user: 请显示与下面列出的汇编代码相匹配的C语言实现:

```asm
<helper_double_8>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  mov    %rdi,-0x18(%rbp)
  movl   $0x0,-0x10(%rbp)
  jmp    L55
L62:
  movl   $0x0,-0xc(%rbp)
  jmp    L27
L78:
  mov    -0x10(%rbp),%eax
  movslq %eax,%rdx
  mov    -0xc(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  mov    -0x10(%rbp),%edx
  movslq %edx,%rcx
  mov    -0xc(%rbp),%edx
  movslq %edx,%rdx
  add    %rcx,%rdx
  add    $0x4,%rdx
  lea    0x0(,%rdx,8),%rcx
  mov    -0x18(%rbp),%rdx
  add    %rcx,%rdx
  mov    -0x10(%rbp),%ecx
  movslq %ecx,%rsi
  mov    -0xc(%rbp),%ecx
  movslq %ecx,%rcx
  add    %rsi,%rcx
  add    $0x8,%rcx
  lea    0x0(,%rcx,8),%rsi
  mov    -0x18(%rbp),%rcx
  add    %rsi,%rcx
  mov    -0x10(%rbp),%esi
  movslq %esi,%rdi
  mov    -0xc(%rbp),%esi
  movslq %esi,%rsi
  add    %rdi,%rsi
  add    $0xc,%rsi
  lea    0x0(,%rsi,8),%rdi
  mov    -0x18(%rbp),%rsi
  add    %rdi,%rsi
  mov    -0x10(%rbp),%edi
  movslq %edi,%r8
  mov    -0xc(%rbp),%edi
  movslq %edi,%rdi
  add    %r8,%rdi
  add    $0x10,%rdi
  lea    0x0(,%rdi,8),%r8
  mov    -0x18(%rbp),%rdi
  add    %r8,%rdi
  mov    -0x10(%rbp),%r8d
  movslq %r8d,%r9
  mov    -0xc(%rbp),%r8d
  movslq %r8d,%r8
  add    %r9,%r8
  add    $0x14,%r8
  lea    0x0(,%r8,8),%r9
  mov    -0x18(%rbp),%r8
  add    %r9,%r8
  mov    -0x10(%rbp),%r9d
  movslq %r9d,%r10
  mov    -0xc(%rbp),%r9d
  movslq %r9d,%r9
  add    %r10,%r9
  add    $0x18,%r9
  lea    0x0(,%r9,8),%r10
  mov    -0x18(%rbp),%r9
  add    %r10,%r9
  mov    -0x10(%rbp),%r10d
  movslq %r10d,%r11
  mov    -0xc(%rbp),%r10d
  movslq %r10d,%r10
  add    %r11,%r10
  add    $0x1c,%r10
  lea    0x0(,%r10,8),%r11
  mov    -0x18(%rbp),%r10
  add    %r11,%r10
  vmovupd (%rax),%ymm0
  vmovupd (%rdx),%ymm1
  vmovupd (%rcx),%ymm2
  vmovupd (%rsi),%ymm3
  vmovupd (%rdi),%ymm4
  vmovupd (%r8),%ymm5
  vmovupd (%r9),%ymm6
  vmovupd (%r10),%ymm7
  vpermilpd $0x0,%ymm0,%ymm8
  vpermilpd $0xf,%ymm0,%ymm9
  vxorpd %ymm10,%ymm10,%ymm10
  vsubpd %ymm9,%ymm10,%ymm11
  vaddsubpd %ymm11,%ymm8,%ymm0
  vpermilpd $0x0,%ymm1,%ymm8
  vpermilpd $0xf,%ymm1,%ymm9
  vxorpd %ymm10,%ymm10,%ymm10
  vsubpd %ymm9,%ymm10,%ymm11
  vaddsubpd %ymm11,%ymm8,%ymm1
  vpermilpd $0x0,%ymm2,%ymm8
  vpermilpd $0xf,%ymm2,%ymm9
  vxorpd %ymm10,%ymm10,%ymm10
  vsubpd %ymm9,%ymm10,%ymm11
  vaddsubpd %ymm11,%ymm8,%ymm2
  vpermilpd $0x0,%ymm3,%ymm8
  vpermilpd $0xf,%ymm3,%ymm9
  vxorpd %ymm10,%ymm10,%ymm10
  vsubpd %ymm9,%ymm10,%ymm11
  vaddsubpd %ymm11,%ymm8,%ymm3
  vpermilpd $0x0,%ymm4,%ymm8
  vpermilpd $0xf,%ymm4,%ymm9
  vxorpd %ymm10,%ymm10,%ymm10
  vsubpd %ymm9,%ymm10,%ymm11
  vaddsubpd %ymm11,%ymm8,%ymm4
  vpermilpd $0x0,%ymm5,%ymm8
  vpermilpd $0xf,%ymm5,%ymm9
  vxorpd %ymm10,%ymm10,%ymm10
  vsubpd %ymm9,%ymm10,%ymm11
  vaddsubpd %ymm11,%ymm8,%ymm5
  vpermilpd $0x0,%ymm6,%ymm8
  vpermilpd $0xf,%ymm6,%ymm9
  vxorpd %ymm10,%ymm10,%ymm10
  vsubpd %ymm9,%ymm10,%ymm11
  vaddsubpd %ymm11,%ymm8,%ymm6
  vpermilpd $0x0,%ymm7,%ymm8
  vpermilpd $0xf,%ymm7,%ymm9
  vxorpd %ymm10,%ymm10,%ymm10
  vsubpd %ymm9,%ymm10,%ymm11
  vaddsubpd %ymm11,%ymm8,%ymm7
  vperm2f128 $0x0,%ymm0,%ymm0,%ymm8
  vxorpd %ymm9,%ymm9,%ymm9
  vsubpd %ymm0,%ymm9,%ymm10
  vperm2f128 $0x31,%ymm10,%ymm0,%ymm11
  vaddpd %ymm11,%ymm8,%ymm0
  vperm2f128 $0x0,%ymm1,%ymm1,%ymm8
  vxorpd %ymm9,%ymm9,%ymm9
  vsubpd %ymm1,%ymm9,%ymm10
  vperm2f128 $0x31,%ymm10,%ymm1,%ymm11
  vaddpd %ymm11,%ymm8,%ymm1
  vperm2f128 $0x0,%ymm2,%ymm2,%ymm8
  vxorpd %ymm9,%ymm9,%ymm9
  vsubpd %ymm2,%ymm9,%ymm10
  vperm2f128 $0x31,%ymm10,%ymm2,%ymm11
  vaddpd %ymm11,%ymm8,%ymm2
  vperm2f128 $0x0,%ymm3,%ymm3,%ymm8
  vxorpd %ymm9,%ymm9,%ymm9
  vsubpd %ymm3,%ymm9,%ymm10
  vperm2f128 $0x31,%ymm10,%ymm3,%ymm11
  vaddpd %ymm11,%ymm8,%ymm3
  vperm2f128 $0x0,%ymm4,%ymm4,%ymm8
  vxorpd %ymm9,%ymm9,%ymm9
  vsubpd %ymm4,%ymm9,%ymm10
  vperm2f128 $0x31,%ymm10,%ymm4,%ymm11
  vaddpd %ymm11,%ymm8,%ymm4
  vperm2f128 $0x0,%ymm5,%ymm5,%ymm8
  vxorpd %ymm9,%ymm9,%ymm9
  vsubpd %ymm5,%ymm9,%ymm10
  vperm2f128 $0x31,%ymm10,%ymm5,%ymm11
  vaddpd %ymm11,%ymm8,%ymm5
  vperm2f128 $0x0,%ymm6,%ymm6,%ymm8
  vxorpd %ymm9,%ymm9,%ymm9
  vsubpd %ymm6,%ymm9,%ymm10
  vperm2f128 $0x31,%ymm10,%ymm6,%ymm11
  vaddpd %ymm11,%ymm8,%ymm6
  vperm2f128 $0x0,%ymm7,%ymm7,%ymm8
  vxorpd %ymm9,%ymm9,%ymm9
  vsubpd %ymm7,%ymm9,%ymm10
  vperm2f128 $0x31,%ymm10,%ymm7,%ymm11
  vaddpd %ymm11,%ymm8,%ymm7
  vaddpd %ymm1,%ymm0,%ymm8
  vsubpd %ymm1,%ymm0,%ymm9
  vaddpd %ymm3,%ymm2,%ymm10
  vsubpd %ymm3,%ymm2,%ymm11
  vaddpd %ymm5,%ymm4,%ymm12
  vsubpd %ymm5,%ymm4,%ymm13
  vaddpd %ymm7,%ymm6,%ymm14
  vsubpd %ymm7,%ymm6,%ymm15
  vaddpd %ymm10,%ymm8,%ymm0
  vsubpd %ymm10,%ymm8,%ymm2
  vaddpd %ymm11,%ymm9,%ymm1
  vsubpd %ymm11,%ymm9,%ymm3
  vaddpd %ymm14,%ymm12,%ymm4
  vsubpd %ymm14,%ymm12,%ymm6
  vaddpd %ymm15,%ymm13,%ymm5
  vsubpd %ymm15,%ymm13,%ymm7
  vaddpd %ymm4,%ymm0,%ymm8
  vsubpd %ymm4,%ymm0,%ymm12
  vaddpd %ymm5,%ymm1,%ymm9
  vsubpd %ymm5,%ymm1,%ymm13
  vaddpd %ymm6,%ymm2,%ymm10
  vsubpd %ymm6,%ymm2,%ymm14
  vaddpd %ymm7,%ymm3,%ymm11
  vsubpd %ymm7,%ymm3,%ymm15
  vmovupd %ymm8,(%rax)
  vmovupd %ymm9,(%rdx)
  vmovupd %ymm10,(%rcx)
  vmovupd %ymm11,(%rsi)
  vmovupd %ymm12,(%rdi)
  vmovupd %ymm13,(%r8)
  vmovupd %ymm14,(%r9)
  vmovupd %ymm15,(%r10)
  addl   $0x4,-0xc(%rbp)
L27:
  cmpl   $0x3,-0xc(%rbp)
  jle    L78
  addl   $0x20,-0x10(%rbp)
L55:
  cmpl   $0xff,-0x10(%rbp)
  jle    L62
  movl   $0x0,-0x8(%rbp)
  jmp    L42
L39:
  movl   $0x0,-0x4(%rbp)
  jmp    L21
L47:
  mov    -0x8(%rbp),%eax
  movslq %eax,%rdx
  mov    -0x4(%rbp),%eax
  cltq
  add    %rdx,%rax
  lea    0x0(,%rax,8),%rdx
  mov    -0x18(%rbp),%rax
  add    %rdx,%rax
  mov    -0x8(%rbp),%edx
  movslq %edx,%rcx
  mov    -0x4(%rbp),%edx
  movslq %edx,%rdx
  add    %rcx,%rdx
  add    $0x20,%rdx
  lea    0x0(,%rdx,8),%rcx
  mov    -0x18(%rbp),%rdx
  add    %rcx,%rdx
  mov    -0x8(%rbp),%ecx
  movslq %ecx,%rsi
  mov    -0x4(%rbp),%ecx
  movslq %ecx,%rcx
  add    %rsi,%rcx
  add    $0x40,%rcx
  lea    0x0(,%rcx,8),%rsi
  mov    -0x18(%rbp),%rcx
  add    %rsi,%rcx
  mov    -0x8(%rbp),%esi
  movslq %esi,%rdi
  mov    -0x4(%rbp),%esi
  movslq %esi,%rsi
  add    %rdi,%rsi
  add    $0x60,%rsi
  lea    0x0(,%rsi,8),%rdi
  mov    -0x18(%rbp),%rsi
  add    %rdi,%rsi
  mov    -0x8(%rbp),%edi
  movslq %edi,%r8
  mov    -0x4(%rbp),%edi
  movslq %edi,%rdi
  add    %r8,%rdi
  sub    $0xffffffffffffff80,%rdi
  lea    0x0(,%rdi,8),%r8
  mov    -0x18(%rbp),%rdi
  add    %r8,%rdi
  mov    -0x8(%rbp),%r8d
  movslq %r8d,%r9
  mov    -0x4(%rbp),%r8d
  movslq %r8d,%r8
  add    %r9,%r8
  add    $0xa0,%r8
  lea    0x0(,%r8,8),%r9
  mov    -0x18(%rbp),%r8
  add    %r9,%r8
  mov    -0x8(%rbp),%r9d
  movslq %r9d,%r10
  mov    -0x4(%rbp),%r9d
  movslq %r9d,%r9
  add    %r10,%r9
  add    $0xc0,%r9
  lea    0x0(,%r9,8),%r10
  mov    -0x18(%rbp),%r9
  add    %r10,%r9
  mov    -0x8(%rbp),%r10d
  movslq %r10d,%r11
  mov    -0x4(%rbp),%r10d
  movslq %r10d,%r10
  add    %r11,%r10
  add    $0xe0,%r10
  lea    0x0(,%r10,8),%r11
  mov    -0x18(%rbp),%r10
  add    %r11,%r10
  vmovupd (%rax),%ymm0
  vmovupd (%rdx),%ymm1
  vmovupd (%rcx),%ymm2
  vmovupd (%rsi),%ymm3
  vmovupd (%rdi),%ymm4
  vmovupd (%r8),%ymm5
  vmovupd (%r9),%ymm6
  vmovupd (%r10),%ymm7
  vaddpd %ymm1,%ymm0,%ymm8
  vsubpd %ymm1,%ymm0,%ymm9
  vaddpd %ymm3,%ymm2,%ymm10
  vsubpd %ymm3,%ymm2,%ymm11
  vaddpd %ymm5,%ymm4,%ymm12
  vsubpd %ymm5,%ymm4,%ymm13
  vaddpd %ymm7,%ymm6,%ymm14
  vsubpd %ymm7,%ymm6,%ymm15
  vaddpd %ymm10,%ymm8,%ymm0
  vsubpd %ymm10,%ymm8,%ymm2
  vaddpd %ymm11,%ymm9,%ymm1
  vsubpd %ymm11,%ymm9,%ymm3
  vaddpd %ymm14,%ymm12,%ymm4
  vsubpd %ymm14,%ymm12,%ymm6
  vaddpd %ymm15,%ymm13,%ymm5
  vsubpd %ymm15,%ymm13,%ymm7
  vaddpd %ymm4,%ymm0,%ymm8
  vsubpd %ymm4,%ymm0,%ymm12
  vaddpd %ymm5,%ymm1,%ymm9
  vsubpd %ymm5,%ymm1,%ymm13
  vaddpd %ymm6,%ymm2,%ymm10
  vsubpd %ymm6,%ymm2,%ymm14
  vaddpd %ymm7,%ymm3,%ymm11
  vsubpd %ymm7,%ymm3,%ymm15
  vmovupd %ymm8,(%rax)
  vmovupd %ymm9,(%rdx)
  vmovupd %ymm10,(%rcx)
  vmovupd %ymm11,(%rsi)
  vmovupd %ymm12,(%rdi)
  vmovupd %ymm13,(%r8)
  vmovupd %ymm14,(%r9)
  vmovupd %ymm15,(%r10)
  addl   $0x4,-0x4(%rbp)
L21:
  cmpl   $0x1f,-0x4(%rbp)
  jle    L47
  addl   $0x100,-0x8(%rbp)
L42:
  cmpl   $0xff,-0x8(%rbp)
  jle    L39
  nop
  nop
  pop    %rbp
  ret
```

assistant: ```c
void helper_double_8(double *buf) {
  for (int j = 0; j < 256; j += 32) {
    for (int k = 0; k < 4; k += 4) {
      __asm__ volatile("vmovupd (%0), %%ymm0\n"
                       "vmovupd (%1), %%ymm1\n"
                       "vmovupd (%2), %%ymm2\n"
                       "vmovupd (%3), %%ymm3\n"
                       "vmovupd (%4), %%ymm4\n"
                       "vmovupd (%5), %%ymm5\n"
                       "vmovupd (%6), %%ymm6\n"
                       "vmovupd (%7), %%ymm7\n"
                       "vpermilpd $0, %%ymm0, %%ymm8\n"
                       "vpermilpd $15, %%ymm0, %%ymm9\n"
                       "vxorpd %%ymm10, %%ymm10, %%ymm10\n"
                       "vsubpd %%ymm9, %%ymm10, %%ymm11\n"
                       "vaddsubpd %%ymm11, %%ymm8, %%ymm0\n"
                       "vpermilpd $0, %%ymm1, %%ymm8\n"
                       "vpermilpd $15, %%ymm1, %%ymm9\n"
                       "vxorpd %%ymm10, %%ymm10, %%ymm10\n"
                       "vsubpd %%ymm9, %%ymm10, %%ymm11\n"
                       "vaddsubpd %%ymm11, %%ymm8, %%ymm1\n"
                       "vpermilpd $0, %%ymm2, %%ymm8\n"
                       "vpermilpd $15, %%ymm2, %%ymm9\n"
                       "vxorpd %%ymm10, %%ymm10, %%ymm10\n"
                       "vsubpd %%ymm9, %%ymm10, %%ymm11\n"
                       "vaddsubpd %%ymm11, %%ymm8, %%ymm2\n"
                       "vpermilpd $0, %%ymm3, %%ymm8\n"
                       "vpermilpd $15, %%ymm3, %%ymm9\n"
                       "vxorpd %%ymm10, %%ymm10, %%ymm10\n"
                       "vsubpd %%ymm9, %%ymm10, %%ymm11\n"
                       "vaddsubpd %%ymm11, %%ymm8, %%ymm3\n"
                       "vpermilpd $0, %%ymm4, %%ymm8\n"
                       "vpermilpd $15, %%ymm4, %%ymm9\n"
                       "vxorpd %%ymm10, %%ymm10, %%ymm10\n"
                       "vsubpd %%ymm9, %%ymm10, %%ymm11\n"
                       "vaddsubpd %%ymm11, %%ymm8, %%ymm4\n"
                       "vpermilpd $0, %%ymm5, %%ymm8\n"
                       "vpermilpd $15, %%ymm5, %%ymm9\n"
                       "vxorpd %%ymm10, %%ymm10, %%ymm10\n"
                       "vsubpd %%ymm9, %%ymm10, %%ymm11\n"
                       "vaddsubpd %%ymm11, %%ymm8, %%ymm5\n"
                       "vpermilpd $0, %%ymm6, %%ymm8\n"
                       "vpermilpd $15, %%ymm6, %%ymm9\n"
                       "vxorpd %%ymm10, %%ymm10, %%ymm10\n"
                       "vsubpd %%ymm9, %%ymm10, %%ymm11\n"
                       "vaddsubpd %%ymm11, %%ymm8, %%ymm6\n"
                       "vpermilpd $0, %%ymm7, %%ymm8\n"
                       "vpermilpd $15, %%ymm7, %%ymm9\n"
                       "vxorpd %%ymm10, %%ymm10, %%ymm10\n"
                       "vsubpd %%ymm9, %%ymm10, %%ymm11\n"
                       "vaddsubpd %%ymm11, %%ymm8, %%ymm7\n"
                       "vperm2f128 $0, %%ymm0, %%ymm0, %%ymm8\n"
                       "vxorpd %%ymm9, %%ymm9, %%ymm9\n"
                       "vsubpd %%ymm0, %%ymm9, %%ymm10\n"
                       "vperm2f128 $49, %%ymm10, %%ymm0, %%ymm11\n"
                       "vaddpd %%ymm11, %%ymm8, %%ymm0\n"
                       "vperm2f128 $0, %%ymm1, %%ymm1, %%ymm8\n"
                       "vxorpd %%ymm9, %%ymm9, %%ymm9\n"
                       "vsubpd %%ymm1, %%ymm9, %%ymm10\n"
                       "vperm2f128 $49, %%ymm10, %%ymm1, %%ymm11\n"
                       "vaddpd %%ymm11, %%ymm8, %%ymm1\n"
                       "vperm2f128 $0, %%ymm2, %%ymm2, %%ymm8\n"
                       "vxorpd %%ymm9, %%ymm9, %%ymm9\n"
                       "vsubpd %%ymm2, %%ymm9, %%ymm10\n"
                       "vperm2f128 $49, %%ymm10, %%ymm2, %%ymm11\n"
                       "vaddpd %%ymm11, %%ymm8, %%ymm2\n"
                       "vperm2f128 $0, %%ymm3, %%ymm3, %%ymm8\n"
                       "vxorpd %%ymm9, %%ymm9, %%ymm9\n"
                       "vsubpd %%ymm3, %%ymm9, %%ymm10\n"
                       "vperm2f128 $49, %%ymm10, %%ymm3, %%ymm11\n"
                       "vaddpd %%ymm11, %%ymm8, %%ymm3\n"
                       "vperm2f128 $0, %%ymm4, %%ymm4, %%ymm8\n"
                       "vxorpd %%ymm9, %%ymm9, %%ymm9\n"
                       "vsubpd %%ymm4, %%ymm9, %%ymm10\n"
                       "vperm2f128 $49, %%ymm10, %%ymm4, %%ymm11\n"
                       "vaddpd %%ymm11, %%ymm8, %%ymm4\n"
                       "vperm2f128 $0, %%ymm5, %%ymm5, %%ymm8\n"
                       "vxorpd %%ymm9, %%ymm9, %%ymm9\n"
                       "vsubpd %%ymm5, %%ymm9, %%ymm10\n"
                       "vperm2f128 $49, %%ymm10, %%ymm5, %%ymm11\n"
                       "vaddpd %%ymm11, %%ymm8, %%ymm5\n"
                       "vperm2f128 $0, %%ymm6, %%ymm6, %%ymm8\n"
                       "vxorpd %%ymm9, %%ymm9, %%ymm9\n"
                       "vsubpd %%ymm6, %%ymm9, %%ymm10\n"
                       "vperm2f128 $49, %%ymm10, %%ymm6, %%ymm11\n"
                       "vaddpd %%ymm11, %%ymm8, %%ymm6\n"
                       "vperm2f128 $0, %%ymm7, %%ymm7, %%ymm8\n"
                       "vxorpd %%ymm9, %%ymm9, %%ymm9\n"
                       "vsubpd %%ymm7, %%ymm9, %%ymm10\n"
                       "vperm2f128 $49, %%ymm10, %%ymm7, %%ymm11\n"
                       "vaddpd %%ymm11, %%ymm8, %%ymm7\n"
                       "vaddpd %%ymm1, %%ymm0, %%ymm8\n"
                       "vsubpd %%ymm1, %%ymm0, %%ymm9\n"
                       "vaddpd %%ymm3, %%ymm2, %%ymm10\n"
                       "vsubpd %%ymm3, %%ymm2, %%ymm11\n"
                       "vaddpd %%ymm5, %%ymm4, %%ymm12\n"
                       "vsubpd %%ymm5, %%ymm4, %%ymm13\n"
                       "vaddpd %%ymm7, %%ymm6, %%ymm14\n"
                       "vsubpd %%ymm7, %%ymm6, %%ymm15\n"
                       "vaddpd %%ymm10, %%ymm8, %%ymm0\n"
                       "vsubpd %%ymm10, %%ymm8, %%ymm2\n"
                       "vaddpd %%ymm11, %%ymm9, %%ymm1\n"
                       "vsubpd %%ymm11, %%ymm9, %%ymm3\n"
                       "vaddpd %%ymm14, %%ymm12, %%ymm4\n"
                       "vsubpd %%ymm14, %%ymm12, %%ymm6\n"
                       "vaddpd %%ymm15, %%ymm13, %%ymm5\n"
                       "vsubpd %%ymm15, %%ymm13, %%ymm7\n"
                       "vaddpd %%ymm4, %%ymm0, %%ymm8\n"
                       "vsubpd %%ymm4, %%ymm0, %%ymm12\n"
                       "vaddpd %%ymm5, %%ymm1, %%ymm9\n"
                       "vsubpd %%ymm5, %%ymm1, %%ymm13\n"
                       "vaddpd %%ymm6, %%ymm2, %%ymm10\n"
                       "vsubpd %%ymm6, %%ymm2, %%ymm14\n"
                       "vaddpd %%ymm7, %%ymm3, %%ymm11\n"
                       "vsubpd %%ymm7, %%ymm3, %%ymm15\n"
                       "vmovupd %%ymm8, (%0)\n"
                       "vmovupd %%ymm9, (%1)\n"
                       "vmovupd %%ymm10, (%2)\n"
                       "vmovupd %%ymm11, (%3)\n"
                       "vmovupd %%ymm12, (%4)\n"
                       "vmovupd %%ymm13, (%5)\n"
                       "vmovupd %%ymm14, (%6)\n"
                       "vmovupd %%ymm15, (%7)\n" ::"r"(buf + j + k + 0),
                       "r"(buf + j + k + 4), "r"(buf + j + k + 8), "r"(buf + j + k + 12), "r"(buf + j + k + 16), "r"(buf + j + k + 20), "r"(buf + j + k + 24), "r"(buf + j + k + 28)
                       : "%ymm0", "%ymm1", "%ymm2", "%ymm3", "%ymm4", "%ymm5", "%ymm6", "%ymm7", "%ymm8", "%ymm9", "%ymm10", "%ymm11", "%ymm12", "%ymm13", "%ymm14", "%ymm15", "memory");
    }
  }
  for (int j = 0; j < 256; j += 256) {
    for (int k = 0; k < 32; k += 4) {
      __asm__ volatile("vmovupd (%0), %%ymm0\n"
                       "vmovupd (%1), %%ymm1\n"
                       "vmovupd (%2), %%ymm2\n"
                       "vmovupd (%3), %%ymm3\n"
                       "vmovupd (%4), %%ymm4\n"
                       "vmovupd (%5), %%ymm5\n"
                       "vmovupd (%6), %%ymm6\n"
                       "vmovupd (%7), %%ymm7\n"
                       "vaddpd %%ymm1, %%ymm0, %%ymm8\n"
                       "vsubpd %%ymm1, %%ymm0, %%ymm9\n"
                       "vaddpd %%ymm3, %%ymm2, %%ymm10\n"
                       "vsubpd %%ymm3, %%ymm2, %%ymm11\n"
                       "vaddpd %%ymm5, %%ymm4, %%ymm12\n"
                       "vsubpd %%ymm5, %%ymm4, %%ymm13\n"
                       "vaddpd %%ymm7, %%ymm6, %%ymm14\n"
                       "vsubpd %%ymm7, %%ymm6, %%ymm15\n"
                       "vaddpd %%ymm10, %%ymm8, %%ymm0\n"
                       "vsubpd %%ymm10, %%ymm8, %%ymm2\n"
                       "vaddpd %%ymm11, %%ymm9, %%ymm1\n"
                       "vsubpd %%ymm11, %%ymm9, %%ymm3\n"
                       "vaddpd %%ymm14, %%ymm12, %%ymm4\n"
                       "vsubpd %%ymm14, %%ymm12, %%ymm6\n"
                       "vaddpd %%ymm15, %%ymm13, %%ymm5\n"
                       "vsubpd %%ymm15, %%ymm13, %%ymm7\n"
                       "vaddpd %%ymm4, %%ymm0, %%ymm8\n"
                       "vsubpd %%ymm4, %%ymm0, %%ymm12\n"
                       "vaddpd %%ymm5, %%ymm1, %%ymm9\n"
                       "vsubpd %%ymm5, %%ymm1, %%ymm13\n"
                       "vaddpd %%ymm6, %%ymm2, %%ymm10\n"
                       "vsubpd %%ymm6, %%ymm2, %%ymm14\n"
                       "vaddpd %%ymm7, %%ymm3, %%ymm11\n"
                       "vsubpd %%ymm7, %%ymm3, %%ymm15\n"
                       "vmovupd %%ymm8, (%0)\n"
                       "vmovupd %%ymm9, (%1)\n"
                       "vmovupd %%ymm10, (%2)\n"
                       "vmovupd %%ymm11, (%3)\n"
                       "vmovupd %%ymm12, (%4)\n"
                       "vmovupd %%ymm13, (%5)\n"
                       "vmovupd %%ymm14, (%6)\n"
                       "vmovupd %%ymm15, (%7)\n" ::"r"(buf + j + k + 0),
                       "r"(buf + j + k + 32), "r"(buf + j + k + 64), "r"(buf + j + k + 96), "r"(buf + j + k + 128), "r"(buf + j + k + 160), "r"(buf + j + k + 192), "r"(buf + j + k + 224)
                       : "%ymm0", "%ymm1", "%ymm2", "%ymm3", "%ymm4", "%ymm5", "%ymm6", "%ymm7", "%ymm8", "%ymm9", "%ymm10", "%ymm11", "%ymm12", "%ymm13", "%ymm14", "%ymm15", "memory");
    }
  }
}
```