[llvm-commits] [llvm] r153035 - /llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

[Duncan Sands]

Author: baldrick
Date: Mon Mar 19 10:35:44 2012
New Revision: 153035

URL: http://llvm.org/viewvc/llvm-project?rev=153035&view=rev
Log:
Fix DAG combine which creates illegal vector shuffles.  Patch by Heikki Kultala.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=153035&r1=153034&r2=153035&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon Mar 19 10:35:44 2012
@@ -7473,6 +7473,12 @@
   // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT
   // operations.  If so, and if the EXTRACT_VECTOR_ELT vector inputs come from
   // at most two distinct vectors, turn this into a shuffle node.
+
+  // May only combine to shuffle after legalize if shuffle is legal.
+  if (LegalOperations &&
+      !TLI.isOperationLegalOrCustom(ISD::VECTOR_SHUFFLE, VT))
+    return SDValue();
+
   SDValue VecIn1, VecIn2;
   for (unsigned i = 0; i != NumInScalars; ++i) {
     // Ignore undef inputs.