user: 提供的汇编代码用C语言表示会是什么样子:

```asm
<dgemm2>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x10,%rsp
  mov    %rdi,-0x50(%rsp)
  mov    %rsi,0x8(%rsp)
  mov    %rdx,-0x48(%rsp)
  mov    %ecx,-0x64(%rsp)
  mov    %r8d,-0x24(%rsp)
  test   %ecx,%ecx
  jle    L66
  mov    %ecx,%eax
  mov    %r8d,%esi
  movl   $0x0,(%rsp)
  add    %eax,%eax
  imul   %ecx,%esi
  movl   $0x0,-0xc(%rsp)
  mov    %eax,-0x28(%rsp)
  cltq
  lea    0x0(,%rax,8),%r15
  movslq %r8d,%rax
  movl   $0x0,-0x68(%rsp)
  mov    %rax,-0x8(%rsp)
  lea    0x18(%rdi),%rax
  mov    %esi,-0x10(%rsp)
  mov    %rax,-0x30(%rsp)
L77:
  mov    -0x68(%rsp),%eax
  mov    -0x24(%rsp),%ebx
  xor    %r14d,%r14d
  movq   $0x0,-0x60(%rsp)
  mov    %eax,0x4(%rsp)
  add    %ebx,%eax
  mov    %eax,-0x68(%rsp)
L70:
  mov    -0x64(%rsp),%eax
  mov    %r14d,-0x6c(%rsp)
  xor    %r12d,%r12d
  xor    %r13d,%r13d
  movq   $0x0,-0x20(%rsp)
  add    -0x24(%rsp),%r14d
  mov    %eax,-0x18(%rsp)
  movl   $0x0,-0x14(%rsp)
L8:
  mov    -0x68(%rsp),%ebx
  add    -0x24(%rsp),%r13d
  cmp    %ebx,-0xc(%rsp)
  jge    L88
  movslq -0x14(%rsp),%rax
  mov    -0x60(%rsp),%rbx
  movslq -0x18(%rsp),%rbp
  lea    (%rax,%rbx,1),%rdx
  mov    0x8(%rsp),%rbx
  sub    %rax,%rbp
  mov    %r13d,%eax
  lea    (%rbx,%rdx,8),%rbx
  sub    %r12d,%eax
  shl    $0x3,%rbp
  mov    %rbx,-0x58(%rsp)
  mov    (%rsp),%ebx
  sub    $0x1,%eax
  shr    %eax
  mov    %ebx,-0x70(%rsp)
  mov    0x4(%rsp),%ebx
  mov    %ebx,-0x74(%rsp)
  mov    -0x20(%rsp),%rbx
  lea    0x1(%rbx),%rdi
  lea    (%rbx,%rax,2),%rax
  mov    %rdi,-0x40(%rsp)
  mov    %rax,-0x38(%rsp)
  nopl   0x0(%rax)
L11:
  cmp    %r14d,-0x6c(%rsp)
  jge    L54
  movslq -0x70(%rsp),%rax
  mov    -0x60(%rsp),%rdi
  mov    -0x48(%rsp),%rcx
  mov    -0x58(%rsp),%r10
  mov    %rax,%rbx
  add    -0x64(%rsp),%ebx
  lea    (%rax,%rdi,1),%rdx
  mov    -0x6c(%rsp),%r11d
  movslq %ebx,%rsi
  mov    -0x40(%rsp),%rbx
  lea    (%rcx,%rdx,8),%r9
  lea    (%rsi,%rdi,1),%rdx
  mov    -0x38(%rsp),%rdi
  sub    %rax,%rsi
  lea    (%rcx,%rdx,8),%r8
  lea    (%rbx,%rax,1),%rdx
  mov    -0x50(%rsp),%rbx
  lea    (%rbx,%rdx,8),%rbx
  lea    (%rdi,%rax,1),%rdx
  mov    -0x30(%rsp),%rdi
  lea    (%rdi,%rdx,8),%rdi
  nopl   (%rax)
L51:
  movsd  (%r9),%xmm8
  movsd  (%r8),%xmm7
  movsd  0x8(%r9),%xmm6
  movsd  0x8(%r8),%xmm5
  cmp    %r13d,%r12d
  jge    L56
  lea    0x0(%rbp,%r10,1),%rcx
  mov    %rbx,%rax
  mov    %r10,%rdx
  nopw   0x0(%rax,%rax,1)
L49:
  movsd  -0x8(%rax),%xmm1
  movsd  (%rax),%xmm4
  movsd  -0x8(%rax,%rsi,8),%xmm0
  movsd  (%rax,%rsi,8),%xmm3
  add    $0x10,%rax
  movsd  (%rdx),%xmm2
  movsd  (%rcx),%xmm11
  movapd %xmm1,%xmm12
  movapd %xmm4,%xmm13
  movsd  0x8(%rdx),%xmm10
  movsd  0x8(%rcx),%xmm9
  add    %r15,%rdx
  add    %r15,%rcx
  mulsd  %xmm2,%xmm12
  mulsd  %xmm11,%xmm13
  mulsd  %xmm0,%xmm2
  mulsd  %xmm3,%xmm11
  mulsd  %xmm10,%xmm1
  mulsd  %xmm9,%xmm4
  mulsd  %xmm10,%xmm0
  addsd  %xmm13,%xmm12
  mulsd  %xmm9,%xmm3
  addsd  %xmm11,%xmm2
  addsd  %xmm12,%xmm8
  addsd  %xmm4,%xmm1
  addsd  %xmm2,%xmm7
  addsd  %xmm3,%xmm0
  addsd  %xmm1,%xmm6
  addsd  %xmm0,%xmm5
  cmp    %rax,%rdi
  jne    L49
L56:
  add    $0x2,%r11d
  add    $0x10,%r9
  add    $0x10,%r8
  add    $0x10,%r10
  movsd  %xmm8,-0x10(%r9)
  movsd  %xmm7,-0x10(%r8)
  movsd  %xmm6,-0x8(%r9)
  movsd  %xmm5,-0x8(%r8)
  cmp    %r14d,%r11d
  jl     L51
L54:
  addl   $0x2,-0x74(%rsp)
  mov    -0x28(%rsp),%edi
  mov    -0x74(%rsp),%eax
  add    %edi,-0x70(%rsp)
  cmp    -0x68(%rsp),%eax
  jl     L11
L88:
  mov    -0x10(%rsp),%ebx
  add    -0x24(%rsp),%r12d
  add    %ebx,-0x14(%rsp)
  add    %ebx,-0x18(%rsp)
  mov    -0x8(%rsp),%rbx
  add    %rbx,-0x20(%rsp)
  cmp    %r13d,-0x64(%rsp)
  jg     L8
  mov    -0x8(%rsp),%rbx
  add    %rbx,-0x60(%rsp)
  cmp    %r14d,-0x64(%rsp)
  jg     L70
  mov    -0x24(%rsp),%ebx
  add    %ebx,-0xc(%rsp)
  mov    -0x10(%rsp),%ebx
  add    %ebx,(%rsp)
  mov    -0x68(%rsp),%ebx
  cmp    %ebx,-0x64(%rsp)
  jg     L77
L66:
  add    $0x10,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void dgemm2(double *a, double *b, double *c, int n, int BLOCK_SIZE) {
  int i, j, k;
  int ii, jj, kk;
  for (i = 0; i < n; i += BLOCK_SIZE) {
    for (j = 0; j < n; j += BLOCK_SIZE) {
      for (k = 0; k < n; k += BLOCK_SIZE) {
        for (ii = i; ii < i + BLOCK_SIZE; ii += 2) {
          for (jj = j; jj < j + BLOCK_SIZE; jj += 2) {
            register double cc0 = c[ii * n + jj];
            register double cc1 = c[(ii + 1) * n + jj];
            register double cc2 = c[ii * n + (jj + 1)];
            register double cc3 = c[(ii + 1) * n + (jj + 1)];
            for (kk = k; kk < k + BLOCK_SIZE; kk += 2) {
              register double aa0 = a[ii * n + kk];
              register double aa1 = a[ii * n + (kk + 1)];
              register double aa2 = a[(ii + 1) * n + kk];
              register double aa3 = a[(ii + 1) * n + (kk + 1)];
              register double bb0 = b[kk * n + jj];
              register double bb1 = b[(kk + 1) * n + jj];
              register double bb2 = b[kk * n + (jj + 1)];
              register double bb3 = b[(kk + 1) * n + (jj + 1)];
              cc0 += aa0 * bb0 + aa1 * bb1;
              cc1 += aa2 * bb0 + aa3 * bb1;
              cc2 += aa0 * bb2 + aa1 * bb3;
              cc3 += aa2 * bb2 + aa3 * bb3;
            }
            c[ii * n + jj] = cc0;
            c[(ii + 1) * n + jj] = cc1;
            c[ii * n + (jj + 1)] = cc2;
            c[(ii + 1) * n + (jj + 1)] = cc3;
          }
        }
      }
    }
  }
}
```