[SCEV] Adding a check on outgoing branches of a terminator instr for SCEVBackedgeConditionFolder, NFC.
Summary:
For a given loop, getLoopLatch returns a non-null value
when a loop has only one latch block. In the modified
context adding an assertion to check that both the outgoing branches of
a terminator instruction (of latch) does not target same header.
+
few minor code reorganization.
Reviewers: jbhateja
Reviewed By: jbhateja
Subscribers: sanjoy
Differential Revision: https://reviews.llvm.org/D40460
llvm-svn: 318997
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 53e216a..faf99c0 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -4049,9 +4049,6 @@
class SCEVInitRewriter : public SCEVRewriteVisitor<SCEVInitRewriter> {
public:
- SCEVInitRewriter(const Loop *L, ScalarEvolution &SE)
- : SCEVRewriteVisitor(SE), L(L) {}
-
static const SCEV *rewrite(const SCEV *S, const Loop *L,
ScalarEvolution &SE) {
SCEVInitRewriter Rewriter(L, SE);
@@ -4076,6 +4073,9 @@
bool isValid() { return Valid; }
private:
+ explicit SCEVInitRewriter(const Loop *L, ScalarEvolution &SE)
+ : SCEVRewriteVisitor(SE), L(L) {}
+
const Loop *L;
bool Valid = true;
};
@@ -4093,6 +4093,8 @@
if (BasicBlock *Latch = L->getLoopLatch()) {
BranchInst *BI = dyn_cast<BranchInst>(Latch->getTerminator());
if (BI && BI->isConditional()) {
+ assert(BI->getSuccessor(0) != BI->getSuccessor(1) &&
+ "Both outgoing branches should not target same header!");
BECond = BI->getCondition();
IsPosBECond = BI->getSuccessor(0) == L->getHeader();
} else {
@@ -4160,9 +4162,6 @@
class SCEVShiftRewriter : public SCEVRewriteVisitor<SCEVShiftRewriter> {
public:
- SCEVShiftRewriter(const Loop *L, ScalarEvolution &SE)
- : SCEVRewriteVisitor(SE), L(L) {}
-
static const SCEV *rewrite(const SCEV *S, const Loop *L,
ScalarEvolution &SE) {
SCEVShiftRewriter Rewriter(L, SE);
@@ -4187,6 +4186,9 @@
bool isValid() { return Valid; }
private:
+ explicit SCEVShiftRewriter(const Loop *L, ScalarEvolution &SE)
+ : SCEVRewriteVisitor(SE), L(L) {}
+
const Loop *L;
bool Valid = true;
};
@@ -11342,10 +11344,6 @@
class SCEVPredicateRewriter : public SCEVRewriteVisitor<SCEVPredicateRewriter> {
public:
- SCEVPredicateRewriter(const Loop *L, ScalarEvolution &SE,
- SmallPtrSetImpl<const SCEVPredicate *> *NewPreds,
- SCEVUnionPredicate *Pred)
- : SCEVRewriteVisitor(SE), NewPreds(NewPreds), Pred(Pred), L(L) {}
/// Rewrites \p S in the context of a loop L and the SCEV predication
/// infrastructure.
@@ -11406,6 +11404,11 @@
}
private:
+ explicit SCEVPredicateRewriter(const Loop *L, ScalarEvolution &SE,
+ SmallPtrSetImpl<const SCEVPredicate *> *NewPreds,
+ SCEVUnionPredicate *Pred)
+ : SCEVRewriteVisitor(SE), NewPreds(NewPreds), Pred(Pred), L(L) {}
+
bool addOverflowAssumption(const SCEVPredicate *P) {
if (!NewPreds) {
// Check if we've already made this assumption.