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Remove -enable-lsr-nested in time for 3.1.

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Tests cases have been removed but attached to open PR12330.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153286 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Trick
2012-03-22 22:42:45 +00:00
parent ee5a53d21e
commit bd618f1b7f
6 changed files with 10 additions and 1167 deletions
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39
lib/Transforms/Scalar/LoopStrengthReduce.cpp
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@@ -77,9 +77,6 @@
#include <algorithm>
using namespace llvm;
static cl::opt<bool> EnableNested(
"enable-lsr-nested", cl::Hidden, cl::desc("Enable LSR on nested loops"));
static cl::opt<bool> EnableRetry(
"enable-lsr-retry", cl::Hidden, cl::desc("Enable LSR retry"));
@@ -824,36 +821,20 @@ void Cost::RateRegister(const SCEV *Reg,
const Loop *L,
ScalarEvolution &SE, DominatorTree &DT) {
if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Reg)) {
if (AR->getLoop() == L)
AddRecCost += 1; /// TODO: This should be a function of the stride.
// If this is an addrec for another loop, don't second-guess its addrec phi
// nodes. LSR isn't currently smart enough to reason about more than one
// loop at a time. LSR has either already run on inner loops, will not run
// on other loops, and cannot be expected to change sibling loops. If the
// AddRec exists, consider it's register free and leave it alone. Otherwise,
// do not consider this formula at all.
else if (!EnableNested || L->contains(AR->getLoop()) ||
(!AR->getLoop()->contains(L) &&
DT.dominates(L->getHeader(), AR->getLoop()->getHeader()))) {
// loop at a time. LSR has already run on inner loops, will not run on outer
// loops, and cannot be expected to change sibling loops.
if (AR->getLoop() != L) {
// If the AddRec exists, consider it's register free and leave it alone.
if (isExistingPhi(AR, SE))
return;
// For !EnableNested, never rewrite IVs in other loops.
if (!EnableNested) {
Loose();
return;
}
// If this isn't one of the addrecs that the loop already has, it
// would require a costly new phi and add. TODO: This isn't
// precisely modeled right now.
++NumBaseAdds;
if (!Regs.count(AR->getStart())) {
RateRegister(AR->getStart(), Regs, L, SE, DT);
if (isLoser())
return;
}
// Otherwise, do not consider this formula at all.
Loose();
return;
}
AddRecCost += 1; /// TODO: This should be a function of the stride.
// Add the step value register, if it needs one.
// TODO: The non-affine case isn't precisely modeled here.
@@ -2193,7 +2174,7 @@ void LSRInstance::CollectInterestingTypesAndFactors() {
do {
const SCEV *S = Worklist.pop_back_val();
if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(S)) {
if (EnableNested || AR->getLoop() == L)
if (AR->getLoop() == L)
Strides.insert(AR->getStepRecurrence(SE));
Worklist.push_back(AR->getStart());
} else if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
@@ -4566,7 +4547,7 @@ LSRInstance::LSRInstance(const TargetLowering *tli, Loop *l, Pass *P)
if (IU.empty()) return;
// Skip nested loops until we can model them better with formulae.
if (!EnableNested && !L->empty()) {
if (!L->empty()) {
DEBUG(dbgs() << "LSR skipping outer loop " << *L << "\n");
return;
}