user: Translate the below assembly code into C programming language:

```asm
<Mupdate>:
  endbr64
  push   %r15
  test   %esi,%esi
  movslq %edi,%rax
  mov    %rcx,%rdi
  push   %r14
  mov    %esi,%ecx
  push   %r13
  push   %r12
  push   %rbp
  lea    0x3(%rsi),%ebp
  cmovns %esi,%ebp
  sar    $0x1f,%ecx
  push   %rbx
  shr    $0x1e,%ecx
  lea    (%rsi,%rcx,1),%r10d
  sar    $0x2,%ebp
  and    $0x3,%r10d
  mov    %rdx,-0x48(%rsp)
  mov    %r8,-0x40(%rsp)
  sub    %ecx,%r10d
  test   %eax,%eax
  jle    L61
  movslq %r9d,%rdx
  mov    %rax,-0x38(%rsp)
  cmp    $0x3,%esi
  mov    %esi,%ebx
  lea    0x0(,%rdx,8),%r14
  lea    0x0(,%rbp,4),%ecx
  movapd %xmm0,%xmm4
  lea    0x20(%r14),%rax
  movslq %ecx,%rcx
  mov    %rax,-0x20(%rsp)
  mov    $0x1,%eax
  lea    0x8(%rdi,%rcx,8),%r9
  lea    0x0(,%rcx,8),%r11
  cmovg  %ebp,%eax
  add    %rcx,%rdx
  xor    %r8d,%r8d
  lea    0x0(,%rdx,8),%rsi
  sub    $0x1,%eax
  mov    %rsi,-0x30(%rsp)
  lea    0x8(%r11),%rsi
  add    $0x1,%rax
  mov    %rsi,-0x18(%rsp)
  mov    %r10d,%esi
  shl    $0x5,%rax
  and    $0xfffffffe,%esi
  mov    %rax,-0x28(%rsp)
  lea    0x10(%r11),%rax
  movslq %esi,%r12
  mov    %esi,-0x4c(%rsp)
  shl    $0x3,%r12
  mov    %rax,-0x10(%rsp)
  lea    (%r11,%r12,1),%r13
  nop
L115:
  mov    -0x48(%rsp),%rax
  movsd  (%rax,%r8,8),%xmm2
  mov    -0x40(%rsp),%rax
  mov    (%rax,%r8,8),%rsi
  mulsd  %xmm4,%xmm2
  lea    (%rsi,%r14,1),%rcx
  cmp    $0x3,%ebx
  jle    L7
  lea    0x20(%rdi),%rax
  mov    %rdi,%rdx
  cmp    %rax,%rcx
  jae    L20
  mov    -0x20(%rsp),%rax
  add    %rsi,%rax
  cmp    %rax,%rdi
  jb     L69
L20:
  mov    -0x28(%rsp),%r15
  movapd %xmm2,%xmm3
  mov    %rcx,%rax
  unpcklpd %xmm3,%xmm3
  add    %rcx,%r15
  nopl   0x0(%rax)
L136:
  movupd (%rdx),%xmm1
  movupd (%rax),%xmm6
  add    $0x20,%rax
  add    $0x20,%rdx
  movupd -0x10(%rdx),%xmm0
  movupd -0x10(%rax),%xmm5
  mulpd  %xmm3,%xmm1
  mulpd  %xmm3,%xmm0
  addpd  %xmm6,%xmm1
  addpd  %xmm5,%xmm0
  movups %xmm1,-0x20(%rax)
  movups %xmm0,-0x10(%rax)
  cmp    %rax,%r15
  jne    L136
L7:
  add    %r11,%rdi
  test   %r10d,%r10d
  jle    L5
  add    -0x30(%rsp),%rsi
  movapd %xmm2,%xmm0
  cmp    %r9,%rsi
  je     L55
  cmp    $0x1,%r10d
  je     L55
  movupd -0x8(%r9),%xmm7
  unpcklpd %xmm0,%xmm0
  mulpd  %xmm7,%xmm0
  movupd (%rsi),%xmm7
  addpd  %xmm7,%xmm0
  movups %xmm0,(%rsi)
  cmp    %r10d,-0x4c(%rsp)
  je     L5
  mulsd  (%rdi,%r12,1),%xmm2
  add    %r13,%rcx
  addsd  (%rcx),%xmm2
  movsd  %xmm2,(%rcx)
L5:
  add    $0x1,%r8
  add    %r11,%r9
  cmp    %r8,-0x38(%rsp)
  jne    L115
L61:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax)
L69:
  mov    %rcx,%rax
  xor    %r15d,%r15d
  xchg   %ax,%ax
L67:
  movsd  (%rdx),%xmm0
  add    $0x1,%r15d
  add    $0x20,%rax
  add    $0x20,%rdx
  mulsd  %xmm2,%xmm0
  addsd  -0x20(%rax),%xmm0
  movsd  %xmm0,-0x20(%rax)
  movsd  -0x18(%rdx),%xmm0
  mulsd  %xmm2,%xmm0
  addsd  -0x18(%rax),%xmm0
  movsd  %xmm0,-0x18(%rax)
  movsd  -0x10(%rdx),%xmm0
  mulsd  %xmm2,%xmm0
  addsd  -0x10(%rax),%xmm0
  movsd  %xmm0,-0x10(%rax)
  movsd  -0x8(%rdx),%xmm0
  mulsd  %xmm2,%xmm0
  addsd  -0x8(%rax),%xmm0
  movsd  %xmm0,-0x8(%rax)
  cmp    %r15d,%ebp
  jg     L67
  jmp    L7
  nopl   0x0(%rax)
L55:
  mulsd  (%rdi),%xmm0
  addsd  (%rsi),%xmm0
  movsd  %xmm0,(%rsi)
  cmp    $0x1,%r10d
  je     L5
  movsd  0x8(%rdi),%xmm0
  mov    -0x18(%rsp),%rax
  mulsd  %xmm2,%xmm0
  add    %rcx,%rax
  addsd  (%rax),%xmm0
  movsd  %xmm0,(%rax)
  cmp    $0x3,%r10d
  jne    L5
  mulsd  0x10(%rdi),%xmm2
  add    -0x10(%rsp),%rcx
  addsd  (%rcx),%xmm2
  movsd  %xmm2,(%rcx)
  jmp    L5
```

assistant: ```c
void Mupdate(m, n, alpha, x, y, A, j0) int m, n, j0;
double alpha;
double **A, *x, *y;
{
  register int i, j, n4;
  register double *Aref;
  register double tmp;
  n4 = n / 4;
  n = n % 4;
  for (i = 0; i < m; i++) {
    tmp = alpha * x[i];
    Aref = &(A[i][j0]);
    for (j = 0; j < n4; j++) {
      Aref[4 * j] += tmp * y[4 * j];
      Aref[4 * j + 1] += tmp * y[4 * j + 1];
      Aref[4 * j + 2] += tmp * y[4 * j + 2];
      Aref[4 * j + 3] += tmp * y[4 * j + 3];
    }
    Aref += 4 * n4;
    y += 4 * n4;
    for (j = 0; j < n; j++)
      Aref[j] += tmp * y[j];
  }
}
```