commit 50b37c79203668af8b223710dc6362d399040fdd
author Bruno Cardoso Lopes <bruno.cardoso@gmail.com> Mon Aug 15 21:45:54 2011 +0000
committer Bruno Cardoso Lopes <bruno.cardoso@gmail.com> Mon Aug 15 21:45:54 2011 +0000
tree 548cb79d6f480311df4ffd6e9e5bdef83442e7d0
parent 7a328270be871f640d94fcebfd48dee02950fb8c

Fix PR10656. It's only profitable to use 128-bit inserts and extracts
when AVX mode is one. Otherwise is just more work for the type
legalizer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137661 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/X86/X86ISelLowering.cpp

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 1ac5c2a..156e7ae 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -11737,7 +11737,8 @@
 
 /// PerformShuffleCombine - Performs several different shuffle combines.
 static SDValue PerformShuffleCombine(SDNode *N, SelectionDAG &DAG,
-                                     TargetLowering::DAGCombinerInfo &DCI) {
+                                     TargetLowering::DAGCombinerInfo &DCI,
+                                     const X86Subtarget *Subtarget) {
   DebugLoc dl = N->getDebugLoc();
   EVT VT = N->getValueType(0);
 
@@ -11746,8 +11747,9 @@
   if (!DCI.isBeforeLegalize() && !TLI.isTypeLegal(VT.getVectorElementType()))
     return SDValue();
 
-  // Only handle pure VECTOR_SHUFFLE nodes.
-  if (VT.getSizeInBits() == 256 && N->getOpcode() == ISD::VECTOR_SHUFFLE)
+  // Combine 256-bit vector shuffles. This is only profitable when in AVX mode
+  if (Subtarget->hasAVX() && VT.getSizeInBits() == 256 &&
+      N->getOpcode() == ISD::VECTOR_SHUFFLE)
     return PerformShuffleCombine256(N, DAG, DCI);
 
   // Only handle 128 wide vector from here on.
@@ -13220,7 +13222,7 @@
   case X86ISD::VPERMILPD:
   case X86ISD::VPERMILPDY:
   case X86ISD::VPERM2F128:
-  case ISD::VECTOR_SHUFFLE: return PerformShuffleCombine(N, DAG, DCI);
+  case ISD::VECTOR_SHUFFLE: return PerformShuffleCombine(N, DAG, DCI,Subtarget);
   }
 
   return SDValue();