[llvm-commits] [llvm] r78484 - in /llvm/trunk: include/llvm/Analysis/LoopInfo.h include/llvm/Analysis/Passes.h include/llvm/LinkAllPasses.h lib/Analysis/CMakeLists.txt lib/Analysis/ProfileEstimatorPass.cpp
Daniel Dunbar
daniel at zuster.org
Sat Aug 8 11:44:18 PDT 2009
Author: ddunbar
Date: Sat Aug 8 13:44:18 2009
New Revision: 78484
URL: http://llvm.org/viewvc/llvm-project?rev=78484&view=rev
Log:
Add a basic static ProfileInfo provider (ProfileEstimatorPass).
- Part of optimal static profiling patch sequence by Andreas Neustifter.
Added:
llvm/trunk/lib/Analysis/ProfileEstimatorPass.cpp
Modified:
llvm/trunk/include/llvm/Analysis/LoopInfo.h
llvm/trunk/include/llvm/Analysis/Passes.h
llvm/trunk/include/llvm/LinkAllPasses.h
llvm/trunk/lib/Analysis/CMakeLists.txt
Modified: llvm/trunk/include/llvm/Analysis/LoopInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/LoopInfo.h?rev=78484&r1=78483&r2=78484&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/LoopInfo.h (original)
+++ llvm/trunk/include/llvm/Analysis/LoopInfo.h Sat Aug 8 13:44:18 2009
@@ -213,6 +213,25 @@
return 0;
}
+ /// getExitEdges - Return all pairs of (_inside_block_,_outside_block_).
+ /// (Modelled after getExitingBlocks().)
+ typedef std::pair<const BlockT*,const BlockT*> Edge;
+ void getExitEdges(SmallVectorImpl<Edge> &ExitEdges) const {
+ // Sort the blocks vector so that we can use binary search to do quick
+ // lookups.
+ SmallVector<BlockT*, 128> LoopBBs(block_begin(), block_end());
+ std::sort(LoopBBs.begin(), LoopBBs.end());
+
+ typedef GraphTraits<BlockT*> BlockTraits;
+ for (block_iterator BI = block_begin(), BE = block_end(); BI != BE; ++BI)
+ for (typename BlockTraits::ChildIteratorType I =
+ BlockTraits::child_begin(*BI), E = BlockTraits::child_end(*BI);
+ I != E; ++I)
+ if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I))
+ // Not in current loop? It must be an exit block.
+ ExitEdges.push_back(std::make_pair(*BI,*I));
+ }
+
/// getUniqueExitBlocks - Return all unique successor blocks of this loop.
/// These are the blocks _outside of the current loop_ which are branched to.
/// This assumes that loop is in canonical form.
Modified: llvm/trunk/include/llvm/Analysis/Passes.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/Passes.h?rev=78484&r1=78483&r2=78484&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/Passes.h (original)
+++ llvm/trunk/include/llvm/Analysis/Passes.h Sat Aug 8 13:44:18 2009
@@ -21,6 +21,7 @@
class LoopPass;
class ModulePass;
class Pass;
+ class PassInfo;
class LibCallInfo;
//===--------------------------------------------------------------------===//
@@ -93,6 +94,14 @@
//===--------------------------------------------------------------------===//
//
+ // createProfileEstimatorPass - This pass estimates profiling information
+ // instead of loading it from a previous run.
+ //
+ FunctionPass *createProfileEstimatorPass();
+ extern const PassInfo *ProfileEstimatorPassID;
+
+ //===--------------------------------------------------------------------===//
+ //
// createDSAAPass - This pass implements simple context sensitive alias
// analysis.
//
Modified: llvm/trunk/include/llvm/LinkAllPasses.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/LinkAllPasses.h?rev=78484&r1=78483&r2=78484&view=diff
==============================================================================
--- llvm/trunk/include/llvm/LinkAllPasses.h (original)
+++ llvm/trunk/include/llvm/LinkAllPasses.h Sat Aug 8 13:44:18 2009
@@ -92,6 +92,7 @@
(void) llvm::createLowerSwitchPass();
(void) llvm::createNoAAPass();
(void) llvm::createNoProfileInfoPass();
+ (void) llvm::createProfileEstimatorPass();
(void) llvm::createProfileLoaderPass();
(void) llvm::createPromoteMemoryToRegisterPass();
(void) llvm::createDemoteRegisterToMemoryPass();
Modified: llvm/trunk/lib/Analysis/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/CMakeLists.txt?rev=78484&r1=78483&r2=78484&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/CMakeLists.txt (original)
+++ llvm/trunk/lib/Analysis/CMakeLists.txt Sat Aug 8 13:44:18 2009
@@ -25,6 +25,7 @@
MemoryDependenceAnalysis.cpp
PointerTracking.cpp
PostDominators.cpp
+ ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
Added: llvm/trunk/lib/Analysis/ProfileEstimatorPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ProfileEstimatorPass.cpp?rev=78484&view=auto
==============================================================================
--- llvm/trunk/lib/Analysis/ProfileEstimatorPass.cpp (added)
+++ llvm/trunk/lib/Analysis/ProfileEstimatorPass.cpp Sat Aug 8 13:44:18 2009
@@ -0,0 +1,236 @@
+//===- ProfileEstimatorPass.cpp - LLVM Pass to estimate profile info ------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a concrete implementation of profiling information that
+// estimates the profiling information in a very crude and unimaginative way.
+//
+//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "profile-estimator"
+#include "llvm/Pass.h"
+#include "llvm/Analysis/Passes.h"
+#include "llvm/Analysis/ProfileInfo.h"
+#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+static cl::opt<double>
+ProfileInfoExecCount(
+ "profile-estimator-loop-weight", cl::init(10),
+ cl::value_desc("loop-weight"),
+ cl::desc("Number of loop executions used for profile-estimator")
+);
+
+namespace {
+ class VISIBILITY_HIDDEN ProfileEstimatorPass :
+ public FunctionPass, public ProfileInfo {
+ double ExecCount;
+ LoopInfo *LI;
+ std::set<BasicBlock*> BBisVisited;
+ std::map<Loop*,double> LoopExitWeights;
+ public:
+ static char ID; // Class identification, replacement for typeinfo
+ explicit ProfileEstimatorPass(const double execcount = 0)
+ : FunctionPass(&ID), ExecCount(execcount) {
+ if (execcount == 0) ExecCount = ProfileInfoExecCount;
+ }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ AU.addRequired<LoopInfo>();
+ }
+
+ virtual const char *getPassName() const {
+ return "Profiling information estimator";
+ }
+
+ /// run - Estimate the profile information from the specified file.
+ virtual bool runOnFunction(Function &F);
+
+ virtual void recurseBasicBlock(BasicBlock *BB);
+ };
+} // End of anonymous namespace
+
+char ProfileEstimatorPass::ID = 0;
+static RegisterPass<ProfileEstimatorPass>
+X("profile-estimator", "Estimate profiling information", false, true);
+
+static RegisterAnalysisGroup<ProfileInfo> Y(X);
+
+namespace llvm {
+ const PassInfo *ProfileEstimatorPassID = &X;
+
+ FunctionPass *createProfileEstimatorPass() {
+ return new ProfileEstimatorPass();
+ }
+
+ // createProfileEstimatorPass - This function returns a Pass that estimates
+ // profiling information using the given loop execution count.
+ Pass *createProfileEstimatorPass(const unsigned execcount) {
+ return new ProfileEstimatorPass(execcount);
+ }
+}
+
+static double ignoreMissing(double w) {
+ if (w == ProfileInfo::MissingValue) return 0;
+ return w;
+}
+
+#define EDGE_ERROR(V1,V2) \
+ DEBUG(errs() << "-- Edge (" <<(V1)->getName() << "," << (V2)->getName() \
+ << ") is not calculated, returning\n")
+
+#define EDGE_WEIGHT(E) \
+ DEBUG(errs() << "-- Weight of Edge (" \
+ << ((E).first ? (E).first->getNameStr() : "0") \
+ << "," << (E).second->getName() << "):" \
+ << getEdgeWeight(E) << "\n")
+
+// recurseBasicBlock() - This calculates the ProfileInfo estimation for a
+// single block and then recurses into the successors.
+void ProfileEstimatorPass::recurseBasicBlock(BasicBlock *BB) {
+
+ // break recursion if already visited
+ if (BBisVisited.find(BB) != BBisVisited.end()) return;
+
+ // check if uncalculated incoming edges are calculated already, if BB is
+ // header allow backedges
+ bool BBisHeader = LI->isLoopHeader(BB);
+ Loop* BBLoop = LI->getLoopFor(BB);
+
+ double BBWeight = 0;
+ std::set<BasicBlock*> ProcessedPreds;
+ for ( pred_iterator bbi = pred_begin(BB), bbe = pred_end(BB);
+ bbi != bbe; ++bbi ) {
+ if (ProcessedPreds.insert(*bbi).second) {
+ Edge edge = getEdge(*bbi,BB);
+ BBWeight += ignoreMissing(getEdgeWeight(edge));
+ }
+ if (BBisHeader && BBLoop == LI->getLoopFor(*bbi)) {
+ EDGE_ERROR(*bbi,BB);
+ continue;
+ }
+ if (BBisVisited.find(*bbi) == BBisVisited.end()) {
+ EDGE_ERROR(*bbi,BB);
+ return;
+ }
+ }
+ if (getExecutionCount(BB) != MissingValue) {
+ BBWeight = getExecutionCount(BB);
+ }
+
+ // fetch all necessary information for current block
+ SmallVector<Edge, 8> ExitEdges;
+ SmallVector<Edge, 8> Edges;
+ if (BBLoop) {
+ BBLoop->getExitEdges(ExitEdges);
+ }
+
+ // if block is an loop header, first subtract all weigths from edges that
+ // exit this loop, then distribute remaining weight on to the edges exiting
+ // this loop. finally the weight of the block is increased, to simulate
+ // several executions of this loop
+ if (BBisHeader) {
+ double incoming = BBWeight;
+ // subtract the flow leaving the loop
+ for (SmallVector<Edge, 8>::iterator ei = ExitEdges.begin(),
+ ee = ExitEdges.end(); ei != ee; ++ei) {
+ double w = getEdgeWeight(*ei);
+ if (w == MissingValue) {
+ Edges.push_back(*ei);
+ } else {
+ incoming -= w;
+ }
+ }
+ // distribute remaining weight onto the exit edges
+ for (SmallVector<Edge, 8>::iterator ei = Edges.begin(), ee = Edges.end();
+ ei != ee; ++ei) {
+ EdgeInformation[BB->getParent()][*ei] += incoming/Edges.size();
+ EDGE_WEIGHT(*ei);
+ }
+ // increase flow into the loop
+ BBWeight *= (ExecCount+1);
+ }
+
+ // remove from current flow of block all the successor edges that already
+ // have some flow on them
+ Edges.clear();
+ std::set<BasicBlock*> ProcessedSuccs;
+ for ( succ_iterator bbi = succ_begin(BB), bbe = succ_end(BB);
+ bbi != bbe; ++bbi ) {
+ if (ProcessedSuccs.insert(*bbi).second) {
+ Edge edge = getEdge(BB,*bbi);
+ double w = getEdgeWeight(edge);
+ if (w != MissingValue) {
+ BBWeight -= getEdgeWeight(edge);
+ } else {
+ Edges.push_back(edge);
+ }
+ }
+ }
+
+ // distribute remaining flow onto the outgoing edges
+ for (SmallVector<Edge, 8>::iterator ei = Edges.begin(), ee = Edges.end();
+ ei != ee; ++ei) {
+ EdgeInformation[BB->getParent()][*ei] += BBWeight/Edges.size();
+ EDGE_WEIGHT(*ei);
+ }
+
+ // mark as visited and recurse into subnodes
+ BBisVisited.insert(BB);
+ for ( succ_iterator bbi = succ_begin(BB), bbe = succ_end(BB);
+ bbi != bbe;
+ ++bbi ) {
+ recurseBasicBlock(*bbi);
+ }
+}
+
+bool ProfileEstimatorPass::runOnFunction(Function &F) {
+ if (F.isDeclaration()) return false;
+
+ LI = &getAnalysis<LoopInfo>();
+ FunctionInformation.erase(&F);
+ BlockInformation[&F].clear();
+ EdgeInformation[&F].clear();
+ BBisVisited.clear();
+
+ DEBUG(errs() << "Working on function " << F.getName() << "\n");
+
+ // since the entry block is the first one and has no predecessors, the edge
+ // (0,entry) is inserted with the starting weight of 1
+ BasicBlock *entry = &F.getEntryBlock();
+ BlockInformation[&F][entry] = 1;
+
+ Edge edge = getEdge(0,entry);
+ EdgeInformation[&F][edge] = 1; EDGE_WEIGHT(edge);
+ recurseBasicBlock(entry);
+
+ // in case something went wrong, clear all results, not profiling info
+ // available
+ if (BBisVisited.size() != F.size()) {
+ DEBUG(errs() << "-- could not estimate profile, using default profile\n");
+ FunctionInformation.erase(&F);
+ BlockInformation[&F].clear();
+ for (Function::iterator BB = F.begin(), BBE = F.end(); BB != BBE; ++BB) {
+ for (pred_iterator bbi = pred_begin(BB), bbe = pred_end(BB);
+ bbi != bbe; ++bbi) {
+ Edge e = getEdge(*bbi,BB);
+ EdgeInformation[&F][e] = 1; EDGE_WEIGHT(edge);
+ }
+ for (succ_iterator bbi = succ_begin(BB), bbe = succ_end(BB);
+ bbi != bbe; ++bbi) {
+ Edge e = getEdge(BB,*bbi);
+ EdgeInformation[&F][e] = 1; EDGE_WEIGHT(edge);
+ }
+ }
+ }
+
+ return false;
+}
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