[llvm] ebd6b5d - [LICM] Minor optimization (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-04-24T17:05:58+02:00
New Revision: ebd6b5dc6426c5a759d9ed588fe6b972319736ff

URL: https://github.com/llvm/llvm-project/commit/ebd6b5dc6426c5a759d9ed588fe6b972319736ff
DIFF: https://github.com/llvm/llvm-project/commit/ebd6b5dc6426c5a759d9ed588fe6b972319736ff.diff

LOG: [LICM] Minor optimization (NFC)

Simplify the match in hoistMinMax and only fetch the preheader
once.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LICM.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index b5298cfd258b..5a1945196a72 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -883,6 +883,7 @@ bool llvm::hoistRegion(DomTreeNode *N, AAResults *AA, LoopInfo *LI,
   LoopBlocksRPO Worklist(CurLoop);
   Worklist.perform(LI);
   bool Changed = false;
+  BasicBlock *Preheader = CurLoop->getLoopPreheader();
   for (BasicBlock *BB : Worklist) {
     // Only need to process the contents of this block if it is not part of a
     // subloop (which would already have been processed).
@@ -916,8 +917,7 @@ bool llvm::hoistRegion(DomTreeNode *N, AAResults *AA, LoopInfo *LI,
           canSinkOrHoistInst(I, AA, DT, CurLoop, MSSAU, true, Flags, ORE) &&
           isSafeToExecuteUnconditionally(
               I, DT, TLI, CurLoop, SafetyInfo, ORE,
-              CurLoop->getLoopPreheader()->getTerminator(), AC,
-              AllowSpeculation)) {
+              Preheader->getTerminator(), AC, AllowSpeculation)) {
         hoist(I, DT, CurLoop, CFH.getOrCreateHoistedBlock(BB), SafetyInfo,
               MSSAU, SE, ORE);
         HoistedInstructions.push_back(&I);
@@ -2421,19 +2421,13 @@ bool pointerInvalidatedByBlock(BasicBlock &BB, MemorySSA &MSSA, MemoryUse &MU) {
 static bool hoistMinMax(Instruction &I, Loop &L, ICFLoopSafetyInfo &SafetyInfo,
                         MemorySSAUpdater &MSSAU) {
   bool Inverse = false;
-  bool IsLogical = false;
   using namespace PatternMatch;
   Value *Cond1, *Cond2;
-  if (match(&I, m_Or(m_Value(Cond1), m_Value(Cond2))))
-    Inverse = true;
-  else if (match(&I, m_LogicalOr(m_Value(Cond1), m_Value(Cond2)))) {
+  if (match(&I, m_LogicalOr(m_Value(Cond1), m_Value(Cond2)))) {
     Inverse = true;
-    IsLogical = true;
-  } else if (match(&I, m_And(m_Value(Cond1), m_Value(Cond2)))) {
+  } else if (match(&I, m_LogicalAnd(m_Value(Cond1), m_Value(Cond2)))) {
     // Do nothing
-  } else if (match(&I, m_LogicalAnd(m_Value(Cond1), m_Value(Cond2))))
-    IsLogical = true;
-  else
+  } else
     return false;
 
   auto MatchICmpAgainstInvariant = [&](Value *C, ICmpInst::Predicate &P,
@@ -2477,7 +2471,7 @@ static bool hoistMinMax(Instruction &I, Loop &L, ICFLoopSafetyInfo &SafetyInfo,
   // before (if it was a non-taken input of logical and/or instruction). If it
   // was poison, we need to freeze it. Note that no new use for LHS and RHS1 are
   // introduced, so they don't need this.
-  if (IsLogical)
+  if (isa<SelectInst>(I))
     RHS2 = Builder.CreateFreeze(RHS2, RHS2->getName() + ".fr");
   Value *NewRHS = Builder.CreateBinaryIntrinsic(
       id, RHS1, RHS2, nullptr, StringRef("invariant.") +