diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 95e25dd76c9..f7b67113bd8 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -2230,14 +2230,13 @@ LSRInstance::CollectLoopInvariantFixupsAndFormulae() { /// separate registers. If C is non-null, multiply each subexpression by C. static void CollectSubexprs(const SCEV *S, const SCEVConstant *C, SmallVectorImpl &Ops, - SmallVectorImpl &UninterestingOps, const Loop *L, ScalarEvolution &SE) { if (const SCEVAddExpr *Add = dyn_cast(S)) { // Break out add operands. for (SCEVAddExpr::op_iterator I = Add->op_begin(), E = Add->op_end(); I != E; ++I) - CollectSubexprs(*I, C, Ops, UninterestingOps, L, SE); + CollectSubexprs(*I, C, Ops, L, SE); return; } else if (const SCEVAddRecExpr *AR = dyn_cast(S)) { // Split a non-zero base out of an addrec. @@ -2245,8 +2244,8 @@ static void CollectSubexprs(const SCEV *S, const SCEVConstant *C, CollectSubexprs(SE.getAddRecExpr(SE.getConstant(AR->getType(), 0), AR->getStepRecurrence(SE), AR->getLoop()), - C, Ops, UninterestingOps, L, SE); - CollectSubexprs(AR->getStart(), C, Ops, UninterestingOps, L, SE); + C, Ops, L, SE); + CollectSubexprs(AR->getStart(), C, Ops, L, SE); return; } } else if (const SCEVMulExpr *Mul = dyn_cast(S)) { @@ -2256,17 +2255,13 @@ static void CollectSubexprs(const SCEV *S, const SCEVConstant *C, dyn_cast(Mul->getOperand(0))) { CollectSubexprs(Mul->getOperand(1), C ? cast(SE.getMulExpr(C, Op0)) : Op0, - Ops, UninterestingOps, L, SE); + Ops, L, SE); return; } } - // Otherwise use the value itself. Loop-variant "unknown" values are - // uninteresting; we won't be able to do anything meaningful with them. - if (!C && isa(S) && !S->isLoopInvariant(L)) - UninterestingOps.push_back(S); - else - Ops.push_back(C ? SE.getMulExpr(C, S) : S); + // Otherwise use the value itself, optionally with a scale applied. + Ops.push_back(C ? SE.getMulExpr(C, S) : S); } /// GenerateReassociations - Split out subexpressions from adds and the bases of @@ -2280,19 +2275,19 @@ void LSRInstance::GenerateReassociations(LSRUse &LU, unsigned LUIdx, for (size_t i = 0, e = Base.BaseRegs.size(); i != e; ++i) { const SCEV *BaseReg = Base.BaseRegs[i]; - SmallVector AddOps, UninterestingAddOps; - CollectSubexprs(BaseReg, 0, AddOps, UninterestingAddOps, L, SE); - - // Add any uninteresting values as one register, as we won't be able to - // form any interesting reassociation opportunities with them. They'll - // just have to be added inside the loop no matter what we do. - if (!UninterestingAddOps.empty()) - AddOps.push_back(SE.getAddExpr(UninterestingAddOps)); + SmallVector AddOps; + CollectSubexprs(BaseReg, 0, AddOps, L, SE); if (AddOps.size() == 1) continue; for (SmallVectorImpl::const_iterator J = AddOps.begin(), JE = AddOps.end(); J != JE; ++J) { + + // Loop-variant "unknown" values are uninteresting; we won't be able to + // do anything meaningful with them. + if (isa(*J) && !(*J)->isLoopInvariant(L)) + continue; + // Don't pull a constant into a register if the constant could be folded // into an immediate field. if (isAlwaysFoldable(*J, LU.MinOffset, LU.MaxOffset,