user: Converte this assembly snippet into its equivalent C code:

```asm
<kernel_dlauum_nt_4x4_lib4>:
  endbr64
  push   %rbp
  pxor   %xmm4,%xmm4
  mov    %rsi,%rax
  lea    0x80(%rsi),%r10
  push   %rbx
  movsd  (%rsi),%xmm2
  mov    %ecx,%r11d
  mulsd  (%rdx),%xmm2
  movsd  0x20(%rdx),%xmm1
  movsd  0x20(%rsi),%xmm3
  movsd  0x40(%rdx),%xmm7
  movsd  0x40(%rsi),%xmm5
  movsd  0x28(%rsi),%xmm0
  mulsd  %xmm1,%xmm3
  movsd  0x48(%rsi),%xmm10
  movsd  0x50(%rsi),%xmm6
  mulsd  %xmm7,%xmm5
  movsd  0x48(%rdx),%xmm9
  movsd  0x70(%rsi),%xmm11
  addsd  %xmm4,%xmm2
  mulsd  %xmm0,%xmm1
  movsd  0x68(%rdx),%xmm13
  movsd  0x78(%rsi),%xmm8
  mulsd  0x28(%rdx),%xmm0
  movsd  0x70(%rdx),%xmm12
  addsd  %xmm3,%xmm2
  movsd  0x68(%rsi),%xmm3
  addsd  %xmm4,%xmm1
  addsd  %xmm2,%xmm5
  movapd %xmm10,%xmm2
  addsd  %xmm4,%xmm0
  mulsd  %xmm7,%xmm2
  mulsd  %xmm9,%xmm10
  mulsd  %xmm6,%xmm9
  mulsd  %xmm6,%xmm7
  mulsd  0x50(%rdx),%xmm6
  addsd  %xmm2,%xmm1
  movsd  0x60(%rdx),%xmm2
  addsd  %xmm0,%xmm10
  movsd  0x60(%rsi),%xmm0
  lea    0x80(%rdx),%rsi
  addsd  %xmm4,%xmm9
  mulsd  %xmm2,%xmm0
  addsd  %xmm4,%xmm7
  addsd  %xmm4,%xmm6
  addsd  %xmm5,%xmm0
  movapd %xmm11,%xmm5
  mulsd  %xmm2,%xmm5
  movapd %xmm0,%xmm15
  movapd %xmm3,%xmm0
  mulsd  %xmm2,%xmm0
  mulsd  %xmm13,%xmm3
  mulsd  %xmm8,%xmm2
  addsd  %xmm7,%xmm5
  addsd  %xmm1,%xmm0
  addsd  %xmm10,%xmm3
  addsd  %xmm4,%xmm2
  movapd %xmm0,%xmm1
  movsd  %xmm0,-0x28(%rsp)
  movapd %xmm11,%xmm0
  mulsd  %xmm13,%xmm0
  mulsd  %xmm12,%xmm11
  mulsd  %xmm8,%xmm13
  mulsd  %xmm8,%xmm12
  mulsd  0x78(%rdx),%xmm8
  addsd  %xmm9,%xmm0
  addsd  %xmm6,%xmm11
  movapd %xmm13,%xmm14
  movapd %xmm12,%xmm7
  addsd  %xmm4,%xmm14
  movapd %xmm0,%xmm10
  movapd %xmm8,%xmm6
  addsd  %xmm4,%xmm7
  addsd  %xmm4,%xmm6
  cmp    $0x7,%edi
  jle    L25
  lea    -0x8(%rdi),%ebp
  movapd %xmm5,%xmm12
  movapd %xmm15,%xmm9
  shr    $0x2,%ebp
  movapd %xmm1,%xmm5
  mov    %ebp,%ebx
  lea    0x2(%rbx),%rdx
  shl    $0x7,%rdx
  lea    (%rax,%rdx,1),%rcx
  mov    %rsi,%rdx
  mov    %r10,%rax
  nopl   0x0(%rax)
L61:
  movsd  (%rdx),%xmm0
  movsd  (%rax),%xmm15
  sub    $0xffffffffffffff80,%rax
  sub    $0xffffffffffffff80,%rdx
  movsd  -0x78(%rax),%xmm13
  movsd  -0x70(%rax),%xmm4
  mulsd  %xmm0,%xmm15
  movsd  -0x68(%rax),%xmm1
  movsd  -0x78(%rdx),%xmm8
  addsd  %xmm9,%xmm15
  movapd %xmm13,%xmm9
  mulsd  %xmm0,%xmm9
  mulsd  %xmm8,%xmm13
  addsd  %xmm5,%xmm9
  movapd %xmm4,%xmm5
  mulsd  %xmm0,%xmm5
  addsd  %xmm13,%xmm3
  movsd  -0x58(%rax),%xmm13
  mulsd  %xmm1,%xmm0
  addsd  %xmm12,%xmm5
  movsd  -0x58(%rdx),%xmm12
  addsd  %xmm0,%xmm2
  movapd %xmm4,%xmm0
  mulsd  %xmm8,%xmm0
  mulsd  -0x70(%rdx),%xmm4
  mulsd  %xmm1,%xmm8
  addsd  %xmm0,%xmm10
  movsd  -0x70(%rdx),%xmm0
  addsd  %xmm11,%xmm4
  movsd  -0x50(%rax),%xmm11
  mulsd  %xmm1,%xmm0
  addsd  %xmm14,%xmm8
  movsd  -0x60(%rax),%xmm14
  mulsd  -0x68(%rdx),%xmm1
  addsd  %xmm0,%xmm7
  movsd  -0x60(%rdx),%xmm0
  addsd  %xmm6,%xmm1
  movsd  -0x48(%rax),%xmm6
  mulsd  %xmm0,%xmm13
  mulsd  %xmm0,%xmm14
  addsd  %xmm9,%xmm13
  movapd %xmm11,%xmm9
  mulsd  %xmm0,%xmm9
  addsd  %xmm15,%xmm14
  mulsd  %xmm6,%xmm0
  addsd  %xmm5,%xmm9
  addsd  %xmm2,%xmm0
  movsd  -0x58(%rax),%xmm2
  mulsd  %xmm12,%xmm2
  addsd  %xmm3,%xmm2
  movapd %xmm11,%xmm3
  mulsd  %xmm12,%xmm3
  mulsd  %xmm6,%xmm12
  mulsd  -0x50(%rdx),%xmm11
  addsd  %xmm10,%xmm3
  movsd  -0x40(%rax),%xmm10
  addsd  %xmm12,%xmm8
  addsd  %xmm4,%xmm11
  movsd  -0x38(%rdx),%xmm4
  movapd %xmm10,%xmm5
  movapd %xmm3,%xmm15
  movsd  -0x50(%rdx),%xmm3
  mulsd  %xmm6,%xmm3
  mulsd  -0x48(%rdx),%xmm6
  addsd  %xmm7,%xmm3
  movsd  -0x38(%rax),%xmm7
  addsd  %xmm1,%xmm6
  movsd  -0x30(%rax),%xmm1
  movapd %xmm7,%xmm12
  movsd  %xmm3,-0x28(%rsp)
  movsd  -0x40(%rdx),%xmm3
  mulsd  %xmm4,%xmm7
  movsd  %xmm6,-0x20(%rsp)
  movsd  -0x28(%rax),%xmm6
  mulsd  %xmm3,%xmm12
  mulsd  %xmm6,%xmm10
  mulsd  %xmm3,%xmm5
  mulsd  %xmm1,%xmm3
  addsd  %xmm2,%xmm7
  addsd  %xmm13,%xmm12
  movapd %xmm1,%xmm13
  mulsd  %xmm4,%xmm13
  addsd  %xmm0,%xmm10
  movsd  -0x28(%rdx),%xmm0
  mulsd  %xmm6,%xmm4
  addsd  %xmm14,%xmm5
  mulsd  %xmm6,%xmm0
  addsd  %xmm9,%xmm3
  mulsd  -0x30(%rdx),%xmm1
  addsd  -0x20(%rsp),%xmm0
  addsd  %xmm15,%xmm13
  addsd  %xmm8,%xmm4
  movsd  -0x30(%rdx),%xmm8
  mulsd  %xmm6,%xmm8
  addsd  %xmm11,%xmm1
  addsd  -0x28(%rsp),%xmm8
  movsd  -0x18(%rax),%xmm15
  movsd  -0x20(%rdx),%xmm2
  movsd  -0x20(%rax),%xmm9
  movsd  -0x10(%rax),%xmm11
  movsd  -0x18(%rdx),%xmm14
  mulsd  %xmm2,%xmm9
  movsd  -0x8(%rax),%xmm6
  addsd  %xmm5,%xmm9
  movapd %xmm15,%xmm5
  mulsd  %xmm2,%xmm5
  addsd  %xmm12,%xmm5
  movapd %xmm11,%xmm12
  mulsd  %xmm2,%xmm12
  mulsd  %xmm6,%xmm2
  addsd  %xmm3,%xmm12
  movapd %xmm15,%xmm3
  mulsd  %xmm14,%xmm3
  addsd  %xmm10,%xmm2
  movapd %xmm11,%xmm10
  mulsd  %xmm14,%xmm10
  mulsd  -0x10(%rdx),%xmm11
  mulsd  %xmm6,%xmm14
  addsd  %xmm7,%xmm3
  movsd  -0x10(%rdx),%xmm7
  addsd  %xmm13,%xmm10
  mulsd  %xmm6,%xmm7
  addsd  %xmm1,%xmm11
  mulsd  -0x8(%rdx),%xmm6
  addsd  %xmm4,%xmm14
  addsd  %xmm8,%xmm7
  addsd  %xmm0,%xmm6
  cmp    %rcx,%rax
  jne    L61
  lea    0x1(%rbx),%rax
  movsd  %xmm5,-0x28(%rsp)
  movapd %xmm9,%xmm15
  movapd %xmm12,%xmm5
  shl    $0x7,%rax
  add    %rax,%r10
  add    %rax,%rsi
  lea    0x8(,%rbp,4),%eax
L23:
  cmp    %eax,%edi
  jle    L0
  movupd 0x10(%rsi),%xmm4
  movupd (%rsi),%xmm0
  unpcklpd %xmm3,%xmm5
  sub    %eax,%edi
  movupd 0x10(%r10),%xmm9
  movupd (%r10),%xmm8
  movapd %xmm4,%xmm1
  movsd  -0x28(%rsp),%xmm3
  unpckhpd %xmm9,%xmm9
  shufpd $0x1,%xmm4,%xmm1
  shufpd $0x2,%xmm0,%xmm4
  mulpd  %xmm9,%xmm1
  unpcklpd %xmm15,%xmm3
  movapd %xmm1,%xmm12
  movapd %xmm6,%xmm1
  unpcklpd %xmm7,%xmm1
  movapd %xmm14,%xmm7
  addpd  %xmm1,%xmm12
  movapd %xmm0,%xmm1
  unpcklpd %xmm2,%xmm7
  shufpd $0x1,%xmm0,%xmm1
  mulpd  %xmm9,%xmm1
  addpd  %xmm7,%xmm1
  movapd %xmm1,%xmm2
  movupd 0x10(%r10),%xmm1
  unpcklpd %xmm1,%xmm1
  mulpd  %xmm1,%xmm4
  movapd %xmm11,%xmm1
  unpcklpd %xmm10,%xmm1
  addpd  %xmm1,%xmm4
  movapd %xmm8,%xmm1
  shufpd $0x1,%xmm8,%xmm8
  movlpd 0x10(%r10),%xmm1
  mulpd  %xmm0,%xmm1
  unpcklpd %xmm0,%xmm0
  mulpd  %xmm8,%xmm0
  addpd  %xmm5,%xmm1
  addpd  %xmm3,%xmm0
  cmp    $0x1,%edi
  je     L50
  movupd 0x30(%rsi),%xmm3
  movupd 0x30(%r10),%xmm9
  movupd 0x20(%rsi),%xmm5
  movupd 0x20(%r10),%xmm7
  unpckhpd %xmm9,%xmm9
  movapd %xmm3,%xmm8
  shufpd $0x1,%xmm3,%xmm8
  mulpd  %xmm9,%xmm8
  shufpd $0x2,%xmm5,%xmm3
  addpd  %xmm8,%xmm12
  movapd %xmm5,%xmm8
  shufpd $0x1,%xmm5,%xmm8
  mulpd  %xmm9,%xmm8
  addpd  %xmm8,%xmm2
  movupd 0x30(%r10),%xmm8
  unpcklpd %xmm8,%xmm8
  mulpd  %xmm8,%xmm3
  addpd  %xmm3,%xmm4
  movapd %xmm7,%xmm3
  shufpd $0x1,%xmm7,%xmm7
  movlpd 0x30(%r10),%xmm3
  mulpd  %xmm5,%xmm3
  unpcklpd %xmm5,%xmm5
  mulpd  %xmm5,%xmm7
  addpd  %xmm3,%xmm1
  addpd  %xmm7,%xmm0
  cmp    $0x2,%edi
  je     L50
  movupd 0x50(%rsi),%xmm5
  movupd 0x50(%r10),%xmm9
  movupd 0x40(%rsi),%xmm3
  movupd 0x40(%r10),%xmm7
  unpckhpd %xmm9,%xmm9
  movapd %xmm5,%xmm8
  shufpd $0x1,%xmm5,%xmm8
  mulpd  %xmm9,%xmm8
  shufpd $0x2,%xmm3,%xmm5
  addpd  %xmm8,%xmm12
  movapd %xmm3,%xmm8
  shufpd $0x1,%xmm3,%xmm8
  mulpd  %xmm9,%xmm8
  addpd  %xmm8,%xmm2
  movupd 0x50(%r10),%xmm8
  unpcklpd %xmm8,%xmm8
  mulpd  %xmm8,%xmm5
  addpd  %xmm5,%xmm4
  movapd %xmm7,%xmm5
  shufpd $0x1,%xmm7,%xmm7
  movlpd 0x50(%r10),%xmm5
  mulpd  %xmm3,%xmm5
  unpcklpd %xmm3,%xmm3
  mulpd  %xmm7,%xmm3
  addpd  %xmm5,%xmm1
  addpd  %xmm3,%xmm0
  cmp    $0x3,%edi
  je     L50
  movupd 0x70(%r10),%xmm5
  movupd 0x70(%rsi),%xmm7
  movupd 0x60(%rsi),%xmm3
  movupd 0x60(%r10),%xmm8
  movapd %xmm5,%xmm10
  movapd %xmm7,%xmm9
  unpckhpd %xmm5,%xmm10
  shufpd $0x1,%xmm7,%xmm9
  shufpd $0x2,%xmm3,%xmm7
  mulpd  %xmm10,%xmm9
  addpd  %xmm9,%xmm12
  movapd %xmm3,%xmm9
  shufpd $0x1,%xmm3,%xmm9
  mulpd  %xmm10,%xmm9
  addpd  %xmm9,%xmm2
  movapd %xmm5,%xmm9
  unpcklpd %xmm5,%xmm9
  shufpd $0x2,%xmm8,%xmm5
  shufpd $0x1,%xmm8,%xmm8
  mulpd  %xmm3,%xmm5
  unpcklpd %xmm3,%xmm3
  mulpd  %xmm9,%xmm7
  mulpd  %xmm8,%xmm3
  addpd  %xmm5,%xmm1
  addpd  %xmm7,%xmm4
  addpd  %xmm3,%xmm0
L50:
  movapd %xmm12,%xmm6
  movapd %xmm4,%xmm11
  unpckhpd %xmm12,%xmm12
  movlpd %xmm0,-0x28(%rsp)
  unpckhpd %xmm4,%xmm4
  movapd %xmm1,%xmm5
  unpckhpd %xmm0,%xmm0
  unpckhpd %xmm1,%xmm1
  movapd %xmm2,%xmm14
  movapd %xmm12,%xmm7
  unpckhpd %xmm2,%xmm2
  movapd %xmm4,%xmm10
  movapd %xmm1,%xmm3
  movapd %xmm0,%xmm15
L0:
  test   %r11d,%r11d
  je     L66
  movsd  0x10(%r8),%xmm4
  movsd  (%r8),%xmm9
  movsd  0x8(%r8),%xmm8
  movsd  0x18(%r8),%xmm12
  movsd  %xmm4,-0x20(%rsp)
  movsd  0x30(%r8),%xmm4
  movsd  0x28(%r8),%xmm13
  movsd  0x58(%r8),%xmm1
  movsd  0x78(%r8),%xmm0
  movsd  %xmm4,-0x18(%rsp)
  movsd  0x38(%r8),%xmm4
  movsd  %xmm4,-0x10(%rsp)
  movsd  0x50(%r8),%xmm4
  cmp    $0x1,%r11d
  je     L95
  subsd  %xmm3,%xmm13
  subsd  -0x28(%rsp),%xmm8
  subsd  %xmm15,%xmm9
  subsd  %xmm2,%xmm12
  subsd  %xmm11,%xmm4
  subsd  %xmm7,%xmm1
  movapd %xmm13,%xmm3
  movsd  -0x18(%rsp),%xmm13
  movsd  %xmm8,-0x28(%rsp)
  movsd  -0x20(%rsp),%xmm8
  subsd  %xmm6,%xmm0
  movapd %xmm9,%xmm15
  movapd %xmm12,%xmm2
  subsd  %xmm10,%xmm13
  subsd  %xmm5,%xmm8
  movapd %xmm4,%xmm11
  movapd %xmm1,%xmm7
  movapd %xmm0,%xmm6
  movapd %xmm13,%xmm10
  movsd  -0x10(%rsp),%xmm13
  movapd %xmm8,%xmm5
  subsd  %xmm14,%xmm13
  movapd %xmm13,%xmm14
L66:
  movsd  -0x28(%rsp),%xmm4
  movsd  %xmm15,(%r9)
  pop    %rbx
  movsd  %xmm5,0x10(%r9)
  pop    %rbp
  movsd  %xmm4,0x8(%r9)
  movsd  %xmm2,0x18(%r9)
  movsd  %xmm3,0x28(%r9)
  movsd  %xmm10,0x30(%r9)
  movsd  %xmm14,0x38(%r9)
  movsd  %xmm11,0x50(%r9)
  movsd  %xmm7,0x58(%r9)
  movsd  %xmm6,0x78(%r9)
  ret
  cs nopw 0x0(%rax,%rax,1)
L95:
  addsd  -0x28(%rsp),%xmm8
  addsd  %xmm9,%xmm15
  addsd  -0x20(%rsp),%xmm5
  addsd  %xmm12,%xmm2
  addsd  %xmm13,%xmm3
  addsd  -0x18(%rsp),%xmm10
  addsd  %xmm4,%xmm11
  addsd  %xmm1,%xmm7
  movsd  %xmm8,-0x28(%rsp)
  addsd  -0x10(%rsp),%xmm14
  addsd  %xmm0,%xmm6
  jmp    L66
  nopl   0x0(%rax,%rax,1)
L25:
  mov    $0x4,%eax
  jmp    L23
```

assistant: ```c
void kernel_dlauum_nt_4x4_lib4(int kmax, double *A, double *B, int alg, double *C, double *D) {
  const int lda = 4;
  const int ldb = 4;
  const int ldc = 4;
  int k;
  double a_0, a_1, a_2, a_3, b_0, b_1, b_2, b_3, c_00 = 0, c_10 = 0, c_11 = 0, c_20 = 0, c_21 = 0, c_22 = 0, c_30 = 0, c_31 = 0, c_32 = 0, c_33 = 0;
  a_0 = A[0 + lda * 0];
  b_0 = B[0 + ldb * 0];
  c_00 += a_0 * b_0;
  a_0 = A[0 + lda * 1];
  a_1 = A[1 + lda * 1];
  b_0 = B[0 + ldb * 1];
  b_1 = B[1 + ldb * 1];
  c_00 += a_0 * b_0;
  c_10 += a_1 * b_0;
  c_11 += a_1 * b_1;
  a_0 = A[0 + lda * 2];
  a_1 = A[1 + lda * 2];
  a_2 = A[2 + lda * 2];
  b_0 = B[0 + ldb * 2];
  b_1 = B[1 + ldb * 2];
  b_2 = B[2 + ldb * 2];
  c_00 += a_0 * b_0;
  c_10 += a_1 * b_0;
  c_20 += a_2 * b_0;
  c_11 += a_1 * b_1;
  c_21 += a_2 * b_1;
  c_22 += a_2 * b_2;
  a_0 = A[0 + lda * 3];
  a_1 = A[1 + lda * 3];
  a_2 = A[2 + lda * 3];
  a_3 = A[3 + lda * 3];
  b_0 = B[0 + ldb * 3];
  b_1 = B[1 + ldb * 3];
  b_2 = B[2 + ldb * 3];
  b_3 = B[3 + ldb * 3];
  c_00 += a_0 * b_0;
  c_10 += a_1 * b_0;
  c_20 += a_2 * b_0;
  c_30 += a_3 * b_0;
  c_11 += a_1 * b_1;
  c_21 += a_2 * b_1;
  c_31 += a_3 * b_1;
  c_22 += a_2 * b_2;
  c_32 += a_3 * b_2;
  c_33 += a_3 * b_3;
  k = 4;
  A += 16;
  B += 16;
  for (; k < kmax - 3; k += 4) {
    a_0 = A[0 + lda * 0];
    a_1 = A[1 + lda * 0];
    a_2 = A[2 + lda * 0];
    a_3 = A[3 + lda * 0];
    b_0 = B[0 + ldb * 0];
    b_1 = B[1 + ldb * 0];
    b_2 = B[2 + ldb * 0];
    b_3 = B[3 + ldb * 0];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_20 += a_2 * b_0;
    c_30 += a_3 * b_0;
    c_11 += a_1 * b_1;
    c_21 += a_2 * b_1;
    c_31 += a_3 * b_1;
    c_22 += a_2 * b_2;
    c_32 += a_3 * b_2;
    c_33 += a_3 * b_3;
    a_0 = A[0 + lda * 1];
    a_1 = A[1 + lda * 1];
    a_2 = A[2 + lda * 1];
    a_3 = A[3 + lda * 1];
    b_0 = B[0 + ldb * 1];
    b_1 = B[1 + ldb * 1];
    b_2 = B[2 + ldb * 1];
    b_3 = B[3 + ldb * 1];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_20 += a_2 * b_0;
    c_30 += a_3 * b_0;
    c_11 += a_1 * b_1;
    c_21 += a_2 * b_1;
    c_31 += a_3 * b_1;
    c_22 += a_2 * b_2;
    c_32 += a_3 * b_2;
    c_33 += a_3 * b_3;
    a_0 = A[0 + lda * 2];
    a_1 = A[1 + lda * 2];
    a_2 = A[2 + lda * 2];
    a_3 = A[3 + lda * 2];
    b_0 = B[0 + ldb * 2];
    b_1 = B[1 + ldb * 2];
    b_2 = B[2 + ldb * 2];
    b_3 = B[3 + ldb * 2];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_20 += a_2 * b_0;
    c_30 += a_3 * a_0;
    c_11 += a_1 * b_1;
    c_21 += a_2 * b_1;
    c_31 += a_3 * b_1;
    c_22 += a_2 * b_2;
    c_32 += a_3 * b_2;
    c_33 += a_3 * b_3;
    a_0 = A[0 + lda * 3];
    a_1 = A[1 + lda * 3];
    a_2 = A[2 + lda * 3];
    a_3 = A[3 + lda * 3];
    b_0 = B[0 + ldb * 3];
    b_1 = B[1 + ldb * 3];
    b_2 = B[2 + ldb * 3];
    b_3 = B[3 + ldb * 3];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_20 += a_2 * b_0;
    c_30 += a_3 * b_0;
    c_11 += a_1 * b_1;
    c_21 += a_2 * b_1;
    c_31 += a_3 * b_1;
    c_22 += a_2 * b_2;
    c_32 += a_3 * b_2;
    c_33 += a_3 * b_3;
    A += 16;
    B += 16;
  }
  for (; k < kmax; k++) {
    a_0 = A[0 + lda * 0];
    a_1 = A[1 + lda * 0];
    a_2 = A[2 + lda * 0];
    a_3 = A[3 + lda * 0];
    b_0 = B[0 + ldb * 0];
    b_1 = B[1 + ldb * 0];
    b_2 = B[2 + ldb * 0];
    b_3 = B[3 + ldb * 0];
    c_00 += a_0 * b_0;
    c_10 += a_1 * b_0;
    c_20 += a_2 * b_0;
    c_30 += a_3 * b_0;
    c_11 += a_1 * b_1;
    c_21 += a_2 * b_1;
    c_31 += a_3 * b_1;
    c_22 += a_2 * b_2;
    c_32 += a_3 * b_2;
    c_33 += a_3 * b_3;
    A += 4;
    B += 4;
  }
  double d_00, d_10, d_11, d_20, d_21, d_22, d_30, d_31, d_32, d_33;
  if (alg == 0) {
    D[0 + ldc * 0] = c_00;
    D[1 + ldc * 0] = c_10;
    D[2 + ldc * 0] = c_20;
    D[3 + ldc * 0] = c_30;
    D[1 + ldc * 1] = c_11;
    D[2 + ldc * 1] = c_21;
    D[3 + ldc * 1] = c_31;
    D[2 + ldc * 2] = c_22;
    D[3 + ldc * 2] = c_32;
    D[3 + ldc * 3] = c_33;
  } else {
    d_00 = C[0 + ldc * 0];
    d_10 = C[1 + ldc * 0];
    d_20 = C[2 + ldc * 0];
    d_30 = C[3 + ldc * 0];
    d_11 = C[1 + ldc * 1];
    d_21 = C[2 + ldc * 1];
    d_31 = C[3 + ldc * 1];
    d_22 = C[2 + ldc * 2];
    d_32 = C[3 + ldc * 2];
    d_33 = C[3 + ldc * 3];
    if (alg == 1) {
      d_00 += c_00;
      d_10 += c_10;
      d_20 += c_20;
      d_30 += c_30;
      d_11 += c_11;
      d_21 += c_21;
      d_31 += c_31;
      d_22 += c_22;
      d_32 += c_32;
      d_33 += c_33;
    } else {
      d_00 -= c_00;
      d_10 -= c_10;
      d_20 -= c_20;
      d_30 -= c_30;
      d_11 -= c_11;
      d_21 -= c_21;
      d_31 -= c_31;
      d_22 -= c_22;
      d_32 -= c_32;
      d_33 -= c_33;
    }
    D[0 + ldc * 0] = d_00;
    D[1 + ldc * 0] = d_10;
    D[2 + ldc * 0] = d_20;
    D[3 + ldc * 0] = d_30;
    D[1 + ldc * 1] = d_11;
    D[2 + ldc * 1] = d_21;
    D[3 + ldc * 1] = d_31;
    D[2 + ldc * 2] = d_22;
    D[3 + ldc * 2] = d_32;
    D[3 + ldc * 3] = d_33;
  }
}
```