[llvm-branch-commits] [llvm-branch] r196614 - Merging r196611:

[Bill Wendling]

Author: void
Date: Fri Dec  6 16:12:13 2013
New Revision: 196614

URL: http://llvm.org/viewvc/llvm-project?rev=196614&view=rev
Log:
Merging r196611:
------------------------------------------------------------------------
r196611 | dexonsmith | 2013-12-06 13:48:36 -0800 (Fri, 06 Dec 2013) | 5 lines

Don't use isNullValue to evaluate ConstantExpr

ConstantExpr can evaluate to false even when isNullValue gives false.

Fixes PR18143.
------------------------------------------------------------------------

Added:
    llvm/branches/release_34/test/Transforms/InstCombine/phi-select-constexpr.ll
      - copied unchanged from r196611, llvm/trunk/test/Transforms/InstCombine/phi-select-constexpr.ll
Modified:
    llvm/branches/release_34/   (props changed)
    llvm/branches/release_34/lib/Transforms/InstCombine/InstructionCombining.cpp

Propchange: llvm/branches/release_34/
------------------------------------------------------------------------------
--- svn:mergeinfo (original)
+++ svn:mergeinfo Fri Dec  6 16:12:13 2013
@@ -1,3 +1,3 @@
 /llvm/branches/Apple/Pertwee:110850,110961
 /llvm/branches/type-system-rewrite:133420-134817
-/llvm/trunk:155241,195092-195094,195100,195102-195103,195118,195129,195136,195138,195148,195152,195156-195157,195161-195162,195193,195272,195317-195318,195327,195330,195333,195339,195343,195355,195364,195379,195397-195399,195401,195408,195421,195423-195424,195432,195439,195444,195455-195456,195469,195476-195477,195479,195491-195493,195514,195528,195547,195567,195573-195576,195590-195591,195599,195632,195635-195636,195670,195677,195679,195682,195684,195713,195716,195769,195773,195779,195782,195787-195788,195791,195803,195812,195827,195834,195843-195844,195878-195881,195887,195903,195905,195912,195915,195932,195936-195943,195972-195973,195975-195976,196004,196044-196046,196069,196100,196104,196129,196151,196153,196267,196508,196532,196538
+/llvm/trunk:155241,195092-195094,195100,195102-195103,195118,195129,195136,195138,195148,195152,195156-195157,195161-195162,195193,195272,195317-195318,195327,195330,195333,195339,195343,195355,195364,195379,195397-195399,195401,195408,195421,195423-195424,195432,195439,195444,195455-195456,195469,195476-195477,195479,195491-195493,195514,195528,195547,195567,195573-195576,195590-195591,195599,195632,195635-195636,195670,195677,195679,195682,195684,195713,195716,195769,195773,195779,195782,195787-195788,195791,195803,195812,195827,195834,195843-195844,195878-195881,195887,195903,195905,195912,195915,195932,195936-195943,195972-195973,195975-195976,196004,196044-196046,196069,196100,196104,196129,196151,196153,196267,196508,196532,196538,196611

Modified: llvm/branches/release_34/lib/Transforms/InstCombine/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_34/lib/Transforms/InstCombine/InstructionCombining.cpp?rev=196614&r1=196613&r2=196614&view=diff
==============================================================================
--- llvm/branches/release_34/lib/Transforms/InstCombine/InstructionCombining.cpp (original)
+++ llvm/branches/release_34/lib/Transforms/InstCombine/InstructionCombining.cpp Fri Dec  6 16:12:13 2013
@@ -699,7 +699,10 @@ Instruction *InstCombiner::FoldOpIntoPhi
       Value *TrueVInPred = TrueV->DoPHITranslation(PhiTransBB, ThisBB);
       Value *FalseVInPred = FalseV->DoPHITranslation(PhiTransBB, ThisBB);
       Value *InV = 0;
-      if (Constant *InC = dyn_cast<Constant>(PN->getIncomingValue(i)))
+      // Beware of ConstantExpr:  it may eventually evaluate to getNullValue,
+      // even if currently isNullValue gives false.
+      Constant *InC = dyn_cast<Constant>(PN->getIncomingValue(i));
+      if (InC && !isa<ConstantExpr>(InC))
         InV = InC->isNullValue() ? FalseVInPred : TrueVInPred;
       else
         InV = Builder->CreateSelect(PN->getIncomingValue(i),