[llvm] r322459 - [X86][SSE] Support combining MOVLHPS undef inputs

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Sun Jan 14 10:50:34 2018
New Revision: 322459

URL: http://llvm.org/viewvc/llvm-project?rev=322459&view=rev
Log:
[X86][SSE] Support combining MOVLHPS undef inputs

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
    llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=322459&r1=322458&r2=322459&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Sun Jan 14 10:50:34 2018
@@ -28233,6 +28233,7 @@ static bool matchBinaryVectorShuffle(MVT
   if (MaskVT.is128BitVector()) {
     if (isTargetShuffleEquivalent(Mask, {0, 0}) && AllowFloatDomain) {
       V2 = V1;
+      V1 = (SM_SentinelUndef == Mask[0] ? DAG.getUNDEF(MVT::v4f32) : V1);
       Shuffle = X86ISD::MOVLHPS;
       SrcVT = DstVT = MVT::v4f32;
       return true;

Modified: llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll?rev=322459&r1=322458&r2=322459&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll (original)
+++ llvm/trunk/test/CodeGen/X86/vector-shuffle-128-v2.ll Sun Jan 14 10:50:34 2018
@@ -301,8 +301,7 @@ define <2 x double> @shuffle_v2f64_21(<2
 define <2 x double> @shuffle_v2f64_u2(<2 x double> %a, <2 x double> %b) {
 ; SSE2-LABEL: shuffle_v2f64_u2:
 ; SSE2:       # %bb.0:
-; SSE2-NEXT:    movlhps {{.*#+}} xmm1 = xmm1[0,0]
-; SSE2-NEXT:    movaps %xmm1, %xmm0
+; SSE2-NEXT:    movlhps {{.*#+}} xmm0 = xmm0[0],xmm1[0]
 ; SSE2-NEXT:    retq
 ;
 ; SSE3-LABEL: shuffle_v2f64_u2: