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Add more constantness in BranchProbabilityInfo.

llvm-svn: 136502
This commit is contained in:
Jakub Staszak 2011-07-29 19:30:00 +00:00
parent 944f1cc9a6
commit 02fa079dc3
2 changed files with 19 additions and 16 deletions

View File

@ -33,12 +33,12 @@ class BranchProbabilityInfo : public FunctionPass {
// weight to just "inherit" the non-zero weight of an adjacent successor.
static const uint32_t DEFAULT_WEIGHT = 16;
typedef std::pair<BasicBlock *, BasicBlock *> Edge;
typedef std::pair<const BasicBlock *, const BasicBlock *> Edge;
DenseMap<Edge, uint32_t> Weights;
// Get sum of the block successors' weights.
uint32_t getSumForBlock(BasicBlock *BB) const;
uint32_t getSumForBlock(const BasicBlock *BB) const;
public:
static char ID;
@ -53,13 +53,14 @@ public:
// Returned value is between 1 and UINT32_MAX. Look at
// BranchProbabilityInfo.cpp for details.
uint32_t getEdgeWeight(BasicBlock *Src, BasicBlock *Dst) const;
uint32_t getEdgeWeight(const BasicBlock *Src, const BasicBlock *Dst) const;
// Look at BranchProbabilityInfo.cpp for details. Use it with caution!
void setEdgeWeight(BasicBlock *Src, BasicBlock *Dst, uint32_t Weight);
void setEdgeWeight(const BasicBlock *Src, const BasicBlock *Dst,
uint32_t Weight);
// A 'Hot' edge is an edge which probability is >= 80%.
bool isEdgeHot(BasicBlock *Src, BasicBlock *Dst) const;
bool isEdgeHot(const BasicBlock *Src, const BasicBlock *Dst) const;
// Return a hot successor for the block BB or null if there isn't one.
BasicBlock *getHotSucc(BasicBlock *BB) const;
@ -67,7 +68,8 @@ public:
// Return a probability as a fraction between 0 (0% probability) and
// 1 (100% probability), however the value is never equal to 0, and can be 1
// only iff SRC block has only one successor.
BranchProbability getEdgeProbability(BasicBlock *Src, BasicBlock *Dst) const;
BranchProbability getEdgeProbability(const BasicBlock *Src,
const BasicBlock *Dst) const;
// Print value between 0 (0% probability) and 1 (100% probability),
// however the value is never equal to 0, and can be 1 only iff SRC block

View File

@ -33,7 +33,7 @@ namespace {
// private methods are hidden in the .cpp file.
class BranchProbabilityAnalysis {
typedef std::pair<BasicBlock *, BasicBlock *> Edge;
typedef std::pair<const BasicBlock *, const BasicBlock *> Edge;
DenseMap<Edge, uint32_t> *Weights;
@ -301,11 +301,11 @@ bool BranchProbabilityInfo::runOnFunction(Function &F) {
return BPA.runOnFunction(F);
}
uint32_t BranchProbabilityInfo::getSumForBlock(BasicBlock *BB) const {
uint32_t BranchProbabilityInfo::getSumForBlock(const BasicBlock *BB) const {
uint32_t Sum = 0;
for (succ_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
BasicBlock *Succ = *I;
for (succ_const_iterator I = succ_begin(BB), E = succ_end(BB); I != E; ++I) {
const BasicBlock *Succ = *I;
uint32_t Weight = getEdgeWeight(BB, Succ);
uint32_t PrevSum = Sum;
@ -316,7 +316,8 @@ uint32_t BranchProbabilityInfo::getSumForBlock(BasicBlock *BB) const {
return Sum;
}
bool BranchProbabilityInfo::isEdgeHot(BasicBlock *Src, BasicBlock *Dst) const {
bool BranchProbabilityInfo::
isEdgeHot(const BasicBlock *Src, const BasicBlock *Dst) const {
// Hot probability is at least 4/5 = 80%
uint32_t Weight = getEdgeWeight(Src, Dst);
uint32_t Sum = getSumForBlock(Src);
@ -353,8 +354,8 @@ BasicBlock *BranchProbabilityInfo::getHotSucc(BasicBlock *BB) const {
}
// Return edge's weight. If can't find it, return DEFAULT_WEIGHT value.
uint32_t
BranchProbabilityInfo::getEdgeWeight(BasicBlock *Src, BasicBlock *Dst) const {
uint32_t BranchProbabilityInfo::
getEdgeWeight(const BasicBlock *Src, const BasicBlock *Dst) const {
Edge E(Src, Dst);
DenseMap<Edge, uint32_t>::const_iterator I = Weights.find(E);
@ -364,8 +365,8 @@ BranchProbabilityInfo::getEdgeWeight(BasicBlock *Src, BasicBlock *Dst) const {
return DEFAULT_WEIGHT;
}
void BranchProbabilityInfo::setEdgeWeight(BasicBlock *Src, BasicBlock *Dst,
uint32_t Weight) {
void BranchProbabilityInfo::
setEdgeWeight(const BasicBlock *Src, const BasicBlock *Dst, uint32_t Weight) {
Weights[std::make_pair(Src, Dst)] = Weight;
DEBUG(dbgs() << "set edge " << Src->getNameStr() << " -> "
<< Dst->getNameStr() << " weight to " << Weight
@ -374,7 +375,7 @@ void BranchProbabilityInfo::setEdgeWeight(BasicBlock *Src, BasicBlock *Dst,
BranchProbability BranchProbabilityInfo::
getEdgeProbability(BasicBlock *Src, BasicBlock *Dst) const {
getEdgeProbability(const BasicBlock *Src, const BasicBlock *Dst) const {
uint32_t N = getEdgeWeight(Src, Dst);
uint32_t D = getSumForBlock(Src);