[NFC][ConstantRange] Add 'icmp' helper method

"Does the predicate hold between two ranges?"

Not very surprisingly, some places were already doing this check,
without explicitly naming the algorithm, cleanup them all.

8 files changed, 107 insertions, 22 deletions

diff --git a/llvm/include/llvm/Analysis/ValueLattice.h b/llvm/include/llvm/Analysis/ValueLattice.h
index 5ff9c4a6b080..1b32fca50697 100644
--- a/llvm/include/llvm/Analysis/ValueLattice.h
+++ b/llvm/include/llvm/Analysis/ValueLattice.h
@@ -474,11 +474,9 @@ public:
 
     const auto &CR = getConstantRange();
     const auto &OtherCR = Other.getConstantRange();
-    if (ConstantRange::makeSatisfyingICmpRegion(Pred, OtherCR).contains(CR))
+    if (CR.icmp(Pred, OtherCR))
       return ConstantInt::getTrue(Ty);
-    if (ConstantRange::makeSatisfyingICmpRegion(
-            CmpInst::getInversePredicate(Pred), OtherCR)
-            .contains(CR))
+    if (CR.icmp(CmpInst::getInversePredicate(Pred), OtherCR))
       return ConstantInt::getFalse(Ty);
 
     return nullptr;
diff --git a/llvm/include/llvm/IR/ConstantRange.h b/llvm/include/llvm/IR/ConstantRange.h
index 20e8e67436a4..44b8c395c89e 100644
--- a/llvm/include/llvm/IR/ConstantRange.h
+++ b/llvm/include/llvm/IR/ConstantRange.h
@@ -124,6 +124,10 @@ public:
   static ConstantRange makeExactICmpRegion(CmpInst::Predicate Pred,
                                            const APInt &Other);
 
+  /// Does the predicate \p Pred hold between ranges this and \p Other?
+  /// NOTE: false does not mean that inverse predicate holds!
+  bool icmp(CmpInst::Predicate Pred, const ConstantRange &Other) const;
+
   /// Produce the largest range containing all X such that "X BinOp Y" is
   /// guaranteed not to wrap (overflow) for *all* Y in Other. However, there may
   /// be *some* Y in Other for which additional X not contained in the result
diff --git a/llvm/include/llvm/IR/IntrinsicInst.h b/llvm/include/llvm/IR/IntrinsicInst.h
index 6c825d380fc9..b688ece7067e 100644
--- a/llvm/include/llvm/IR/IntrinsicInst.h
+++ b/llvm/include/llvm/IR/IntrinsicInst.h
@@ -458,6 +458,47 @@ public:
   }
 };
 
+/// This class represents min/max intrinsics.
+class LimitingIntrinsic : public IntrinsicInst {
+public:
+  static bool classof(const IntrinsicInst *I) {
+    switch (I->getIntrinsicID()) {
+    case Intrinsic::umin:
+    case Intrinsic::umax:
+    case Intrinsic::smin:
+    case Intrinsic::smax:
+      return true;
+    default:
+      return false;
+    }
+  }
+  static bool classof(const Value *V) {
+    return isa<IntrinsicInst>(V) && classof(cast<IntrinsicInst>(V));
+  }
+
+  Value *getLHS() const { return const_cast<Value *>(getArgOperand(0)); }
+  Value *getRHS() const { return const_cast<Value *>(getArgOperand(1)); }
+
+  /// Returns the comparison predicate underlying the intrinsic.
+  ICmpInst::Predicate getPredicate() const {
+    switch (getIntrinsicID()) {
+    case Intrinsic::umin:
+      return ICmpInst::Predicate::ICMP_ULT;
+    case Intrinsic::umax:
+      return ICmpInst::Predicate::ICMP_UGT;
+    case Intrinsic::smin:
+      return ICmpInst::Predicate::ICMP_SLT;
+    case Intrinsic::smax:
+      return ICmpInst::Predicate::ICMP_SGT;
+    default:
+      llvm_unreachable("Invalid intrinsic");
+    }
+  }
+
+  /// Whether the intrinsic is signed or unsigned.
+  bool isSigned() const { return ICmpInst::isSigned(getPredicate()); };
+};
+
 /// This class represents an intrinsic that is based on a binary operation.
 /// This includes op.with.overflow and saturating add/sub intrinsics.
 class BinaryOpIntrinsic : public IntrinsicInst {
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index a6d3ca64189d..b233a0f3eb2d 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -3451,13 +3451,10 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS,
       auto LHS_CR = getConstantRangeFromMetadata(
           *LHS_Instr->getMetadata(LLVMContext::MD_range));
 
-      auto Satisfied_CR = ConstantRange::makeSatisfyingICmpRegion(Pred, RHS_CR);
-      if (Satisfied_CR.contains(LHS_CR))
+      if (LHS_CR.icmp(Pred, RHS_CR))
         return ConstantInt::getTrue(RHS->getContext());
 
-      auto InversedSatisfied_CR = ConstantRange::makeSatisfyingICmpRegion(
-                CmpInst::getInversePredicate(Pred), RHS_CR);
-      if (InversedSatisfied_CR.contains(LHS_CR))
+      if (LHS_CR.icmp(CmpInst::getInversePredicate(Pred), RHS_CR))
         return ConstantInt::getFalse(RHS->getContext());
     }
   }
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index a481c23c3d05..4630c5562623 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -9843,10 +9843,9 @@ bool ScalarEvolution::isKnownPredicateViaConstantRanges(
   // This code is split out from isKnownPredicate because it is called from
   // within isLoopEntryGuardedByCond.
 
-  auto CheckRanges =
-      [&](const ConstantRange &RangeLHS, const ConstantRange &RangeRHS) {
-    return ConstantRange::makeSatisfyingICmpRegion(Pred, RangeRHS)
-        .contains(RangeLHS);
+  auto CheckRanges = [&](const ConstantRange &RangeLHS,
+                         const ConstantRange &RangeRHS) {
+    return RangeLHS.icmp(Pred, RangeRHS);
   };
 
   // The check at the top of the function catches the case where the values are
@@ -11148,12 +11147,9 @@ bool ScalarEvolution::isImpliedCondOperandsViaRanges(ICmpInst::Predicate Pred,
   // We can also compute the range of values for `LHS` that satisfy the
   // consequent, "`LHS` `Pred` `RHS`":
   const APInt &ConstRHS = cast<SCEVConstant>(RHS)->getAPInt();
-  ConstantRange SatisfyingLHSRange =
-      ConstantRange::makeSatisfyingICmpRegion(Pred, ConstRHS);
-
   // The antecedent implies the consequent if every value of `LHS` that
   // satisfies the antecedent also satisfies the consequent.
-  return SatisfyingLHSRange.contains(LHSRange);
+  return LHSRange.icmp(Pred, ConstRHS);
 }
 
 bool ScalarEvolution::doesIVOverflowOnLT(const SCEV *RHS, const SCEV *Stride,
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp
index 4dbe1a1b902d..b38599fa7d98 100644
--- a/llvm/lib/IR/ConstantRange.cpp
+++ b/llvm/lib/IR/ConstantRange.cpp
@@ -181,6 +181,11 @@ bool ConstantRange::getEquivalentICmp(CmpInst::Predicate &Pred,
   return Success;
 }
 
+bool ConstantRange::icmp(CmpInst::Predicate Pred,
+                         const ConstantRange &Other) const {
+  return makeSatisfyingICmpRegion(Pred, Other).contains(*this);
+}
+
 /// Exact mul nuw region for single element RHS.
 static ConstantRange makeExactMulNUWRegion(const APInt &V) {
   unsigned BitWidth = V.getBitWidth();
diff --git a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
index 867dd3118cea..33ed2b4423a8 100644
--- a/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
+++ b/llvm/lib/Transforms/IPO/AttributorAttributes.cpp
@@ -7328,13 +7328,10 @@ struct AAValueConstantRangeFloating : AAValueConstantRangeImpl {
     auto AllowedRegion =
         ConstantRange::makeAllowedICmpRegion(CmpI->getPredicate(), RHSAARange);
 
-    auto SatisfyingRegion = ConstantRange::makeSatisfyingICmpRegion(
-        CmpI->getPredicate(), RHSAARange);
-
     if (AllowedRegion.intersectWith(LHSAARange).isEmptySet())
       MustFalse = true;
 
-    if (SatisfyingRegion.contains(LHSAARange))
+    if (LHSAARange.icmp(CmpI->getPredicate(), RHSAARange))
       MustTrue = true;
 
     assert((!MustTrue || !MustFalse) &&
diff --git a/llvm/unittests/IR/ConstantRangeTest.cpp b/llvm/unittests/IR/ConstantRangeTest.cpp
index 12362b9460f9..f8816e4d43df 100644
--- a/llvm/unittests/IR/ConstantRangeTest.cpp
+++ b/llvm/unittests/IR/ConstantRangeTest.cpp
@@ -6,9 +6,10 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/IR/ConstantRange.h"
 #include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/Sequence.h"
 #include "llvm/ADT/SmallBitVector.h"
-#include "llvm/IR/ConstantRange.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Operator.h"
 #include "llvm/Support/KnownBits.h"
@@ -1509,6 +1510,52 @@ TEST(ConstantRange, MakeSatisfyingICmpRegion) {
       ConstantRange(APInt(8, 4), APInt(8, -128)));
 }
 
+static bool icmp(CmpInst::Predicate Pred, const APInt &LHS, const APInt &RHS) {
+  switch (Pred) {
+  case CmpInst::Predicate::ICMP_EQ:
+    return LHS.eq(RHS);
+  case CmpInst::Predicate::ICMP_NE:
+    return LHS.ne(RHS);
+  case CmpInst::Predicate::ICMP_UGT:
+    return LHS.ugt(RHS);
+  case CmpInst::Predicate::ICMP_UGE:
+    return LHS.uge(RHS);
+  case CmpInst::Predicate::ICMP_ULT:
+    return LHS.ult(RHS);
+  case CmpInst::Predicate::ICMP_ULE:
+    return LHS.ule(RHS);
+  case CmpInst::Predicate::ICMP_SGT:
+    return LHS.sgt(RHS);
+  case CmpInst::Predicate::ICMP_SGE:
+    return LHS.sge(RHS);
+  case CmpInst::Predicate::ICMP_SLT:
+    return LHS.slt(RHS);
+  case CmpInst::Predicate::ICMP_SLE:
+    return LHS.sle(RHS);
+  default:
+    llvm_unreachable("Not an ICmp predicate!");
+  }
+}
+
+void ICmpTestImpl(CmpInst::Predicate Pred) {
+  unsigned Bits = 4;
+  EnumerateTwoConstantRanges(
+      Bits, [&](const ConstantRange &CR1, const ConstantRange &CR2) {
+        bool Exhaustive = true;
+        ForeachNumInConstantRange(CR1, [&](const APInt &N1) {
+          ForeachNumInConstantRange(
+              CR2, [&](const APInt &N2) { Exhaustive &= icmp(Pred, N1, N2); });
+        });
+        EXPECT_EQ(CR1.icmp(Pred, CR2), Exhaustive);
+      });
+}
+
+TEST(ConstantRange, ICmp) {
+  for (auto Pred : seq<unsigned>(CmpInst::Predicate::FIRST_ICMP_PREDICATE,
+                                 1 + CmpInst::Predicate::LAST_ICMP_PREDICATE))
+    ICmpTestImpl((CmpInst::Predicate)Pred);
+}
+
 TEST(ConstantRange, MakeGuaranteedNoWrapRegion) {
   const int IntMin4Bits = 8;
   const int IntMax4Bits = 7;