user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<smatvec>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  mov    %edi,-0x7c(%rbp)
  mov    %esi,-0x80(%rbp)
  mov    %edx,-0x84(%rbp)
  mov    %rcx,-0x90(%rbp)
  mov    %r8,-0x98(%rbp)
  mov    %r9,-0xa0(%rbp)
  mov    $0x0,%ebx
  mov    -0x90(%rbp),%rax
  mov    %rax,-0x70(%rbp)
  jmp    L51
L117:
  mov    -0x70(%rbp),%r12
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    (%r12,%rax,1),%r13
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    0x0(%r13,%rax,1),%r14
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    (%r14,%rax,1),%r15
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    (%r15,%rax,1),%rdi
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  add    %rdi,%rax
  mov    %rax,%rcx
  mov    %rcx,%r10
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  add    %rcx,%rax
  mov    %rax,%rsi
  mov    %rsi,%r11
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  add    %rsi,%rax
  mov    %rax,%r8
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x68(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x60(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x58(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x50(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x48(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x40(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x38(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x30(%rbp)
  movl   $0x0,-0x74(%rbp)
  jmp    L4
L66:
  mov    %r12,%rax
  lea    0x8(%rax),%r12
  movsd  (%rax),%xmm0
  movapd %xmm0,%xmm1
  mulsd  -0x68(%rbp),%xmm1
  mov    %r13,%rax
  lea    0x8(%rax),%r13
  movsd  (%rax),%xmm0
  mulsd  -0x60(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    %r14,%rax
  lea    0x8(%rax),%r14
  movsd  (%rax),%xmm0
  mulsd  -0x58(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    %r15,%rax
  lea    0x8(%rax),%r15
  movsd  (%rax),%xmm0
  mulsd  -0x50(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    %rdi,%rax
  lea    0x8(%rax),%rcx
  mov    %rcx,%rdi
  movsd  (%rax),%xmm0
  mulsd  -0x48(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    %r10,%rax
  lea    0x8(%rax),%rsi
  mov    %rsi,%r10
  movsd  (%rax),%xmm0
  mulsd  -0x40(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    %r11,%rax
  lea    0x8(%rax),%rcx
  mov    %rcx,%r11
  movsd  (%rax),%xmm0
  mulsd  -0x38(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    %r8,%rax
  lea    0x8(%rax),%rsi
  mov    %rsi,%r8
  movsd  (%rax),%xmm0
  mulsd  -0x30(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    -0x74(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0xa0(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x74(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0xa0(%rbp),%rax
  add    %rdx,%rax
  addsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x74(%rbp)
L4:
  mov    -0x74(%rbp),%eax
  cmp    -0x80(%rbp),%eax
  jl     L66
  mov    -0x7c(%rbp),%eax
  shl    $0x3,%eax
  cltq
  shl    $0x3,%rax
  add    %rax,-0x70(%rbp)
L51:
  mov    -0x84(%rbp),%eax
  sub    $0x7,%eax
  cmp    %eax,%ebx
  jl     L117
  jmp    L114
L53:
  mov    -0x70(%rbp),%r12
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    (%r12,%rax,1),%r13
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    0x0(%r13,%rax,1),%r14
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  lea    (%r14,%rax,1),%r15
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x68(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x60(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x58(%rbp)
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x50(%rbp)
  movl   $0x0,-0x74(%rbp)
  jmp    L42
L111:
  mov    %r12,%rax
  lea    0x8(%rax),%r12
  movsd  (%rax),%xmm0
  movapd %xmm0,%xmm1
  mulsd  -0x68(%rbp),%xmm1
  mov    %r13,%rax
  lea    0x8(%rax),%r13
  movsd  (%rax),%xmm0
  mulsd  -0x60(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    %r14,%rax
  lea    0x8(%rax),%r14
  movsd  (%rax),%xmm0
  mulsd  -0x58(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    %r15,%rax
  lea    0x8(%rax),%r15
  movsd  (%rax),%xmm0
  mulsd  -0x50(%rbp),%xmm0
  addsd  %xmm0,%xmm1
  mov    -0x74(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0xa0(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x74(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0xa0(%rbp),%rax
  add    %rdx,%rax
  addsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x74(%rbp)
L42:
  mov    -0x74(%rbp),%eax
  cmp    -0x80(%rbp),%eax
  jl     L111
  mov    -0x7c(%rbp),%eax
  shl    $0x2,%eax
  cltq
  shl    $0x3,%rax
  add    %rax,-0x70(%rbp)
L114:
  mov    -0x84(%rbp),%eax
  sub    $0x3,%eax
  cmp    %eax,%ebx
  jl     L53
  jmp    L8
L70:
  mov    -0x70(%rbp),%r12
  mov    %ebx,%eax
  lea    0x1(%rax),%ebx
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0x98(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  movsd  %xmm0,-0x68(%rbp)
  movl   $0x0,-0x74(%rbp)
  jmp    L102
L22:
  mov    %r12,%rax
  lea    0x8(%rax),%r12
  movsd  (%rax),%xmm0
  movapd %xmm0,%xmm1
  mulsd  -0x68(%rbp),%xmm1
  mov    -0x74(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0xa0(%rbp),%rax
  add    %rdx,%rax
  movsd  (%rax),%xmm0
  mov    -0x74(%rbp),%eax
  cltq
  lea    0x0(,%rax,8),%rdx
  mov    -0xa0(%rbp),%rax
  add    %rdx,%rax
  addsd  %xmm1,%xmm0
  movsd  %xmm0,(%rax)
  addl   $0x1,-0x74(%rbp)
L102:
  mov    -0x74(%rbp),%eax
  cmp    -0x80(%rbp),%eax
  jl     L22
  mov    -0x7c(%rbp),%eax
  cltq
  shl    $0x3,%rax
  add    %rax,-0x70(%rbp)
L8:
  cmp    -0x84(%rbp),%ebx
  jl     L70
  nop
  nop
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

assistant: ```c
void smatvec(ldm, nrow, ncol, M, vec, Mxvec) int ldm;
int nrow;
int ncol;
double *M;
double *vec;
double *Mxvec;
{
  double vi0, vi1, vi2, vi3, vi4, vi5, vi6, vi7;
  double *M0;
  register double *Mki0, *Mki1, *Mki2, *Mki3, *Mki4, *Mki5, *Mki6, *Mki7;
  register int firstcol = 0;
  int k;
  M0 = &M[0];
  while (firstcol < ncol - 7) {
    Mki0 = M0;
    Mki1 = Mki0 + ldm;
    Mki2 = Mki1 + ldm;
    Mki3 = Mki2 + ldm;
    Mki4 = Mki3 + ldm;
    Mki5 = Mki4 + ldm;
    Mki6 = Mki5 + ldm;
    Mki7 = Mki6 + ldm;
    vi0 = vec[firstcol++];
    vi1 = vec[firstcol++];
    vi2 = vec[firstcol++];
    vi3 = vec[firstcol++];
    vi4 = vec[firstcol++];
    vi5 = vec[firstcol++];
    vi6 = vec[firstcol++];
    vi7 = vec[firstcol++];
    for (k = 0; k < nrow; k++)
      Mxvec[k] += vi0 * *Mki0++ + vi1 * *Mki1++ + vi2 * *Mki2++ + vi3 * *Mki3++ + vi4 * *Mki4++ + vi5 * *Mki5++ + vi6 * *Mki6++ + vi7 * *Mki7++;
    M0 += 8 * ldm;
  }
  while (firstcol < ncol - 3) {
    Mki0 = M0;
    Mki1 = Mki0 + ldm;
    Mki2 = Mki1 + ldm;
    Mki3 = Mki2 + ldm;
    vi0 = vec[firstcol++];
    vi1 = vec[firstcol++];
    vi2 = vec[firstcol++];
    vi3 = vec[firstcol++];
    for (k = 0; k < nrow; k++)
      Mxvec[k] += vi0 * *Mki0++ + vi1 * *Mki1++ + vi2 * *Mki2++ + vi3 * *Mki3++;
    M0 += 4 * ldm;
  }
  while (firstcol < ncol) {
    Mki0 = M0;
    vi0 = vec[firstcol++];
    for (k = 0; k < nrow; k++)
      Mxvec[k] += vi0 * *Mki0++;
    M0 += ldm;
  }
}
```