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[NFC][SimplifyCFG] removeEmptyCleanup(): use BasicBlock::phis()

This commit is contained in:
Roman Lebedev 2021-05-19 12:19:45 +03:00
parent c1eaa1168a
commit a0be081646
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GPG Key ID: 083C3EBB4A1689E0
1 changed files with 11 additions and 18 deletions
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29
llvm/lib/Transforms/Utils/SimplifyCFG.cpp
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@ -4468,12 +4468,8 @@ static bool removeEmptyCleanup(CleanupReturnInst *RI, DomTreeUpdater *DTU) {
if (UnwindDest) { if (UnwindDest) {
// First, go through the PHI nodes in UnwindDest and update any nodes that // First, go through the PHI nodes in UnwindDest and update any nodes that
// reference the block we are removing // reference the block we are removing
for (BasicBlock::iterator I = UnwindDest->begin(), for (PHINode &DestPN : UnwindDest->phis()) {
IE = DestEHPad->getIterator(); int Idx = DestPN.getBasicBlockIndex(BB);
I != IE; ++I) {
PHINode *DestPN = cast<PHINode>(I);
int Idx = DestPN->getBasicBlockIndex(BB);
// Since BB unwinds to UnwindDest, it has to be in the PHI node. // Since BB unwinds to UnwindDest, it has to be in the PHI node.
assert(Idx != -1); assert(Idx != -1);
// This PHI node has an incoming value that corresponds to a control // This PHI node has an incoming value that corresponds to a control
@ -4487,11 +4483,11 @@ static bool removeEmptyCleanup(CleanupReturnInst *RI, DomTreeUpdater *DTU) {
// predecessors must unwind to these blocks, and since no instruction // predecessors must unwind to these blocks, and since no instruction
// can have multiple unwind destinations, there will be no overlap in // can have multiple unwind destinations, there will be no overlap in
// incoming blocks between SrcPN and DestPN. // incoming blocks between SrcPN and DestPN.
Value *SrcVal = DestPN->getIncomingValue(Idx); Value *SrcVal = DestPN.getIncomingValue(Idx);
PHINode *SrcPN = dyn_cast<PHINode>(SrcVal); PHINode *SrcPN = dyn_cast<PHINode>(SrcVal);
// Remove the entry for the block we are deleting. // Remove the entry for the block we are deleting.
DestPN->removeIncomingValue(Idx, false); DestPN.removeIncomingValue(Idx, false);
if (SrcPN && SrcPN->getParent() == BB) { if (SrcPN && SrcPN->getParent() == BB) {
// If the incoming value was a PHI node in the cleanup pad we are // If the incoming value was a PHI node in the cleanup pad we are
@ -4499,28 +4495,25 @@ static bool removeEmptyCleanup(CleanupReturnInst *RI, DomTreeUpdater *DTU) {
// DestPN. // DestPN.
for (unsigned SrcIdx = 0, SrcE = SrcPN->getNumIncomingValues(); for (unsigned SrcIdx = 0, SrcE = SrcPN->getNumIncomingValues();
SrcIdx != SrcE; ++SrcIdx) { SrcIdx != SrcE; ++SrcIdx) {
DestPN->addIncoming(SrcPN->getIncomingValue(SrcIdx), DestPN.addIncoming(SrcPN->getIncomingValue(SrcIdx),
SrcPN->getIncomingBlock(SrcIdx)); SrcPN->getIncomingBlock(SrcIdx));
} }
} else { } else {
// Otherwise, the incoming value came from above BB and // Otherwise, the incoming value came from above BB and
// so we can just reuse it. We must associate all of BB's // so we can just reuse it. We must associate all of BB's
// predecessors with this value. // predecessors with this value.
for (auto *pred : predecessors(BB)) { for (auto *pred : predecessors(BB)) {
DestPN->addIncoming(SrcVal, pred); DestPN.addIncoming(SrcVal, pred);
} }
} }
} }
// Sink any remaining PHI nodes directly into UnwindDest. // Sink any remaining PHI nodes directly into UnwindDest.
Instruction *InsertPt = DestEHPad; Instruction *InsertPt = DestEHPad;
for (BasicBlock::iterator I = BB->begin(), for (PHINode &PN : BB->phis()) {
IE = BB->getFirstNonPHI()->getIterator();
I != IE;) {
// The iterator must be incremented here because the instructions are // The iterator must be incremented here because the instructions are
// being moved to another block. // being moved to another block.
PHINode *PN = cast<PHINode>(I++); if (PN.use_empty() || !PN.isUsedOutsideOfBlock(BB))
if (PN->use_empty() || !PN->isUsedOutsideOfBlock(BB))
// If the PHI node has no uses or all of its uses are in this basic // If the PHI node has no uses or all of its uses are in this basic
// block (meaning they are debug or lifetime intrinsics), just leave // block (meaning they are debug or lifetime intrinsics), just leave
// it. It will be erased when we erase BB below. // it. It will be erased when we erase BB below.
@ -4532,8 +4525,8 @@ static bool removeEmptyCleanup(CleanupReturnInst *RI, DomTreeUpdater *DTU) {
// BB. In this case, the PHI value must reference itself. // BB. In this case, the PHI value must reference itself.
for (auto *pred : predecessors(UnwindDest)) for (auto *pred : predecessors(UnwindDest))
if (pred != BB) if (pred != BB)
PN->addIncoming(PN, pred); PN.addIncoming(&PN, pred);
PN->moveBefore(InsertPt); PN.moveBefore(InsertPt);
} }
} }