user: What is the c source code of the assembly code below:

```asm
<sumCATMULT>:
  endbr64
  push   %rbp
  mov    %edi,%ebp
  mov    %rcx,%rax
  push   %rbx
  mov    %rsi,%rbx
  mov    0x18(%rsp),%r11
  mov    0x20(%rsp),%rsi
  movslq 0x28(%rsp),%rdi
  mov    0x30(%rsp),%ecx
  cmp    $0x1,%ebp
  je     L28
  cmp    $0x2,%ebp
  je     L19
  test   %ebp,%ebp
  je     L85
  pop    %rbx
  xor    %edi,%edi
  pop    %rbp
  jmp    1050 <assert@plt>
L28:
  cmp    %ecx,%edi
  jge    L27
  movslq %edi,%r10
  mov    %r10,%rdx
  shl    $0x5,%rdx
  lea    (%rax,%rdx,1),%rdi
  add    %rbx,%rdx
  nopl   (%rax)
L62:
  mov    (%rsi,%r10,4),%eax
  movsbl (%r9,%r10,1),%r11d
  add    $0x1,%r10
  add    $0x20,%rdi
  add    $0x20,%rdx
  shl    $0x4,%eax
  add    %r11d,%eax
  shl    $0x2,%eax
  cltq
  lea    (%r8,%rax,8),%rax
  movsd  (%rax),%xmm0
  mulsd  -0x20(%rdi),%xmm0
  movsd  %xmm0,-0x20(%rdx)
  movsd  0x8(%rax),%xmm0
  mulsd  -0x18(%rdi),%xmm0
  movsd  %xmm0,-0x18(%rdx)
  movsd  0x10(%rax),%xmm0
  mulsd  -0x10(%rdi),%xmm0
  movsd  %xmm0,-0x10(%rdx)
  movsd  0x18(%rax),%xmm0
  mulsd  -0x8(%rdi),%xmm0
  movsd  %xmm0,-0x8(%rdx)
  cmp    %r10d,%ecx
  jg     L62
L27:
  pop    %rbx
  pop    %rbp
  ret
  nop
L85:
  cmp    %ecx,%edi
  jge    L27
  mov    %rdi,%rax
  shl    $0x5,%rax
  lea    (%rbx,%rax,1),%rdx
  nop
L65:
  mov    (%rsi,%rdi,4),%ebx
  movsbl (%r9,%rdi,1),%eax
  add    $0x20,%rdx
  shl    $0x4,%ebx
  add    %ebx,%eax
  shl    $0x2,%eax
  cltq
  lea    (%r8,%rax,8),%r10
  movsbl (%r11,%rdi,1),%eax
  add    $0x1,%rdi
  movsd  (%r10),%xmm0
  add    %ebx,%eax
  shl    $0x2,%eax
  cltq
  lea    (%r8,%rax,8),%rax
  mulsd  (%rax),%xmm0
  movsd  %xmm0,-0x20(%rdx)
  movsd  0x8(%r10),%xmm0
  mulsd  0x8(%rax),%xmm0
  movsd  %xmm0,-0x18(%rdx)
  movsd  0x10(%r10),%xmm0
  mulsd  0x10(%rax),%xmm0
  movsd  %xmm0,-0x10(%rdx)
  movsd  0x18(%r10),%xmm0
  mulsd  0x18(%rax),%xmm0
  movsd  %xmm0,-0x8(%rdx)
  cmp    %edi,%ecx
  jg     L65
  pop    %rbx
  pop    %rbp
  ret
  nopl   0x0(%rax,%rax,1)
L19:
  cmp    %ecx,%edi
  jge    L27
  sub    $0x1,%ecx
  lea    0x0(,%rdi,4),%r8d
  sub    %edi,%ecx
  movslq %r8d,%r8
  add    %rdi,%rcx
  shl    $0x3,%r8
  shl    $0x5,%rcx
  lea    (%rbx,%r8,1),%rsi
  add    %r8,%rdx
  add    %r8,%rax
  lea    0x20(%rbx,%rcx,1),%rcx
  nopw   0x0(%rax,%rax,1)
L3:
  movsd  (%rdx),%xmm0
  mulsd  (%rax),%xmm0
  add    $0x20,%rsi
  add    $0x20,%rdx
  add    $0x20,%rax
  movsd  %xmm0,-0x20(%rsi)
  movsd  -0x18(%rdx),%xmm0
  mulsd  -0x18(%rax),%xmm0
  movsd  %xmm0,-0x18(%rsi)
  movsd  -0x10(%rdx),%xmm0
  mulsd  -0x10(%rax),%xmm0
  movsd  %xmm0,-0x10(%rsi)
  movsd  -0x8(%rdx),%xmm0
  mulsd  -0x8(%rax),%xmm0
  movsd  %xmm0,-0x8(%rsi)
  cmp    %rsi,%rcx
  jne    L3
  pop    %rbx
  pop    %rbp
  ret
```

assistant: ```c
void sumCATMULT(int tipCase, double *sum, double *x1_start, double *x2_start, double *tipVector, char *tipX1, char *tipX2, int *modelptr, int loopStart, int n) {
  double *x1, *x2;
  int i, model;
  switch (tipCase) {
  case 0:
    for (i = loopStart; i < n; i++) {
      model = modelptr[i];
      x1 = &(tipVector[model * 64 + tipX1[i] * 4]);
      x2 = &(tipVector[model * 64 + tipX2[i] * 4]);
      sum[i * 4] = x1[0] * x2[0];
      sum[i * 4 + 1] = x1[1] * x2[1];
      sum[i * 4 + 2] = x1[2] * x2[2];
      sum[i * 4 + 3] = x1[3] * x2[3];
    }
    break;
  case 1:
    for (i = loopStart; i < n; i++) {
      model = modelptr[i];
      x1 = &(tipVector[model * 64 + 4 * tipX1[i]]);
      x2 = &x2_start[4 * i];
      sum[i * 4] = x1[0] * x2[0];
      sum[i * 4 + 1] = x1[1] * x2[1];
      sum[i * 4 + 2] = x1[2] * x2[2];
      sum[i * 4 + 3] = x1[3] * x2[3];
    }
    break;
  case 2:
    for (i = loopStart; i < n; i++) {
      x1 = &x1_start[4 * i];
      x2 = &x2_start[4 * i];
      sum[i * 4] = x1[0] * x2[0];
      sum[i * 4 + 1] = x1[1] * x2[1];
      sum[i * 4 + 2] = x1[2] * x2[2];
      sum[i * 4 + 3] = x1[3] * x2[3];
    }
    break;
  default:
    assert(0);
  }
}
```