Revert "Relax constraints for reduction vectorization"

This reverts commit r355868.  Breaks hexagon.

llvm-svn: 355873

1 files changed, 2 insertions, 8 deletions

diff --git a/llvm/lib/Analysis/IVDescriptors.cpp b/llvm/lib/Analysis/IVDescriptors.cpp
index 19f1a77..555e3c9 100644
--- a/llvm/lib/Analysis/IVDescriptors.cpp
+++ b/llvm/lib/Analysis/IVDescriptors.cpp
@@ -251,10 +251,6 @@ bool RecurrenceDescriptor::AddReductionVar(PHINode *Phi, RecurrenceKind Kind,
   Worklist.push_back(Start);
   VisitedInsts.insert(Start);
 
-  // Start with all flags set because we will intersect this with the reduction
-  // flags from all the reduction operations.
-  FastMathFlags FMF = FastMathFlags::getFast();
-
   // A value in the reduction can be used:
   //  - By the reduction:
   //      - Reduction operation:
@@ -300,8 +296,6 @@ bool RecurrenceDescriptor::AddReductionVar(PHINode *Phi, RecurrenceKind Kind,
       ReduxDesc = isRecurrenceInstr(Cur, Kind, ReduxDesc, HasFunNoNaNAttr);
       if (!ReduxDesc.isRecurrence())
         return false;
-      if (isa<FPMathOperator>(ReduxDesc.getPatternInst()))
-        FMF &= ReduxDesc.getPatternInst()->getFastMathFlags();
     }
 
     bool IsASelect = isa<SelectInst>(Cur);
@@ -447,7 +441,7 @@ bool RecurrenceDescriptor::AddReductionVar(PHINode *Phi, RecurrenceKind Kind,
 
   // Save the description of this reduction variable.
   RecurrenceDescriptor RD(
-      RdxStart, ExitInstruction, Kind, FMF, ReduxDesc.getMinMaxKind(),
+      RdxStart, ExitInstruction, Kind, ReduxDesc.getMinMaxKind(),
       ReduxDesc.getUnsafeAlgebraInst(), RecurrenceType, IsSigned, CastInsts);
   RedDes = RD;
 
@@ -556,7 +550,7 @@ RecurrenceDescriptor::InstDesc
 RecurrenceDescriptor::isRecurrenceInstr(Instruction *I, RecurrenceKind Kind,
                                         InstDesc &Prev, bool HasFunNoNaNAttr) {
   Instruction *UAI = Prev.getUnsafeAlgebraInst();
-  if (!UAI && isa<FPMathOperator>(I) && !I->hasAllowReassoc())
+  if (!UAI && isa<FPMathOperator>(I) && !I->isFast())
     UAI = I; // Found an unsafe (unvectorizable) algebra instruction.
 
   switch (I->getOpcode()) {