Revert "[ScalarEvolution] Handling for ICmp occuring in the evolution chain."
This reverts commit r316054. There was some confusion over the review process:
http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20171016/495884.html
llvm-svn: 316129
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index e872e81..c69bd60 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -4756,26 +4756,11 @@
Ops.push_back(Add->getOperand(i));
const SCEV *Accum = getAddExpr(Ops);
- bool InvariantF = isLoopInvariant(Accum, L);
-
- if (!InvariantF && Accum->getSCEVType() == scZeroExtend) {
- const SCEV *Op = dyn_cast<SCEVZeroExtendExpr>(Accum)->getOperand();
- const SCEVUnknown *Un = dyn_cast<SCEVUnknown>(Op);
- if (Un && Un->getValue() && isa<Instruction>(Un->getValue()) &&
- dyn_cast<Instruction>(Un->getValue())->getOpcode() ==
- Instruction::ICmp) {
- const SCEV *ICmpSC = evaluateForICmp(cast<ICmpInst>(Un->getValue()));
- bool IsConstSC = ICmpSC->getSCEVType() == scConstant;
- Accum =
- IsConstSC ? getZeroExtendExpr(ICmpSC, Accum->getType()) : Accum;
- InvariantF = IsConstSC ? true : false;
- }
- }
-
// This is not a valid addrec if the step amount is varying each
// loop iteration, but is not itself an addrec in this loop.
- if (InvariantF || (isa<SCEVAddRecExpr>(Accum) &&
- cast<SCEVAddRecExpr>(Accum)->getLoop() == L)) {
+ if (isLoopInvariant(Accum, L) ||
+ (isa<SCEVAddRecExpr>(Accum) &&
+ cast<SCEVAddRecExpr>(Accum)->getLoop() == L)) {
SCEV::NoWrapFlags Flags = SCEV::FlagAnyWrap;
if (auto BO = MatchBinaryOp(BEValueV, DT)) {
@@ -6458,30 +6443,6 @@
}
}
-
-const SCEV *ScalarEvolution::evaluateForICmp(ICmpInst *IC) {
- BasicBlock *Latch = nullptr;
- const Loop *L = LI.getLoopFor(IC->getParent());
-
- // If compare instruction is same or inverse of the compare in the
- // branch of the loop latch, then return a constant evolution
- // node. This shall facilitate computations of loop exit counts
- // in cases where compare appears in the evolution chain of induction
- // variables.
- if (L && (Latch = L->getLoopLatch())) {
- BranchInst *BI = dyn_cast<BranchInst>(Latch->getTerminator());
- if (BI && BI->isConditional() && BI->getCondition() == IC) {
- if (BI->getSuccessor(0) != L->getHeader())
- return getZero(Type::getInt1Ty(getContext()));
- else
- return getOne(Type::getInt1Ty(getContext()));
- }
- }
-
- return getUnknown(IC);
-}
-
-
void ScalarEvolution::forgetValue(Value *V) {
Instruction *I = dyn_cast<Instruction>(V);
if (!I) return;