Fix more instances of dropped fast math flags when optimizing FADD instructions. All found by inspection (aka grep).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199528 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 33 insertions, 7 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index 71990a27ac..29ab6c0623 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -1232,7 +1232,10 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
             LHSOrig = Builder->CreateFPExt(LHSOrig, CI.getType());
           if (RHSOrig->getType() != CI.getType())
             RHSOrig = Builder->CreateFPExt(RHSOrig, CI.getType());
-          return BinaryOperator::Create(OpI->getOpcode(), LHSOrig, RHSOrig);
+          Instruction *RI =
+            BinaryOperator::Create(OpI->getOpcode(), LHSOrig, RHSOrig);
+          RI->copyFastMathFlags(OpI);
+          return RI;
         }
         break;
       case Instruction::FMul:
@@ -1246,7 +1249,10 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
             LHSOrig = Builder->CreateFPExt(LHSOrig, CI.getType());
           if (RHSOrig->getType() != CI.getType())
             RHSOrig = Builder->CreateFPExt(RHSOrig, CI.getType());
-          return BinaryOperator::CreateFMul(LHSOrig, RHSOrig);
+          Instruction *RI =
+            BinaryOperator::CreateFMul(LHSOrig, RHSOrig);
+          RI->copyFastMathFlags(OpI);
+          return RI;
         }
         break;
       case Instruction::FDiv:
@@ -1261,7 +1267,10 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
             LHSOrig = Builder->CreateFPExt(LHSOrig, CI.getType());
           if (RHSOrig->getType() != CI.getType())
             RHSOrig = Builder->CreateFPExt(RHSOrig, CI.getType());
-          return BinaryOperator::CreateFDiv(LHSOrig, RHSOrig);
+          Instruction *RI =
+            BinaryOperator::CreateFDiv(LHSOrig, RHSOrig);
+          RI->copyFastMathFlags(OpI);
+          return RI;
         }
         break;
       case Instruction::FRem:
@@ -1274,6 +1283,8 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
         else if (RHSWidth <= SrcWidth)
           RHSOrig = Builder->CreateFPExt(RHSOrig, LHSOrig->getType());
         Value *ExactResult = Builder->CreateFRem(LHSOrig, RHSOrig);
+        if (Instruction *RI = dyn_cast<Instruction>(ExactResult))
+          RI->copyFastMathFlags(OpI);
         return CastInst::CreateFPCast(ExactResult, CI.getType());
     }
 
@@ -1281,7 +1292,9 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
     if (BinaryOperator::isFNeg(OpI)) {
       Value *InnerTrunc = Builder->CreateFPTrunc(OpI->getOperand(1),
                                                  CI.getType());
-      return BinaryOperator::CreateFNeg(InnerTrunc);
+      Instruction *RI = BinaryOperator::CreateFNeg(InnerTrunc);
+      RI->copyFastMathFlags(OpI);
+      return RI;
     }
   }
 
diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 283bec2881..555ffc7752 100644
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -901,6 +901,11 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
             Value *NegVal;  // Compute -Z
             if (SI.getType()->isFPOrFPVectorTy()) {
               NegVal = Builder->CreateFNeg(SubOp->getOperand(1));
+              if (Instruction *NegInst = dyn_cast<Instruction>(NegVal)) {
+                FastMathFlags Flags = AddOp->getFastMathFlags();
+                Flags &= SubOp->getFastMathFlags();
+                NegInst->setFastMathFlags(Flags);
+              }
             } else {
               NegVal = Builder->CreateNeg(SubOp->getOperand(1));
             }
@@ -913,9 +918,15 @@ Instruction *InstCombiner::visitSelectInst(SelectInst &SI) {
               Builder->CreateSelect(CondVal, NewTrueOp,
                                     NewFalseOp, SI.getName() + ".p");
 
-            if (SI.getType()->isFPOrFPVectorTy())
-              return BinaryOperator::CreateFAdd(SubOp->getOperand(0), NewSel);
-            else
+            if (SI.getType()->isFPOrFPVectorTy()) {
+              Instruction *RI =
+                BinaryOperator::CreateFAdd(SubOp->getOperand(0), NewSel);
+
+              FastMathFlags Flags = AddOp->getFastMathFlags();
+              Flags &= SubOp->getFastMathFlags();
+              RI->setFastMathFlags(Flags);
+              return RI;
+            } else
               return BinaryOperator::CreateAdd(SubOp->getOperand(0), NewSel);
           }
         }
diff --git a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index c0b9b2fc3e..178be61b43 100644
--- a/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -638,6 +638,8 @@ static Value *BuildNew(Instruction *I, ArrayRef<Value*> NewOps) {
       if (isa<PossiblyExactOperator>(BO)) {
         New->setIsExact(BO->isExact());
       }
+      if (isa<FPMathOperator>(BO))
+        New->copyFastMathFlags(I);
       return New;
     }
     case Instruction::ICmp: