[InstCombine] reduce code; NFC

llvm-svn: 346235
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 1946f89..975cb83 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5284,7 +5284,7 @@
   // Finally emit the new fcmp.
   Value *X = LHSI->getOperand(1);
   FCmpInst *NewFCI = new FCmpInst(Pred, X, RHSC);
-  NewFCI->setFastMathFlags(I.getFastMathFlags());
+  NewFCI->copyFastMathFlags(&I);
   return NewFCI;
 }