[llvm-commits] [llvm] r148285 - /llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

[Craig Topper]

Author: ctopper
Date: Mon Jan 16 22:44:50 2012
New Revision: 148285

URL: http://llvm.org/viewvc/llvm-project?rev=148285&view=rev
Log:
Fix a crasher when PerformShiftCombine receives a BUILD_VECTOR of all UNDEF. Probably could use better handling in DAG combine or getNode. Fixes PR11772.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=148285&r1=148284&r2=148285&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Jan 16 22:44:50 2012
@@ -13430,6 +13430,11 @@
       BaseShAmt = Arg;
       break;
     }
+    // Handle the case where the build_vector is all undef
+    // FIXME: Should DAG allow this?
+    if (i == NumElts)
+      return SDValue();
+
     for (; i != NumElts; ++i) {
       SDValue Arg = ShAmtOp.getOperand(i);
       if (Arg.getOpcode() == ISD::UNDEF) continue;