Add PR26491 horizontal add test
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=x86_64-unknown -mattr=+sse2 | FileCheck %s --check-prefixes=SSE,SSE2
; RUN: llc < %s -mtriple=x86_64-unknown -mattr=+ssse3 | FileCheck %s --check-prefixes=SSE,SSSE3
; RUN: llc < %s -mtriple=x86_64-unknown -mattr=+avx | FileCheck %s --check-prefixes=AVX

define float @pr26491(<4 x float> %a0) {
; SSE2-LABEL: pr26491:
; SSE2:       # %bb.0:
; SSE2-NEXT:    movaps %xmm0, %xmm1
; SSE2-NEXT:    shufps {{.*#+}} xmm1 = xmm1[1,1,3,3]
; SSE2-NEXT:    addps %xmm0, %xmm1
; SSE2-NEXT:    movaps %xmm1, %xmm0
; SSE2-NEXT:    movhlps {{.*#+}} xmm0 = xmm0[1,1]
; SSE2-NEXT:    addss %xmm1, %xmm0
; SSE2-NEXT:    retq
;
; SSSE3-LABEL: pr26491:
; SSSE3:       # %bb.0:
; SSSE3-NEXT:    movshdup {{.*#+}} xmm1 = xmm0[1,1,3,3]
; SSSE3-NEXT:    addps %xmm0, %xmm1
; SSSE3-NEXT:    movaps %xmm1, %xmm0
; SSSE3-NEXT:    movhlps {{.*#+}} xmm0 = xmm0[1,1]
; SSSE3-NEXT:    addss %xmm1, %xmm0
; SSSE3-NEXT:    retq
;
; AVX-LABEL: pr26491:
; AVX:       # %bb.0:
; AVX-NEXT:    vmovshdup {{.*#+}} xmm1 = xmm0[1,1,3,3]
; AVX-NEXT:    vaddps %xmm0, %xmm1, %xmm0
; AVX-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm0[1,0]
; AVX-NEXT:    vaddss %xmm0, %xmm1, %xmm0
; AVX-NEXT:    retq
  %1 = shufflevector <4 x float> %a0, <4 x float> undef, <4 x i32> <i32 1, i32 1, i32 3, i32 3>
  %2 = fadd <4 x float> %1, %a0
  %3 = extractelement <4 x float> %2, i32 2
  %4 = extractelement <4 x float> %2, i32 0
  %5 = fadd float %3, %4
  ret float %5
}