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Make ProfileEstimator even more robust on general CFGs.

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81516 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andreas Neustifter
2009-09-11 08:39:33 +00:00
parent 9e6ffba26b
commit 8a58c180c2
2 changed files with 112 additions and 55 deletions
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39
lib/Analysis/ProfileVerifierPass.cpp
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@ -153,7 +153,7 @@ void ProfileVerifierPass::debugEntry (DetailedBlockInfo *DI) {
}
}
// compare with relative error
// This compares A and B but considering maybe small differences.
static bool Equals(double A, double B) {
double maxRelativeError = 0.0000001;
if (A == B)
@ -167,6 +167,9 @@ static bool Equals(double A, double B) {
return false;
}
// This checks if the function "exit" is reachable from an given function
// via calls, this is necessary to check if a profile is valid despite the
// counts not fitting exactly.
bool ProfileVerifierPass::exitReachable(const Function *F) {
if (!F) return false;
@ -196,7 +199,7 @@ double ProfileVerifierPass::ReadOrAssert(ProfileInfo::Edge E) {
double EdgeWeight = PI->getEdgeWeight(E);
if (EdgeWeight == ProfileInfo::MissingValue) {
errs() << "Edge " << E << " in Function "
<< E.first->getParent()->getNameStr() << ": ";
<< ProfileInfo.getFunction(E)->getNameStr() << ": ";
ASSERTMESSAGE("ASSERT:Edge has missing value");
return 0;
} else {
@ -215,15 +218,23 @@ void ProfileVerifierPass::CheckValue(bool Error, const char *Message,
return;
}
// This calculates the Information for a block and then recurses into the
// successors.
void ProfileVerifierPass::recurseBasicBlock(const BasicBlock *BB) {
// Break the recursion by remembering all visited blocks.
if (BBisVisited.find(BB) != BBisVisited.end()) return;
// Use a data structure to store all the information, this can then be handed
// to debug printers.
DetailedBlockInfo DI;
DI.BB = BB;
DI.outCount = DI.inCount = DI.inWeight = DI.outWeight = 0;
// Read predecessors.
std::set<const BasicBlock*> ProcessedPreds;
pred_const_iterator bpi = pred_begin(BB), bpe = pred_end(BB);
// If there are none, check for (0,BB) edge.
if (bpi == bpe) {
DI.inWeight += ReadOrAssert(PI->getEdge(0,BB));
DI.inCount++;
@ -235,14 +246,16 @@ void ProfileVerifierPass::recurseBasicBlock(const BasicBlock *BB) {
}
}
// Read successors.
std::set<const BasicBlock*> ProcessedSuccs;
succ_const_iterator bbi = succ_begin(BB), bbe = succ_end(BB);
if (bbi == bbe) {
double w = PI->getEdgeWeight(PI->getEdge(BB,0));
if (w != ProfileInfo::MissingValue) {
DI.outWeight += w;
DI.outCount++;
}
// If there is an (0,BB) edge, consider it too. (This is done not only when
// there are no successors, but every time; not every function contains
// return blocks with no successors (think loop latch as return block)).
double w = PI->getEdgeWeight(PI->getEdge(BB,0));
if (w != ProfileInfo::MissingValue) {
DI.outWeight += w;
DI.outCount++;
}
for (;bbi != bbe; ++bbi) {
if (ProcessedSuccs.insert(*bbi).second) {
@ -251,6 +264,7 @@ void ProfileVerifierPass::recurseBasicBlock(const BasicBlock *BB) {
}
}
// Read block weight.
DI.BBWeight = PI->getExecutionCount(BB);
CheckValue(DI.BBWeight == ProfileInfo::MissingValue,
"ASSERT:BasicBlock has missing value", &DI);
@ -303,7 +317,7 @@ void ProfileVerifierPass::recurseBasicBlock(const BasicBlock *BB) {
}
// mark as visited and recurse into subnodes
// Mark this block as visited, rescurse into successors.
BBisVisited.insert(BB);
for ( succ_const_iterator bbi = succ_begin(BB), bbe = succ_end(BB);
bbi != bbe; ++bbi ) {
@ -314,14 +328,11 @@ void ProfileVerifierPass::recurseBasicBlock(const BasicBlock *BB) {
bool ProfileVerifierPass::runOnFunction(Function &F) {
PI = &getAnalysis<ProfileInfo>();
if (PI->getExecutionCount(&F) == ProfileInfo::MissingValue) {
DEBUG(errs() << "Function " << F.getNameStr() << " has no profile\n");
return false;
}
// Prepare global variables.
PrintedDebugTree = false;
BBisVisited.clear();
// Fetch entry block and recurse into it.
const BasicBlock *entry = &F.getEntryBlock();
recurseBasicBlock(entry);