mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-11-01 00:11:00 +00:00
ecd94c804a
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@36873 91177308-0d34-0410-b5e6-96231b3b80d8
102 lines
4.0 KiB
C++
102 lines
4.0 KiB
C++
//===- EdgeProfiling.cpp - Insert counters for edge profiling -------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file was developed by the LLVM research group and is distributed under
|
|
// the University of Illinois Open Source License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This pass instruments the specified program with counters for edge profiling.
|
|
// Edge profiling can give a reasonable approximation of the hot paths through a
|
|
// program, and is used for a wide variety of program transformations.
|
|
//
|
|
// Note that this implementation is very naive. We insert a counter for *every*
|
|
// edge in the program, instead of using control flow information to prune the
|
|
// number of counters inserted.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "ProfilingUtils.h"
|
|
#include "llvm/Constants.h"
|
|
#include "llvm/DerivedTypes.h"
|
|
#include "llvm/Module.h"
|
|
#include "llvm/Pass.h"
|
|
#include "llvm/Support/Compiler.h"
|
|
#include "llvm/Support/Streams.h"
|
|
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
|
|
#include "llvm/Transforms/Instrumentation.h"
|
|
#include <set>
|
|
using namespace llvm;
|
|
|
|
namespace {
|
|
class VISIBILITY_HIDDEN EdgeProfiler : public ModulePass {
|
|
bool runOnModule(Module &M);
|
|
public:
|
|
static char ID; // Pass identification, replacement for typeid
|
|
EdgeProfiler() : ModulePass((intptr_t)&ID) {}
|
|
};
|
|
|
|
char EdgeProfiler::ID = 0;
|
|
RegisterPass<EdgeProfiler> X("insert-edge-profiling",
|
|
"Insert instrumentation for edge profiling");
|
|
}
|
|
|
|
ModulePass *llvm::createEdgeProfilerPass() { return new EdgeProfiler(); }
|
|
|
|
bool EdgeProfiler::runOnModule(Module &M) {
|
|
Function *Main = M.getFunction("main");
|
|
if (Main == 0) {
|
|
cerr << "WARNING: cannot insert edge profiling into a module"
|
|
<< " with no main function!\n";
|
|
return false; // No main, no instrumentation!
|
|
}
|
|
|
|
std::set<BasicBlock*> BlocksToInstrument;
|
|
unsigned NumEdges = 0;
|
|
for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F)
|
|
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
|
|
// Keep track of which blocks need to be instrumented. We don't want to
|
|
// instrument blocks that are added as the result of breaking critical
|
|
// edges!
|
|
BlocksToInstrument.insert(BB);
|
|
NumEdges += BB->getTerminator()->getNumSuccessors();
|
|
}
|
|
|
|
const Type *ATy = ArrayType::get(Type::Int32Ty, NumEdges);
|
|
GlobalVariable *Counters =
|
|
new GlobalVariable(ATy, false, GlobalValue::InternalLinkage,
|
|
Constant::getNullValue(ATy), "EdgeProfCounters", &M);
|
|
|
|
// Instrument all of the edges...
|
|
unsigned i = 0;
|
|
for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F)
|
|
for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
|
|
if (BlocksToInstrument.count(BB)) { // Don't instrument inserted blocks
|
|
// Okay, we have to add a counter of each outgoing edge. If the
|
|
// outgoing edge is not critical don't split it, just insert the counter
|
|
// in the source or destination of the edge.
|
|
TerminatorInst *TI = BB->getTerminator();
|
|
for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
|
|
// If the edge is critical, split it.
|
|
SplitCriticalEdge(TI, s, this);
|
|
|
|
// Okay, we are guaranteed that the edge is no longer critical. If we
|
|
// only have a single successor, insert the counter in this block,
|
|
// otherwise insert it in the successor block.
|
|
if (TI->getNumSuccessors() == 0) {
|
|
// Insert counter at the start of the block
|
|
IncrementCounterInBlock(BB, i++, Counters);
|
|
} else {
|
|
// Insert counter at the start of the block
|
|
IncrementCounterInBlock(TI->getSuccessor(s), i++, Counters);
|
|
}
|
|
}
|
|
}
|
|
|
|
// Add the initialization call to main.
|
|
InsertProfilingInitCall(Main, "llvm_start_edge_profiling", Counters);
|
|
return true;
|
|
}
|
|
|