From: Craig Topper <craig.topper@gmail.com>
Date: Tue, 25 Apr 2017 17:54:12 +0000 (+0000)
Subject: [InstCombine] Remove redundant code from SimplifyUsingDistributiveLaws
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=4b3dea8edf33f01fd72eef9a69a01ca63c330c21;p=llvm

[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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301341 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index 81f2d9fa179..c23b45ca0f3 100644
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -641,14 +641,6 @@ Value *InstCombiner::SimplifyUsingDistributiveLaws(BinaryOperator &I) {
       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::SimplifyUsingDistributiveLaws(BinaryOperator &I) {
       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;