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Change indentation of a whole bunch of code, no real changes here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@18843 91177308-0d34-0410-b5e6-96231b3b80d8
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Chris Lattner
parent
387bc13575
commit
6b8efcd697
@ -305,9 +305,7 @@ bool ADCE::doADCE() {
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}
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});
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// Find the first postdominator of the entry node that is alive. Make it the
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// new entry node...
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//
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// All blocks being live is a common case, handle it specially.
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if (AliveBlocks.size() == Func->size()) { // No dead blocks?
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for (Function::iterator I = Func->begin(), E = Func->end(); I != E; ++I) {
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// Loop over all of the instructions in the function deleting instructions
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@ -319,123 +317,125 @@ bool ADCE::doADCE() {
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// unconditional branch), is not needed to make the decision of where to
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// go to, because all outgoing edges go to the same place. We must remove
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// the use of the condition (because it's probably dead), so we convert
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// the terminator to a conditional branch.
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// the terminator to an unconditional branch.
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//
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TerminatorInst *TI = I->getTerminator();
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if (!LiveSet.count(TI))
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convertToUnconditionalBranch(TI);
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}
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return MadeChanges;
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}
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// If the entry node is dead, insert a new entry node to eliminate the entry
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// node as a special case.
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//
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if (!AliveBlocks.count(&Func->front())) {
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BasicBlock *NewEntry = new BasicBlock();
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new BranchInst(&Func->front(), NewEntry);
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Func->getBasicBlockList().push_front(NewEntry);
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AliveBlocks.insert(NewEntry); // This block is always alive!
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LiveSet.insert(NewEntry->getTerminator()); // The branch is live
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}
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} else { // If there are some blocks dead...
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// If the entry node is dead, insert a new entry node to eliminate the entry
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// node as a special case.
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//
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if (!AliveBlocks.count(&Func->front())) {
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BasicBlock *NewEntry = new BasicBlock();
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new BranchInst(&Func->front(), NewEntry);
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Func->getBasicBlockList().push_front(NewEntry);
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AliveBlocks.insert(NewEntry); // This block is always alive!
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LiveSet.insert(NewEntry->getTerminator()); // The branch is live
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}
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// Loop over all of the alive blocks in the function. If any successor
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// blocks are not alive, we adjust the outgoing branches to branch to the
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// first live postdominator of the live block, adjusting any PHI nodes in
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// the block to reflect this.
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//
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for (Function::iterator I = Func->begin(), E = Func->end(); I != E; ++I)
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if (AliveBlocks.count(I)) {
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BasicBlock *BB = I;
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TerminatorInst *TI = BB->getTerminator();
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// Loop over all of the alive blocks in the function. If any successor
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// blocks are not alive, we adjust the outgoing branches to branch to the
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// first live postdominator of the live block, adjusting any PHI nodes in
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// the block to reflect this.
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//
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for (Function::iterator I = Func->begin(), E = Func->end(); I != E; ++I)
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if (AliveBlocks.count(I)) {
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BasicBlock *BB = I;
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TerminatorInst *TI = BB->getTerminator();
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// If the terminator instruction is alive, but the block it is contained
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// in IS alive, this means that this terminator is a conditional branch
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// on a condition that doesn't matter. Make it an unconditional branch
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// to ONE of the successors. This has the side effect of dropping a use
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// of the conditional value, which may also be dead.
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if (!LiveSet.count(TI))
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TI = convertToUnconditionalBranch(TI);
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// If the terminator instruction is alive, but the block it is contained
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// in IS alive, this means that this terminator is a conditional branch on
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// a condition that doesn't matter. Make it an unconditional branch to
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// ONE of the successors. This has the side effect of dropping a use of
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// the conditional value, which may also be dead.
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if (!LiveSet.count(TI))
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TI = convertToUnconditionalBranch(TI);
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// Loop over all of the successors, looking for ones that are not alive.
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// We cannot save the number of successors in the terminator instruction
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// here because we may remove them if we don't have a postdominator...
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//
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for (unsigned i = 0; i != TI->getNumSuccessors(); ++i)
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if (!AliveBlocks.count(TI->getSuccessor(i))) {
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// Scan up the postdominator tree, looking for the first
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// postdominator that is alive, and the last postdominator that is
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// dead...
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// Loop over all of the successors, looking for ones that are not alive.
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// We cannot save the number of successors in the terminator instruction
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// here because we may remove them if we don't have a postdominator...
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//
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for (unsigned i = 0; i != TI->getNumSuccessors(); ++i)
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if (!AliveBlocks.count(TI->getSuccessor(i))) {
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// Scan up the postdominator tree, looking for the first
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// postdominator that is alive, and the last postdominator that is
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// dead...
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//
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PostDominatorTree::Node *LastNode = DT[TI->getSuccessor(i)];
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// There is a special case here... if there IS no post-dominator for
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// the block we have no owhere to point our branch to. Instead,
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// convert it to a return. This can only happen if the code branched
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// into an infinite loop. Note that this may not be desirable,
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// because we _are_ altering the behavior of the code. This is a well
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// known drawback of ADCE, so in the future if we choose to revisit
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// the decision, this is where it should be.
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//
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if (LastNode == 0) { // No postdominator!
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// Call RemoveSuccessor to transmogrify the terminator instruction
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// to not contain the outgoing branch, or to create a new terminator
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// if the form fundamentally changes (i.e., unconditional branch to
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// return). Note that this will change a branch into an infinite
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// loop into a return instruction!
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//
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PostDominatorTree::Node *LastNode = DT[TI->getSuccessor(i)];
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RemoveSuccessor(TI, i);
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// There is a special case here... if there IS no post-dominator for
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// the block we have no owhere to point our branch to. Instead,
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// convert it to a return. This can only happen if the code
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// branched into an infinite loop. Note that this may not be
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// desirable, because we _are_ altering the behavior of the code.
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// This is a well known drawback of ADCE, so in the future if we
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// choose to revisit the decision, this is where it should be.
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// RemoveSuccessor may replace TI... make sure we have a fresh
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// pointer... and e variable.
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//
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if (LastNode == 0) { // No postdominator!
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// Call RemoveSuccessor to transmogrify the terminator instruction
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// to not contain the outgoing branch, or to create a new
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// terminator if the form fundamentally changes (i.e.,
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// unconditional branch to return). Note that this will change a
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// branch into an infinite loop into a return instruction!
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//
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RemoveSuccessor(TI, i);
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TI = BB->getTerminator();
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// RemoveSuccessor may replace TI... make sure we have a fresh
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// pointer... and e variable.
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//
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TI = BB->getTerminator();
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// Rescan this successor...
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--i;
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} else {
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PostDominatorTree::Node *NextNode = LastNode->getIDom();
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// Rescan this successor...
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--i;
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} else {
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PostDominatorTree::Node *NextNode = LastNode->getIDom();
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while (!AliveBlocks.count(NextNode->getBlock())) {
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LastNode = NextNode;
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NextNode = NextNode->getIDom();
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}
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while (!AliveBlocks.count(NextNode->getBlock())) {
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LastNode = NextNode;
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NextNode = NextNode->getIDom();
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}
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// Get the basic blocks that we need...
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BasicBlock *LastDead = LastNode->getBlock();
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BasicBlock *NextAlive = NextNode->getBlock();
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// Get the basic blocks that we need...
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BasicBlock *LastDead = LastNode->getBlock();
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BasicBlock *NextAlive = NextNode->getBlock();
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// Make the conditional branch now go to the next alive block...
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TI->getSuccessor(i)->removePredecessor(BB);
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TI->setSuccessor(i, NextAlive);
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// Make the conditional branch now go to the next alive block...
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TI->getSuccessor(i)->removePredecessor(BB);
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TI->setSuccessor(i, NextAlive);
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// If there are PHI nodes in NextAlive, we need to add entries to
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// the PHI nodes for the new incoming edge. The incoming values
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// should be identical to the incoming values for LastDead.
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//
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for (BasicBlock::iterator II = NextAlive->begin();
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isa<PHINode>(II); ++II) {
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PHINode *PN = cast<PHINode>(II);
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if (LiveSet.count(PN)) { // Only modify live phi nodes
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// Get the incoming value for LastDead...
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int OldIdx = PN->getBasicBlockIndex(LastDead);
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assert(OldIdx != -1 &&"LastDead is not a pred of NextAlive!");
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Value *InVal = PN->getIncomingValue(OldIdx);
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// If there are PHI nodes in NextAlive, we need to add entries to
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// the PHI nodes for the new incoming edge. The incoming values
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// should be identical to the incoming values for LastDead.
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//
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for (BasicBlock::iterator II = NextAlive->begin();
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isa<PHINode>(II); ++II) {
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PHINode *PN = cast<PHINode>(II);
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if (LiveSet.count(PN)) { // Only modify live phi nodes
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// Get the incoming value for LastDead...
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int OldIdx = PN->getBasicBlockIndex(LastDead);
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assert(OldIdx != -1 &&"LastDead is not a pred of NextAlive!");
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Value *InVal = PN->getIncomingValue(OldIdx);
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// Add an incoming value for BB now...
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PN->addIncoming(InVal, BB);
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}
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// Add an incoming value for BB now...
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PN->addIncoming(InVal, BB);
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}
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}
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}
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}
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// Now loop over all of the instructions in the basic block, deleting
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// dead instructions. This is so that the next sweep over the program
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// can safely delete dead instructions without other dead instructions
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// still referring to them.
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//
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deleteDeadInstructionsInLiveBlock(BB);
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}
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}
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// Now loop over all of the instructions in the basic block, deleting
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// dead instructions. This is so that the next sweep over the program
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// can safely delete dead instructions without other dead instructions
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// still referring to them.
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//
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deleteDeadInstructionsInLiveBlock(BB);
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}
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// Loop over all of the basic blocks in the function, dropping references of
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// the dead basic blocks. We must do this after the previous step to avoid
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