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Diffstat (limited to 'llvm/lib/Transforms/Utils/BasicBlockUtils.cpp')
-rw-r--r--llvm/lib/Transforms/Utils/BasicBlockUtils.cpp109
1 files changed, 88 insertions, 21 deletions
diff --git a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
index 257a143..6bcd42c 100644
--- a/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/llvm/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -659,11 +659,31 @@ BasicBlock *llvm::splitBlockBefore(BasicBlock *Old, Instruction *SplitPt,
/// Update DominatorTree, LoopInfo, and LCCSA analysis information.
static void UpdateAnalysisInformation(BasicBlock *OldBB, BasicBlock *NewBB,
ArrayRef<BasicBlock *> Preds,
- DominatorTree *DT, LoopInfo *LI,
- MemorySSAUpdater *MSSAU,
+ DomTreeUpdater *DTU, DominatorTree *DT,
+ LoopInfo *LI, MemorySSAUpdater *MSSAU,
bool PreserveLCSSA, bool &HasLoopExit) {
// Update dominator tree if available.
- if (DT) {
+ if (DTU) {
+ // Recalculation of DomTree is needed when updating a forward DomTree and
+ // the Entry BB is replaced.
+ if (NewBB == &NewBB->getParent()->getEntryBlock() && DTU->hasDomTree()) {
+ // The entry block was removed and there is no external interface for
+ // the dominator tree to be notified of this change. In this corner-case
+ // we recalculate the entire tree.
+ DTU->recalculate(*NewBB->getParent());
+ } else {
+ // Split block expects NewBB to have a non-empty set of predecessors.
+ SmallVector<DominatorTree::UpdateType, 8> Updates;
+ SmallSetVector<BasicBlock *, 8> UniquePreds(Preds.begin(), Preds.end());
+ Updates.push_back({DominatorTree::Insert, NewBB, OldBB});
+ Updates.reserve(Updates.size() + 2 * UniquePreds.size());
+ for (auto *UniquePred : UniquePreds) {
+ Updates.push_back({DominatorTree::Insert, UniquePred, NewBB});
+ Updates.push_back({DominatorTree::Delete, UniquePred, OldBB});
+ }
+ DTU->applyUpdates(Updates);
+ }
+ } else if (DT) {
if (OldBB == DT->getRootNode()->getBlock()) {
assert(NewBB == &NewBB->getParent()->getEntryBlock());
DT->setNewRoot(NewBB);
@@ -681,6 +701,8 @@ static void UpdateAnalysisInformation(BasicBlock *OldBB, BasicBlock *NewBB,
if (!LI)
return;
+ if (DTU && DTU->hasDomTree())
+ DT = &DTU->getDomTree();
assert(DT && "DT should be available to update LoopInfo!");
Loop *L = LI->getLoopFor(OldBB);
@@ -814,11 +836,17 @@ static void UpdatePHINodes(BasicBlock *OrigBB, BasicBlock *NewBB,
}
}
-BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
- ArrayRef<BasicBlock *> Preds,
- const char *Suffix, DominatorTree *DT,
- LoopInfo *LI, MemorySSAUpdater *MSSAU,
- bool PreserveLCSSA) {
+static void SplitLandingPadPredecessorsImpl(
+ BasicBlock *OrigBB, ArrayRef<BasicBlock *> Preds, const char *Suffix1,
+ const char *Suffix2, SmallVectorImpl<BasicBlock *> &NewBBs,
+ DomTreeUpdater *DTU, DominatorTree *DT, LoopInfo *LI,
+ MemorySSAUpdater *MSSAU, bool PreserveLCSSA);
+
+static BasicBlock *
+SplitBlockPredecessorsImpl(BasicBlock *BB, ArrayRef<BasicBlock *> Preds,
+ const char *Suffix, DomTreeUpdater *DTU,
+ DominatorTree *DT, LoopInfo *LI,
+ MemorySSAUpdater *MSSAU, bool PreserveLCSSA) {
// Do not attempt to split that which cannot be split.
if (!BB->canSplitPredecessors())
return nullptr;
@@ -829,8 +857,8 @@ BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
SmallVector<BasicBlock*, 2> NewBBs;
std::string NewName = std::string(Suffix) + ".split-lp";
- SplitLandingPadPredecessors(BB, Preds, Suffix, NewName.c_str(), NewBBs, DT,
- LI, MSSAU, PreserveLCSSA);
+ SplitLandingPadPredecessorsImpl(BB, Preds, Suffix, NewName.c_str(), NewBBs,
+ DTU, DT, LI, MSSAU, PreserveLCSSA);
return NewBBs[0];
}
@@ -882,7 +910,7 @@ BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
// Update DominatorTree, LoopInfo, and LCCSA analysis information.
bool HasLoopExit = false;
- UpdateAnalysisInformation(BB, NewBB, Preds, DT, LI, MSSAU, PreserveLCSSA,
+ UpdateAnalysisInformation(BB, NewBB, Preds, DTU, DT, LI, MSSAU, PreserveLCSSA,
HasLoopExit);
if (!Preds.empty()) {
@@ -902,13 +930,29 @@ BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
return NewBB;
}
-void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
- ArrayRef<BasicBlock *> Preds,
- const char *Suffix1, const char *Suffix2,
- SmallVectorImpl<BasicBlock *> &NewBBs,
- DominatorTree *DT, LoopInfo *LI,
- MemorySSAUpdater *MSSAU,
- bool PreserveLCSSA) {
+BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
+ ArrayRef<BasicBlock *> Preds,
+ const char *Suffix, DominatorTree *DT,
+ LoopInfo *LI, MemorySSAUpdater *MSSAU,
+ bool PreserveLCSSA) {
+ return SplitBlockPredecessorsImpl(BB, Preds, Suffix, /*DTU=*/nullptr, DT, LI,
+ MSSAU, PreserveLCSSA);
+}
+BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
+ ArrayRef<BasicBlock *> Preds,
+ const char *Suffix,
+ DomTreeUpdater *DTU, LoopInfo *LI,
+ MemorySSAUpdater *MSSAU,
+ bool PreserveLCSSA) {
+ return SplitBlockPredecessorsImpl(BB, Preds, Suffix, DTU,
+ /*DT=*/nullptr, LI, MSSAU, PreserveLCSSA);
+}
+
+static void SplitLandingPadPredecessorsImpl(
+ BasicBlock *OrigBB, ArrayRef<BasicBlock *> Preds, const char *Suffix1,
+ const char *Suffix2, SmallVectorImpl<BasicBlock *> &NewBBs,
+ DomTreeUpdater *DTU, DominatorTree *DT, LoopInfo *LI,
+ MemorySSAUpdater *MSSAU, bool PreserveLCSSA) {
assert(OrigBB->isLandingPad() && "Trying to split a non-landing pad!");
// Create a new basic block for OrigBB's predecessors listed in Preds. Insert
@@ -933,8 +977,8 @@ void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
}
bool HasLoopExit = false;
- UpdateAnalysisInformation(OrigBB, NewBB1, Preds, DT, LI, MSSAU, PreserveLCSSA,
- HasLoopExit);
+ UpdateAnalysisInformation(OrigBB, NewBB1, Preds, DTU, DT, LI, MSSAU,
+ PreserveLCSSA, HasLoopExit);
// Update the PHI nodes in OrigBB with the values coming from NewBB1.
UpdatePHINodes(OrigBB, NewBB1, Preds, BI1, HasLoopExit);
@@ -969,7 +1013,7 @@ void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
// Update DominatorTree, LoopInfo, and LCCSA analysis information.
HasLoopExit = false;
- UpdateAnalysisInformation(OrigBB, NewBB2, NewBB2Preds, DT, LI, MSSAU,
+ UpdateAnalysisInformation(OrigBB, NewBB2, NewBB2Preds, DTU, DT, LI, MSSAU,
PreserveLCSSA, HasLoopExit);
// Update the PHI nodes in OrigBB with the values coming from NewBB2.
@@ -1006,6 +1050,29 @@ void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
}
}
+void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
+ ArrayRef<BasicBlock *> Preds,
+ const char *Suffix1, const char *Suffix2,
+ SmallVectorImpl<BasicBlock *> &NewBBs,
+ DominatorTree *DT, LoopInfo *LI,
+ MemorySSAUpdater *MSSAU,
+ bool PreserveLCSSA) {
+ return SplitLandingPadPredecessorsImpl(
+ OrigBB, Preds, Suffix1, Suffix2, NewBBs,
+ /*DTU=*/nullptr, DT, LI, MSSAU, PreserveLCSSA);
+}
+void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
+ ArrayRef<BasicBlock *> Preds,
+ const char *Suffix1, const char *Suffix2,
+ SmallVectorImpl<BasicBlock *> &NewBBs,
+ DomTreeUpdater *DTU, LoopInfo *LI,
+ MemorySSAUpdater *MSSAU,
+ bool PreserveLCSSA) {
+ return SplitLandingPadPredecessorsImpl(OrigBB, Preds, Suffix1, Suffix2,
+ NewBBs, DTU, /*DT=*/nullptr, LI, MSSAU,
+ PreserveLCSSA);
+}
+
ReturnInst *llvm::FoldReturnIntoUncondBranch(ReturnInst *RI, BasicBlock *BB,
BasicBlock *Pred,
DomTreeUpdater *DTU) {
generated by cgit v1.1 at 2025-10-07 05:43:08 +0000