void fct3_4(float *x) {
  float tmp00, tmp01, tmp10, tmp11, wc, ws;
  ;
  ;
  ;
  x[1] *= 0.7071067812f;
  ;
  tmp00 = x[0] + x[1];
  tmp01 = x[0] - x[1];
  wc = 0.923879532511287f;
  ws = 0.382683432365090f;
  ;
  ;
  ;
  tmp10 = x[2] * wc + x[3] * ws;
  tmp11 = x[2] * ws - x[3] * wc;
  ;
  ;
  x[0] = tmp00 + tmp10;
  x[3] = tmp00 - tmp10;
  x[1] = tmp01 + tmp11;
  x[2] = tmp01 - tmp11;
  ;
}


x86 assembly (clang, -O0):
<fct3_4>:
push   %rbp
mov    %rsp,%rbp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rax
movss  0xef4(%rip),%xmm0
mulss  0x4(%rax),%xmm0
movss  %xmm0,0x4(%rax)
mov    -0x8(%rbp),%rax
movss  (%rax),%xmm0
mov    -0x8(%rbp),%rax
addss  0x4(%rax),%xmm0
movss  %xmm0,-0xc(%rbp)
mov    -0x8(%rbp),%rax
movss  (%rax),%xmm0
mov    -0x8(%rbp),%rax
subss  0x4(%rax),%xmm0
movss  %xmm0,-0x10(%rbp)
movss  0xeb2(%rip),%xmm0
movss  %xmm0,-0x1c(%rbp)
movss  0xea1(%rip),%xmm0
movss  %xmm0,-0x20(%rbp)
mov    -0x8(%rbp),%rax
movss  0x8(%rax),%xmm0
movss  -0x1c(%rbp),%xmm2
mov    -0x8(%rbp),%rax
movss  0xc(%rax),%xmm1
mulss  -0x20(%rbp),%xmm1
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x14(%rbp)
mov    -0x8(%rbp),%rax
movss  0x8(%rax),%xmm0
movss  -0x20(%rbp),%xmm2
mov    -0x8(%rbp),%rax
movss  0xc(%rax),%xmm1
mulss  -0x1c(%rbp),%xmm1
movd   %xmm1,%eax
xor    $0x80000000,%eax
movd   %eax,%xmm1
mulss  %xmm2,%xmm0
addss  %xmm1,%xmm0
movss  %xmm0,-0x18(%rbp)
movss  -0xc(%rbp),%xmm0
addss  -0x14(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,(%rax)
movss  -0xc(%rbp),%xmm0
subss  -0x14(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0xc(%rax)
movss  -0x10(%rbp),%xmm0
addss  -0x18(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x4(%rax)
movss  -0x10(%rbp),%xmm0
subss  -0x18(%rbp),%xmm0
mov    -0x8(%rbp),%rax
movss  %xmm0,0x8(%rax)
pop    %rbp
ret

x86 assembly (clang, -O2):
<fct3_4>:
movss  (%rdi),%xmm0
movss  0x4(%rdi),%xmm1
mulss  0xeef(%rip),%xmm1
movaps %xmm0,%xmm2
addss  %xmm1,%xmm2
subss  %xmm1,%xmm0
shufps $0x0,%xmm0,%xmm2
shufps $0x78,%xmm2,%xmm2
movss  0xc(%rdi),%xmm0
shufps $0x0,%xmm0,%xmm0
mulps  0xedc(%rip),%xmm0
movss  0x8(%rdi),%xmm1
shufps $0x0,%xmm1,%xmm1
mulps  0xedc(%rip),%xmm1
addps  %xmm0,%xmm1
movaps %xmm2,%xmm0
addps  %xmm1,%xmm0
shufps $0x14,%xmm1,%xmm1
subps  %xmm1,%xmm2
movsd  %xmm0,%xmm2
movupd %xmm2,(%rdi)
ret

LLVM IR (-O0):
define void @fct3_4(float* %0) {
%2 = alloca float*
%3 = alloca float
%4 = alloca float
%5 = alloca float
%6 = alloca float
%7 = alloca float
%8 = alloca float
store float* %0, float** %2
%9 = load float*, float** %2
%10 = getelementptr inbounds float, float* %9, i64 1
%11 = load float, float* %10
%12 = fmul float %11, 0x3FE6A09E60000000
store float %12, float* %10
%13 = load float*, float** %2
%14 = getelementptr inbounds float, float* %13, i64 0
%15 = load float, float* %14
%16 = load float*, float** %2
%17 = getelementptr inbounds float, float* %16, i64 1
%18 = load float, float* %17
%19 = fadd float %15, %18
store float %19, float* %3
%20 = load float*, float** %2
%21 = getelementptr inbounds float, float* %20, i64 0
%22 = load float, float* %21
%23 = load float*, float** %2
%24 = getelementptr inbounds float, float* %23, i64 1
%25 = load float, float* %24
%26 = fsub float %22, %25
store float %26, float* %4
store float 0x3FED906BC0000000, float* %7
store float 0x3FD87DE2A0000000, float* %8
%27 = load float*, float** %2
%28 = getelementptr inbounds float, float* %27, i64 2
%29 = load float, float* %28
%30 = load float, float* %7
%31 = load float*, float** %2
%32 = getelementptr inbounds float, float* %31, i64 3
%33 = load float, float* %32
%34 = load float, float* %8
%35 = fmul float %33, %34
%36 = call float @llvm.fmuladd.f32(float %29, float %30, float %35)
store float %36, float* %5
%37 = load float*, float** %2
%38 = getelementptr inbounds float, float* %37, i64 2
%39 = load float, float* %38
%40 = load float, float* %8
%41 = load float*, float** %2
%42 = getelementptr inbounds float, float* %41, i64 3
%43 = load float, float* %42
%44 = load float, float* %7
%45 = fmul float %43, %44
%46 = fneg float %45
%47 = call float @llvm.fmuladd.f32(float %39, float %40, float %46)
store float %47, float* %6
%48 = load float, float* %3
%49 = load float, float* %5
%50 = fadd float %48, %49
%51 = load float*, float** %2
%52 = getelementptr inbounds float, float* %51, i64 0
store float %50, float* %52
%53 = load float, float* %3
%54 = load float, float* %5
%55 = fsub float %53, %54
%56 = load float*, float** %2
%57 = getelementptr inbounds float, float* %56, i64 3
store float %55, float* %57
%58 = load float, float* %4
%59 = load float, float* %6
%60 = fadd float %58, %59
%61 = load float*, float** %2
%62 = getelementptr inbounds float, float* %61, i64 1
store float %60, float* %62
%63 = load float, float* %4
%64 = load float, float* %6
%65 = fsub float %63, %64
%66 = load float*, float** %2
%67 = getelementptr inbounds float, float* %66, i64 2
store float %65, float* %67
ret void
}

LLVM IR (-O2):
define void @fct3_4(float* nocapture %0) {
%2 = getelementptr inbounds float, float* %0, i64 1
%3 = load float, float* %2
%4 = fmul float %3, 0x3FE6A09E60000000
%5 = load float, float* %0
%6 = insertelement <2 x float> poison, float %5, i64 0
%7 = shufflevector <2 x float> %6, <2 x float> poison, <2 x i32> zeroinitializer
%8 = insertelement <2 x float> poison, float %4, i64 0
%9 = shufflevector <2 x float> %8, <2 x float> poison, <2 x i32> zeroinitializer
%10 = fadd <2 x float> %7, %9
%11 = fsub <2 x float> %7, %9
%12 = shufflevector <2 x float> %10, <2 x float> %11, <4 x i32> <i32 0, i32 3, i32 3, i32 0>
%13 = getelementptr inbounds float, float* %0, i64 2
%14 = load float, float* %13
%15 = getelementptr inbounds float, float* %0, i64 3
%16 = load float, float* %15
%17 = insertelement <2 x float> poison, float %16, i64 0
%18 = shufflevector <2 x float> %17, <2 x float> poison, <2 x i32> zeroinitializer
%19 = fmul <2 x float> %18, <float 0x3FD87DE2A0000000, float 0xBFED906BC0000000>
%20 = insertelement <2 x float> poison, float %14, i64 0
%21 = shufflevector <2 x float> %20, <2 x float> poison, <2 x i32> zeroinitializer
%22 = call <2 x float> @llvm.fmuladd.v2f32(<2 x float> %21, <2 x float> <float 0x3FED906BC0000000, float 0x3FD87DE2A0000000>, <2 x float> %19)
%23 = shufflevector <2 x float> %22, <2 x float> poison, <4 x i32> <i32 0, i32 1, i32 1, i32 0>
%24 = fadd <4 x float> %12, %23
%25 = fsub <4 x float> %12, %23
%26 = shufflevector <4 x float> %24, <4 x float> %25, <4 x i32> <i32 0, i32 1, i32 6, i32 7>
%27 = bitcast float* %0 to <4 x float>*
store <4 x float> %26, <4 x float>* %27
ret void
}