[llvm] r307486 - [InstCombine] Speculatively implement a fix for what might be the root cause of PR33721 by making sure that we have integer types before doing select C, -1, 0 -> sext C to int

[Craig Topper via llvm-commits]

Author: ctopper
Date: Sat Jul  8 20:25:17 2017
New Revision: 307486

URL: http://llvm.org/viewvc/llvm-project?rev=307486&view=rev
Log:
[InstCombine] Speculatively implement a fix for what might be the root cause of PR33721 by making sure that we have integer types before doing select C, -1, 0 -> sext C to int

I recently changed m_One and m_AllOnes to use Constant::isOneValue/isAllOnesValue which work on floating point values too. The original implementation looked specifically for ConstantInt scalars and splats. So I'm guessing we are accidentally trying to issue sext/zexts on floating point types now.

Hopefully I figure out how to reproduce the failure from the PR soon.

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp?rev=307486&r1=307485&r2=307486&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineSelect.cpp Sat Jul  8 20:25:17 2017
@@ -1223,7 +1223,8 @@ Instruction *InstCombiner::visitSelectIn
   // select i1 %c, <2 x i8> <1, 1>, <2 x i8> <0, 0>
   // because that may need 3 instructions to splat the condition value:
   // extend, insertelement, shufflevector.
-  if (CondVal->getType()->isVectorTy() == SelType->isVectorTy()) {
+  if (SelType->isIntOrIntVectorTy() &&
+      CondVal->getType()->isVectorTy() == SelType->isVectorTy()) {
     // select C, 1, 0 -> zext C to int
     if (match(TrueVal, m_One()) && match(FalseVal, m_Zero()))
       return new ZExtInst(CondVal, SelType);