,1)
L115:
  lea    0x2(%r14),%esi
  lea    D4(%rip),%r8
  movslq %r14d,%r14
  movslq %esi,%rsi
  lea    0x1(%r8),%rcx
  add    %r14,%r10
  mov    %r8,%rax
  mov    %dl,0x40(%rsp,%rsi,1)
  add    %r11,%rcx
  nopw   0x0(%rax,%rax,1)
L149:
  movzbl 0x1(%r10),%ebx
  add    $0x1,%rax
  sub    $0x1,%r10
  lea    0x30(%rbx),%edx
  mov    %dl,-0x1(%rax)
  cmp    %rax,%rcx
  jne    L149
L86:
  movb   $0x0,(%r8,%rsi,1)
  mov    0x4e68(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L110
  add    $0x4e78,%rsp
  mov    %r8,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L85:
  lea    D4(%rip),%r8
  xor    %esi,%esi
  jmp    L86
L110:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
char *multiply(char a[], char b[]) {
  static char mul[10000];
  char c[10000];
  char temp[10000];
  int la, lb;
  int i, j, k = 0, x = 0, y;
  long int r = 0;
  long sum = 0;
  la = strlen(a) - 1;
  lb = strlen(b) - 1;
  for (i = 0; i <= la; i++) {
    a[i] = a[i] - 48;
  }
  for (i = 0; i <= lb; i++) {
    b[i] = b[i] - 48;
  }
  for (i = lb; i >= 0; i--) {
    r = 0;
    for (j = la; j >= 0; j--) {
      temp[k++] = (b[i] * a[j] + r) % 10;
      r = (b[i] * a[j] + r) / 10;
    }
    temp[k++] = r;
    x++;
    for (y = 0; y < x; y++) {
      temp[k++] = 0;
    }
  }
  k = 0;
  r = 0;
  for (i = 0; i < la + lb + 2; i++) {
    sum = 0;
    y = 0;
    for (j = 1; j <= lb + 1; j++) {
      if (i <= la + j) {
        sum = sum + temp[y + i];
      }
      y += j + la + 1;
    }
    c[k++] = (sum + r) % 10;
    r = (sum + r) / 10;
  }
  c[k] = r;
  j = 0;
  for (i = k - 1; i >= 0; i--) {
    mul[j++] = c[i] + 48;
  }
  mul[j] = '\0';
  return mul;
}
```