[llvm] d672c81 - [InstCombine] use safe transformation by default

[Juneyoung Lee via llvm-commits]

Author: Juneyoung Lee
Date: 2021-03-08T02:25:29+09:00
New Revision: d672c81126550a1b74ef77adfb7e7d1dd728a61e

URL: https://github.com/llvm/llvm-project/commit/d672c81126550a1b74ef77adfb7e7d1dd728a61e
DIFF: https://github.com/llvm/llvm-project/commit/d672c81126550a1b74ef77adfb7e7d1dd728a61e.diff

LOG: [InstCombine] use safe transformation by default

.. since it will be folded into and/or anyway

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 7d9383c346c8..6ad10f90d7ca 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -2890,11 +2890,7 @@ Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) {
       // shortening paths for the values (this helps getUnderlyingObjects() for
       // example).
       if (TrueSI->getFalseValue() == FalseVal && TrueSI->hasOneUse()) {
-        // Simply merging into and i1 isn't poison-safe. Do it only when
-        // EnableUnsafeSelectTransform is set.
-        Value *And = EnableUnsafeSelectTransform ?
-            Builder.CreateAnd(CondVal, TrueSI->getCondition()) :
-            Builder.CreateLogicalAnd(CondVal, TrueSI->getCondition());
+        Value *And = Builder.CreateLogicalAnd(CondVal, TrueSI->getCondition());
         replaceOperand(SI, 0, And);
         replaceOperand(SI, 1, TrueSI->getTrueValue());
         return &SI;
@@ -2911,11 +2907,7 @@ Instruction *InstCombinerImpl::visitSelectInst(SelectInst &SI) {
       }
       // select(C0, a, select(C1, a, b)) -> select(C0|C1, a, b)
       if (FalseSI->getTrueValue() == TrueVal && FalseSI->hasOneUse()) {
-        // Simply merging into or i1 isn't poison-safe. Do it only when
-        // EnableUnsafeSelectTransform is set.
-        Value *Or = EnableUnsafeSelectTransform ?
-            Builder.CreateOr(CondVal, FalseSI->getCondition()) :
-            Builder.CreateLogicalOr(CondVal, FalseSI->getCondition());
+        Value *Or = Builder.CreateLogicalOr(CondVal, FalseSI->getCondition());
         replaceOperand(SI, 0, Or);
         replaceOperand(SI, 2, FalseSI->getFalseValue());
         return &SI;