[PATCH] D156579: InstCombine: Fold fneg (ldexp x, n) -> ldexp (fneg x), n

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp:2529
+        Builder.CreateFNegFMF(X, &FMFSource), Y, &FMFSource));
+  }
+
----------------
goldstein.w.n wrote:
> style: No branches around single expression if
It covers multiple lines


================
Comment at: llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp:2542
 
-  if (match(FNegOp, m_FDiv(m_Value(X), m_Value(Y))))
-    return BinaryOperator::CreateFDivFMF(Builder.CreateFNegFMF(X, &FMFSource),
-                                         Y, &FMFSource);
+      IRBuilder<>::FastMathFlagGuard FMFGuard(Builder);
+      Builder.setFastMathFlags(FMF);
----------------
goldstein.w.n wrote:
> IRBuilder is unused?
It's a flag guard, it only does anything on destruct. The actual builder is the member


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D156579/new/

https://reviews.llvm.org/D156579