Revert "Revert r222040 because of bot failure."

This reverts commit r222203, reverting r222040 didn't end up turning the
bot green.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222261 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index b41cdc65202f6dc6edbc00765a58b0c7dea9785b..a0570f7ebd474d5d61b4afcc1a7f7598dec8465d 100644 (file)
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -1269,14 +1269,17 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
         // type of OpI doesn't enter into things at all.  We simply evaluate
         // in whichever source type is larger, then convert to the
         // destination type.
+        Value *NewLHS = LHSOrig, *NewRHS = RHSOrig;
         if (LHSWidth < SrcWidth)
-          LHSOrig = Builder->CreateFPExt(LHSOrig, RHSOrig->getType());
+          NewLHS = Builder->CreateFPExt(NewLHS, RHSOrig->getType());
         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());
+          NewRHS = Builder->CreateFPExt(NewRHS, LHSOrig->getType());
+        if (NewLHS != LHSOrig || NewRHS != RHSOrig) {
+          Value *ExactResult = Builder->CreateFRem(NewLHS, NewRHS);
+          if (Instruction *RI = dyn_cast<Instruction>(ExactResult))
+            RI->copyFastMathFlags(OpI);
+          return CastInst::CreateFPCast(ExactResult, CI.getType());
+        }
     }
 
     // (fptrunc (fneg x)) -> (fneg (fptrunc x))

diff --git a/test/Transforms/InstCombine/fpcast.ll b/test/Transforms/InstCombine/fpcast.ll
index 9be66fd42c68d75a1d03cd6e478a078431a9daf0..c4c8578198b557f2a04ff986e390ca324e7f463b 100644 (file)
--- a/test/Transforms/InstCombine/fpcast.ll
+++ b/test/Transforms/InstCombine/fpcast.ll
@@ -53,3 +53,13 @@ define half @test5(float %a, float %b, float %c) {
 }
 
 declare float @llvm.fabs.f32(float) nounwind readonly
+
+define <1 x float> @test6(<1 x double> %V) {
+  %frem = frem <1 x double> %V, %V
+  %trunc = fptrunc <1 x double> %frem to <1 x float>
+  ret <1 x float> %trunc
+; CHECK-LABEL: @test6
+; CHECK-NEXT: %[[frem:.*]]  = frem <1 x double> %V, %V
+; CHECK-NEXT: %[[trunc:.*]] = fptrunc <1 x double> %[[frem]] to <1 x float>
+; CHECK-NEXT: ret <1 x float> %trunc
+}