[NFC] Move some functions to LoopUtils

llvm-svn: 351179

1 files changed, 36 insertions, 0 deletions

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));
+}