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

```asm
<memcpy>:
  endbr64
  mov    %rdi,%rax
  mov    %rdx,%rcx
  xor    %rsi,%rax
  and    $0x7,%eax
  jne    L190
  test   $0x7,%sil
  je     L118
  lea    -0x1(%rdx),%r8
  test   %rdx,%rdx
  jne    L234
  jmp    L53
  xchg   %ax,%ax
L249:
  sub    $0x1,%r8
  jb     L122
L234:
  movsb  %ds:(%rsi),%es:(%rdi)
  test   $0x7,%sil
  jne    L249
L231:
  mov    %r8,%rcx
  cmp    $0x7,%r8
  jbe    L190
L122:
  lea    0x8(%rsi),%rdx
  lea    -0x8(%r8),%r9
  cmp    %rdx,%rdi
  je     L272
  cmp    $0x17,%r9
  jbe    L272
  mov    %r9,%rcx
  shr    $0x3,%rcx
  add    $0x1,%rcx
  mov    %rcx,%rdx
  shr    %rdx
  shl    $0x4,%rdx
  nopw   0x0(%rax,%rax,1)
L138:
  movdqu (%rsi,%rax,1),%xmm1
  movups %xmm1,(%rdi,%rax,1)
  add    $0x10,%rax
  cmp    %rdx,%rax
  jne    L138
  mov    %rcx,%r10
  and    $0xfffffffffffffffe,%r10
  lea    0x0(,%r10,8),%rax
  lea    (%rdi,%rax,1),%rdx
  add    %rsi,%rax
  cmp    %r10,%rcx
  je     L78
  mov    (%rax),%rax
  mov    %rax,(%rdx)
L78:
  shr    $0x3,%r9
  mov    %r8,%rcx
  lea    0x8(,%r9,8),%rax
  and    $0x7,%ecx
  add    %rax,%rdi
  add    %rax,%rsi
L190:
  lea    -0x1(%rcx),%r8
  test   %rcx,%rcx
  je     L102
  lea    0x1(%rsi),%rdx
  mov    %rdi,%rax
  sub    %rdx,%rax
  cmp    $0xe,%rax
  jbe    L211
  cmp    $0x6,%r8
  jbe    L211
  cmp    $0xe,%r8
  jbe    L126
  mov    %rcx,%rdx
  xor    %eax,%eax
  and    $0xfffffffffffffff0,%rdx
  nopl   0x0(%rax)
L224:
  movdqu (%rsi,%rax,1),%xmm0
  movups %xmm0,(%rdi,%rax,1)
  add    $0x10,%rax
  cmp    %rax,%rdx
  jne    L224
  mov    %rcx,%rax
  and    $0xfffffffffffffff0,%rax
  lea    (%rdi,%rax,1),%rdx
  lea    (%rsi,%rax,1),%r9
  sub    %rax,%r8
  cmp    %rax,%rcx
  je     L113
  sub    %rax,%rcx
  lea    -0x1(%rcx),%r10
  cmp    $0x6,%r10
  jbe    L260
L276:
  mov    (%rsi,%rax,1),%rsi
  mov    %rsi,(%rdi,%rax,1)
  mov    %rcx,%rax
  and    $0xfffffffffffffff8,%rax
  add    %rax,%rdx
  add    %rax,%r9
  sub    %rax,%r8
  cmp    %rax,%rcx
  je     L113
L260:
  movzbl (%r9),%eax
  mov    %al,(%rdx)
  test   %r8,%r8
  je     L113
  movzbl 0x1(%r9),%eax
  mov    %al,0x1(%rdx)
  cmp    $0x1,%r8
  je     L113
  movzbl 0x2(%r9),%eax
  mov    %al,0x2(%rdx)
  cmp    $0x2,%r8
  je     L113
  movzbl 0x3(%r9),%eax
  mov    %al,0x3(%rdx)
  cmp    $0x3,%r8
  je     L113
  movzbl 0x4(%r9),%eax
  mov    %al,0x4(%rdx)
  cmp    $0x4,%r8
  je     L113
  movzbl 0x5(%r9),%eax
  mov    %al,0x5(%rdx)
  cmp    $0x5,%r8
  je     L113
  movzbl 0x6(%r9),%eax
  mov    %al,0x6(%rdx)
  ret
  nopl   0x0(%rax)
L211:
  xor    %eax,%eax
  nopw   0x0(%rax,%rax,1)
L47:
  movzbl (%rsi,%rax,1),%edx
  mov    %dl,(%rdi,%rax,1)
  add    $0x1,%rax
  cmp    %rax,%rcx
  jne    L47
L113:
  ret
  nopl   0x0(%rax)
L102:
  ret
L272:
  mov    %r9,%rdx
  shr    $0x3,%rdx
  lea    0x8(,%rdx,8),%rcx
  nopl   0x0(%rax,%rax,1)
L250:
  mov    (%rsi,%rax,1),%rdx
  mov    %rdx,(%rdi,%rax,1)
  add    $0x8,%rax
  cmp    %rax,%rcx
  jne    L250
  jmp    L78
L126:
  mov    %rsi,%r9
  mov    %rdi,%rdx
  xor    %eax,%eax
  jmp    L276
L118:
  mov    %rdx,%r8
  jmp    L231
L53:
  mov    $0xffffffffffffffff,%r8
  jmp    L122
```

assistant: ```c
void memcpy(void *dest, const void *src, size_t size) {
  char *destc = (char *)dest;
  const char *srcc = (const char *)src;
  if ((uintptr_t)srcc % sizeof(size_t) == (uintptr_t)destc % sizeof(size_t)) {
    while ((uintptr_t)srcc % sizeof(size_t) && size--) {
      *destc++ = *srcc++;
    }
    for (; size >= sizeof(size_t); size -= sizeof(size_t), destc += sizeof(size_t), srcc += sizeof(size_t)) {
      *(size_t *)destc = *(size_t *)srcc;
    }
  }
  while (size--) {
    *destc++ = *srcc++;
  }
}
```