!fixup add unary matcher for ZExt and SExt

Author: fhahn

llvm/include/llvm/Analysis/ScalarEvolutionPatternMatch.h

@@ -79,6 +79,18 @@ inline bind_ty<const SCEVUnknown> m_SCEVUnknown(const SCEVUnknown *&V) {
   return V;
 }
 
+/// Match a specified const SCEV *.
+struct specificscev_ty {
+  const SCEV *Expr;
+
+  specificscev_ty(const SCEV *Expr) : Expr(Expr) {}
+
+  template <typename ITy> bool match(ITy *S) { return S == Expr; }
+};
+
+/// Match if we have a specific specified SCEV.
+inline specificscev_ty m_Specific(const SCEV *S) { return S; }
+
 namespace detail {
 
 template <typename TupleTy, typename Fn, std::size_t... Is>
@@ -133,6 +145,26 @@ m_scev_Add(const Op0_t &Op0, const Op1_t &Op1) {
   return BinarySCEV_match<Op0_t, Op1_t, SCEVAddExpr>(Op0, Op1);
 }
 
+template <typename Op0_t, typename SCEVTy>
+using UnarySCEV_match = SCEV_match<std::tuple<Op0_t>, SCEVTy>;
+
+template <typename Op0_t, typename Op1_t, typename SCEVTy>
+inline UnarySCEV_match<Op0_t, SCEVTy> m_scev_Unary(const Op0_t &Op0) {
+  return UnarySCEV_match<Op0_t, SCEVTy>(Op0);
+}
+
+template <typename Op0_t>
+inline UnarySCEV_match<Op0_t, SCEVSignExtendExpr>
+m_scev_SExt(const Op0_t &Op0) {
+  return UnarySCEV_match<Op0_t, SCEVSignExtendExpr>(Op0);
+}
+
+template <typename Op0_t>
+inline UnarySCEV_match<Op0_t, SCEVZeroExtendExpr>
+m_scev_ZExt(const Op0_t &Op0) {
+  return UnarySCEV_match<Op0_t, SCEVZeroExtendExpr>(Op0);
+}
+
 } // namespace SCEVPatternMatch
 } // namespace llvm
 

llvm/lib/Analysis/ScalarEvolution.cpp

@@ -12724,33 +12724,28 @@ bool ScalarEvolution::isImpliedViaOperations(ICmpInst::Predicate Pred,
 static bool isKnownPredicateExtendIdiom(ICmpInst::Predicate Pred,
                                         const SCEV *LHS, const SCEV *RHS) {
   // zext x u<= sext x, sext x s<= zext x
+  const SCEV *Op;
   switch (Pred) {
   case ICmpInst::ICMP_SGE:
     std::swap(LHS, RHS);
     [[fallthrough]];
   case ICmpInst::ICMP_SLE: {
-    // If operand >=s 0 then ZExt == SExt.  If operand <s 0 then SExt <s ZExt.
-    const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(LHS);
-    const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(RHS);
-    if (SExt && ZExt && SExt->getOperand() == ZExt->getOperand())
-      return true;
-    break;
+    // If operand >=s 0 then ZExt == SExt. If operand <s 0 then SExt <s ZExt.
+    return match(LHS, m_scev_SExt(m_SCEV(Op))) &&
+           match(RHS, m_scev_ZExt(m_Specific(Op)));
   }
   case ICmpInst::ICMP_UGE:
     std::swap(LHS, RHS);
     [[fallthrough]];
   case ICmpInst::ICMP_ULE: {
-    // If operand >=s 0 then ZExt == SExt.  If operand <s 0 then ZExt <u SExt.
-    const SCEVZeroExtendExpr *ZExt = dyn_cast<SCEVZeroExtendExpr>(LHS);
-    const SCEVSignExtendExpr *SExt = dyn_cast<SCEVSignExtendExpr>(RHS);
-    if (SExt && ZExt && SExt->getOperand() == ZExt->getOperand())
-      return true;
-    break;
+    // If operand >=u 0 then ZExt == SExt.  If operand <u 0 then ZExt <u SExt.
+    return match(LHS, m_scev_ZExt(m_SCEV(Op))) &&
+           match(RHS, m_scev_SExt(m_Specific(Op)));
   }
   default:
-    break;
+    return false;
   };
-  return false;
+  llvm_unreachable("unhandled case");
 }
 
 bool