user: 这段汇编代码用C语言表示是什么样的:

```asm
<kernel_dtrsv_t_3_lib4_new>:
  endbr64
  test   %edi,%edi
  jle    L79
  push   %r15
  mov    %edi,%r11d
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  mov    %ecx,%ebp
  push   %rbx
  mov    %rsi,%rbx
  cmp    $0x4,%edi
  jg     L118
  pxor   %xmm0,%xmm0
  lea    0x18(%rsi),%rsi
  lea    0x8(%r9),%rdx
  mov    $0x3,%ecx
  movapd %xmm0,%xmm1
  movapd %xmm0,%xmm2
L20:
  cmp    %r11d,%ecx
  jge    L31
  sub    $0x1,%r11d
  sub    %ecx,%r11d
  lea    0x8(%rdx,%r11,8),%rax
  nopl   0x0(%rax)
L44:
  movsd  (%rdx),%xmm3
  movsd  (%rsi),%xmm4
  add    $0x8,%rdx
  add    $0x8,%rsi
  mulsd  %xmm3,%xmm4
  addsd  %xmm4,%xmm2
  movsd  0x18(%rsi),%xmm4
  mulsd  %xmm3,%xmm4
  mulsd  0x38(%rsi),%xmm3
  addsd  %xmm4,%xmm1
  addsd  %xmm3,%xmm0
  cmp    %rax,%rdx
  jne    L44
L31:
  movsd  0x10(%r9),%xmm3
  movsd  0x8(%r9),%xmm4
  movsd  (%r9),%xmm5
  subsd  %xmm0,%xmm3
  test   %ebp,%ebp
  je     L47
  mulsd  0x10(%r8),%xmm3
  movsd  %xmm3,0x10(%r9)
  movsd  0x10(%rbx),%xmm0
  mulsd  %xmm3,%xmm0
  mulsd  0x30(%rbx),%xmm3
  addsd  %xmm2,%xmm0
  addsd  %xmm1,%xmm3
  subsd  %xmm3,%xmm4
  mulsd  0x8(%r8),%xmm4
  movsd  %xmm4,0x8(%r9)
  mulsd  0x8(%rbx),%xmm4
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  subsd  %xmm4,%xmm5
  subsd  %xmm0,%xmm5
  mulsd  (%r8),%xmm5
  movsd  %xmm5,(%r9)
  ret
  nopl   0x0(%rax)
L118:
  movsd  0x18(%rsi),%xmm2
  shl    $0x2,%edx
  pxor   %xmm3,%xmm3
  lea    0x20(%r9),%rdi
  movsd  0x18(%r9),%xmm0
  movsd  0x38(%rsi),%xmm1
  movslq %edx,%r10
  lea    0x0(,%r10,8),%r12
  mulsd  %xmm0,%xmm2
  mulsd  %xmm0,%xmm1
  mulsd  0x58(%rsi),%xmm0
  lea    (%rsi,%r12,1),%rsi
  addsd  %xmm3,%xmm2
  addsd  %xmm3,%xmm1
  addsd  %xmm3,%xmm0
  cmp    $0xb,%r11d
  jle    L23
  lea    -0xc(%r11),%r14d
  shl    $0x4,%r10
  lea    (%rsi,%r12,1),%rdx
  mov    %rdi,%rcx
  shr    $0x3,%r14d
  mov    %r14d,%r15d
  mov    %r15,%rax
  shl    $0x6,%rax
  lea    0x60(%r9,%rax,1),%r13
  mov    %rsi,%rax
  nopw   0x0(%rax,%rax,1)
L38:
  movsd  (%rcx),%xmm6
  movsd  (%rax),%xmm7
  add    $0x40,%rcx
  movsd  -0x38(%rcx),%xmm5
  movsd  -0x30(%rcx),%xmm4
  mulsd  %xmm6,%xmm7
  movsd  -0x28(%rcx),%xmm3
  addsd  %xmm2,%xmm7
  movsd  0x20(%rax),%xmm2
  mulsd  %xmm6,%xmm2
  mulsd  0x40(%rax),%xmm6
  addsd  %xmm2,%xmm1
  movsd  0x28(%rax),%xmm2
  addsd  %xmm0,%xmm6
  movsd  0x8(%rax),%xmm0
  mulsd  %xmm5,%xmm2
  mulsd  %xmm5,%xmm0
  mulsd  0x48(%rax),%xmm5
  addsd  %xmm1,%xmm2
  movsd  0x10(%rax),%xmm1
  addsd  %xmm7,%xmm0
  movsd  0x38(%rax),%xmm7
  mulsd  %xmm4,%xmm1
  addsd  %xmm6,%xmm5
  movsd  (%rdx),%xmm6
  mulsd  %xmm3,%xmm7
  addsd  %xmm0,%xmm1
  movsd  0x30(%rax),%xmm0
  mulsd  %xmm4,%xmm0
  mulsd  0x50(%rax),%xmm4
  addsd  %xmm2,%xmm0
  movsd  -0x18(%rcx),%xmm2
  addsd  %xmm5,%xmm4
  movsd  0x18(%rax),%xmm5
  mulsd  %xmm3,%xmm5
  addsd  %xmm0,%xmm7
  movsd  -0x8(%rcx),%xmm0
  mulsd  0x58(%rax),%xmm3
  add    %r10,%rax
  addsd  %xmm1,%xmm5
  movsd  -0x10(%rcx),%xmm1
  addsd  %xmm3,%xmm4
  movsd  -0x20(%rcx),%xmm3
  mulsd  %xmm3,%xmm6
  addsd  %xmm5,%xmm6
  movsd  0x20(%rdx),%xmm5
  mulsd  %xmm3,%xmm5
  mulsd  0x40(%rdx),%xmm3
  addsd  %xmm7,%xmm5
  addsd  %xmm4,%xmm3
  movsd  0x8(%rdx),%xmm4
  mulsd  %xmm2,%xmm4
  addsd  %xmm6,%xmm4
  movsd  0x28(%rdx),%xmm6
  mulsd  %xmm2,%xmm6
  mulsd  0x48(%rdx),%xmm2
  addsd  %xmm5,%xmm6
  movsd  0x10(%rdx),%xmm5
  addsd  %xmm3,%xmm2
  mulsd  %xmm1,%xmm5
  addsd  %xmm4,%xmm5
  movsd  0x30(%rdx),%xmm4
  mulsd  %xmm1,%xmm4
  mulsd  0x50(%rdx),%xmm1
  addsd  %xmm6,%xmm4
  addsd  %xmm2,%xmm1
  movsd  0x18(%rdx),%xmm2
  mulsd  %xmm0,%xmm2
  movapd %xmm1,%xmm3
  movsd  0x38(%rdx),%xmm1
  mulsd  %xmm0,%xmm1
  mulsd  0x58(%rdx),%xmm0
  add    %r10,%rdx
  addsd  %xmm5,%xmm2
  addsd  %xmm4,%xmm1
  addsd  %xmm3,%xmm0
  cmp    %r13,%rcx
  jne    L38
  lea    0x1(%r15),%rax
  lea    0xc(,%r14,8),%ecx
  imul   %rax,%r10
  shl    $0x6,%rax
  add    %rax,%rdi
  add    %r10,%rsi
L73:
  lea    -0x3(%r11),%eax
  cmp    %eax,%ecx
  jge    L25
  lea    -0x4(%r11),%r10d
  mov    %rsi,%rax
  sub    %ecx,%r10d
  shr    $0x2,%r10d
  lea    0x1(%r10),%r13d
  mov    %r13,%rdx
  shl    $0x5,%rdx
  add    %rdi,%rdx
  xchg   %ax,%ax
L10:
  movsd  (%rdi),%xmm5
  movsd  (%rax),%xmm7
  add    $0x20,%rdi
  movsd  -0x18(%rdi),%xmm4
  movsd  -0x10(%rdi),%xmm3
  mulsd  %xmm5,%xmm7
  movsd  -0x8(%rdi),%xmm6
  addsd  %xmm2,%xmm7
  movsd  0x20(%rax),%xmm2
  mulsd  %xmm5,%xmm2
  mulsd  0x40(%rax),%xmm5
  addsd  %xmm2,%xmm1
  movsd  0x28(%rax),%xmm2
  addsd  %xmm0,%xmm5
  movsd  0x8(%rax),%xmm0
  mulsd  %xmm4,%xmm2
  mulsd  %xmm4,%xmm0
  mulsd  0x48(%rax),%xmm4
  addsd  %xmm1,%xmm2
  movsd  0x10(%rax),%xmm1
  addsd  %xmm7,%xmm0
  mulsd  %xmm3,%xmm1
  addsd  %xmm5,%xmm4
  addsd  %xmm0,%xmm1
  movsd  0x30(%rax),%xmm0
  mulsd  %xmm3,%xmm0
  mulsd  0x50(%rax),%xmm3
  addsd  %xmm2,%xmm0
  movsd  0x18(%rax),%xmm2
  addsd  %xmm4,%xmm3
  mulsd  %xmm6,%xmm2
  addsd  %xmm1,%xmm2
  movsd  0x38(%rax),%xmm1
  mulsd  %xmm6,%xmm1
  mulsd  0x58(%rax),%xmm6
  add    %r12,%rax
  addsd  %xmm0,%xmm1
  addsd  %xmm3,%xmm6
  movapd %xmm6,%xmm0
  cmp    %rdx,%rdi
  jne    L10
  imul   %r13,%r12
  lea    0x4(%rcx,%r10,4),%ecx
  add    %r12,%rsi
  jmp    L20
  nopl   0x0(%rax,%rax,1)
L47:
  divsd  0x50(%rbx),%xmm3
  movsd  %xmm3,0x10(%r9)
  movsd  0x10(%rbx),%xmm0
  mulsd  %xmm3,%xmm0
  mulsd  0x30(%rbx),%xmm3
  addsd  %xmm2,%xmm0
  addsd  %xmm1,%xmm3
  subsd  %xmm3,%xmm4
  divsd  0x28(%rbx),%xmm4
  movsd  %xmm4,0x8(%r9)
  mulsd  0x8(%rbx),%xmm4
  subsd  %xmm4,%xmm5
  subsd  %xmm0,%xmm5
  divsd  (%rbx),%xmm5
  pop    %rbx
  movsd  %xmm5,(%r9)
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax)
L79:
  ret
L23:
  mov    $0x4,%ecx
  jmp    L73
L25:
  mov    %rdi,%rdx
  jmp    L20
```

assistant: ```c
void kernel_dtrsv_t_3_lib4_new(int kmax, double *A, int sda, int use_inv_diag_A, double *inv_diag_A, double *x) {
  if (kmax <= 0)
    return;
  const int bs = 4;
  int k;
  double *tA, *tx;
  tA = A;
  tx = x;
  double x_0, x_1, x_2, x_3, y_0 = 0, y_1 = 0, y_2 = 0;
  k = 3;
  if (kmax > 4) {
    x_3 = x[3];
    y_0 += A[3 + bs * 0] * x_3;
    y_1 += A[3 + bs * 1] * x_3;
    y_2 += A[3 + bs * 2] * x_3;
    k = 4;
    A += 4 + (sda - 1) * bs;
    x += 4;
    for (; k < kmax - 7; k += 8) {
      x_0 = x[0];
      x_1 = x[1];
      x_2 = x[2];
      x_3 = x[3];
      y_0 += A[0 + bs * 0] * x_0;
      y_1 += A[0 + bs * 1] * x_0;
      y_2 += A[0 + bs * 2] * x_0;
      y_0 += A[1 + bs * 0] * x_1;
      y_1 += A[1 + bs * 1] * x_1;
      y_2 += A[1 + bs * 2] * x_1;
      y_0 += A[2 + bs * 0] * x_2;
      y_1 += A[2 + bs * 1] * x_2;
      y_2 += A[2 + bs * 2] * x_2;
      y_0 += A[3 + bs * 0] * x_3;
      y_1 += A[3 + bs * 1] * x_3;
      y_2 += A[3 + bs * 2] * x_3;
      A += sda * bs;
      x += 4;
      x_0 = x[0];
      x_1 = x[1];
      x_2 = x[2];
      x_3 = x[3];
      y_0 += A[0 + bs * 0] * x_0;
      y_1 += A[0 + bs * 1] * x_0;
      y_2 += A[0 + bs * 2] * x_0;
      y_0 += A[1 + bs * 0] * x_1;
      y_1 += A[1 + bs * 1] * x_1;
      y_2 += A[1 + bs * 2] * x_1;
      y_0 += A[2 + bs * 0] * x_2;
      y_1 += A[2 + bs * 1] * x_2;
      y_2 += A[2 + bs * 2] * x_2;
      y_0 += A[3 + bs * 0] * x_3;
      y_1 += A[3 + bs * 1] * x_3;
      y_2 += A[3 + bs * 2] * x_3;
      A += sda * bs;
      x += 4;
    }
    for (; k < kmax - 3; k += 4) {
      x_0 = x[0];
      x_1 = x[1];
      x_2 = x[2];
      x_3 = x[3];
      y_0 += A[0 + bs * 0] * x_0;
      y_1 += A[0 + bs * 1] * x_0;
      y_2 += A[0 + bs * 2] * x_0;
      y_0 += A[1 + bs * 0] * x_1;
      y_1 += A[1 + bs * 1] * x_1;
      y_2 += A[1 + bs * 2] * x_1;
      y_0 += A[2 + bs * 0] * x_2;
      y_1 += A[2 + bs * 1] * x_2;
      y_2 += A[2 + bs * 2] * x_2;
      y_0 += A[3 + bs * 0] * x_3;
      y_1 += A[3 + bs * 1] * x_3;
      y_2 += A[3 + bs * 2] * x_3;
      A += sda * bs;
      x += 4;
    }
  } else {
    A += 3;
    x += 1;
  }
  for (; k < kmax; k++) {
    x_0 = x[0];
    y_0 += A[0 + bs * 0] * x_0;
    y_1 += A[0 + bs * 1] * x_0;
    y_2 += A[0 + bs * 2] * x_0;
    A += 1;
    x += 1;
  }
  A = tA;
  x = tx;
  if (use_inv_diag_A) {
    y_2 = x[2] - y_2;
    y_2 *= inv_diag_A[2];
    x[2] = y_2;
    y_0 += A[2 + bs * 0] * y_2;
    y_1 += A[2 + bs * 1] * y_2;
    y_1 = x[1] - y_1;
    y_1 *= inv_diag_A[1];
    x[1] = y_1;
    y_0 = x[0] - A[1 + bs * 0] * y_1 - y_0;
    y_0 *= inv_diag_A[0];
    x[0] = y_0;
  } else {
    y_2 = x[2] - y_2;
    y_2 /= A[2 + bs * 2];
    x[2] = y_2;
    y_0 += A[2 + bs * 0] * y_2;
    y_1 += A[2 + bs * 1] * y_2;
    y_1 = x[1] - y_1;
    y_1 /= A[1 + bs * 1];
    x[1] = y_1;
    y_0 = x[0] - A[1 + bs * 0] * y_1 - y_0;
    y_0 /= A[0 + bs * 0];
    x[0] = y_0;
  }
}
```