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
  mov    %edi,%r13d
  push   %r12
  mov    %esi,%r12d
  push   %rbx
  sub    $0x28,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  movslq %esi,%rax
  mov    %rsp,%rcx
  mov    %rax,-0x48(%rbp)
  lea    0xf(,%rax,4),%rax
  mov    %rax,%rsi
  mov    %rax,%rdx
  and    $0xfffffffffffff000,%rsi
  and    $0xfffffffffffffff0,%rdx
  sub    %rsi,%rcx
  cmp    %rcx,%rsp
  je     L46
L36:
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  cmp    %rcx,%rsp
  jne    L36
L46:
  and    $0xfff,%edx
  sub    %rdx,%rsp
  test   %rdx,%rdx
  jne    L148
L22:
  mov    %rax,%rdx
  mov    %rsp,%rcx
  and    $0xfffffffffffff000,%rax
  mov    %rsp,%rbx
  sub    %rax,%rcx
  and    $0xfffffffffffffff0,%rdx
  cmp    %rcx,%rsp
  je     L11
L6:
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  cmp    %rcx,%rsp
  jne    L6
L11:
  and    $0xfff,%edx
  sub    %rdx,%rsp
  test   %rdx,%rdx
  jne    L155
L27:
  lea    0x3(%rsp),%rcx
  mov    %rcx,%rax
  and    $0xfffffffffffffffc,%rcx
  shr    $0x2,%rax
  mov    %rcx,%r15
  mov    %rax,-0x50(%rbp)
  test   %r12d,%r12d
  jle    L120
  xor    %r14d,%r14d
  nopl   (%rax)
L159:
  xor    %eax,%eax
  call   <rand_float@plt>
  mulss  D29(%rip),%xmm0
  xor    %eax,%eax
  subss  D13(%rip),%xmm0
  movss  %xmm0,(%rbx,%r14,4)
  call   <rand_float@plt>
  mulss  D11(%rip),%xmm0
  subss  D66(%rip),%xmm0
  movss  %xmm0,(%r15,%r14,4)
  add    $0x1,%r14
  cmp    -0x48(%rbp),%r14
  jne    L159
L120:
  xor    %eax,%eax
  call   <tic@plt>
  movsd  %xmm0,-0x48(%rbp)
  test   %r13d,%r13d
  jle    L13
  xor    %r14d,%r14d
  jmp    L63
  nopw   0x0(%rax,%rax,1)
L48:
  add    $0x1,%r14d
  cmp    %r14d,%r13d
  je     L13
L63:
  mov    $0x1,%r8d
  mov    %r15,%rcx
  mov    %rbx,%rsi
  mov    %r12d,%edi
  movss  D63(%rip),%xmm0
  mov    $0x1,%edx
  call   <c_saxpy@plt>
  movss  (%r15),%xmm0
  ucomiss %xmm0,%xmm0
  jnp    L48
  lea    D68(%rip),%rdi
  call   <printf@plt>
L13:
  xor    %eax,%eax
  call   <tic@plt>
  mov    -0x50(%rbp),%rax
  subsd  -0x48(%rbp),%xmm0
  movss  0x0(,%rax,4),%xmm1
  ucomiss %xmm1,%xmm1
  jp     L54
L67:
  mov    -0x38(%rbp),%rax
  sub    %fs:0x28,%rax
  jne    L124
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
  nopl   0x0(%rax)
L148:
  orq    $0x0,-0x8(%rsp,%rdx,1)
  jmp    L22
  nopl   0x0(%rax,%rax,1)
L54:
  lea    D68(%rip),%rdi
  movsd  %xmm0,-0x48(%rbp)
  call   <printf@plt>
  movsd  -0x48(%rbp),%xmm0
  jmp    L67
L155:
  orq    $0x0,-0x8(%rsp,%rdx,1)
  jmp    L27
L124:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: retrieve_data
arguments: tag: D29
data_type: byte[4]
name: retrieve_data
arguments: tag: D13
data_type: byte[4]
name: retrieve_data
arguments: tag: D11
data_type: byte[4]
name: retrieve_data
arguments: tag: D66
data_type: byte[4]
name: retrieve_data
arguments: tag: D63
data_type: byte[4]
name: retrieve_data
arguments: tag: D68
data_type: string

tool: {"D29": [0x00,0x00,0xc8,0x42]}

tool: {"D13": [0x00,0x00,0x48,0x43]}

tool: {"D11": [0x00,0x40,0x1c,0x46]}

tool: {"D66": [0x00,0x40,0x9c,0x46]}

tool: {"D63": [0x00,0x00,0xa0,0x40]}

tool: D68: should not return NaN


assistant: ```c
double benchmark(int iterations, int len) {
  double elapsed;
  float x[len];
  float y[len];
  double t;
  int i;
  for (i = 0; i < len; i++) {
    x[i] = (rand_float() * 100.0f) - 200.0f;
    y[i] = (rand_float() * 10000.0f) - 20000.0f;
  }
  t = tic();
  for (i = 0; i < iterations; i++) {
    c_saxpy(len, 5.0f, x, 1, y, 1);
    if (y[0] != y[0]) {
      printf("should not return NaN\n");
      break;
    }
  }
  elapsed = tic() - t;
  if (y[0] != y[0]) {
    printf("should not return NaN\n");
  }
  return elapsed;
}
```