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Expose isCriticalEdge & SplitCriticalEdge methods from crit-edges pass

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4075 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-10-08 21:06:27 +00:00
parent 7ca266fe1f
commit e802a023d9
3 changed files with 36 additions and 18 deletions
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16
include/llvm/Transforms/Scalar.h
View File

@ -11,6 +11,7 @@
class Pass;
class GetElementPtrInst;
class PassInfo;
class TerminatorInst;
//===----------------------------------------------------------------------===//
//
@ -188,6 +189,21 @@ Pass *createCFGSimplificationPass();
Pass *createBreakCriticalEdgesPass();
extern const PassInfo *BreakCriticalEdgesID;
// The BreakCriticalEdges pass also exposes some low-level functionality that
// may be used by other passes.
/// isCriticalEdge - Return true if the specified edge is a critical edge.
/// Critical edges are edges from a block with multiple successors to a block
/// with multiple predecessors.
///
bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum);
/// SplitCriticalEdge - Insert a new node node to split the critical edge. This
/// will update DominatorSet, ImmediateDominator and DominatorTree information
/// if a pass is specified, thus calling this pass will not invalidate these
/// analyses.
///
void SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P = 0);
//===----------------------------------------------------------------------===//
//

19
lib/Transforms/Scalar/BreakCriticalEdges.cpp
View File

@ -28,8 +28,6 @@ namespace {
AU.addPreserved<DominatorTree>();
AU.addPreservedID(LoopPreheadersID); // No preheaders deleted.
}
private:
void SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum);
};
RegisterOpt<BreakCriticalEdges> X("break-crit-edges",
@ -45,9 +43,9 @@ Pass *createBreakCriticalEdgesPass() { return new BreakCriticalEdges(); }
// Critical edges are edges from a block with multiple successors to a block
// with multiple predecessors.
//
static bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum) {
bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum) {
assert(SuccNum < TI->getNumSuccessors() && "Illegal edge specification!");
assert (TI->getNumSuccessors() > 1);
if (TI->getNumSuccessors() == 1) return false;
const BasicBlock *Dest = TI->getSuccessor(SuccNum);
pred_const_iterator I = pred_begin(Dest), E = pred_end(Dest);
@ -62,7 +60,7 @@ static bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum) {
// will update DominatorSet, ImmediateDominator and DominatorTree information if
// it is available, thus calling this pass will not invalidate either of them.
//
void BreakCriticalEdges::SplitCriticalEdge(TerminatorInst *TI,unsigned SuccNum){
void SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P) {
assert(isCriticalEdge(TI, SuccNum) &&
"Cannot break a critical edge, if it isn't a critical edge");
BasicBlock *TIBB = TI->getParent();
@ -90,12 +88,15 @@ void BreakCriticalEdges::SplitCriticalEdge(TerminatorInst *TI,unsigned SuccNum){
PN->replaceUsesOfWith(TIBB, NewBB);
}
// If we don't have a pass object, we can't update anything...
if (P == 0) return;
// Now update analysis information. These are the analyses that we are
// currently capable of updating...
//
// Should we update DominatorSet information?
if (DominatorSet *DS = getAnalysisToUpdate<DominatorSet>()) {
if (DominatorSet *DS = P->getAnalysisToUpdate<DominatorSet>()) {
// The blocks that dominate the new one are the blocks that dominate TIBB
// plus the new block itself.
DominatorSet::DomSetType DomSet = DS->getDominators(TIBB);
@ -104,14 +105,14 @@ void BreakCriticalEdges::SplitCriticalEdge(TerminatorInst *TI,unsigned SuccNum){
}
// Should we update ImmdediateDominator information?
if (ImmediateDominators *ID = getAnalysisToUpdate<ImmediateDominators>()) {
if (ImmediateDominators *ID = P->getAnalysisToUpdate<ImmediateDominators>()) {
// TIBB is the new immediate dominator for NewBB. NewBB doesn't dominate
// anything.
ID->addNewBlock(NewBB, TIBB);
}
// Should we update DominatorTree information?
if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) {
if (DominatorTree *DT = P->getAnalysisToUpdate<DominatorTree>()) {
DominatorTree::Node *TINode = DT->getNode(TIBB);
// The new block is not the immediate dominator for any other nodes, but
@ -131,7 +132,7 @@ bool BreakCriticalEdges::runOnFunction(Function &F) {
if (TI->getNumSuccessors() > 1)
for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
if (isCriticalEdge(TI, i)) {
SplitCriticalEdge(TI, i);
SplitCriticalEdge(TI, i, this);
++NumBroken;
Changed = true;
}

19
lib/Transforms/Utils/BreakCriticalEdges.cpp
View File

@ -28,8 +28,6 @@ namespace {
AU.addPreserved<DominatorTree>();
AU.addPreservedID(LoopPreheadersID); // No preheaders deleted.
}
private:
void SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum);
};
RegisterOpt<BreakCriticalEdges> X("break-crit-edges",
@ -45,9 +43,9 @@ Pass *createBreakCriticalEdgesPass() { return new BreakCriticalEdges(); }
// Critical edges are edges from a block with multiple successors to a block
// with multiple predecessors.
//
static bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum) {
bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum) {
assert(SuccNum < TI->getNumSuccessors() && "Illegal edge specification!");
assert (TI->getNumSuccessors() > 1);
if (TI->getNumSuccessors() == 1) return false;
const BasicBlock *Dest = TI->getSuccessor(SuccNum);
pred_const_iterator I = pred_begin(Dest), E = pred_end(Dest);
@ -62,7 +60,7 @@ static bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum) {
// will update DominatorSet, ImmediateDominator and DominatorTree information if
// it is available, thus calling this pass will not invalidate either of them.
//
void BreakCriticalEdges::SplitCriticalEdge(TerminatorInst *TI,unsigned SuccNum){
void SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P) {
assert(isCriticalEdge(TI, SuccNum) &&
"Cannot break a critical edge, if it isn't a critical edge");
BasicBlock *TIBB = TI->getParent();
@ -90,12 +88,15 @@ void BreakCriticalEdges::SplitCriticalEdge(TerminatorInst *TI,unsigned SuccNum){
PN->replaceUsesOfWith(TIBB, NewBB);
}
// If we don't have a pass object, we can't update anything...
if (P == 0) return;
// Now update analysis information. These are the analyses that we are
// currently capable of updating...
//
// Should we update DominatorSet information?
if (DominatorSet *DS = getAnalysisToUpdate<DominatorSet>()) {
if (DominatorSet *DS = P->getAnalysisToUpdate<DominatorSet>()) {
// The blocks that dominate the new one are the blocks that dominate TIBB
// plus the new block itself.
DominatorSet::DomSetType DomSet = DS->getDominators(TIBB);
@ -104,14 +105,14 @@ void BreakCriticalEdges::SplitCriticalEdge(TerminatorInst *TI,unsigned SuccNum){
}
// Should we update ImmdediateDominator information?
if (ImmediateDominators *ID = getAnalysisToUpdate<ImmediateDominators>()) {
if (ImmediateDominators *ID = P->getAnalysisToUpdate<ImmediateDominators>()) {
// TIBB is the new immediate dominator for NewBB. NewBB doesn't dominate
// anything.
ID->addNewBlock(NewBB, TIBB);
}
// Should we update DominatorTree information?
if (DominatorTree *DT = getAnalysisToUpdate<DominatorTree>()) {
if (DominatorTree *DT = P->getAnalysisToUpdate<DominatorTree>()) {
DominatorTree::Node *TINode = DT->getNode(TIBB);
// The new block is not the immediate dominator for any other nodes, but
@ -131,7 +132,7 @@ bool BreakCriticalEdges::runOnFunction(Function &F) {
if (TI->getNumSuccessors() > 1)
for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i)
if (isCriticalEdge(TI, i)) {
SplitCriticalEdge(TI, i);
SplitCriticalEdge(TI, i, this);
++NumBroken;
Changed = true;
}