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https://github.com/c64scene-ar/llvm-6502.git
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58446916b7
This reverts r171041. This was a nice idea that didn't work out well. Clang warnings need to be associated with warning groups so that they can be selectively disabled, promoted to errors, etc. This simplistic patch didn't allow for that. Enhancing it to provide some way for the backend to specify a front-end warning type seems like overkill for the few uses of this, at least for now. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174748 91177308-0d34-0410-b5e6-96231b3b80d8
118 lines
4.4 KiB
C++
118 lines
4.4 KiB
C++
//===- EdgeProfiling.cpp - Insert counters for edge profiling -------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This pass instruments the specified program with counters for edge profiling.
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// Edge profiling can give a reasonable approximation of the hot paths through a
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// program, and is used for a wide variety of program transformations.
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//
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// Note that this implementation is very naive. We insert a counter for *every*
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// edge in the program, instead of using control flow information to prune the
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// number of counters inserted.
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "insert-edge-profiling"
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#include "llvm/Transforms/Instrumentation.h"
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#include "ProfilingUtils.h"
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#include "llvm/ADT/Statistic.h"
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#include "llvm/IR/Module.h"
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#include "llvm/Pass.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Transforms/Utils/BasicBlockUtils.h"
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#include <set>
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using namespace llvm;
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STATISTIC(NumEdgesInserted, "The # of edges inserted.");
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namespace {
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class EdgeProfiler : public ModulePass {
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bool runOnModule(Module &M);
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public:
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static char ID; // Pass identification, replacement for typeid
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EdgeProfiler() : ModulePass(ID) {
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initializeEdgeProfilerPass(*PassRegistry::getPassRegistry());
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}
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virtual const char *getPassName() const {
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return "Edge Profiler";
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}
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};
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}
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char EdgeProfiler::ID = 0;
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INITIALIZE_PASS(EdgeProfiler, "insert-edge-profiling",
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"Insert instrumentation for edge profiling", false, false)
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ModulePass *llvm::createEdgeProfilerPass() { return new EdgeProfiler(); }
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bool EdgeProfiler::runOnModule(Module &M) {
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Function *Main = M.getFunction("main");
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if (Main == 0) {
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errs() << "WARNING: cannot insert edge profiling into a module"
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<< " with no main function!\n";
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return false; // No main, no instrumentation!
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}
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std::set<BasicBlock*> BlocksToInstrument;
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unsigned NumEdges = 0;
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for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
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if (F->isDeclaration()) continue;
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// Reserve space for (0,entry) edge.
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++NumEdges;
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for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB) {
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// Keep track of which blocks need to be instrumented. We don't want to
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// instrument blocks that are added as the result of breaking critical
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// edges!
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BlocksToInstrument.insert(BB);
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NumEdges += BB->getTerminator()->getNumSuccessors();
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}
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}
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Type *ATy = ArrayType::get(Type::getInt32Ty(M.getContext()), NumEdges);
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GlobalVariable *Counters =
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new GlobalVariable(M, ATy, false, GlobalValue::InternalLinkage,
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Constant::getNullValue(ATy), "EdgeProfCounters");
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NumEdgesInserted = NumEdges;
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// Instrument all of the edges...
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unsigned i = 0;
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for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
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if (F->isDeclaration()) continue;
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// Create counter for (0,entry) edge.
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IncrementCounterInBlock(&F->getEntryBlock(), i++, Counters);
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for (Function::iterator BB = F->begin(), E = F->end(); BB != E; ++BB)
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if (BlocksToInstrument.count(BB)) { // Don't instrument inserted blocks
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// Okay, we have to add a counter of each outgoing edge. If the
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// outgoing edge is not critical don't split it, just insert the counter
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// in the source or destination of the edge.
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TerminatorInst *TI = BB->getTerminator();
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for (unsigned s = 0, e = TI->getNumSuccessors(); s != e; ++s) {
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// If the edge is critical, split it.
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SplitCriticalEdge(TI, s, this);
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// Okay, we are guaranteed that the edge is no longer critical. If we
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// only have a single successor, insert the counter in this block,
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// otherwise insert it in the successor block.
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if (TI->getNumSuccessors() == 1) {
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// Insert counter at the start of the block
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IncrementCounterInBlock(BB, i++, Counters, false);
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} else {
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// Insert counter at the start of the block
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IncrementCounterInBlock(TI->getSuccessor(s), i++, Counters);
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}
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}
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}
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}
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// Add the initialization call to main.
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InsertProfilingInitCall(Main, "llvm_start_edge_profiling", Counters);
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return true;
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}
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