!fixup use predicates

Author: fhahn

llvm/include/llvm/Analysis/ScalarEvolutionPatternMatch.h

@@ -1,5 +1,4 @@
-//===- ScalarEvolutionPatternMatch.h - Match on SCEVs -----------*- C++ -*-===//
-//
+//===----------------------------------------------------------------------===//
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
@@ -15,7 +14,6 @@
 #define LLVM_ANALYSIS_SCALAREVOLUTIONPATTERNMATCH_H
 
 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
-#include "llvm/IR/PatternMatch.h"
 
 namespace llvm {
 namespace SCEVPatternMatch {
@@ -25,19 +23,39 @@ bool match(const SCEV *S, const Pattern &P) {
   return P.match(S);
 }
 
-struct specific_intval64 : public PatternMatch::specific_intval64<false> {
-  specific_intval64(uint64_t V) : PatternMatch::specific_intval64<false>(V) {}
-
+template <typename Predicate> struct cst_pred_ty : public Predicate {
   bool match(const SCEV *S) {
-    auto *Cast = dyn_cast<SCEVConstant>(S);
-    return Cast &&
-           PatternMatch::specific_intval64<false>::match(Cast->getValue());
+    assert((isa<SCEVCouldNotCompute>(S) || !S->getType()->isVectorTy()) &&
+           "no vector types expected from SCEVs");
+    auto *C = dyn_cast<SCEVConstant>(S);
+    return C && this->isValue(C->getAPInt());
+  }
+};
+
+struct is_zero {
+  template <typename ITy> bool match(ITy *S) {
+    assert((isa<SCEVCouldNotCompute>(S) || !S->getType()->isVectorTy()) &&
+           "no vector types expected from SCEVs");
+    auto *C = dyn_cast<SCEVConstant>(S);
+    return C && C->getValue()->isNullValue();
   }
 };
+/// Match any null constant.
+inline is_zero m_scev_Zero() { return is_zero(); }
+
+struct is_one {
+  bool isValue(const APInt &C) { return C.isOne(); }
+};
+/// Match an integer 1.
+inline cst_pred_ty<is_one> m_scev_One() { return cst_pred_ty<is_one>(); }
 
-inline specific_intval64 m_scev_Zero() { return specific_intval64(0); }
-inline specific_intval64 m_scev_One() { return specific_intval64(1); }
-inline specific_intval64 m_scev_MinusOne() { return specific_intval64(-1); }
+struct is_all_ones {
+  bool isValue(const APInt &C) { return C.isAllOnes(); }
+};
+/// Match an integer with all bits set.
+inline cst_pred_ty<is_all_ones> m_scev_AllOnes() {
+  return cst_pred_ty<is_all_ones>();
+}
 
 } // namespace SCEVPatternMatch
 } // namespace llvm

llvm/lib/Analysis/ScalarEvolution.cpp

@@ -445,23 +445,11 @@ ArrayRef<const SCEV *> SCEV::operands() const {
   llvm_unreachable("Unknown SCEV kind!");
 }
 
-bool SCEV::isZero() const {
-  if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(this))
-    return SC->getValue()->isZero();
-  return false;
-}
+bool SCEV::isZero() const { return match(this, m_scev_Zero()); }
 
-bool SCEV::isOne() const {
-  if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(this))
-    return SC->getValue()->isOne();
-  return false;
-}
+bool SCEV::isOne() const { return match(this, m_scev_One()); }
 
-bool SCEV::isAllOnesValue() const {
-  if (const SCEVConstant *SC = dyn_cast<SCEVConstant>(this))
-    return SC->getValue()->isMinusOne();
-  return false;
-}
+bool SCEV::isAllOnesValue() const { return match(this, m_scev_AllOnes()); }
 
 bool SCEV::isNonConstantNegative() const {
   const SCEVMulExpr *Mul = dyn_cast<SCEVMulExpr>(this);
@@ -10616,7 +10604,7 @@ ScalarEvolution::ExitLimit ScalarEvolution::howFarToZero(const SCEV *V,
   // 1*N = -Start; -1*N = Start (mod 2^BW), so:
   //   N = Distance (as unsigned)
 
-  if (match(Step, m_CombineOr(m_scev_One(), m_scev_MinusOne()))) {
+  if (match(Step, m_CombineOr(m_scev_One(), m_scev_AllOnes()))) {
     APInt MaxBECount = getUnsignedRangeMax(applyLoopGuards(Distance, Guards));
     MaxBECount = APIntOps::umin(MaxBECount, getUnsignedRangeMax(Distance));
 
@@ -15511,9 +15499,7 @@ void ScalarEvolution::LoopGuards::collectFromBlock(
 
     // If we have LHS == 0, check if LHS is computing a property of some unknown
     // SCEV %v which we can rewrite %v to express explicitly.
-    const SCEVConstant *RHSC = dyn_cast<SCEVConstant>(RHS);
-    if (Predicate == CmpInst::ICMP_EQ && RHSC &&
-        RHSC->getValue()->isNullValue()) {
+    if (Predicate == CmpInst::ICMP_EQ && match(RHS, m_scev_Zero())) {
       // If LHS is A % B, i.e. A % B == 0, rewrite A to (A /u B) * B to
       // explicitly express that.
       const SCEV *URemLHS = nullptr;
@@ -15694,8 +15680,7 @@ void ScalarEvolution::LoopGuards::collectFromBlock(
           To = RHS;
         break;
       case CmpInst::ICMP_NE:
-        if (isa<SCEVConstant>(RHS) &&
-            cast<SCEVConstant>(RHS)->getValue()->isNullValue()) {
+        if (match(RHS, m_scev_Zero())) {
           const SCEV *OneAlignedUp =
               DividesBy ? GetNextSCEVDividesByDivisor(One, DividesBy) : One;
           To = SE.getUMaxExpr(FromRewritten, OneAlignedUp);