#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
float sqrt(float const);
float QuaternionNorm(const float quat[4]) {
  return sqrt(quat[0] * quat[0] + quat[1] * quat[1] + quat[2] * quat[2] +
              quat[3] * quat[3]);
}


x86 assembly (clang, -O0):
<QuaternionNorm>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rax
movss  (%rax),%xmm0
mov    -0x8(%rbp),%rax
movss  (%rax),%xmm2
mov    -0x8(%rbp),%rax
movss  0x4(%rax),%xmm1
mov    -0x8(%rbp),%rax
mulss  0x4(%rax),%xmm1
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
mov    -0x8(%rbp),%rax
movss  0x8(%rax),%xmm1
mov    -0x8(%rbp),%rax
movss  0x8(%rax),%xmm2
mulss  %xmm2,%xmm1
addss  %xmm0,%xmm1
mov    -0x8(%rbp),%rax
movss  0xc(%rax),%xmm0
mov    -0x8(%rbp),%rax
movss  0xc(%rax),%xmm2
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
call   1030 <sqrt@plt>
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<QuaternionNorm>:
movss  (%rdi),%xmm0
movss  0x4(%rdi),%xmm1
mulss  %xmm1,%xmm1
mulss  %xmm0,%xmm0
addss  %xmm1,%xmm0
movss  0x8(%rdi),%xmm1
mulss  %xmm1,%xmm1
addss  %xmm0,%xmm1
movss  0xc(%rdi),%xmm0
mulss  %xmm0,%xmm0
addss  %xmm1,%xmm0
xorps  %xmm1,%xmm1
ucomiss %xmm1,%xmm0
jb     114c <QuaternionNorm+0x3c>
sqrtss %xmm0,%xmm0
ret
jmp    1030 <sqrt@plt>

LLVM IR (-O0):
define float @QuaternionNorm(float* %0) {
%2 = alloca float*
store float* %0, float** %2
%3 = load float*, float** %2
%4 = getelementptr inbounds float, float* %3, i64 0
%5 = load float, float* %4
%6 = load float*, float** %2
%7 = getelementptr inbounds float, float* %6, i64 0
%8 = load float, float* %7
%9 = load float*, float** %2
%10 = getelementptr inbounds float, float* %9, i64 1
%11 = load float, float* %10
%12 = load float*, float** %2
%13 = getelementptr inbounds float, float* %12, i64 1
%14 = load float, float* %13
%15 = fmul float %11, %14
%16 = call float @llvm.fmuladd.f32(float %5, float %8, float %15)
%17 = load float*, float** %2
%18 = getelementptr inbounds float, float* %17, i64 2
%19 = load float, float* %18
%20 = load float*, float** %2
%21 = getelementptr inbounds float, float* %20, i64 2
%22 = load float, float* %21
%23 = call float @llvm.fmuladd.f32(float %19, float %22, float %16)
%24 = load float*, float** %2
%25 = getelementptr inbounds float, float* %24, i64 3
%26 = load float, float* %25
%27 = load float*, float** %2
%28 = getelementptr inbounds float, float* %27, i64 3
%29 = load float, float* %28
%30 = call float @llvm.fmuladd.f32(float %26, float %29, float %23)
%31 = call float @sqrt(float %30)
ret float %31
}

LLVM IR (-O2):
define float @QuaternionNorm(float* nocapture %0) {
%2 = load float, float* %0
%3 = getelementptr inbounds float, float* %0, i64 1
%4 = load float, float* %3
%5 = fmul float %4, %4
%6 = tail call float @llvm.fmuladd.f32(float %2, float %2, float %5)
%7 = getelementptr inbounds float, float* %0, i64 2
%8 = load float, float* %7
%9 = tail call float @llvm.fmuladd.f32(float %8, float %8, float %6)
%10 = getelementptr inbounds float, float* %0, i64 3
%11 = load float, float* %10
%12 = tail call float @llvm.fmuladd.f32(float %11, float %11, float %9)
%13 = tail call float @sqrt(float %12)
ret float %13
}