#include "llvm/Instructions.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/LoopPass.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
Threshold("loop-unswitch-threshold", cl::desc("Max loop size to unswitch"),
cl::init(10), cl::Hidden);
- class VISIBILITY_HIDDEN LoopUnswitch : public FunctionPass {
+ class VISIBILITY_HIDDEN LoopUnswitch : public LoopPass {
LoopInfo *LI; // Loop information
+ LPPassManager *LPM;
- // LoopProcessWorklist - List of loops we need to process.
+ // LoopProcessWorklist - Used to check if second loop needs processing
+ // after RewriteLoopBodyWithConditionConstant rewrites first loop.
std::vector<Loop*> LoopProcessWorklist;
SmallPtrSet<Value *,8> UnswitchedVals;
public:
- virtual bool runOnFunction(Function &F);
- bool visitLoop(Loop *L);
+ bool runOnLoop(Loop *L, LPPassManager &LPM);
/// This transformation requires natural loop information & requires that
/// loop preheaders be inserted into the CFG...
RegisterPass<LoopUnswitch> X("loop-unswitch", "Unswitch loops");
}
-FunctionPass *llvm::createLoopUnswitchPass() { return new LoopUnswitch(); }
-
-bool LoopUnswitch::runOnFunction(Function &F) {
- bool Changed = false;
- LI = &getAnalysis<LoopInfo>();
-
- // Populate the worklist of loops to process in post-order.
- for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I)
- for (po_iterator<Loop*> LI = po_begin(*I), E = po_end(*I); LI != E; ++LI)
- LoopProcessWorklist.push_back(*LI);
-
- // Process the loops in worklist order, this is a post-order visitation of
- // the loops. We use a worklist of loops so that loops can be removed at any
- // time if they are deleted (e.g. the backedge of a loop is removed).
- while (!LoopProcessWorklist.empty()) {
- Loop *L = LoopProcessWorklist.back();
- LoopProcessWorklist.pop_back();
- Changed |= visitLoop(L);
- }
-
- UnswitchedVals.clear();
- return Changed;
-}
+LoopPass *llvm::createLoopUnswitchPass() { return new LoopUnswitch(); }
/// FindLIVLoopCondition - Cond is a condition that occurs in L. If it is
/// invariant in the loop, or has an invariant piece, return the invariant.
return 0;
}
-bool LoopUnswitch::visitLoop(Loop *L) {
+bool LoopUnswitch::runOnLoop(Loop *L, LPPassManager &LPM_Ref) {
assert(L->isLCSSAForm());
-
+ LI = &getAnalysis<LoopInfo>();
+ LPM = &LPM_Ref;
bool Changed = false;
// Loop over all of the basic blocks in the loop. If we find an interior
/// CloneLoop - Recursively clone the specified loop and all of its children,
/// mapping the blocks with the specified map.
static Loop *CloneLoop(Loop *L, Loop *PL, DenseMap<const Value*, Value*> &VM,
- LoopInfo *LI) {
+ LoopInfo *LI, LPPassManager *LPM) {
Loop *New = new Loop();
- if (PL)
- PL->addChildLoop(New);
- else
- LI->addTopLevelLoop(New);
+ LPM->insertLoop(New, PL);
// Add all of the blocks in L to the new loop.
for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
// Add all of the subloops to the new loop.
for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I)
- CloneLoop(*I, New, VM, LI);
+ CloneLoop(*I, New, VM, LI, LPM);
return New;
}
OrigPH->getTerminator()->eraseFromParent();
// We need to reprocess this loop, it could be unswitched again.
- LoopProcessWorklist.push_back(L);
+ LPM->redoLoop(L);
// Now that we know that the loop is never entered when this condition is a
// particular value, rewrite the loop with this info. We know that this will
NewBlocks[0], F->end());
// Now we create the new Loop object for the versioned loop.
- Loop *NewLoop = CloneLoop(L, L->getParentLoop(), ValueMap, LI);
+ Loop *NewLoop = CloneLoop(L, L->getParentLoop(), ValueMap, LI, LPM);
Loop *ParentLoop = L->getParentLoop();
if (ParentLoop) {
// Make sure to add the cloned preheader and exit blocks to the parent loop
EmitPreheaderBranchOnCondition(LIC, Val, NewBlocks[0], LoopBlocks[0], OldBR);
OldBR->eraseFromParent();
- LoopProcessWorklist.push_back(L);
LoopProcessWorklist.push_back(NewLoop);
+ LPM->redoLoop(L);
// Now we rewrite the original code to know that the condition is true and the
// new code to know that the condition is false.
/// so they just reparent loops. If the loops are actually dead, they will be
/// removed later.
void LoopUnswitch::RemoveLoopFromHierarchy(Loop *L) {
- if (Loop *ParentLoop = L->getParentLoop()) { // Not a top-level loop.
- // Reparent all of the blocks in this loop. Since BBLoop had a parent,
- // they are now all in it.
- for (Loop::block_iterator I = L->block_begin(), E = L->block_end();
- I != E; ++I)
- if (LI->getLoopFor(*I) == L) // Don't change blocks in subloops.
- LI->changeLoopFor(*I, ParentLoop);
-
- // Remove the loop from its parent loop.
- for (Loop::iterator I = ParentLoop->begin(), E = ParentLoop->end();;
- ++I) {
- assert(I != E && "Couldn't find loop");
- if (*I == L) {
- ParentLoop->removeChildLoop(I);
- break;
- }
- }
-
- // Move all subloops into the parent loop.
- while (L->begin() != L->end())
- ParentLoop->addChildLoop(L->removeChildLoop(L->end()-1));
- } else {
- // Reparent all of the blocks in this loop. Since BBLoop had no parent,
- // they no longer in a loop at all.
-
- for (unsigned i = 0; i != L->getBlocks().size(); ++i) {
- // Don't change blocks in subloops.
- if (LI->getLoopFor(L->getBlocks()[i]) == L) {
- LI->removeBlock(L->getBlocks()[i]);
- --i;
- }
- }
-
- // Remove the loop from the top-level LoopInfo object.
- for (LoopInfo::iterator I = LI->begin(), E = LI->end();; ++I) {
- assert(I != E && "Couldn't find loop");
- if (*I == L) {
- LI->removeLoop(I);
- break;
- }
- }
-
- // Move all of the subloops to the top-level.
- while (L->begin() != L->end())
- LI->addTopLevelLoop(L->removeChildLoop(L->end()-1));
- }
-
- delete L;
+ LPM->deleteLoopFromQueue(L);
RemoveLoopFromWorklist(L);
}
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