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If we have edge counts, we can produce block counts. I've verified that

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using an edge profile to produce block counts gives the exact same numbers
as using a block count directly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12232 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2004-03-08 20:03:52 +00:00
parent 9f717ef279
commit dbbbfef165
1 changed files with 67 additions and 11 deletions
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78
lib/Analysis/ProfileInfoLoader.cpp
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@ -16,6 +16,7 @@
#include "llvm/Module.h"
#include "llvm/InstrTypes.h"
#include <cstdio>
#include <map>
using namespace llvm;
enum ProfilingType {
@ -145,15 +146,19 @@ ProfileInfoLoader::ProfileInfoLoader(const char *ToolName,
void ProfileInfoLoader::getFunctionCounts(std::vector<std::pair<Function*,
unsigned> > &Counts) {
if (FunctionCounts.empty()) {
// Synthesize function frequency information from the number of times their
// entry blocks were executed.
std::vector<std::pair<BasicBlock*, unsigned> > BlockCounts;
getBlockCounts(BlockCounts);
for (unsigned i = 0, e = BlockCounts.size(); i != e; ++i)
if (&BlockCounts[i].first->getParent()->front() == BlockCounts[i].first)
Counts.push_back(std::make_pair(BlockCounts[i].first->getParent(),
BlockCounts[i].second));
if (hasAccurateBlockCounts()) {
// Synthesize function frequency information from the number of times
// their entry blocks were executed.
std::vector<std::pair<BasicBlock*, unsigned> > BlockCounts;
getBlockCounts(BlockCounts);
for (unsigned i = 0, e = BlockCounts.size(); i != e; ++i)
if (&BlockCounts[i].first->getParent()->front() == BlockCounts[i].first)
Counts.push_back(std::make_pair(BlockCounts[i].first->getParent(),
BlockCounts[i].second));
} else {
std::cerr << "Function counts are not available!\n";
}
return;
}
@ -171,8 +176,59 @@ void ProfileInfoLoader::getFunctionCounts(std::vector<std::pair<Function*,
void ProfileInfoLoader::getBlockCounts(std::vector<std::pair<BasicBlock*,
unsigned> > &Counts) {
if (BlockCounts.empty()) {
std::cerr << "Block counts not available, and no synthesis "
<< "is implemented yet!\n";
if (hasAccurateEdgeCounts()) {
// Synthesize block count information from edge frequency information.
// The block execution frequency is equal to the sum of the execution
// frequency of all outgoing edges from a block.
//
// If a block has no successors, this will not be correct, so we have to
// special case it. :(
std::vector<std::pair<Edge, unsigned> > EdgeCounts;
getEdgeCounts(EdgeCounts);
std::map<BasicBlock*, unsigned> InEdgeFreqs;
BasicBlock *LastBlock = 0;
TerminatorInst *TI = 0;
for (unsigned i = 0, e = EdgeCounts.size(); i != e; ++i) {
if (EdgeCounts[i].first.first != LastBlock) {
LastBlock = EdgeCounts[i].first.first;
TI = LastBlock->getTerminator();
Counts.push_back(std::make_pair(LastBlock, 0));
}
Counts.back().second += EdgeCounts[i].second;
unsigned SuccNum = EdgeCounts[i].first.second;
if (SuccNum >= TI->getNumSuccessors()) {
static bool Warned = false;
if (!Warned) {
std::cerr << "WARNING: profile info doesn't seem to match"
<< " the program!\n";
Warned = true;
}
} else {
// If this successor has no successors of its own, we will never
// compute an execution count for that block. Remember the incoming
// edge frequencies to add later.
BasicBlock *Succ = TI->getSuccessor(SuccNum);
if (Succ->getTerminator()->getNumSuccessors() == 0)
InEdgeFreqs[Succ] += EdgeCounts[i].second;
}
}
// Now we have to accumulate information for those blocks without
// successors into our table.
for (std::map<BasicBlock*, unsigned>::iterator I = InEdgeFreqs.begin(),
E = InEdgeFreqs.end(); I != E; ++I) {
unsigned i = 0;
for (; i != Counts.size() && Counts[i].first != I->first; ++i)
/*empty*/;
if (i == Counts.size()) Counts.push_back(std::make_pair(I->first, 0));
Counts[i].second += I->second;
}
} else {
std::cerr << "Block counts are not available!\n";
}
return;
}