[llvm-commits] [llvm] r170024 - /llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp

[Eli Friedman]

On Wed, Dec 12, 2012 at 12:59 PM, Michael Ilseman <milseman at apple.com> wrote:
> Author: milseman
> Date: Wed Dec 12 14:59:36 2012
> New Revision: 170024
>
> URL: http://llvm.org/viewvc/llvm-project?rev=170024&view=rev
> Log:
> Restore the PHI optimization I accidently removed
>
> Modified:
>     llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
>
> Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp?rev=170024&r1=170023&r2=170024&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp (original)
> +++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAddSub.cpp Wed Dec 12 14:59:36 2012
> @@ -354,6 +354,10 @@
>    if (Value *V = SimplifyFAddInst(LHS, RHS, I.getFastMathFlags(), TD))
>      return ReplaceInstUsesWith(I, V);
>
> +  if (isa<PHINode>(LHS))
> +    if (Instruction *NV = FoldOpIntoPhi(I))
> +      return NV;
> +
>    // -A + B  -->  B - A
>    // -A + -B  -->  -(A + B)
>    if (Value *LHSV = dyn_castFNegVal(LHS))

Test?

-Eli