[llvm-commits] [llvm] r81101 - in /llvm/trunk: include/llvm/Analysis/LoopInfo.h include/llvm/Transforms/Utils/BasicBlockUtils.h lib/Analysis/LoopInfo.cpp lib/Transforms/Scalar/LICM.cpp lib/Transforms/Scalar/LoopStrengthReduce.cpp lib/Transforms/Scalar/LoopUnswitch.cpp lib/Transforms/Utils/BasicBlockUtils.cpp lib/Transforms/Utils/BreakCriticalEdges.cpp lib/Transforms/Utils/LCSSA.cpp lib/Transforms/Utils/LoopSimplify.cpp test/Transforms/LoopUnswitch/2009-09-05-DomAssert.ll
Evan Cheng
evan.cheng at apple.com
Sat Sep 5 19:26:11 PDT 2009
Author: evancheng
Date: Sat Sep 5 21:26:10 2009
New Revision: 81101
URL: http://llvm.org/viewvc/llvm-project?rev=81101&view=rev
Log:
Revert r80926. It causes loop unswitch assertion and slow down some JIT tests significantly.
Added:
llvm/trunk/test/Transforms/LoopUnswitch/2009-09-05-DomAssert.ll
Modified:
llvm/trunk/include/llvm/Analysis/LoopInfo.h
llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h
llvm/trunk/lib/Analysis/LoopInfo.cpp
llvm/trunk/lib/Transforms/Scalar/LICM.cpp
llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp
llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp
llvm/trunk/lib/Transforms/Utils/BreakCriticalEdges.cpp
llvm/trunk/lib/Transforms/Utils/LCSSA.cpp
llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp
Modified: llvm/trunk/include/llvm/Analysis/LoopInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/LoopInfo.h?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/LoopInfo.h (original)
+++ llvm/trunk/include/llvm/Analysis/LoopInfo.h Sat Sep 5 21:26:10 2009
@@ -376,73 +376,11 @@
/// verifyLoop - Verify loop structure
void verifyLoop() const {
#ifndef NDEBUG
- assert(!Blocks.empty() && "Loop header is missing");
- assert(getHeader() && "Loop header is missing");
-
- // Verify the individual blocks.
- for (block_iterator I = block_begin(), E = block_end(); I != E; ++I) {
- BlockT *BB = *I;
- bool HasInsideLoopSuccs = false;
- bool HasInsideLoopPreds = false;
- SmallVector<BlockT *, 2> OutsideLoopPreds;
-
- typedef GraphTraits<BlockT*> BlockTraits;
- for (typename BlockTraits::ChildIteratorType SI =
- BlockTraits::child_begin(BB), SE = BlockTraits::child_end(BB);
- SI != SE; ++SI)
- if (contains(*SI))
- HasInsideLoopSuccs = true;
- typedef GraphTraits<Inverse<BlockT*> > InvBlockTraits;
- for (typename InvBlockTraits::ChildIteratorType PI =
- InvBlockTraits::child_begin(BB), PE = InvBlockTraits::child_end(BB);
- PI != PE; ++PI) {
- if (contains(*PI))
- HasInsideLoopPreds = true;
- else
- OutsideLoopPreds.push_back(*PI);
- }
-
- if (BB == getHeader()) {
- assert(!OutsideLoopPreds.empty() && "Loop is unreachable!");
- } else if (!OutsideLoopPreds.empty()) {
- // A non-header loop shouldn't be reachable from outside the loop,
- // though it is permitted if the predecessor is not itself actually
- // reachable.
- BlockT *EntryBB = BB->getParent()->begin();
- for (df_iterator<BlockT *> NI = df_begin(EntryBB),
- NE = df_end(EntryBB); NI != NE; ++NI)
- for (unsigned i = 0, e = OutsideLoopPreds.size(); i != e; ++i)
- assert(*NI != OutsideLoopPreds[i] &&
- "Loop has multiple entry points!");
- }
- assert(HasInsideLoopPreds && "Loop block has no in-loop predecessors!");
- assert(HasInsideLoopSuccs && "Loop block has no in-loop successors!");
- assert(BB != getHeader()->getParent()->begin() &&
- "Loop contains function entry block!");
- }
-
- // Verify the subloops.
- for (iterator I = begin(), E = end(); I != E; ++I) {
- // Each block in each subloop should be contained within this loop.
- for (block_iterator BI = (*I)->block_begin(), BE = (*I)->block_end();
- BI != BE; ++BI) {
- assert(contains(*BI) &&
- "Loop does not contain all the blocks of a subloop!");
- }
- // Recursively check the subloop.
+ assert (getHeader() && "Loop header is missing");
+ assert (getLoopPreheader() && "Loop preheader is missing");
+ assert (getLoopLatch() && "Loop latch is missing");
+ for (iterator I = SubLoops.begin(), E = SubLoops.end(); I != E; ++I)
(*I)->verifyLoop();
- }
-
- // Verify the parent loop.
- if (ParentLoop) {
- bool FoundSelf = false;
- for (iterator I = ParentLoop->begin(), E = ParentLoop->end(); I != E; ++I)
- if (*I == this) {
- FoundSelf = true;
- break;
- }
- assert(FoundSelf && "Loop is not a subloop of its parent!");
- }
#endif
}
@@ -935,8 +873,6 @@
///
virtual bool runOnFunction(Function &F);
- virtual void verifyAnalysis() const;
-
virtual void releaseMemory() { LI.releaseMemory(); }
virtual void print(raw_ostream &O, const Module* M = 0) const;
Modified: llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/BasicBlockUtils.h Sat Sep 5 21:26:10 2009
@@ -126,10 +126,10 @@
/// dest go to one block instead of each going to a different block, but isn't
/// the standard definition of a "critical edge".
///
-BasicBlock *SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum,
- Pass *P = 0, bool MergeIdenticalEdges = false);
+bool SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P = 0,
+ bool MergeIdenticalEdges = false);
-inline BasicBlock *SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, Pass *P = 0) {
+inline bool SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, Pass *P = 0) {
return SplitCriticalEdge(BB->getTerminator(), SI.getSuccessorIndex(), P);
}
@@ -143,7 +143,7 @@
TerminatorInst *TI = (*PI)->getTerminator();
for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
if (TI->getSuccessor(i) == Succ)
- MadeChange |= !!SplitCriticalEdge(TI, i, P);
+ MadeChange |= SplitCriticalEdge(TI, i, P);
return MadeChange;
}
@@ -151,9 +151,8 @@
/// and return true, otherwise return false. This method requires that there be
/// an edge between the two blocks. If P is specified, it updates the analyses
/// described above.
-inline BasicBlock *SplitCriticalEdge(BasicBlock *Src, BasicBlock *Dst,
- Pass *P = 0,
- bool MergeIdenticalEdges = false) {
+inline bool SplitCriticalEdge(BasicBlock *Src, BasicBlock *Dst, Pass *P = 0,
+ bool MergeIdenticalEdges = false) {
TerminatorInst *TI = Src->getTerminator();
unsigned i = 0;
while (1) {
@@ -181,12 +180,8 @@
/// Preds array, which has NumPreds elements in it. The new block is given a
/// suffix of 'Suffix'. This function returns the new block.
///
-/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree,
-/// DominanceFrontier, LoopInfo, and LCCSA but no other analyses.
-/// In particular, it does not preserve LoopSimplify (because it's
-/// complicated to handle the case where one of the edges being split
-/// is an exit of a loop with other exits).
-///
+/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree and
+/// DominanceFrontier, but no other analyses.
BasicBlock *SplitBlockPredecessors(BasicBlock *BB, BasicBlock *const *Preds,
unsigned NumPreds, const char *Suffix,
Pass *P = 0);
Modified: llvm/trunk/lib/Analysis/LoopInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/LoopInfo.cpp?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/LoopInfo.cpp (original)
+++ llvm/trunk/lib/Analysis/LoopInfo.cpp Sat Sep 5 21:26:10 2009
@@ -300,9 +300,6 @@
///
void
Loop::getUniqueExitBlocks(SmallVectorImpl<BasicBlock *> &ExitBlocks) const {
- assert(isLoopSimplifyForm() &&
- "getUniqueExitBlocks assumes the loop is in canonical form!");
-
// Sort the blocks vector so that we can use binary search to do quick
// lookups.
SmallVector<BasicBlock *, 128> LoopBBs(block_begin(), block_end());
@@ -374,13 +371,6 @@
return false;
}
-void LoopInfo::verifyAnalysis() const {
- for (iterator I = begin(), E = end(); I != E; ++I) {
- assert(!(*I)->getParentLoop() && "Top-level loop has a parent!");
- (*I)->verifyLoop();
- }
-}
-
void LoopInfo::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<DominatorTree>();
Modified: llvm/trunk/lib/Transforms/Scalar/LICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LICM.cpp?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LICM.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp Sat Sep 5 21:26:10 2009
@@ -91,7 +91,6 @@
AU.addRequired<AliasAnalysis>();
AU.addPreserved<ScalarEvolution>();
AU.addPreserved<DominanceFrontier>();
- AU.addPreservedID(LoopSimplifyID);
}
bool doFinalization() {
Modified: llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopStrengthReduce.cpp Sat Sep 5 21:26:10 2009
@@ -484,37 +484,36 @@
// loop because multiple copies sometimes do useful sinking of code in
// that case(?).
Instruction *OldLoc = dyn_cast<Instruction>(OperandValToReplace);
- BasicBlock *PHIPred = PN->getIncomingBlock(i);
if (L->contains(OldLoc->getParent())) {
// If this is a critical edge, split the edge so that we do not insert
// the code on all predecessor/successor paths. We do this unless this
// is the canonical backedge for this loop, as this can make some
// inserted code be in an illegal position.
+ BasicBlock *PHIPred = PN->getIncomingBlock(i);
if (e != 1 && PHIPred->getTerminator()->getNumSuccessors() > 1 &&
(PN->getParent() != L->getHeader() || !L->contains(PHIPred))) {
// First step, split the critical edge.
- BasicBlock *NewBB = SplitCriticalEdge(PHIPred, PN->getParent(),
- P, false);
+ SplitCriticalEdge(PHIPred, PN->getParent(), P, false);
// Next step: move the basic block. In particular, if the PHI node
// is outside of the loop, and PredTI is in the loop, we want to
// move the block to be immediately before the PHI block, not
// immediately after PredTI.
- if (L->contains(PHIPred) && !L->contains(PN->getParent()))
+ if (L->contains(PHIPred) && !L->contains(PN->getParent())) {
+ BasicBlock *NewBB = PN->getIncomingBlock(i);
NewBB->moveBefore(PN->getParent());
+ }
// Splitting the edge can reduce the number of PHI entries we have.
e = PN->getNumIncomingValues();
- PHIPred = NewBB;
- i = PN->getBasicBlockIndex(PHIPred);
}
}
- Value *&Code = InsertedCode[PHIPred];
+ Value *&Code = InsertedCode[PN->getIncomingBlock(i)];
if (!Code) {
// Insert the code into the end of the predecessor block.
Instruction *InsertPt = (L->contains(OldLoc->getParent())) ?
- PHIPred->getTerminator() :
+ PN->getIncomingBlock(i)->getTerminator() :
OldLoc->getParent()->getTerminator();
Code = InsertCodeForBaseAtPosition(NewBase, PN->getType(),
Rewriter, InsertPt, L, LI);
Modified: llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp Sat Sep 5 21:26:10 2009
@@ -518,12 +518,7 @@
std::swap(TrueDest, FalseDest);
// Insert the new branch.
- BranchInst *BI = BranchInst::Create(TrueDest, FalseDest, BranchVal, InsertPt);
-
- // If either edge is critical, split it. This helps preserve LoopSimplify
- // form for enclosing loops.
- SplitCriticalEdge(BI, 0, this);
- SplitCriticalEdge(BI, 1, this);
+ BranchInst::Create(TrueDest, FalseDest, BranchVal, InsertPt);
}
/// UnswitchTrivialCondition - Given a loop that has a trivial unswitchable
@@ -580,11 +575,47 @@
for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i) {
BasicBlock *ExitBlock = ExitBlocks[i];
- SmallVector<BasicBlock *, 4> Preds(pred_begin(ExitBlock),
- pred_end(ExitBlock));
- SplitBlockPredecessors(ExitBlock, Preds.data(), Preds.size(),
- ".us-lcssa", this);
+ std::vector<BasicBlock*> Preds(pred_begin(ExitBlock), pred_end(ExitBlock));
+
+ for (unsigned j = 0, e = Preds.size(); j != e; ++j) {
+ BasicBlock* NewExitBlock = SplitEdge(Preds[j], ExitBlock, this);
+ BasicBlock* StartBlock = Preds[j];
+ BasicBlock* EndBlock;
+ if (NewExitBlock->getSinglePredecessor() == ExitBlock) {
+ EndBlock = NewExitBlock;
+ NewExitBlock = EndBlock->getSinglePredecessor();
+ } else {
+ EndBlock = ExitBlock;
+ }
+
+ std::set<PHINode*> InsertedPHIs;
+ PHINode* OldLCSSA = 0;
+ for (BasicBlock::iterator I = EndBlock->begin();
+ (OldLCSSA = dyn_cast<PHINode>(I)); ++I) {
+ Value* OldValue = OldLCSSA->getIncomingValueForBlock(NewExitBlock);
+ PHINode* NewLCSSA = PHINode::Create(OldLCSSA->getType(),
+ OldLCSSA->getName() + ".us-lcssa",
+ NewExitBlock->getTerminator());
+ NewLCSSA->addIncoming(OldValue, StartBlock);
+ OldLCSSA->setIncomingValue(OldLCSSA->getBasicBlockIndex(NewExitBlock),
+ NewLCSSA);
+ InsertedPHIs.insert(NewLCSSA);
+ }
+
+ BasicBlock::iterator InsertPt = EndBlock->getFirstNonPHI();
+ for (BasicBlock::iterator I = NewExitBlock->begin();
+ (OldLCSSA = dyn_cast<PHINode>(I)) && InsertedPHIs.count(OldLCSSA) == 0;
+ ++I) {
+ PHINode *NewLCSSA = PHINode::Create(OldLCSSA->getType(),
+ OldLCSSA->getName() + ".us-lcssa",
+ InsertPt);
+ OldLCSSA->replaceAllUsesWith(NewLCSSA);
+ NewLCSSA->addIncoming(OldLCSSA, NewExitBlock);
+ }
+
+ }
}
+
}
/// UnswitchNontrivialCondition - We determined that the loop is profitable
@@ -914,29 +945,27 @@
// FIXME: This is a hack. We need to keep the successor around
// and hooked up so as to preserve the loop structure, because
// trying to update it is complicated. So instead we preserve the
- // loop structure and put the block on a dead code path.
- BasicBlock *Switch = SI->getParent();
- SplitEdge(Switch, SI->getSuccessor(i), this);
- // Compute the successors instead of relying on the return value
- // of SplitEdge, since it may have split the switch successor
- // after PHI nodes.
- BasicBlock *NewSISucc = SI->getSuccessor(i);
- BasicBlock *OldSISucc = *succ_begin(NewSISucc);
- // Create an "unreachable" destination.
- BasicBlock *Abort = BasicBlock::Create(Context, "us-unreachable",
- Switch->getParent(),
- OldSISucc);
- new UnreachableInst(Context, Abort);
- // Force the new case destination to branch to the "unreachable"
- // block while maintaining a (dead) CFG edge to the old block.
- NewSISucc->getTerminator()->eraseFromParent();
- BranchInst::Create(Abort, OldSISucc,
- ConstantInt::getTrue(Context), NewSISucc);
- // Release the PHI operands for this edge.
- for (BasicBlock::iterator II = NewSISucc->begin();
- PHINode *PN = dyn_cast<PHINode>(II); ++II)
- PN->setIncomingValue(PN->getBasicBlockIndex(Switch),
- UndefValue::get(PN->getType()));
+ // loop structure and put the block on an dead code path.
+
+ BasicBlock *SISucc = SI->getSuccessor(i);
+ BasicBlock* Old = SI->getParent();
+ BasicBlock* Split = SplitBlock(Old, SI, this);
+
+ Instruction* OldTerm = Old->getTerminator();
+ BranchInst::Create(Split, SISucc,
+ ConstantInt::getTrue(Context), OldTerm);
+
+ LPM->deleteSimpleAnalysisValue(Old->getTerminator(), L);
+ Old->getTerminator()->eraseFromParent();
+
+ PHINode *PN;
+ for (BasicBlock::iterator II = SISucc->begin();
+ (PN = dyn_cast<PHINode>(II)); ++II) {
+ Value *InVal = PN->removeIncomingValue(Split, false);
+ PN->addIncoming(InVal, Old);
+ }
+
+ SI->removeCase(i);
break;
}
}
Modified: llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/BasicBlockUtils.cpp Sat Sep 5 21:26:10 2009
@@ -24,7 +24,6 @@
#include "llvm/Analysis/Dominators.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Transforms/Scalar.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/ValueHandle.h"
#include <algorithm>
@@ -320,8 +319,7 @@
++SplitIt;
BasicBlock *New = Old->splitBasicBlock(SplitIt, Old->getName()+".split");
- // The new block lives in whichever loop the old one did. This preserves
- // LCSSA as well, because we force the split point to be after any PHI nodes.
+ // The new block lives in whichever loop the old one did.
if (LoopInfo* LI = P->getAnalysisIfAvailable<LoopInfo>())
if (Loop *L = LI->getLoopFor(Old))
L->addBasicBlockToLoop(New, LI->getBase());
@@ -355,12 +353,8 @@
/// Preds array, which has NumPreds elements in it. The new block is given a
/// suffix of 'Suffix'.
///
-/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree,
-/// DominanceFrontier, LoopInfo, and LCCSA but no other analyses.
-/// In particular, it does not preserve LoopSimplify (because it's
-/// complicated to handle the case where one of the edges being split
-/// is an exit of a loop with other exits).
-///
+/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree and
+/// DominanceFrontier, but no other analyses.
BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
BasicBlock *const *Preds,
unsigned NumPreds, const char *Suffix,
@@ -372,44 +366,19 @@
// The new block unconditionally branches to the old block.
BranchInst *BI = BranchInst::Create(BB, NewBB);
- LoopInfo *LI = P ? P->getAnalysisIfAvailable<LoopInfo>() : 0;
- Loop *L = LI ? LI->getLoopFor(BB) : 0;
- bool PreserveLCSSA = P->mustPreserveAnalysisID(LCSSAID);
-
// Move the edges from Preds to point to NewBB instead of BB.
- // While here, if we need to preserve loop analyses, collect
- // some information about how this split will affect loops.
- bool HasLoopExit = false;
- bool IsLoopEntry = !!L;
- bool SplitMakesNewLoopHeader = false;
- for (unsigned i = 0; i != NumPreds; ++i) {
+ for (unsigned i = 0; i != NumPreds; ++i)
Preds[i]->getTerminator()->replaceUsesOfWith(BB, NewBB);
-
- if (LI) {
- // If we need to preserve LCSSA, determine if any of
- // the preds is a loop exit.
- if (PreserveLCSSA)
- if (Loop *PL = LI->getLoopFor(Preds[i]))
- if (!PL->contains(BB))
- HasLoopExit = true;
- // If we need to preserve LoopInfo, note whether any of the
- // preds crosses an interesting loop boundary.
- if (L) {
- if (L->contains(Preds[i]))
- IsLoopEntry = false;
- else
- SplitMakesNewLoopHeader = true;
- }
- }
- }
-
+
// Update dominator tree and dominator frontier if available.
DominatorTree *DT = P ? P->getAnalysisIfAvailable<DominatorTree>() : 0;
if (DT)
DT->splitBlock(NewBB);
if (DominanceFrontier *DF = P ? P->getAnalysisIfAvailable<DominanceFrontier>():0)
DF->splitBlock(NewBB);
-
+ AliasAnalysis *AA = P ? P->getAnalysisIfAvailable<AliasAnalysis>() : 0;
+
+
// Insert a new PHI node into NewBB for every PHI node in BB and that new PHI
// node becomes an incoming value for BB's phi node. However, if the Preds
// list is empty, we need to insert dummy entries into the PHI nodes in BB to
@@ -420,42 +389,20 @@
cast<PHINode>(I)->addIncoming(UndefValue::get(I->getType()), NewBB);
return NewBB;
}
-
- AliasAnalysis *AA = P ? P->getAnalysisIfAvailable<AliasAnalysis>() : 0;
-
- if (L) {
- if (IsLoopEntry) {
- if (Loop *PredLoop = LI->getLoopFor(Preds[0])) {
- // Add the new block to the nearest enclosing loop (and not an
- // adjacent loop).
- while (PredLoop && !PredLoop->contains(BB))
- PredLoop = PredLoop->getParentLoop();
- if (PredLoop)
- PredLoop->addBasicBlockToLoop(NewBB, LI->getBase());
- }
- } else {
- L->addBasicBlockToLoop(NewBB, LI->getBase());
- if (SplitMakesNewLoopHeader)
- L->moveToHeader(NewBB);
- }
- }
// Otherwise, create a new PHI node in NewBB for each PHI node in BB.
for (BasicBlock::iterator I = BB->begin(); isa<PHINode>(I); ) {
PHINode *PN = cast<PHINode>(I++);
// Check to see if all of the values coming in are the same. If so, we
- // don't need to create a new PHI node, unless it's needed for LCSSA.
- Value *InVal = 0;
- if (!HasLoopExit) {
- InVal = PN->getIncomingValueForBlock(Preds[0]);
- for (unsigned i = 1; i != NumPreds; ++i)
- if (InVal != PN->getIncomingValueForBlock(Preds[i])) {
- InVal = 0;
- break;
- }
- }
-
+ // don't need to create a new PHI node.
+ Value *InVal = PN->getIncomingValueForBlock(Preds[0]);
+ for (unsigned i = 1; i != NumPreds; ++i)
+ if (InVal != PN->getIncomingValueForBlock(Preds[i])) {
+ InVal = 0;
+ break;
+ }
+
if (InVal) {
// If all incoming values for the new PHI would be the same, just don't
// make a new PHI. Instead, just remove the incoming values from the old
@@ -480,6 +427,13 @@
// Add an incoming value to the PHI node in the loop for the preheader
// edge.
PN->addIncoming(InVal, NewBB);
+
+ // Check to see if we can eliminate this phi node.
+ if (Value *V = PN->hasConstantValue(DT)) {
+ PN->replaceAllUsesWith(V);
+ if (AA) AA->deleteValue(PN);
+ PN->eraseFromParent();
+ }
}
return NewBB;
Modified: llvm/trunk/lib/Transforms/Utils/BreakCriticalEdges.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/BreakCriticalEdges.cpp?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/BreakCriticalEdges.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/BreakCriticalEdges.cpp Sat Sep 5 21:26:10 2009
@@ -122,9 +122,9 @@
/// false otherwise. This ensures that all edges to that dest go to one block
/// instead of each going to a different block.
//
-BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum,
- Pass *P, bool MergeIdenticalEdges) {
- if (!isCriticalEdge(TI, SuccNum, MergeIdenticalEdges)) return 0;
+bool llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P,
+ bool MergeIdenticalEdges) {
+ if (!isCriticalEdge(TI, SuccNum, MergeIdenticalEdges)) return false;
BasicBlock *TIBB = TI->getParent();
BasicBlock *DestBB = TI->getSuccessor(SuccNum);
@@ -172,7 +172,7 @@
// If we don't have a pass object, we can't update anything...
- if (P == 0) return NewBB;
+ if (P == 0) return true;
// Now update analysis information. Since the only predecessor of NewBB is
// the TIBB, TIBB clearly dominates NewBB. TIBB usually doesn't dominate
@@ -254,9 +254,9 @@
// Update LoopInfo if it is around.
if (LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>()) {
- if (Loop *TIL = LI->getLoopFor(TIBB)) {
- // If one or the other blocks were not in a loop, the new block is not
- // either, and thus LI doesn't need to be updated.
+ // If one or the other blocks were not in a loop, the new block is not
+ // either, and thus LI doesn't need to be updated.
+ if (Loop *TIL = LI->getLoopFor(TIBB))
if (Loop *DestLoop = LI->getLoopFor(DestBB)) {
if (TIL == DestLoop) {
// Both in the same loop, the NewBB joins loop.
@@ -278,55 +278,6 @@
P->addBasicBlockToLoop(NewBB, LI->getBase());
}
}
- // If TIBB is in a loop and DestBB is outside of that loop, split the
- // other exit blocks of the loop that also have predecessors outside
- // the loop, to maintain a LoopSimplify guarantee.
- if (!TIL->contains(DestBB) &&
- P->mustPreserveAnalysisID(LoopSimplifyID)) {
- // For each unique exit block...
- SmallVector<BasicBlock *, 4> ExitBlocks;
- TIL->getExitBlocks(ExitBlocks);
- for (unsigned i = 0, e = ExitBlocks.size(); i != e; ++i) {
- // Collect all the preds that are inside the loop, and note
- // whether there are any preds outside the loop.
- SmallVector<BasicBlock *, 4> Preds;
- bool AllPredsInLoop = false;
- BasicBlock *Exit = ExitBlocks[i];
- for (pred_iterator I = pred_begin(Exit), E = pred_end(Exit);
- I != E; ++I)
- if (TIL->contains(*I))
- Preds.push_back(*I);
- else
- AllPredsInLoop = true;
- // If there are any preds not in the loop, we'll need to split
- // the edges. The Preds.empty() check is needed because a block
- // may appear multiple times in the list. We can't use
- // getUniqueExitBlocks above because that depends on LoopSimplify
- // form, which we're in the process of restoring!
- if (Preds.empty() || !AllPredsInLoop) continue;
- BasicBlock *NewBB = SplitBlockPredecessors(Exit,
- Preds.data(), Preds.size(),
- "split", P);
- // Update LCSSA form. This is fairly simple in LoopSimplify form:
- // just move the existing LCSSA-mandated PHI nodes from the old exit
- // block to the new one.
- if (P->mustPreserveAnalysisID(LCSSAID))
- for (BasicBlock::iterator I = Exit->begin();
- PHINode *PN = dyn_cast<PHINode>(I); ++I)
- PN->moveBefore(NewBB->getTerminator());
- }
- }
- // LCSSA form was updated above for the case where LoopSimplify is
- // 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)) &&
- "SplitCriticalEdge doesn't know how to update LCCSA form "
- "without LoopSimplify!");
- }
-
}
-
- return NewBB;
+ return true;
}
Modified: llvm/trunk/lib/Transforms/Utils/LCSSA.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LCSSA.cpp?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LCSSA.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LCSSA.cpp Sat Sep 5 21:26:10 2009
@@ -58,7 +58,6 @@
DominatorTree *DT;
std::vector<BasicBlock*> LoopBlocks;
PredIteratorCache PredCache;
- Loop *L;
virtual bool runOnLoop(Loop *L, LPPassManager &LPM);
@@ -73,9 +72,9 @@
AU.setPreservesCFG();
AU.addRequiredID(LoopSimplifyID);
AU.addPreservedID(LoopSimplifyID);
- AU.addRequiredTransitive<LoopInfo>();
+ AU.addRequired<LoopInfo>();
AU.addPreserved<LoopInfo>();
- AU.addRequiredTransitive<DominatorTree>();
+ AU.addRequired<DominatorTree>();
AU.addPreserved<ScalarEvolution>();
AU.addPreserved<DominatorTree>();
@@ -87,17 +86,6 @@
AU.addPreserved<DominanceFrontier>();
}
private:
-
- /// verifyAnalysis() - Verify loop nest.
- virtual void verifyAnalysis() const {
-#ifndef NDEBUG
- // Sanity check: Check basic loop invariants.
- L->verifyLoop();
- // Check the special guarantees that LCSSA makes.
- assert(L->isLCSSAForm());
-#endif
- }
-
void getLoopValuesUsedOutsideLoop(Loop *L,
SetVector<Instruction*> &AffectedValues,
const SmallVector<BasicBlock*, 8>& exitBlocks);
@@ -119,8 +107,7 @@
const PassInfo *const llvm::LCSSAID = &X;
/// runOnFunction - Process all loops in the function, inner-most out.
-bool LCSSA::runOnLoop(Loop *l, LPPassManager &LPM) {
- L = l;
+bool LCSSA::runOnLoop(Loop *L, LPPassManager &LPM) {
PredCache.clear();
LI = &LPM.getAnalysis<LoopInfo>();
Modified: llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp?rev=81101&r1=81100&r2=81101&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp Sat Sep 5 21:26:10 2009
@@ -69,8 +69,8 @@
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
// We need loop information to identify the loops...
- AU.addRequiredTransitive<LoopInfo>();
- AU.addRequiredTransitive<DominatorTree>();
+ AU.addRequired<LoopInfo>();
+ AU.addRequired<DominatorTree>();
AU.addPreserved<LoopInfo>();
AU.addPreserved<DominatorTree>();
@@ -83,13 +83,9 @@
void verifyAnalysis() const {
#ifndef NDEBUG
LoopInfo *NLI = &getAnalysis<LoopInfo>();
- for (LoopInfo::iterator I = NLI->begin(), E = NLI->end(); I != E; ++I) {
- // Sanity check: Check basic loop invariants.
+ for (LoopInfo::iterator I = NLI->begin(), E = NLI->end(); I != E; ++I)
(*I)->verifyLoop();
- // Check the special guarantees that LoopSimplify makes.
- assert((*I)->isLoopSimplifyForm());
- }
-#endif
+#endif
}
private:
@@ -350,6 +346,15 @@
BasicBlock *NewBB =
SplitBlockPredecessors(Header, &OutsideBlocks[0], OutsideBlocks.size(),
".preheader", this);
+
+
+ //===--------------------------------------------------------------------===//
+ // Update analysis results now that we have performed the transformation
+ //
+
+ // We know that we have loop information to update... update it now.
+ if (Loop *Parent = L->getParentLoop())
+ Parent->addBasicBlockToLoop(NewBB, LI->getBase());
// Make sure that NewBB is put someplace intelligent, which doesn't mess up
// code layout too horribly.
@@ -372,6 +377,17 @@
LoopBlocks.size(), ".loopexit",
this);
+ // Update Loop Information - we know that the new block will be in whichever
+ // loop the Exit block is in. Note that it may not be in that immediate loop,
+ // if the successor is some other loop header. In that case, we continue
+ // walking up the loop tree to find a loop that contains both the successor
+ // block and the predecessor block.
+ Loop *SuccLoop = LI->getLoopFor(Exit);
+ while (SuccLoop && !SuccLoop->contains(L->getHeader()))
+ SuccLoop = SuccLoop->getParentLoop();
+ if (SuccLoop)
+ SuccLoop->addBasicBlockToLoop(NewBB, LI->getBase());
+
return NewBB;
}
@@ -505,6 +521,10 @@
else
LI->changeTopLevelLoop(L, NewOuter);
+ // This block is going to be our new header block: add it to this loop and all
+ // parent loops.
+ NewOuter->addBasicBlockToLoop(NewBB, LI->getBase());
+
// L is now a subloop of our outer loop.
NewOuter->addChildLoop(L);
@@ -512,10 +532,6 @@
I != E; ++I)
NewOuter->addBlockEntry(*I);
- // Now reset the header in L, which had been moved by
- // SplitBlockPredecessors for the outer loop.
- L->moveToHeader(Header);
-
// Determine which blocks should stay in L and which should be moved out to
// the Outer loop now.
std::set<BasicBlock*> BlocksInL;
Added: llvm/trunk/test/Transforms/LoopUnswitch/2009-09-05-DomAssert.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopUnswitch/2009-09-05-DomAssert.ll?rev=81101&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopUnswitch/2009-09-05-DomAssert.ll (added)
+++ llvm/trunk/test/Transforms/LoopUnswitch/2009-09-05-DomAssert.ll Sat Sep 5 21:26:10 2009
@@ -0,0 +1,52 @@
+; RUN: llvm-as < %s | opt -loop-unswitch -disable-output
+; rdar://7197574
+
+target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:64:64-v128:128:128-a0:0:32"
+target triple = "thumbv7-apple-darwin9"
+ %struct.frame = type { i16*, i16*, i16* }
+
+declare arm_apcscc i32 @ercCollect8PredBlocks(i32* nocapture, i32, i32, i32* nocapture, i32, i32, i32, i8 zeroext) nounwind
+
+define arm_apcscc void @concealBlocks(i32 %lastColumn, i32 %lastRow, i32 %comp, %struct.frame* nocapture %recfr, i32 %picSizeX, i32* nocapture %condition) nounwind {
+entry:
+ br i1 undef, label %bb.nph12, label %return
+
+bb28: ; preds = %bb.nph12
+ unreachable
+
+bb42: ; preds = %bb.nph12
+ br label %bb43
+
+bb43: ; preds = %bb61, %bb42
+ %0 = call arm_apcscc i32 @ercCollect8PredBlocks(i32* undef, i32 undef, i32 0, i32* %condition, i32 %lastRow, i32 %lastColumn, i32 undef, i8 zeroext 1) nounwind ; <i32> [#uses=0]
+ switch i32 %comp, label %bb58 [
+ i32 0, label %bb52
+ i32 1, label %bb54
+ i32 2, label %bb56
+ ]
+
+bb52: ; preds = %bb43
+ br label %bb58
+
+bb54: ; preds = %bb43
+ br label %bb58
+
+bb56: ; preds = %bb43
+ unreachable
+
+bb58: ; preds = %bb54, %bb52, %bb43
+ br i1 %1, label %bb59, label %bb61
+
+bb59: ; preds = %bb58
+ br label %bb61
+
+bb61: ; preds = %bb59, %bb58
+ br label %bb43
+
+bb.nph12: ; preds = %entry
+ %1 = icmp eq i32 %comp, 0 ; <i1> [#uses=1]
+ br i1 undef, label %bb28, label %bb42
+
+return: ; preds = %entry
+ ret void
+}
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