[llvm] r301341 - [InstCombine] Remove redundant code from SimplifyUsingDistributiveLaws

[Craig Topper via llvm-commits]

Author: ctopper
Date: Tue Apr 25 12:54:12 2017
New Revision: 301341

URL: http://llvm.org/viewvc/llvm-project?rev=301341&view=rev
Log:
[InstCombine] Remove redundant code from SimplifyUsingDistributiveLaws

The code I've removed here exists in ExpandBinOp in InstSimplify which we call into before SimplifyUsingDistributiveLaws. The code in InstSimplify looks to have been copied from here.

I verified this code doesn't fire on any lit tests. Not that that proves its definitely dead.

Differential Revision: https://reviews.llvm.org/D32472

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp?rev=301341&r1=301340&r2=301341&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstructionCombining.cpp Tue Apr 25 12:54:12 2017
@@ -641,14 +641,6 @@ Value *InstCombiner::SimplifyUsingDistri
       if (Value *R = SimplifyBinOp(TopLevelOpcode, B, C, DL)) {
         // They do! Return "L op' R".
         ++NumExpand;
-        // If "L op' R" equals "A op' B" then "L op' R" is just the LHS.
-        if ((L == A && R == B) ||
-            (Instruction::isCommutative(InnerOpcode) && L == B && R == A))
-          return Op0;
-        // Otherwise return "L op' R" if it simplifies.
-        if (Value *V = SimplifyBinOp(InnerOpcode, L, R, DL))
-          return V;
-        // Otherwise, create a new instruction.
         C = Builder->CreateBinOp(InnerOpcode, L, R);
         C->takeName(&I);
         return C;
@@ -666,14 +658,6 @@ Value *InstCombiner::SimplifyUsingDistri
       if (Value *R = SimplifyBinOp(TopLevelOpcode, A, C, DL)) {
         // They do! Return "L op' R".
         ++NumExpand;
-        // If "L op' R" equals "B op' C" then "L op' R" is just the RHS.
-        if ((L == B && R == C) ||
-            (Instruction::isCommutative(InnerOpcode) && L == C && R == B))
-          return Op1;
-        // Otherwise return "L op' R" if it simplifies.
-        if (Value *V = SimplifyBinOp(InnerOpcode, L, R, DL))
-          return V;
-        // Otherwise, create a new instruction.
         A = Builder->CreateBinOp(InnerOpcode, L, R);
         A->takeName(&I);
         return A;