-/// containsAddRecFromDifferentLoop - Determine whether expression S involves a
-/// subexpression that is an AddRec from a loop other than L. An outer loop
-/// of L is OK, but not an inner loop nor a disjoint loop.
-static bool containsAddRecFromDifferentLoop(SCEVHandle S, Loop *L) {
- // This is very common, put it first.
- if (isa<SCEVConstant>(S))
- return false;
- if (const SCEVCommutativeExpr *AE = dyn_cast<SCEVCommutativeExpr>(S)) {
- for (unsigned int i=0; i< AE->getNumOperands(); i++)
- if (containsAddRecFromDifferentLoop(AE->getOperand(i), L))
- return true;
- return false;
- }
- if (const SCEVAddRecExpr *AE = dyn_cast<SCEVAddRecExpr>(S)) {
- if (const Loop *newLoop = AE->getLoop()) {
- if (newLoop == L)
- return false;
- // if newLoop is an outer loop of L, this is OK.
- if (!LoopInfoBase<BasicBlock>::isNotAlreadyContainedIn(L, newLoop))
- return false;
+/// CollectSubexprs - Split S into subexpressions which can be pulled out into
+/// separate registers.
+static void CollectSubexprs(const SCEV *S,
+ SmallVectorImpl<const SCEV *> &Ops,
+ ScalarEvolution &SE) {
+ if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
+ // Break out add operands.
+ for (SCEVAddExpr::op_iterator I = Add->op_begin(), E = Add->op_end();
+ I != E; ++I)
+ CollectSubexprs(*I, Ops, SE);
+ return;
+ } else if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) {
+ // Split a non-zero base out of an addrec.
+ if (!AR->getStart()->isZero()) {
+ CollectSubexprs(AR->getStart(), Ops, SE);
+ CollectSubexprs(SE.getAddRecExpr(SE.getIntegerSCEV(0, AR->getType()),
+ AR->getStepRecurrence(SE),
+ AR->getLoop()), Ops, SE);
+ return;