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[PlaceSafepoints] Use analysis infrastructure to get dominator tree

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The old code computed dominators for every loop. This was terribly slow with no good reason. Just use the standard infrastructure for analysis passes.

Differential Revision: http://reviews.llvm.org/D9586



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237176 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Philip Reames 2015-05-12 20:56:33 +00:00
parent 0d8dadf96e
commit 6214347294
1 changed files with 4 additions and 6 deletions
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10
lib/Transforms/Scalar/PlaceSafepoints.cpp
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@ -130,6 +130,7 @@ struct PlaceBackedgeSafepointsImpl : public LoopPass {
bool runOnLoop(Loop *, LPPassManager &LPM) override;
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<DominatorTreeWrapperPass>();
AU.addRequired<ScalarEvolution>();
// We no longer modify the IR at all in this pass. Thus all
// analysis are preserved.
@ -312,6 +313,7 @@ static void scanInlinedCode(Instruction *start, Instruction *end,
bool PlaceBackedgeSafepointsImpl::runOnLoop(Loop *L, LPPassManager &LPM) {
ScalarEvolution *SE = &getAnalysis<ScalarEvolution>();
DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
// Loop through all loop latches (branches controlling backedges). We need
// to place a safepoint on every backedge (potentially).
@ -320,11 +322,6 @@ bool PlaceBackedgeSafepointsImpl::runOnLoop(Loop *L, LPPassManager &LPM) {
// w.r.t. loops with multiple backedges.
BasicBlock *header = L->getHeader();
// TODO: Use the analysis pass infrastructure for this. There is no reason
// to recalculate this here.
DominatorTree DT;
DT.recalculate(*header->getParent());
SmallVector<BasicBlock*, 16> LoopLatches;
L->getLoopLatches(LoopLatches);
for (BasicBlock *pred : LoopLatches) {
@ -341,7 +338,7 @@ bool PlaceBackedgeSafepointsImpl::runOnLoop(Loop *L, LPPassManager &LPM) {
continue;
}
if (CallSafepointsEnabled &&
containsUnconditionalCallSafepoint(L, header, pred, DT)) {
containsUnconditionalCallSafepoint(L, header, pred, *DT)) {
// Note: This is only semantically legal since we won't do any further
// IPO or inlining before the actual call insertion.. If we hadn't, we
// might latter loose this call safepoint.
@ -746,6 +743,7 @@ INITIALIZE_PASS_BEGIN(PlaceBackedgeSafepointsImpl,
"place-backedge-safepoints-impl",
"Place Backedge Safepoints", false, false)
INITIALIZE_PASS_DEPENDENCY(ScalarEvolution)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_END(PlaceBackedgeSafepointsImpl,
"place-backedge-safepoints-impl",
"Place Backedge Safepoints", false, false)