[NFC] Move some functions to LoopUtils

3 files changed, 59 insertions, 42 deletions

diff --git a/llvm/include/llvm/Transforms/Utils/LoopUtils.h b/llvm/include/llvm/Transforms/Utils/LoopUtils.h
index 1740e9e37d4..8c2527b6ae6 100644
--- a/llvm/include/llvm/Transforms/Utils/LoopUtils.h
+++ b/llvm/include/llvm/Transforms/Utils/LoopUtils.h
@@ -323,6 +323,23 @@ Value *createTargetReduction(IRBuilder<> &B, const TargetTransformInfo *TTI,
 /// Flag set: NSW, NUW, exact, and all of fast-math.
 void propagateIRFlags(Value *I, ArrayRef<Value *> VL, Value *OpValue = nullptr);
 
+/// Returns true if we can prove that \p S is defined and always negative in
+/// loop \p L.
+bool isKnownNegativeInLoop(const SCEV *S, const Loop *L, ScalarEvolution &SE);
+
+/// Returns true if we can prove that \p S is defined and always non-negative in
+/// loop \p L.
+bool isKnownNonNegativeInLoop(const SCEV *S, const Loop *L,
+                              ScalarEvolution &SE);
+
+/// Returns true if \p S is defined and never is equal to signed/unsigned max.
+bool cannotBeMaxInLoop(const SCEV *S, const Loop *L, ScalarEvolution &SE,
+                       bool Signed);
+
+/// Returns true if \p S is defined and never is equal to signed/unsigned min.
+bool cannotBeMinInLoop(const SCEV *S, const Loop *L, ScalarEvolution &SE,
+                       bool Signed);
+
 } // end namespace llvm
 
 #endif // LLVM_TRANSFORMS_UTILS_LOOPUTILS_H
diff --git a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
index c5ed6d5c1b8..0e6dcfd4328 100644
--- a/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
+++ b/llvm/lib/Transforms/Scalar/InductiveRangeCheckElimination.cpp
@@ -689,17 +689,6 @@ void LoopConstrainer::replacePHIBlock(PHINode *PN, BasicBlock *Block,
       PN->setIncomingBlock(i, ReplaceBy);
 }
 
-static bool CannotBeMaxInLoop(const SCEV *BoundSCEV, Loop *L,
-                              ScalarEvolution &SE, bool Signed) {
-  unsigned BitWidth = cast<IntegerType>(BoundSCEV->getType())->getBitWidth();
-  APInt Max = Signed ? APInt::getSignedMaxValue(BitWidth) :
-    APInt::getMaxValue(BitWidth);
-  auto Predicate = Signed ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
-  return SE.isAvailableAtLoopEntry(BoundSCEV, L) &&
-         SE.isLoopEntryGuardedByCond(L, Predicate, BoundSCEV,
-                                     SE.getConstant(Max));
-}
-
 /// Given a loop with an deccreasing induction variable, is it possible to
 /// safely calculate the bounds of a new loop using the given Predicate.
 static bool isSafeDecreasingBound(const SCEV *Start,
@@ -795,31 +784,6 @@ static bool isSafeIncreasingBound(const SCEV *Start,
           SE.isLoopEntryGuardedByCond(L, BoundPred, BoundSCEV, Limit));
 }
 
-static bool CannotBeMinInLoop(const SCEV *BoundSCEV, Loop *L,
-                              ScalarEvolution &SE, bool Signed) {
-  unsigned BitWidth = cast<IntegerType>(BoundSCEV->getType())->getBitWidth();
-  APInt Min = Signed ? APInt::getSignedMinValue(BitWidth) :
-    APInt::getMinValue(BitWidth);
-  auto Predicate = Signed ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
-  return SE.isAvailableAtLoopEntry(BoundSCEV, L) &&
-         SE.isLoopEntryGuardedByCond(L, Predicate, BoundSCEV,
-                                     SE.getConstant(Min));
-}
-
-static bool isKnownNonNegativeInLoop(const SCEV *BoundSCEV, const Loop *L,
-                                     ScalarEvolution &SE) {
-  const SCEV *Zero = SE.getZero(BoundSCEV->getType());
-  return SE.isAvailableAtLoopEntry(BoundSCEV, L) &&
-         SE.isLoopEntryGuardedByCond(L, ICmpInst::ICMP_SGE, BoundSCEV, Zero);
-}
-
-static bool isKnownNegativeInLoop(const SCEV *BoundSCEV, const Loop *L,
-                                  ScalarEvolution &SE) {
-  const SCEV *Zero = SE.getZero(BoundSCEV->getType());
-  return SE.isAvailableAtLoopEntry(BoundSCEV, L) &&
-         SE.isLoopEntryGuardedByCond(L, ICmpInst::ICMP_SLT, BoundSCEV, Zero);
-}
-
 Optional<LoopStructure>
 LoopStructure::parseLoopStructure(ScalarEvolution &SE,
                                   BranchProbabilityInfo *BPI, Loop &L,
@@ -977,12 +941,12 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE,
         //   ...                          ...
         // }                            }
         if (IndVarBase->getNoWrapFlags(SCEV::FlagNUW) &&
-            CannotBeMinInLoop(RightSCEV, &L, SE, /*Signed*/false)) {
+            cannotBeMinInLoop(RightSCEV, &L, SE, /*Signed*/false)) {
           Pred = ICmpInst::ICMP_UGT;
           RightSCEV = SE.getMinusSCEV(RightSCEV,
                                       SE.getOne(RightSCEV->getType()));
           DecreasedRightValueByOne = true;
-        } else if (CannotBeMinInLoop(RightSCEV, &L, SE, /*Signed*/true)) {
+        } else if (cannotBeMinInLoop(RightSCEV, &L, SE, /*Signed*/true)) {
           Pred = ICmpInst::ICMP_SGT;
           RightSCEV = SE.getMinusSCEV(RightSCEV,
                                       SE.getOne(RightSCEV->getType()));
@@ -1042,11 +1006,11 @@ LoopStructure::parseLoopStructure(ScalarEvolution &SE,
         //   ...                          ...
         // }                            }
         if (IndVarBase->getNoWrapFlags(SCEV::FlagNUW) &&
-            CannotBeMaxInLoop(RightSCEV, &L, SE, /* Signed */ false)) {
+            cannotBeMaxInLoop(RightSCEV, &L, SE, /* Signed */ false)) {
           Pred = ICmpInst::ICMP_ULT;
           RightSCEV = SE.getAddExpr(RightSCEV, SE.getOne(RightSCEV->getType()));
           IncreasedRightValueByOne = true;
-        } else if (CannotBeMaxInLoop(RightSCEV, &L, SE, /* Signed */ true)) {
+        } else if (cannotBeMaxInLoop(RightSCEV, &L, SE, /* Signed */ true)) {
           Pred = ICmpInst::ICMP_SLT;
           RightSCEV = SE.getAddExpr(RightSCEV, SE.getOne(RightSCEV->getType()));
           IncreasedRightValueByOne = true;
@@ -1514,7 +1478,7 @@ bool LoopConstrainer::run() {
     if (Increasing)
       ExitPreLoopAtSCEV = *SR.LowLimit;
     else {
-      if (CannotBeMinInLoop(*SR.HighLimit, &OriginalLoop, SE,
+      if (cannotBeMinInLoop(*SR.HighLimit, &OriginalLoop, SE,
                             IsSignedPredicate))
         ExitPreLoopAtSCEV = SE.getAddExpr(*SR.HighLimit, MinusOneS);
       else {
@@ -1543,7 +1507,7 @@ bool LoopConstrainer::run() {
     if (Increasing)
       ExitMainLoopAtSCEV = *SR.HighLimit;
     else {
-      if (CannotBeMinInLoop(*SR.LowLimit, &OriginalLoop, SE,
+      if (cannotBeMinInLoop(*SR.LowLimit, &OriginalLoop, SE,
                             IsSignedPredicate))
         ExitMainLoopAtSCEV = SE.getAddExpr(*SR.LowLimit, MinusOneS);
       else {
diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp
index 3866395a32c..a93d1aeb62e 100644
--- a/llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -928,3 +928,39 @@ void llvm::propagateIRFlags(Value *I, ArrayRef<Value *> VL, Value *OpValue) {
       VecOp->andIRFlags(V);
   }
 }
+
+bool llvm::isKnownNegativeInLoop(const SCEV *S, const Loop *L,
+                                 ScalarEvolution &SE) {
+  const SCEV *Zero = SE.getZero(S->getType());
+  return SE.isAvailableAtLoopEntry(S, L) &&
+         SE.isLoopEntryGuardedByCond(L, ICmpInst::ICMP_SLT, S, Zero);
+}
+
+bool llvm::isKnownNonNegativeInLoop(const SCEV *S, const Loop *L,
+                                    ScalarEvolution &SE) {
+  const SCEV *Zero = SE.getZero(S->getType());
+  return SE.isAvailableAtLoopEntry(S, L) &&
+         SE.isLoopEntryGuardedByCond(L, ICmpInst::ICMP_SGE, S, Zero);
+}
+
+bool llvm::cannotBeMinInLoop(const SCEV *S, const Loop *L, ScalarEvolution &SE,
+                             bool Signed) {
+  unsigned BitWidth = cast<IntegerType>(S->getType())->getBitWidth();
+  APInt Min = Signed ? APInt::getSignedMinValue(BitWidth) :
+    APInt::getMinValue(BitWidth);
+  auto Predicate = Signed ? ICmpInst::ICMP_SGT : ICmpInst::ICMP_UGT;
+  return SE.isAvailableAtLoopEntry(S, L) &&
+         SE.isLoopEntryGuardedByCond(L, Predicate, S,
+                                     SE.getConstant(Min));
+}
+
+bool llvm::cannotBeMaxInLoop(const SCEV *S, const Loop *L, ScalarEvolution &SE,
+                             bool Signed) {
+  unsigned BitWidth = cast<IntegerType>(S->getType())->getBitWidth();
+  APInt Max = Signed ? APInt::getSignedMaxValue(BitWidth) :
+    APInt::getMaxValue(BitWidth);
+  auto Predicate = Signed ? ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT;
+  return SE.isAvailableAtLoopEntry(S, L) &&
+         SE.isLoopEntryGuardedByCond(L, Predicate, S,
+                                     SE.getConstant(Max));
+}