user: 请从给定的汇编指令推导出C源代码：

```asm
<kernel_dtrmm_nt_l_2x2_lib4>:
  endbr64
  mov    %rdx,%r8
  mov    %rcx,%r9
  cmp    $0x4,%edi
  jle    L27
  sub    $0x5,%edi
  mov    %edi,%eax
  shr    $0x2,%eax
  cmp    $0x3,%edi
  jbe    L20
  pxor   %xmm8,%xmm8
  mov    %rsi,%rcx
  xor    %edi,%edi
  movapd %xmm8,%xmm10
  nopl   0x0(%rax,%rax,1)
L6:
  movupd (%rdx),%xmm6
  movupd (%rcx),%xmm2
  add    $0x1,%edi
  sub    $0xffffffffffffff80,%rcx
  movupd -0x60(%rcx),%xmm4
  movlpd -0x78(%rcx),%xmm4
  sub    $0xffffffffffffff80,%rdx
  movhpd -0x60(%rdx),%xmm6
  movhpd -0x60(%rcx),%xmm2
  movupd -0x40(%rdx),%xmm5
  movupd -0x40(%rcx),%xmm0
  movapd %xmm6,%xmm9
  movupd -0x20(%rcx),%xmm3
  movlpd -0x38(%rcx),%xmm3
  mulpd  %xmm2,%xmm9
  movhpd -0x20(%rdx),%xmm5
  movhpd -0x20(%rcx),%xmm0
  mulpd  %xmm4,%xmm6
  movapd %xmm5,%xmm7
  mulpd  %xmm0,%xmm7
  mulpd  %xmm3,%xmm5
  movapd %xmm9,%xmm1
  unpcklpd %xmm6,%xmm1
  unpckhpd %xmm6,%xmm9
  addpd  %xmm10,%xmm1
  movapd %xmm7,%xmm6
  unpcklpd %xmm5,%xmm6
  unpckhpd %xmm5,%xmm7
  movupd -0x60(%rdx),%xmm5
  movlpd -0x78(%rdx),%xmm5
  addpd  %xmm9,%xmm1
  mulpd  %xmm5,%xmm2
  mulpd  %xmm5,%xmm4
  addpd  %xmm6,%xmm1
  addpd  %xmm7,%xmm1
  movapd %xmm1,%xmm10
  movupd -0x20(%rdx),%xmm1
  movlpd -0x38(%rdx),%xmm1
  mulpd  %xmm1,%xmm0
  mulpd  %xmm1,%xmm3
  movapd %xmm2,%xmm1
  unpckhpd %xmm4,%xmm2
  unpcklpd %xmm4,%xmm1
  addpd  %xmm8,%xmm1
  addpd  %xmm2,%xmm1
  movapd %xmm0,%xmm2
  unpckhpd %xmm3,%xmm0
  unpcklpd %xmm3,%xmm2
  addpd  %xmm2,%xmm1
  addpd  %xmm0,%xmm1
  movapd %xmm1,%xmm8
  cmp    %edi,%eax
  ja     L6
  mov    %eax,%edx
  shl    $0x7,%rdx
  lea    (%rsi,%rdx,1),%rcx
  add    %r8,%rdx
L36:
  movupd (%rdx),%xmm0
  movupd (%rcx),%xmm9
  add    $0x1,%eax
  movupd 0x20(%rdx),%xmm6
  movupd 0x20(%rcx),%xmm7
  shl    $0x7,%rax
  movapd %xmm0,%xmm1
  movupd 0x40(%rdx),%xmm3
  add    %rax,%rsi
  add    %rax,%r8
  unpcklpd %xmm0,%xmm1
  unpckhpd %xmm0,%xmm0
  movupd 0x40(%rcx),%xmm5
  movupd 0x60(%rdx),%xmm2
  mulpd  %xmm9,%xmm1
  movupd 0x60(%rcx),%xmm4
  mulpd  %xmm9,%xmm0
  addpd  %xmm10,%xmm1
  movapd %xmm6,%xmm10
  unpcklpd %xmm6,%xmm10
  unpckhpd %xmm6,%xmm6
  addpd  %xmm8,%xmm0
  mulpd  %xmm7,%xmm10
  mulpd  %xmm7,%xmm6
  addpd  %xmm10,%xmm1
  movapd %xmm3,%xmm10
  unpcklpd %xmm3,%xmm10
  unpckhpd %xmm3,%xmm3
  addpd  %xmm6,%xmm0
  mulpd  %xmm5,%xmm10
  mulpd  %xmm5,%xmm3
  addpd  %xmm10,%xmm1
  movapd %xmm2,%xmm10
  unpcklpd %xmm2,%xmm10
  unpckhpd %xmm2,%xmm2
  addpd  %xmm3,%xmm0
  mulpd  %xmm4,%xmm10
  mulpd  %xmm4,%xmm2
  addpd  %xmm10,%xmm1
  addpd  %xmm2,%xmm0
L41:
  movupd (%r8),%xmm2
  movupd (%rsi),%xmm4
  movapd %xmm2,%xmm3
  unpcklpd %xmm2,%xmm3
  unpckhpd %xmm2,%xmm2
  mulpd  %xmm4,%xmm3
  mulpd  %xmm4,%xmm2
  addpd  %xmm3,%xmm1
  addpd  %xmm0,%xmm2
  movups %xmm1,(%r9)
  movupd 0x20(%r8),%xmm3
  movupd 0x20(%rsi),%xmm1
  unpckhpd %xmm3,%xmm3
  mulpd  %xmm3,%xmm1
  movapd %xmm1,%xmm0
  addpd  %xmm2,%xmm0
  movups %xmm0,0x20(%r9)
  ret
  nopl   (%rax)
L27:
  pxor   %xmm0,%xmm0
  movapd %xmm0,%xmm1
  jmp    L41
L20:
  pxor   %xmm8,%xmm8
  mov    %rsi,%rcx
  movapd %xmm8,%xmm10
  jmp    L36
```

assistant: ```c
void kernel_dtrmm_nt_l_2x2_lib4(int kmax, double *A, double *B, double *D) {
  const int lda = 4;
  const int ldc = 4;
  int k;
  double a_0, a_1, b_0, b_1, c_00 = 0, c_01 = 0, c_10 = 0, c_11 = 0;
  for (k = 0; k < kmax - 4; k += 4) {
    a_0 = A[0 + lda * 0];
    a_1 = A[1 + lda * 0];
    b_0 = B[0 + lda * 0];
    b_1 = B[1 + lda * 0];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_01 += a_0 * b_1;
    c_11 += a_1 * b_1;
    a_0 = A[0 + lda * 1];
    a_1 = A[1 + lda * 1];
    b_0 = B[0 + lda * 1];
    b_1 = B[1 + lda * 1];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_01 += a_0 * b_1;
    c_11 += a_1 * b_1;
    a_0 = A[0 + lda * 2];
    a_1 = A[1 + lda * 2];
    b_0 = B[0 + lda * 2];
    b_1 = B[1 + lda * 2];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_01 += a_0 * b_1;
    c_11 += a_1 * b_1;
    a_0 = A[0 + lda * 3];
    a_1 = A[1 + lda * 3];
    b_0 = B[0 + lda * 3];
    b_1 = B[1 + lda * 3];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_01 += a_0 * b_1;
    c_11 += a_1 * b_1;
    A += 16;
    B += 16;
  }
  a_0 = A[0 + lda * 0];
  a_1 = A[1 + lda * 0];
  b_0 = B[0 + lda * 0];
  b_1 = B[1 + lda * 0];
  c_00 += a_0 * b_0;
  c_10 += a_1 * b_0;
  D[0 + ldc * 0] = c_00;
  D[1 + ldc * 0] = c_10;
  c_01 += a_0 * b_1;
  c_11 += a_1 * b_1;
  a_0 = A[0 + lda * 1];
  a_1 = A[1 + lda * 1];
  b_1 = B[1 + lda * 1];
  c_01 += a_0 * b_1;
  c_11 += a_1 * b_1;
  D[0 + ldc * 1] = c_01;
  D[1 + ldc * 1] = c_11;
}
```