summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--llvm/include/llvm/Analysis/LoopInfo.h30
-rw-r--r--llvm/lib/Analysis/LoopInfo.cpp6
-rw-r--r--llvm/lib/Analysis/LoopPass.cpp21
-rw-r--r--llvm/lib/Transforms/IPO/LoopExtractor.cpp4
-rw-r--r--llvm/lib/Transforms/Scalar/LoopDeletion.cpp2
-rw-r--r--llvm/lib/Transforms/Utils/LoopUnroll.cpp4
-rw-r--r--llvm/test/Transforms/LoopUnroll/unloop.ll2
7 files changed, 36 insertions, 33 deletions
diff --git a/llvm/include/llvm/Analysis/LoopInfo.h b/llvm/include/llvm/Analysis/LoopInfo.h
index c219bd85a48..a2bd6574e61 100644
--- a/llvm/include/llvm/Analysis/LoopInfo.h
+++ b/llvm/include/llvm/Analysis/LoopInfo.h
@@ -73,9 +73,8 @@ class LoopBase {
SmallPtrSet<const BlockT*, 8> DenseBlockSet;
- /// Indicator that this loops has been "unlooped", so there's no loop here
- /// anymore.
- bool IsUnloop = false;
+ /// Indicator that this loop is no longer a valid loop.
+ bool IsInvalid = false;
LoopBase(const LoopBase<BlockT, LoopT> &) = delete;
const LoopBase<BlockT, LoopT>&
@@ -154,12 +153,11 @@ public:
return Blocks.size();
}
- /// Mark this loop as having been unlooped - the last backedge was removed and
- /// we no longer have a loop.
- void markUnlooped() { IsUnloop = true; }
+ /// Invalidate the loop, indicating that it is no longer a loop.
+ void invalidate() { IsInvalid = true; }
- /// Return true if this no longer represents a loop.
- bool isUnloop() const { return IsUnloop; }
+ /// Return true if this loop is no longer valid.
+ bool isInvalid() { return IsInvalid; }
/// isLoopExiting - True if terminator in the block can branch to another
/// block that is outside of the current loop.
@@ -507,6 +505,8 @@ class LoopInfoBase {
// BBMap - Mapping of basic blocks to the inner most loop they occur in
DenseMap<const BlockT *, LoopT *> BBMap;
std::vector<LoopT *> TopLevelLoops;
+ std::vector<LoopT *> RemovedLoops;
+
friend class LoopBase<BlockT, LoopT>;
friend class LoopInfo;
@@ -538,6 +538,9 @@ public:
for (auto *L : TopLevelLoops)
delete L;
TopLevelLoops.clear();
+ for (auto *L : RemovedLoops)
+ delete L;
+ RemovedLoops.clear();
}
/// iterator/begin/end - The interface to the top-level loops in the current
@@ -670,12 +673,11 @@ public:
// Most of the public interface is provided via LoopInfoBase.
- /// updateUnloop - Update LoopInfo after removing the last backedge from a
- /// loop--now the "unloop". This updates the loop forest and parent loops for
- /// each block so that Unloop is no longer referenced, but does not actually
- /// delete the Unloop object. Generally, the loop pass manager should manage
- /// deleting the Unloop.
- void updateUnloop(Loop *Unloop);
+ /// Update LoopInfo after removing the last backedge from a loop. This updates
+ /// the loop forest and parent loops for each block so that \c L is no longer
+ /// referenced, but does not actually delete \c L immediately. The pointer
+ /// will remain valid until this LoopInfo's memory is released.
+ void markAsRemoved(Loop *L);
/// replacementPreservesLCSSAForm - Returns true if replacing From with To
/// everywhere is guaranteed to preserve LCSSA form.
diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp
index 9ab9eead584..0c725fcadff 100644
--- a/llvm/lib/Analysis/LoopInfo.cpp
+++ b/llvm/lib/Analysis/LoopInfo.cpp
@@ -637,8 +637,10 @@ LoopInfo::LoopInfo(const DominatorTreeBase<BasicBlock> &DomTree) {
analyze(DomTree);
}
-void LoopInfo::updateUnloop(Loop *Unloop) {
- Unloop->markUnlooped();
+void LoopInfo::markAsRemoved(Loop *Unloop) {
+ assert(!Unloop->isInvalid() && "Loop has already been removed");
+ Unloop->invalidate();
+ RemovedLoops.push_back(Unloop);
// First handle the special case of no parent loop to simplify the algorithm.
if (!Unloop->getParentLoop()) {
diff --git a/llvm/lib/Analysis/LoopPass.cpp b/llvm/lib/Analysis/LoopPass.cpp
index e24a9e46fc1..8163231c332 100644
--- a/llvm/lib/Analysis/LoopPass.cpp
+++ b/llvm/lib/Analysis/LoopPass.cpp
@@ -178,8 +178,9 @@ bool LPPassManager::runOnFunction(Function &F) {
// Walk Loops
while (!LQ.empty()) {
-
+ bool LoopWasDeleted = false;
CurrentLoop = LQ.back();
+
// Run all passes on the current Loop.
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
LoopPass *P = getContainedPass(Index);
@@ -196,15 +197,15 @@ bool LPPassManager::runOnFunction(Function &F) {
Changed |= P->runOnLoop(CurrentLoop, *this);
}
+ LoopWasDeleted = CurrentLoop->isInvalid();
if (Changed)
dumpPassInfo(P, MODIFICATION_MSG, ON_LOOP_MSG,
- CurrentLoop->isUnloop()
- ? "<deleted>"
- : CurrentLoop->getHeader()->getName());
+ LoopWasDeleted ? "<deleted>"
+ : CurrentLoop->getHeader()->getName());
dumpPreservedSet(P);
- if (CurrentLoop->isUnloop()) {
+ if (LoopWasDeleted) {
// Notify passes that the loop is being deleted.
deleteSimpleAnalysisLoop(CurrentLoop);
} else {
@@ -226,12 +227,11 @@ bool LPPassManager::runOnFunction(Function &F) {
removeNotPreservedAnalysis(P);
recordAvailableAnalysis(P);
- removeDeadPasses(P, CurrentLoop->isUnloop()
- ? "<deleted>"
- : CurrentLoop->getHeader()->getName(),
+ removeDeadPasses(P, LoopWasDeleted ? "<deleted>"
+ : CurrentLoop->getHeader()->getName(),
ON_LOOP_MSG);
- if (CurrentLoop->isUnloop())
+ if (LoopWasDeleted)
// Do not run other passes on this loop.
break;
}
@@ -239,12 +239,11 @@ bool LPPassManager::runOnFunction(Function &F) {
// If the loop was deleted, release all the loop passes. This frees up
// some memory, and avoids trouble with the pass manager trying to call
// verifyAnalysis on them.
- if (CurrentLoop->isUnloop()) {
+ if (LoopWasDeleted) {
for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
Pass *P = getContainedPass(Index);
freePass(P, "<deleted>", ON_LOOP_MSG);
}
- delete CurrentLoop;
}
// Pop the loop from queue after running all passes.
diff --git a/llvm/lib/Transforms/IPO/LoopExtractor.cpp b/llvm/lib/Transforms/IPO/LoopExtractor.cpp
index 8e4ad642ddd..3c6a7bb7a17 100644
--- a/llvm/lib/Transforms/IPO/LoopExtractor.cpp
+++ b/llvm/lib/Transforms/IPO/LoopExtractor.cpp
@@ -38,7 +38,7 @@ namespace {
static char ID; // Pass identification, replacement for typeid
unsigned NumLoops;
- explicit LoopExtractor(unsigned numLoops = ~0)
+ explicit LoopExtractor(unsigned numLoops = ~0)
: LoopPass(ID), NumLoops(numLoops) {
initializeLoopExtractorPass(*PassRegistry::getPassRegistry());
}
@@ -143,7 +143,7 @@ bool LoopExtractor::runOnLoop(Loop *L, LPPassManager &) {
Changed = true;
// After extraction, the loop is replaced by a function call, so
// we shouldn't try to run any more loop passes on it.
- LI.updateUnloop(L);
+ LI.markAsRemoved(L);
}
++NumExtracted;
}
diff --git a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
index bc00ff3f3a4..7b1940b48c3 100644
--- a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp
@@ -245,7 +245,7 @@ bool LoopDeletion::runOnLoop(Loop *L, LPPassManager &) {
loopInfo.removeBlock(BB);
// The last step is to update LoopInfo now that we've eliminated this loop.
- loopInfo.updateUnloop(L);
+ loopInfo.markAsRemoved(L);
Changed = true;
++NumDeleted;
diff --git a/llvm/lib/Transforms/Utils/LoopUnroll.cpp b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
index 2499b88741f..eea9237ba80 100644
--- a/llvm/lib/Transforms/Utils/LoopUnroll.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUnroll.cpp
@@ -528,7 +528,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount,
Loop *OuterL = L->getParentLoop();
// Update LoopInfo if the loop is completely removed.
if (CompletelyUnroll)
- LI->updateUnloop(L);;
+ LI->markAsRemoved(L);
// If we have a pass and a DominatorTree we should re-simplify impacted loops
// to ensure subsequent analyses can rely on this form. We want to simplify
@@ -542,7 +542,7 @@ bool llvm::UnrollLoop(Loop *L, unsigned Count, unsigned TripCount,
// LCSSA must be performed on the outermost affected loop. The unrolled
// loop's last loop latch is guaranteed to be in the outermost loop after
- // LoopInfo's been updated by updateUnloop.
+ // LoopInfo's been updated by markAsRemoved.
Loop *LatchLoop = LI->getLoopFor(Latches.back());
if (!OuterL->contains(LatchLoop))
while (OuterL->getParentLoop() != LatchLoop)
diff --git a/llvm/test/Transforms/LoopUnroll/unloop.ll b/llvm/test/Transforms/LoopUnroll/unloop.ll
index b98b4a3fffb..720b2ae1bdb 100644
--- a/llvm/test/Transforms/LoopUnroll/unloop.ll
+++ b/llvm/test/Transforms/LoopUnroll/unloop.ll
@@ -1,6 +1,6 @@
; RUN: opt < %s -S -loop-unroll -verify-loop-info | FileCheck %s
;
-; Unit tests for LoopInfo::updateUnloop.
+; Unit tests for LoopInfo::markAsRemoved.
declare i1 @check() nounwind
OpenPOWER on IntegriCloud