user: 下面的汇编指令对应的C源代码是什么:

```asm
<dmatvec>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  mov    %rcx,%r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %edi,-0x10(%rsp)
  mov    %esi,-0x28(%rsp)
  mov    %edx,-0x24(%rsp)
  mov    %r8,-0x20(%rsp)
  cmp    $0x7,%edx
  jle    L84
  movslq %edi,%rax
  mov    %edx,%ebx
  mov    %esi,%ebp
  mov    %r13,-0x8(%rsp)
  lea    (%rax,%rax,2),%rdx
  mov    %rax,%r14
  mov    %r8,%rsi
  movslq %ebp,%r12
  lea    0x0(,%rax,8),%r15
  lea    (%rcx,%rdx,8),%rcx
  shl    $0x4,%rdx
  shl    $0x4,%rax
  mov    %rdx,%r10
  lea    (%r15,%rdx,1),%rdi
  lea    -0x8(%rbx),%edx
  mov    %rax,-0x38(%rsp)
  shr    $0x3,%edx
  add    %r13,%rdi
  shl    $0x6,%r14
  mov    %edx,%ebx
  mov    %edx,-0xc(%rsp)
  mov    %rbx,%rdx
  mov    %rbx,-0x18(%rsp)
  shl    $0x6,%rdx
  lea    0x40(%r8,%rdx,1),%rbx
  mov    %r13,%rdx
  mov    %r10,%r13
  mov    %rbx,-0x30(%rsp)
  nopl   0x0(%rax,%rax,1)
L67:
  mov    -0x38(%rsp),%rax
  lea    (%r15,%rcx,1),%r8
  movsd  (%rsi),%xmm1
  lea    (%r15,%rdx,1),%rbp
  movsd  0x8(%rsi),%xmm2
  movsd  0x10(%rsi),%xmm3
  lea    (%r15,%r8,1),%r11
  lea    (%rdx,%r13,1),%r10
  lea    (%rax,%rdx,1),%rbx
  mov    -0x28(%rsp),%eax
  movsd  0x18(%rsi),%xmm4
  movsd  0x20(%rsi),%xmm5
  movsd  0x28(%rsi),%xmm6
  movsd  0x30(%rsi),%xmm7
  movsd  0x38(%rsi),%xmm8
  test   %eax,%eax
  jle    L66
  xor    %eax,%eax
  nopw   0x0(%rax,%rax,1)
L65:
  movsd  (%rdx,%rax,8),%xmm0
  movsd  0x0(%rbp,%rax,8),%xmm9
  mulsd  %xmm1,%xmm0
  mulsd  %xmm2,%xmm9
  addsd  %xmm9,%xmm0
  movsd  (%rbx,%rax,8),%xmm9
  mulsd  %xmm3,%xmm9
  addsd  %xmm9,%xmm0
  movsd  (%rcx,%rax,8),%xmm9
  mulsd  %xmm4,%xmm9
  addsd  %xmm9,%xmm0
  movsd  (%r8,%rax,8),%xmm9
  mulsd  %xmm5,%xmm9
  addsd  %xmm9,%xmm0
  movsd  (%r11,%rax,8),%xmm9
  mulsd  %xmm6,%xmm9
  addsd  %xmm9,%xmm0
  movsd  (%r10,%rax,8),%xmm9
  mulsd  %xmm7,%xmm9
  addsd  %xmm9,%xmm0
  movsd  (%rdi,%rax,8),%xmm9
  mulsd  %xmm8,%xmm9
  addsd  %xmm9,%xmm0
  addsd  (%r9,%rax,8),%xmm0
  movsd  %xmm0,(%r9,%rax,8)
  add    $0x1,%rax
  cmp    %rax,%r12
  jne    L65
L66:
  add    %r14,%rdx
  add    $0x40,%rsi
  add    %r14,%rcx
  add    %r14,%rdi
  cmp    %rsi,-0x30(%rsp)
  jne    L67
  mov    -0xc(%rsp),%eax
  mov    -0x8(%rsp),%r13
  lea    0x8(,%rax,8),%ebx
  mov    -0x18(%rsp),%rax
  add    $0x1,%rax
  imul   %r14,%rax
  add    %rax,%r13
L74:
  mov    -0x24(%rsp),%edi
  lea    -0x3(%rdi),%eax
  cmp    %ebx,%eax
  jle    L124
  movslq -0x10(%rsp),%rbp
  mov    -0x20(%rsp),%rsi
  movslq %ebx,%rax
  mov    %ebx,-0x30(%rsp)
  movslq -0x28(%rsp),%r8
  lea    0x0(%rbp,%rbp,2),%rdx
  lea    0x0(,%rbp,4),%r11d
  lea    0x0(%r13,%rdx,8),%rcx
  lea    -0x4(%rdi),%edx
  movslq %r11d,%r11
  sub    %ebx,%edx
  lea    (%rsi,%rax,8),%r10
  shl    $0x3,%r11
  mov    %r8d,%ebx
  shr    $0x2,%edx
  lea    0x0(,%rbp,8),%r14
  shl    $0x4,%rbp
  mov    %edx,%r15d
  mov    %edx,-0x38(%rsp)
  mov    %r13,%rdx
  lea    (%rax,%r15,4),%rax
  lea    0x20(%rsi,%rax,8),%r12
  nopw   0x0(%rax,%rax,1)
L46:
  movsd  (%r10),%xmm2
  movsd  0x8(%r10),%xmm3
  lea    (%r14,%rdx,1),%rdi
  lea    0x0(%rbp,%rdx,1),%rsi
  movsd  0x10(%r10),%xmm4
  movsd  0x18(%r10),%xmm5
  test   %ebx,%ebx
  jle    L52
  xor    %eax,%eax
  cs nopw 0x0(%rax,%rax,1)
L81:
  movsd  (%rdx,%rax,8),%xmm0
  movsd  (%rdi,%rax,8),%xmm1
  mulsd  %xmm2,%xmm0
  mulsd  %xmm3,%xmm1
  addsd  %xmm1,%xmm0
  movsd  (%rsi,%rax,8),%xmm1
  mulsd  %xmm4,%xmm1
  addsd  %xmm1,%xmm0
  movsd  (%rcx,%rax,8),%xmm1
  mulsd  %xmm5,%xmm1
  addsd  %xmm1,%xmm0
  addsd  (%r9,%rax,8),%xmm0
  movsd  %xmm0,(%r9,%rax,8)
  add    $0x1,%rax
  cmp    %rax,%r8
  jne    L81
L52:
  add    $0x20,%r10
  add    %r11,%rdx
  add    %r11,%rcx
  cmp    %r10,%r12
  jne    L46
  add    $0x1,%r15
  mov    -0x30(%rsp),%ebx
  mov    -0x38(%rsp),%eax
  imul   %r11,%r15
  lea    0x4(%rbx,%rax,4),%ebx
  add    %r15,%r13
L124:
  mov    -0x24(%rsp),%edi
  cmp    %ebx,%edi
  jle    L55
  movslq -0x10(%rsp),%rcx
  movslq -0x28(%rsp),%rdx
  movslq %ebx,%rbx
  mov    -0x20(%rsp),%r8
  shl    $0x3,%rcx
  mov    %rdx,%rsi
L118:
  movsd  (%r8,%rbx,8),%xmm1
  test   %esi,%esi
  jle    L62
  xor    %eax,%eax
  nopl   0x0(%rax)
L86:
  movsd  0x0(%r13,%rax,8),%xmm0
  mulsd  %xmm1,%xmm0
  addsd  (%r9,%rax,8),%xmm0
  movsd  %xmm0,(%r9,%rax,8)
  add    $0x1,%rax
  cmp    %rax,%rdx
  jne    L86
L62:
  add    $0x1,%rbx
  add    %rcx,%r13
  cmp    %ebx,%edi
  jg     L118
L55:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L84:
  xor    %ebx,%ebx
  jmp    L74
```

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