[llvm-commits] [llvm] r89456 - /llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

[Duncan Sands]

Author: baldrick
Date: Fri Nov 20 07:19:51 2009
New Revision: 89456

URL: http://llvm.org/viewvc/llvm-project?rev=89456&view=rev
Log:
Fix PR5563, an expensive checks failure when running on
tests/Transforms/InstCombine/shufflemask-undef.ll.  If
anyone cares, the use of 2*e here (and the equivalent
all over the place in instcombine) seems wrong, though
harmless: it should really be twice the length of the
input vector.  I think shufflevector used to require
that the mask have the same length as the input, but I
don't think that's true any more.  I don't care enough
about vectors to do anything about this...

Modified:
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=89456&r1=89455&r2=89456&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Fri Nov 20 07:19:51 2009
@@ -12920,7 +12920,7 @@
       if (LHSMask.size() == Mask.size()) {
         std::vector<unsigned> NewMask;
         for (unsigned i = 0, e = Mask.size(); i != e; ++i)
-          if (Mask[i] >= 2*e)
+          if (Mask[i] >= e)
             NewMask.push_back(2*e);
           else
             NewMask.push_back(LHSMask[Mask[i]]);