llvm-6502/lib/Analysis/DataStructure/BottomUpClosure.cpp
Chris Lattner 3567937f16 Instead of cloning the globals for main into the globals graph at the end of
BU propagation, clone the globals into the GG of EACH FUNCTION that finishes
processing!  The GlobalsGraph *must* include all globals and effects from
all functions in the program.  Fixing this makes pool allocation work better
on 175.vpr, but it still ultimately crashes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11686 91177308-0d34-0410-b5e6-96231b3b80d8
2004-02-21 00:30:28 +00:00

328 lines
12 KiB
C++

//===- BottomUpClosure.cpp - Compute bottom-up interprocedural closure ----===//
//
// 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 file implements the BUDataStructures class, which represents the
// Bottom-Up Interprocedural closure of the data structure graph over the
// program. This is useful for applications like pool allocation, but **not**
// applications like alias analysis.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/DataStructure.h"
#include "llvm/Module.h"
#include "Support/Statistic.h"
#include "Support/Debug.h"
#include "DSCallSiteIterator.h"
using namespace llvm;
namespace {
Statistic<> MaxSCC("budatastructure", "Maximum SCC Size in Call Graph");
Statistic<> NumBUInlines("budatastructures", "Number of graphs inlined");
Statistic<> NumCallEdges("budatastructures", "Number of 'actual' call edges");
RegisterAnalysis<BUDataStructures>
X("budatastructure", "Bottom-up Data Structure Analysis");
}
using namespace DS;
// run - Calculate the bottom up data structure graphs for each function in the
// program.
//
bool BUDataStructures::run(Module &M) {
LocalDataStructures &LocalDSA = getAnalysis<LocalDataStructures>();
GlobalsGraph = new DSGraph(LocalDSA.getGlobalsGraph());
GlobalsGraph->setPrintAuxCalls();
Function *MainFunc = M.getMainFunction();
if (MainFunc)
calculateReachableGraphs(MainFunc);
// Calculate the graphs for any functions that are unreachable from main...
for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
if (!I->isExternal() && !DSInfo.count(I)) {
#ifndef NDEBUG
if (MainFunc)
std::cerr << "*** Function unreachable from main: "
<< I->getName() << "\n";
#endif
calculateReachableGraphs(I); // Calculate all graphs...
}
NumCallEdges += ActualCallees.size();
// At the end of the bottom-up pass, the globals graph becomes complete.
// FIXME: This is not the right way to do this, but it is sorta better than
// nothing! In particular, externally visible globals and unresolvable call
// nodes at the end of the BU phase should make things that they point to
// incomplete in the globals graph.
//
GlobalsGraph->removeTriviallyDeadNodes();
GlobalsGraph->maskIncompleteMarkers();
return false;
}
void BUDataStructures::calculateReachableGraphs(Function *F) {
std::vector<Function*> Stack;
hash_map<Function*, unsigned> ValMap;
unsigned NextID = 1;
calculateGraphs(F, Stack, NextID, ValMap);
}
DSGraph &BUDataStructures::getOrCreateGraph(Function *F) {
// Has the graph already been created?
DSGraph *&Graph = DSInfo[F];
if (Graph) return *Graph;
// Copy the local version into DSInfo...
Graph = new DSGraph(getAnalysis<LocalDataStructures>().getDSGraph(*F));
Graph->setGlobalsGraph(GlobalsGraph);
Graph->setPrintAuxCalls();
// Start with a copy of the original call sites...
Graph->getAuxFunctionCalls() = Graph->getFunctionCalls();
return *Graph;
}
unsigned BUDataStructures::calculateGraphs(Function *F,
std::vector<Function*> &Stack,
unsigned &NextID,
hash_map<Function*, unsigned> &ValMap) {
assert(!ValMap.count(F) && "Shouldn't revisit functions!");
unsigned Min = NextID++, MyID = Min;
ValMap[F] = Min;
Stack.push_back(F);
if (F->isExternal()) { // sprintf, fprintf, sscanf, etc...
// No callees!
Stack.pop_back();
ValMap[F] = ~0;
return Min;
}
DSGraph &Graph = getOrCreateGraph(F);
// The edges out of the current node are the call site targets...
for (DSCallSiteIterator I = DSCallSiteIterator::begin_aux(Graph),
E = DSCallSiteIterator::end_aux(Graph); I != E; ++I) {
Function *Callee = *I;
unsigned M;
// Have we visited the destination function yet?
hash_map<Function*, unsigned>::iterator It = ValMap.find(Callee);
if (It == ValMap.end()) // No, visit it now.
M = calculateGraphs(Callee, Stack, NextID, ValMap);
else // Yes, get it's number.
M = It->second;
if (M < Min) Min = M;
}
assert(ValMap[F] == MyID && "SCC construction assumption wrong!");
if (Min != MyID)
return Min; // This is part of a larger SCC!
// If this is a new SCC, process it now.
if (Stack.back() == F) { // Special case the single "SCC" case here.
DEBUG(std::cerr << "Visiting single node SCC #: " << MyID << " fn: "
<< F->getName() << "\n");
Stack.pop_back();
DSGraph &G = getDSGraph(*F);
DEBUG(std::cerr << " [BU] Calculating graph for: " << F->getName()<< "\n");
calculateGraph(G);
DEBUG(std::cerr << " [BU] Done inlining: " << F->getName() << " ["
<< G.getGraphSize() << "+" << G.getAuxFunctionCalls().size()
<< "]\n");
if (MaxSCC < 1) MaxSCC = 1;
// Should we revisit the graph?
if (DSCallSiteIterator::begin_aux(G) != DSCallSiteIterator::end_aux(G)) {
ValMap.erase(F);
return calculateGraphs(F, Stack, NextID, ValMap);
} else {
ValMap[F] = ~0U;
}
return MyID;
} else {
// SCCFunctions - Keep track of the functions in the current SCC
//
hash_set<DSGraph*> SCCGraphs;
Function *NF;
std::vector<Function*>::iterator FirstInSCC = Stack.end();
DSGraph *SCCGraph = 0;
do {
NF = *--FirstInSCC;
ValMap[NF] = ~0U;
// Figure out which graph is the largest one, in order to speed things up
// a bit in situations where functions in the SCC have widely different
// graph sizes.
DSGraph &NFGraph = getDSGraph(*NF);
SCCGraphs.insert(&NFGraph);
if (!SCCGraph || SCCGraph->getGraphSize() < NFGraph.getGraphSize())
SCCGraph = &NFGraph;
} while (NF != F);
std::cerr << "Calculating graph for SCC #: " << MyID << " of size: "
<< SCCGraphs.size() << "\n";
// Compute the Max SCC Size...
if (MaxSCC < SCCGraphs.size())
MaxSCC = SCCGraphs.size();
// First thing first, collapse all of the DSGraphs into a single graph for
// the entire SCC. We computed the largest graph, so clone all of the other
// (smaller) graphs into it. Discard all of the old graphs.
//
for (hash_set<DSGraph*>::iterator I = SCCGraphs.begin(),
E = SCCGraphs.end(); I != E; ++I) {
DSGraph &G = **I;
if (&G != SCCGraph) {
DSGraph::NodeMapTy NodeMap;
SCCGraph->cloneInto(G, SCCGraph->getScalarMap(),
SCCGraph->getReturnNodes(), NodeMap);
// Update the DSInfo map and delete the old graph...
for (DSGraph::ReturnNodesTy::iterator I = G.getReturnNodes().begin(),
E = G.getReturnNodes().end(); I != E; ++I)
DSInfo[I->first] = SCCGraph;
delete &G;
}
}
// Clean up the graph before we start inlining a bunch again...
SCCGraph->removeDeadNodes(DSGraph::RemoveUnreachableGlobals);
// Now that we have one big happy family, resolve all of the call sites in
// the graph...
calculateGraph(*SCCGraph);
DEBUG(std::cerr << " [BU] Done inlining SCC [" << SCCGraph->getGraphSize()
<< "+" << SCCGraph->getAuxFunctionCalls().size() << "]\n");
std::cerr << "DONE with SCC #: " << MyID << "\n";
// We never have to revisit "SCC" processed functions...
// Drop the stuff we don't need from the end of the stack
Stack.erase(FirstInSCC, Stack.end());
return MyID;
}
return MyID; // == Min
}
// releaseMemory - If the pass pipeline is done with this pass, we can release
// our memory... here...
//
void BUDataStructures::releaseMemory() {
for (hash_map<Function*, DSGraph*>::iterator I = DSInfo.begin(),
E = DSInfo.end(); I != E; ++I) {
I->second->getReturnNodes().erase(I->first);
if (I->second->getReturnNodes().empty())
delete I->second;
}
// Empty map so next time memory is released, data structures are not
// re-deleted.
DSInfo.clear();
delete GlobalsGraph;
GlobalsGraph = 0;
}
void BUDataStructures::calculateGraph(DSGraph &Graph) {
// Move our call site list into TempFCs so that inline call sites go into the
// new call site list and doesn't invalidate our iterators!
std::vector<DSCallSite> TempFCs;
std::vector<DSCallSite> &AuxCallsList = Graph.getAuxFunctionCalls();
TempFCs.swap(AuxCallsList);
DSGraph::ReturnNodesTy &ReturnNodes = Graph.getReturnNodes();
// Loop over all of the resolvable call sites
unsigned LastCallSiteIdx = ~0U;
for (DSCallSiteIterator I = DSCallSiteIterator::begin(TempFCs),
E = DSCallSiteIterator::end(TempFCs); I != E; ++I) {
// If we skipped over any call sites, they must be unresolvable, copy them
// to the real call site list.
LastCallSiteIdx++;
for (; LastCallSiteIdx < I.getCallSiteIdx(); ++LastCallSiteIdx)
AuxCallsList.push_back(TempFCs[LastCallSiteIdx]);
LastCallSiteIdx = I.getCallSiteIdx();
// Resolve the current call...
Function *Callee = *I;
DSCallSite CS = I.getCallSite();
if (Callee->isExternal()) {
// Ignore this case, simple varargs functions we cannot stub out!
} else if (ReturnNodes.count(Callee)) {
// Self recursion... simply link up the formal arguments with the
// actual arguments...
DEBUG(std::cerr << " Self Inlining: " << Callee->getName() << "\n");
// Handle self recursion by resolving the arguments and return value
Graph.mergeInGraph(CS, *Callee, Graph, 0);
} else {
ActualCallees.insert(std::make_pair(CS.getCallSite().getInstruction(),
Callee));
// Get the data structure graph for the called function.
//
DSGraph &GI = getDSGraph(*Callee); // Graph to inline
DEBUG(std::cerr << " Inlining graph for " << Callee->getName()
<< "[" << GI.getGraphSize() << "+"
<< GI.getAuxFunctionCalls().size() << "] into '"
<< Graph.getFunctionNames() << "' [" << Graph.getGraphSize() << "+"
<< Graph.getAuxFunctionCalls().size() << "]\n");
Graph.mergeInGraph(CS, *Callee, GI,
DSGraph::KeepModRefBits |
DSGraph::StripAllocaBit | DSGraph::DontCloneCallNodes);
++NumBUInlines;
#if 0
Graph.writeGraphToFile(std::cerr, "bu_" + F.getName() + "_after_" +
Callee->getName());
#endif
}
}
// Make sure to catch any leftover unresolvable calls...
for (++LastCallSiteIdx; LastCallSiteIdx < TempFCs.size(); ++LastCallSiteIdx)
AuxCallsList.push_back(TempFCs[LastCallSiteIdx]);
TempFCs.clear();
// Recompute the Incomplete markers
assert(Graph.getInlinedGlobals().empty());
Graph.maskIncompleteMarkers();
Graph.markIncompleteNodes(DSGraph::MarkFormalArgs);
// Delete dead nodes. Treat globals that are unreachable but that can
// reach live nodes as live.
Graph.removeDeadNodes(DSGraph::KeepUnreachableGlobals);
// When this graph is finalized, clone the globals in the graph into the
// globals graph to make sure it has everything, from all graphs.
DSScalarMap &MainSM = Graph.getScalarMap();
ReachabilityCloner RC(*GlobalsGraph, Graph, DSGraph::StripAllocaBit);
// Clone everything reachable from globals in the "main" graph into the
// globals graph.
for (DSScalarMap::global_iterator I = MainSM.global_begin(),
E = MainSM.global_end(); I != E; ++I)
RC.getClonedNH(MainSM[*I]);
//Graph.writeGraphToFile(std::cerr, "bu_" + F.getName());
}