Generalize IVUsers to track arbitrary expressions rather than expressions
explicitly split into stride-and-offset pairs. Also, add the
ability to track multiple post-increment loops on the same expression.
This refines the concept of "normalizing" SCEV expressions used for
to post-increment uses, and introduces a dedicated utility routine for
normalizing and denormalizing expressions.
This fixes the expansion of expressions which are post-increment users
of more than one loop at a time. More broadly, this takes LSR another
step closer to being able to reason about more than one loop at a time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100699 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp
index 2e18cea..dd8ab43 100644
--- a/lib/Analysis/ScalarEvolutionExpander.cpp
+++ b/lib/Analysis/ScalarEvolutionExpander.cpp
@@ -966,9 +966,12 @@
// Determine a normalized form of this expression, which is the expression
// before any post-inc adjustment is made.
const SCEVAddRecExpr *Normalized = S;
- if (L == PostIncLoop) {
- const SCEV *Step = S->getStepRecurrence(SE);
- Normalized = cast<SCEVAddRecExpr>(SE.getMinusSCEV(S, Step));
+ if (PostIncLoops.count(L)) {
+ PostIncLoopSet Loops;
+ Loops.insert(L);
+ Normalized =
+ cast<SCEVAddRecExpr>(TransformForPostIncUse(Normalize, S, 0, 0,
+ Loops, SE, *SE.DT));
}
// Strip off any non-loop-dominating component from the addrec start.
@@ -1002,7 +1005,7 @@
// Accommodate post-inc mode, if necessary.
Value *Result;
- if (L != PostIncLoop)
+ if (!PostIncLoops.count(L))
Result = PN;
else {
// In PostInc mode, use the post-incremented value.
@@ -1274,7 +1277,7 @@
// If the SCEV is computable at this level, insert it into the header
// after the PHIs (and after any other instructions that we've inserted
// there) so that it is guaranteed to dominate any user inside the loop.
- if (L && S->hasComputableLoopEvolution(L) && L != PostIncLoop)
+ if (L && S->hasComputableLoopEvolution(L) && !PostIncLoops.count(L))
InsertPt = L->getHeader()->getFirstNonPHI();
while (isInsertedInstruction(InsertPt) || isa<DbgInfoIntrinsic>(InsertPt))
InsertPt = llvm::next(BasicBlock::iterator(InsertPt));
@@ -1296,7 +1299,7 @@
Value *V = visit(S);
// Remember the expanded value for this SCEV at this location.
- if (!PostIncLoop)
+ if (PostIncLoops.empty())
InsertedExpressions[std::make_pair(S, InsertPt)] = V;
restoreInsertPoint(SaveInsertBB, SaveInsertPt);
@@ -1304,7 +1307,7 @@
}
void SCEVExpander::rememberInstruction(Value *I) {
- if (!PostIncLoop)
+ if (PostIncLoops.empty())
InsertedValues.insert(I);
// If we just claimed an existing instruction and that instruction had