[SimplifyCFG] Update FoldTwoEntryPHINode to handle and/or of select and binop equally

This is a minor change that fixes FoldTwoEntryPHINode to handle
phis with and/ors of select form and binop form equally.

diff --git a/llvm/include/llvm/IR/PatternMatch.h b/llvm/include/llvm/IR/PatternMatch.h
index 6edbf32..575eff4 100644 (file)
--- a/llvm/include/llvm/IR/PatternMatch.h
+++ b/llvm/include/llvm/IR/PatternMatch.h
@@ -2446,6 +2446,9 @@ m_LogicalAnd(const LHS &L, const RHS &R) {
   return LogicalOp_match<LHS, RHS, Instruction::And>(L, R);
 }
 
+/// Matches L && R where L and R are arbitrary values.
+inline auto m_LogicalAnd() { return m_LogicalAnd(m_Value(), m_Value()); }
+
 /// Matches L || R either in the form of L | R or L ? true : R.
 /// Note that the latter form is poison-blocking.
 template <typename LHS, typename RHS>

diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index e8dd033..8ca3242 100644 (file)
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -2598,13 +2598,17 @@ static bool FoldTwoEntryPHINode(PHINode *PN, const TargetTransformInfo &TTI,
     return match(V0, m_Not(m_Value())) && match(V1, Invertible);
   };
 
-  // Don't fold i1 branches on PHIs which contain binary operators, unless one
-  // of the incoming values is an 'not' and another one is freely invertible.
+  // Don't fold i1 branches on PHIs which contain binary operators or
+  // select form of or/ands, unless one of the incoming values is an 'not' and
+  // another one is freely invertible.
   // These can often be turned into switches and other things.
+  auto IsBinOpOrAnd = [](Value *V) {
+    return match(
+        V, m_CombineOr(m_BinOp(), m_CombineOr(m_LogicalAnd(), m_LogicalOr())));
+  };
   if (PN->getType()->isIntegerTy(1) &&
-      (isa<BinaryOperator>(PN->getIncomingValue(0)) ||
-       isa<BinaryOperator>(PN->getIncomingValue(1)) ||
-       isa<BinaryOperator>(IfCond)) &&
+      (IsBinOpOrAnd(PN->getIncomingValue(0)) ||
+       IsBinOpOrAnd(PN->getIncomingValue(1)) || IsBinOpOrAnd(IfCond)) &&
       !CanHoistNotFromBothValues(PN->getIncomingValue(0),
                                  PN->getIncomingValue(1)))
     return Changed;