user: Please show me the C implementation that matches the assembly code listed below:

```asm
<benchmark>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x28,%rsp
  mov    %edi,%r14d
  mov    %esi,-0x44(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  mov    %esi,%eax
  cltq
  shl    $0x2,%rax
  lea    0xf(%rax),%rdx
  mov    %rdx,%rsi
  and    $0xfffffffffffffff0,%rsi
  and    $0xfffffffffffff000,%rdx
  mov    %rsp,%rcx
  sub    %rdx,%rcx
L15:
  cmp    %rcx,%rsp
  je     L105
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L15
L105:
  mov    %rsi,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  test   %rdx,%rdx
  je     L2
  orq    $0x0,-0x8(%rsp,%rdx,1)
L2:
  mov    %rsp,%r12
  add    $0xf,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffffff0,%rcx
  and    $0xfffffffffffff000,%rax
  mov    %rsp,%rdx
  sub    %rax,%rdx
L83:
  cmp    %rdx,%rsp
  je     L41
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L83
L41:
  mov    %rcx,%rax
  and    $0xfff,%eax
  sub    %rax,%rsp
  test   %rax,%rax
  je     L123
  orq    $0x0,-0x8(%rsp,%rax,1)
L123:
  mov    %rsp,%r13
  mov    -0x44(%rbp),%eax
  test   %eax,%eax
  jle    L64
  mov    %eax,%r15d
  mov    $0x0,%ebx
L12:
  mov    $0x0,%eax
  call   <rand_float@plt>
  mulss  D9(%rip),%xmm0
  subss  D40(%rip),%xmm0
  movss  %xmm0,(%r12,%rbx,4)
  mov    $0x0,%eax
  call   <rand_float@plt>
  mulss  D9(%rip),%xmm0
  subss  D40(%rip),%xmm0
  movss  %xmm0,0x0(%r13,%rbx,4)
  add    $0x1,%rbx
  cmp    %r15,%rbx
  jne    L12
L64:
  mov    $0x0,%eax
  call   <tic@plt>
  movq   %xmm0,%r15
  test   %r14d,%r14d
  jle    L28
  mov    $0x0,%ebx
L59:
  mov    $0x1,%r8d
  mov    %r13,%rcx
  mov    $0x1,%edx
  mov    %r12,%rsi
  mov    -0x44(%rbp),%edi
  call   <c_sdot@plt>
  ucomiss %xmm0,%xmm0
  jp     L101
  add    $0x1,%ebx
  cmp    %ebx,%r14d
  jne    L59
L28:
  mov    $0x0,%eax
  call   <tic@plt>
  movq   %r15,%xmm1
  subsd  %xmm1,%xmm0
  movq   %xmm0,%rbx
L62:
  mov    -0x38(%rbp),%rax
  sub    %fs:0x28,%rax
  jne    L113
  movq   %rbx,%xmm0
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
L101:
  lea    D44(%rip),%r12
  mov    %r12,%rdi
  call   <printf@plt>
  mov    $0x0,%eax
  call   <tic@plt>
  movq   %r15,%xmm2
  subsd  %xmm2,%xmm0
  movq   %xmm0,%rbx
  mov    %r12,%rdi
  call   <printf@plt>
  jmp    L62
L113:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: disassemble_data
arguments: tag: D9
data_type: byte[4]
name: disassemble_data
arguments: tag: D40
data_type: byte[4]
name: disassemble_data
arguments: tag: D44
data_type: string

tool: {"D9": [0x00,0x40,0x9c,0x46]}

tool: {"D40": [0x00,0x40,0x1c,0x46]}

tool: D44: should not return NaN


assistant: ```c
double benchmark(int iterations, int len) {
  double elapsed;
  float x[len];
  float y[len];
  float z;
  double t;
  int i;
  for (i = 0; i < len; i++) {
    x[i] = (rand_float() * 20000.0f) - 10000.0f;
    y[i] = (rand_float() * 20000.0f) - 10000.0f;
  }
  z = 0.0f;
  t = tic();
  for (i = 0; i < iterations; i++) {
    z = c_sdot(len, x, 1, y, 1);
    if (z != z) {
      printf("should not return NaN\n");
      break;
    }
  }
  elapsed = tic() - t;
  if (z != z) {
    printf("should not return NaN\n");
  }
  return elapsed;
}
```