/// complicated to handle the case where one of the edges being split
/// is an exit of a loop with other exits).
///
-BasicBlock *SplitBlockPredecessors(BasicBlock *BB, ArrayRef<BasicBlock*> Preds,
- const char *Suffix, Pass *P = nullptr);
+BasicBlock *SplitBlockPredecessors(BasicBlock *BB, ArrayRef<BasicBlock *> Preds,
+ const char *Suffix,
+ AliasAnalysis *AA = nullptr,
+ DominatorTree *DT = nullptr,
+ LoopInfo *LI = nullptr,
+ bool PreserveLCSSA = false);
/// SplitLandingPadPredecessors - This method transforms the landing pad,
/// OrigBB, by introducing two new basic blocks into the function. One of those
// Split them out to their own block.
UnavailablePred =
- SplitBlockPredecessors(LoadBB, PredsToSplit, "thread-pre-split", this);
+ SplitBlockPredecessors(LoadBB, PredsToSplit, "thread-pre-split");
}
// If the value isn't available in all predecessors, then there will be
else {
DEBUG(dbgs() << " Factoring out " << PredBBs.size()
<< " common predecessors.\n");
- PredBB = SplitBlockPredecessors(BB, PredBBs, ".thr_comm", this);
+ PredBB = SplitBlockPredecessors(BB, PredBBs, ".thr_comm");
}
// And finally, do it!
else {
DEBUG(dbgs() << " Factoring out " << PredBBs.size()
<< " common predecessors.\n");
- PredBB = SplitBlockPredecessors(BB, PredBBs, ".thr_comm", this);
+ PredBB = SplitBlockPredecessors(BB, PredBBs, ".thr_comm");
}
// Okay, we decided to do this! Clone all the instructions in BB onto the end
// Although SplitBlockPredecessors doesn't preserve loop-simplify in
// general, if we call it on all predecessors of all exits then it does.
if (!ExitBlock->isLandingPad()) {
- SplitBlockPredecessors(ExitBlock, Preds, ".us-lcssa", this);
+ SplitBlockPredecessors(ExitBlock, Preds, ".us-lcssa",
+ /*AliasAnalysis*/ nullptr, DT, LI,
+ /*PreserveLCSSA*/ true);
} else {
SmallVector<BasicBlock*, 2> NewBBs;
SplitLandingPadPredecessors(ExitBlock, Preds, ".us-lcssa", ".us-lcssa",
/// analysis information.
static void UpdateAnalysisInformation(BasicBlock *OldBB, BasicBlock *NewBB,
ArrayRef<BasicBlock *> Preds,
- Pass *P, bool &HasLoopExit) {
- if (!P) return;
+ DominatorTree *DT, LoopInfo *LI,
+ bool PreserveLCSSA, bool &HasLoopExit) {
+ // Update dominator tree if available.
+ if (DT)
+ DT->splitBlock(NewBB);
- auto *LIWP = P->getAnalysisIfAvailable<LoopInfoWrapperPass>();
- LoopInfo *LI = LIWP ? &LIWP->getLoopInfo() : nullptr;
- Loop *L = LI ? LI->getLoopFor(OldBB) : nullptr;
+ // The rest of the logic is only relevant for updating the loop structures.
+ if (!LI)
+ return;
+
+ Loop *L = LI->getLoopFor(OldBB);
// If we need to preserve loop analyses, collect some information about how
// this split will affect loops.
bool IsLoopEntry = !!L;
bool SplitMakesNewLoopHeader = false;
- if (LI) {
- bool PreserveLCSSA = P->mustPreserveAnalysisID(LCSSAID);
- for (ArrayRef<BasicBlock*>::iterator
- i = Preds.begin(), e = Preds.end(); i != e; ++i) {
- BasicBlock *Pred = *i;
-
- // If we need to preserve LCSSA, determine if any of the preds is a loop
- // exit.
- if (PreserveLCSSA)
- if (Loop *PL = LI->getLoopFor(Pred))
- if (!PL->contains(OldBB))
- HasLoopExit = true;
-
- // If we need to preserve LoopInfo, note whether any of the preds crosses
- // an interesting loop boundary.
- if (!L) continue;
- if (L->contains(Pred))
- IsLoopEntry = false;
- else
- SplitMakesNewLoopHeader = true;
- }
+ for (ArrayRef<BasicBlock *>::iterator i = Preds.begin(), e = Preds.end();
+ i != e; ++i) {
+ BasicBlock *Pred = *i;
+
+ // If we need to preserve LCSSA, determine if any of the preds is a loop
+ // exit.
+ if (PreserveLCSSA)
+ if (Loop *PL = LI->getLoopFor(Pred))
+ if (!PL->contains(OldBB))
+ HasLoopExit = true;
+
+ // If we need to preserve LoopInfo, note whether any of the preds crosses
+ // an interesting loop boundary.
+ if (!L)
+ continue;
+ if (L->contains(Pred))
+ IsLoopEntry = false;
+ else
+ SplitMakesNewLoopHeader = true;
}
- // Update dominator tree if available.
- if (DominatorTreeWrapperPass *DTWP =
- P->getAnalysisIfAvailable<DominatorTreeWrapperPass>())
- DTWP->getDomTree().splitBlock(NewBB);
-
- if (!L) return;
+ // Unless we have a loop for OldBB, nothing else to do here.
+ if (!L)
+ return;
if (IsLoopEntry) {
// Add the new block to the nearest enclosing loop (and not an adjacent
/// UpdatePHINodes - Update the PHI nodes in OrigBB to include the values coming
/// from NewBB. This also updates AliasAnalysis, if available.
static void UpdatePHINodes(BasicBlock *OrigBB, BasicBlock *NewBB,
- ArrayRef<BasicBlock*> Preds, BranchInst *BI,
- Pass *P, bool HasLoopExit) {
+ ArrayRef<BasicBlock *> Preds, BranchInst *BI,
+ AliasAnalysis *AA, bool HasLoopExit) {
// Otherwise, create a new PHI node in NewBB for each PHI node in OrigBB.
- AliasAnalysis *AA = P ? P->getAnalysisIfAvailable<AliasAnalysis>() : nullptr;
SmallPtrSet<BasicBlock *, 16> PredSet(Preds.begin(), Preds.end());
for (BasicBlock::iterator I = OrigBB->begin(); isa<PHINode>(I); ) {
PHINode *PN = cast<PHINode>(I++);
/// of the edges being split is an exit of a loop with other exits).
///
BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
- ArrayRef<BasicBlock*> Preds,
- const char *Suffix, Pass *P) {
+ ArrayRef<BasicBlock *> Preds,
+ const char *Suffix, AliasAnalysis *AA,
+ DominatorTree *DT, LoopInfo *LI,
+ bool PreserveLCSSA) {
// Create new basic block, insert right before the original block.
BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), BB->getName()+Suffix,
BB->getParent(), BB);
// Update DominatorTree, LoopInfo, and LCCSA analysis information.
bool HasLoopExit = false;
- UpdateAnalysisInformation(BB, NewBB, Preds, P, HasLoopExit);
+ UpdateAnalysisInformation(BB, NewBB, Preds, DT, LI, PreserveLCSSA,
+ HasLoopExit);
// Update the PHI nodes in BB with the values coming from NewBB.
- UpdatePHINodes(BB, NewBB, Preds, BI, P, HasLoopExit);
+ UpdatePHINodes(BB, NewBB, Preds, BI, AA, HasLoopExit);
return NewBB;
}
}
// Update DominatorTree, LoopInfo, and LCCSA analysis information.
+ auto *DTWP = P->getAnalysisIfAvailable<DominatorTreeWrapperPass>();
+ auto *DT = DTWP ? &DTWP->getDomTree() : nullptr;
+ auto *LIWP = P->getAnalysisIfAvailable<LoopInfoWrapperPass>();
+ auto *LI = LIWP ? &LIWP->getLoopInfo() : nullptr;
+ bool PreserveLCSSA = P->mustPreserveAnalysisID(LCSSAID);
bool HasLoopExit = false;
- UpdateAnalysisInformation(OrigBB, NewBB1, Preds, P, HasLoopExit);
+ UpdateAnalysisInformation(OrigBB, NewBB1, Preds, DT, LI, PreserveLCSSA,
+ HasLoopExit);
// Update the PHI nodes in OrigBB with the values coming from NewBB1.
- UpdatePHINodes(OrigBB, NewBB1, Preds, BI1, P, HasLoopExit);
+ AliasAnalysis *AA = P ? P->getAnalysisIfAvailable<AliasAnalysis>() : nullptr;
+ UpdatePHINodes(OrigBB, NewBB1, Preds, BI1, AA, HasLoopExit);
// Move the remaining edges from OrigBB to point to NewBB2.
SmallVector<BasicBlock*, 8> NewBB2Preds;
// Update DominatorTree, LoopInfo, and LCCSA analysis information.
HasLoopExit = false;
- UpdateAnalysisInformation(OrigBB, NewBB2, NewBB2Preds, P, HasLoopExit);
+ UpdateAnalysisInformation(OrigBB, NewBB2, NewBB2Preds, DT, LI,
+ PreserveLCSSA, HasLoopExit);
// Update the PHI nodes in OrigBB with the values coming from NewBB2.
- UpdatePHINodes(OrigBB, NewBB2, NewBB2Preds, BI2, P, HasLoopExit);
+ UpdatePHINodes(OrigBB, NewBB2, NewBB2Preds, BI2, AA, HasLoopExit);
}
LandingPadInst *LPad = OrigBB->getLandingPadInst();
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/CFG.h"
// If we don't have a pass object, we can't update anything...
if (!P) return NewBB;
+
+ auto *AA = P->getAnalysisIfAvailable<AliasAnalysis>();
DominatorTreeWrapperPass *DTWP =
P->getAnalysisIfAvailable<DominatorTreeWrapperPass>();
DominatorTree *DT = DTWP ? &DTWP->getDomTree() : nullptr;
auto *LIWP = P->getAnalysisIfAvailable<LoopInfoWrapperPass>();
LoopInfo *LI = LIWP ? &LIWP->getLoopInfo() : nullptr;
+ bool PreserveLCSSA = P->mustPreserveAnalysisID(LCSSAID);
// If we have nothing to update, just return.
if (!DT && !LI)
"Split point for loop exit is contained in loop!");
// Update LCSSA form in the newly created exit block.
- if (P->mustPreserveAnalysisID(LCSSAID))
+ if (PreserveLCSSA)
createPHIsForSplitLoopExit(TIBB, NewBB, DestBB);
// The only that we can break LoopSimplify form by splitting a critical
if (!LoopPreds.empty()) {
assert(!DestBB->isLandingPad() &&
"We don't split edges to landing pads!");
- BasicBlock *NewExitBB =
- SplitBlockPredecessors(DestBB, LoopPreds, "split", P);
- if (P->mustPreserveAnalysisID(LCSSAID))
+ BasicBlock *NewExitBB = SplitBlockPredecessors(
+ DestBB, LoopPreds, "split", AA, DT, LI, PreserveLCSSA);
+ if (PreserveLCSSA)
createPHIsForSplitLoopExit(LoopPreds, NewExitBB, DestBB);
}
}
// available, which means that all predecessors of loop exit blocks
// are within the loop. Without LoopSimplify form, it would be
// necessary to insert a new phi.
- assert((!P->mustPreserveAnalysisID(LCSSAID) ||
- P->mustPreserveAnalysisID(LoopSimplifyID)) &&
+ assert((!PreserveLCSSA || P->mustPreserveAnalysisID(LoopSimplifyID)) &&
"SplitCriticalEdge doesn't know how to update LCCSA form "
"without LoopSimplify!");
}
BasicBlock *llvm::InsertPreheaderForLoop(Loop *L, Pass *PP) {
BasicBlock *Header = L->getHeader();
+ // Get analyses that we try to update.
+ auto *AA = PP->getAnalysisIfAvailable<AliasAnalysis>();
+ auto *DTWP = PP->getAnalysisIfAvailable<DominatorTreeWrapperPass>();
+ auto *DT = DTWP ? &DTWP->getDomTree() : nullptr;
+ auto *LIWP = PP->getAnalysisIfAvailable<LoopInfoWrapperPass>();
+ auto *LI = LIWP ? &LIWP->getLoopInfo() : nullptr;
+ bool PreserveLCSSA = PP->mustPreserveAnalysisID(LCSSAID);
+
// Compute the set of predecessors of the loop that are not in the loop.
SmallVector<BasicBlock*, 8> OutsideBlocks;
for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
BasicBlock *PreheaderBB;
if (!Header->isLandingPad()) {
PreheaderBB = SplitBlockPredecessors(Header, OutsideBlocks, ".preheader",
- PP);
+ AA, DT, LI, PreserveLCSSA);
} else {
SmallVector<BasicBlock*, 2> NewBBs;
SplitLandingPadPredecessors(Header, OutsideBlocks, ".preheader",
///
/// This method is used to split exit blocks that have predecessors outside of
/// the loop.
-static BasicBlock *rewriteLoopExitBlock(Loop *L, BasicBlock *Exit, Pass *PP) {
+static BasicBlock *rewriteLoopExitBlock(Loop *L, BasicBlock *Exit,
+ AliasAnalysis *AA, DominatorTree *DT,
+ LoopInfo *LI, Pass *PP) {
SmallVector<BasicBlock*, 8> LoopBlocks;
for (pred_iterator I = pred_begin(Exit), E = pred_end(Exit); I != E; ++I) {
BasicBlock *P = *I;
assert(!LoopBlocks.empty() && "No edges coming in from outside the loop?");
BasicBlock *NewExitBB = nullptr;
+ bool PreserveLCSSA = PP->mustPreserveAnalysisID(LCSSAID);
+
if (Exit->isLandingPad()) {
SmallVector<BasicBlock*, 2> NewBBs;
SplitLandingPadPredecessors(Exit, LoopBlocks,
PP, NewBBs);
NewExitBB = NewBBs[0];
} else {
- NewExitBB = SplitBlockPredecessors(Exit, LoopBlocks, ".loopexit", PP);
+ NewExitBB = SplitBlockPredecessors(Exit, LoopBlocks, ".loopexit", AA, DT,
+ LI, PreserveLCSSA);
}
DEBUG(dbgs() << "LoopSimplify: Creating dedicated exit block "
if (SE)
SE->forgetLoop(L);
+ bool PreserveLCSSA = PP->mustPreserveAnalysisID(LCSSAID);
+
BasicBlock *Header = L->getHeader();
- BasicBlock *NewBB =
- SplitBlockPredecessors(Header, OuterLoopPreds, ".outer", PP);
+ BasicBlock *NewBB = SplitBlockPredecessors(Header, OuterLoopPreds, ".outer",
+ AA, DT, LI, PreserveLCSSA);
// Make sure that NewBB is put someplace intelligent, which doesn't mess up
// code layout too horribly.
// Must be exactly this loop: no subloops, parent loops, or non-loop preds
// allowed.
if (!L->contains(*PI)) {
- if (rewriteLoopExitBlock(L, ExitBlock, PP)) {
+ if (rewriteLoopExitBlock(L, ExitBlock, AA, DT, LI, PP)) {
++NumInserted;
Changed = true;
}
#include "llvm/Transforms/Utils/UnrollLoop.h"
#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/LoopIterator.h"
#include "llvm/Analysis/LoopPass.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/IR/Metadata.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include <algorithm>
static void ConnectProlog(Loop *L, Value *TripCount, unsigned Count,
BasicBlock *LastPrologBB, BasicBlock *PrologEnd,
BasicBlock *OrigPH, BasicBlock *NewPH,
- ValueToValueMapTy &VMap, Pass *P) {
+ ValueToValueMapTy &VMap, AliasAnalysis *AA,
+ DominatorTree *DT, LoopInfo *LI, Pass *P) {
BasicBlock *Latch = L->getLoopLatch();
assert(Latch && "Loop must have a latch");
// Split the exit to maintain loop canonicalization guarantees
SmallVector<BasicBlock*, 4> Preds(pred_begin(Exit), pred_end(Exit));
if (!Exit->isLandingPad()) {
- SplitBlockPredecessors(Exit, Preds, ".unr-lcssa", P);
+ SplitBlockPredecessors(Exit, Preds, ".unr-lcssa", AA, DT, LI,
+ P->mustPreserveAnalysisID(LCSSAID));
} else {
SmallVector<BasicBlock*, 2> NewBBs;
SplitLandingPadPredecessors(Exit, Preds, ".unr1-lcssa", ".unr2-lcssa",
if (Loop *ParentLoop = L->getParentLoop())
SE->forgetLoop(ParentLoop);
- // Grab the dominator tree so we can preserve it.
+ // Grab analyses that we preserve.
+ auto *AA = LPM->getAnalysisIfAvailable<AliasAnalysis>();
auto *DTWP = LPM->getAnalysisIfAvailable<DominatorTreeWrapperPass>();
auto *DT = DTWP ? &DTWP->getDomTree() : nullptr;
// PHI functions.
BasicBlock *LastLoopBB = cast<BasicBlock>(VMap[Latch]);
ConnectProlog(L, TripCount, Count, LastLoopBB, PEnd, PH, NewPH, VMap,
- LPM->getAsPass());
+ AA, DT, LI, LPM->getAsPass());
NumRuntimeUnrolled++;
return true;
}