#include "llvm/DerivedTypes.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Assembly/Writer.h"
+#include "Support/CommandLine.h"
#include "Support/Debug.h"
#include "Support/STLExtras.h"
#include "Support/Statistic.h"
namespace {
Statistic<> NumFolds ("dsnode", "Number of nodes completely folded");
Statistic<> NumCallNodesMerged("dsnode", "Number of call nodes merged");
+ Statistic<> NumNodeAllocated ("dsnode", "Number of nodes allocated");
+
+ cl::opt<bool>
+ EnableDSNodeGlobalRootsHack("enable-dsa-globalrootshack", cl::Hidden,
+ cl::desc("Make DSA less aggressive when cloning graphs"));
};
+#if 1
+#define TIME_REGION(VARNAME, DESC) \
+ NamedRegionTimer VARNAME(DESC)
+#else
+#define TIME_REGION(VARNAME, DESC)
+#endif
+
using namespace DS;
DSNode *DSNodeHandle::HandleForwarding() const {
// Add the type entry if it is specified...
if (T) mergeTypeInfo(T, 0);
G->getNodes().push_back(this);
+ ++NumNodeAllocated;
}
// DSNode copy constructor... do not copy over the referrers list!
-DSNode::DSNode(const DSNode &N, DSGraph *G)
+DSNode::DSNode(const DSNode &N, DSGraph *G, bool NullLinks)
: NumReferrers(0), Size(N.Size), ParentGraph(G),
- Ty(N.Ty), Links(N.Links), Globals(N.Globals), NodeType(N.NodeType) {
+ Ty(N.Ty), Globals(N.Globals), NodeType(N.NodeType) {
+ if (!NullLinks)
+ Links = N.Links;
+ else
+ Links.resize(N.Links.size()); // Create the appropriate number of null links
G->getNodes().push_back(this);
+ ++NumNodeAllocated;
}
/// getTargetData - Get the target data object used to construct this node.
assert(ParentGraph && "Node has no parent?");
const DSGraph::ScalarMapTy &SM = ParentGraph->getScalarMap();
for (unsigned i = 0, e = Globals.size(); i != e; ++i) {
- assert(SM.find(Globals[i]) != SM.end());
+ assert(SM.count(Globals[i]));
assert(SM.find(Globals[i])->second.getNode() == this);
}
}
++NumFolds;
- // Create the node we are going to forward to...
- DSNode *DestNode = new DSNode(0, ParentGraph);
- DestNode->NodeType = NodeType|DSNode::Array;
- DestNode->Ty = Type::VoidTy;
- DestNode->Size = 1;
- DestNode->Globals.swap(Globals);
-
- // Start forwarding to the destination node...
- forwardNode(DestNode, 0);
-
- if (Links.size()) {
- DestNode->Links.push_back(Links[0]);
- DSNodeHandle NH(DestNode);
-
- // If we have links, merge all of our outgoing links together...
- for (unsigned i = Links.size()-1; i != 0; --i)
- NH.getNode()->Links[0].mergeWith(Links[i]);
- Links.clear();
+ // If this node has a size that is <= 1, we don't need to create a forwarding
+ // node.
+ if (getSize() <= 1) {
+ NodeType |= DSNode::Array;
+ Ty = Type::VoidTy;
+ Size = 1;
+ assert(Links.size() <= 1 && "Size is 1, but has more links?");
+ Links.resize(1);
} else {
- DestNode->Links.resize(1);
+ // Create the node we are going to forward to. This is required because
+ // some referrers may have an offset that is > 0. By forcing them to
+ // forward, the forwarder has the opportunity to correct the offset.
+ DSNode *DestNode = new DSNode(0, ParentGraph);
+ DestNode->NodeType = NodeType|DSNode::Array;
+ DestNode->Ty = Type::VoidTy;
+ DestNode->Size = 1;
+ DestNode->Globals.swap(Globals);
+
+ // Start forwarding to the destination node...
+ forwardNode(DestNode, 0);
+
+ if (!Links.empty()) {
+ DestNode->Links.reserve(1);
+
+ DSNodeHandle NH(DestNode);
+ DestNode->Links.push_back(Links[0]);
+
+ // If we have links, merge all of our outgoing links together...
+ for (unsigned i = Links.size()-1; i != 0; --i)
+ NH.getNode()->Links[0].mergeWith(Links[i]);
+ Links.clear();
+ } else {
+ DestNode->Links.resize(1);
+ }
}
}
// If we found our type exactly, early exit
if (SubType == NewTy) return false;
+ // Differing function types don't require us to merge. They are not values anyway.
+ if (isa<FunctionType>(SubType) &&
+ isa<FunctionType>(NewTy)) return false;
+
unsigned SubTypeSize = SubType->isSized() ? TD.getTypeSize(SubType) : 0;
// Ok, we are getting desperate now. Check for physical subtyping, where we
// can cause merging of nodes in the graph.
//
void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
- if (NH.getNode() == 0) return; // Nothing to do
+ if (NH.isNull()) return; // Nothing to do
DSNodeHandle &ExistingEdge = getLink(Offset);
- if (ExistingEdge.getNode()) {
+ if (!ExistingEdge.isNull()) {
// Merge the two nodes...
ExistingEdge.mergeWith(NH);
} else { // No merging to perform...
}
}
+void DSNode::mergeGlobals(const std::vector<GlobalValue*> &RHS) {
+ MergeSortedVectors(Globals, RHS);
+}
-// MergeNodes() - Helper function for DSNode::mergeWith().
+// MergeNodes - Helper function for DSNode::mergeWith().
// This function does the hard work of merging two nodes, CurNodeH
// and NH after filtering out trivial cases and making sure that
// CurNodeH.offset >= NH.offset.
if (CurNodeH.getNode() == N || N == 0) return;
assert(!CurNodeH.getNode()->isDeadNode());
- // Merge the NodeType information...
+ // Merge the NodeType information.
CurNodeH.getNode()->NodeType |= N->NodeType;
// Start forwarding to the new node!
// Merge the globals list...
if (!N->Globals.empty()) {
- MergeSortedVectors(CurNodeH.getNode()->Globals, N->Globals);
+ CurNodeH.getNode()->mergeGlobals(N->Globals);
// Delete the globals from the old node...
std::vector<GlobalValue*>().swap(N->Globals);
// Offset indicates what offset the specified node is to be merged into the
// current node.
//
-// The specified node may be a null pointer (in which case, nothing happens).
+// The specified node may be a null pointer (in which case, we update it to
+// point to this node).
//
void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
DSNode *N = NH.getNode();
- if (N == 0 || (N == this && NH.getOffset() == Offset))
+ if (N == this && NH.getOffset() == Offset)
return; // Noop
+ // If the RHS is a null node, make it point to this node!
+ if (N == 0) {
+ NH.mergeWith(DSNodeHandle(this, Offset));
+ return;
+ }
+
assert(!N->isDeadNode() && !isDeadNode());
assert(!hasNoReferrers() && "Should not try to fold a useless node!");
DSNode::MergeNodes(CurNodeH, NHCopy);
}
+
+//===----------------------------------------------------------------------===//
+// ReachabilityCloner Implementation
+//===----------------------------------------------------------------------===//
+
+DSNodeHandle ReachabilityCloner::getClonedNH(const DSNodeHandle &SrcNH) {
+ if (SrcNH.isNull()) return DSNodeHandle();
+ const DSNode *SN = SrcNH.getNode();
+
+ DSNodeHandle &NH = NodeMap[SN];
+ if (!NH.isNull()) // Node already mapped?
+ return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
+
+ DSNode *DN = new DSNode(*SN, &Dest, true /* Null out all links */);
+ DN->maskNodeTypes(BitsToKeep);
+ NH = DN;
+
+ // Next, recursively clone all outgoing links as necessary. Note that
+ // adding these links can cause the node to collapse itself at any time, and
+ // the current node may be merged with arbitrary other nodes. For this
+ // reason, we must always go through NH.
+ DN = 0;
+ for (unsigned i = 0, e = SN->getNumLinks(); i != e; ++i) {
+ const DSNodeHandle &SrcEdge = SN->getLink(i << DS::PointerShift);
+ if (!SrcEdge.isNull()) {
+ const DSNodeHandle &DestEdge = getClonedNH(SrcEdge);
+ // Compute the offset into the current node at which to
+ // merge this link. In the common case, this is a linear
+ // relation to the offset in the original node (with
+ // wrapping), but if the current node gets collapsed due to
+ // recursive merging, we must make sure to merge in all remaining
+ // links at offset zero.
+ unsigned MergeOffset = 0;
+ DSNode *CN = NH.getNode();
+ if (CN->getSize() != 1)
+ MergeOffset = ((i << DS::PointerShift)+NH.getOffset()
+ - SrcNH.getOffset()) %CN->getSize();
+ CN->addEdgeTo(MergeOffset, DestEdge);
+ }
+ }
+
+ // If this node contains any globals, make sure they end up in the scalar
+ // map with the correct offset.
+ for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
+ I != E; ++I) {
+ GlobalValue *GV = *I;
+ const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
+ DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
+ assert(DestGNH.getNode() == NH.getNode() &&"Global mapping inconsistent");
+ Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
+ DestGNH.getOffset()+SrcGNH.getOffset()));
+
+ if (CloneFlags & DSGraph::UpdateInlinedGlobals)
+ Dest.getInlinedGlobals().insert(GV);
+ }
+
+ return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
+}
+
+void ReachabilityCloner::merge(const DSNodeHandle &NH,
+ const DSNodeHandle &SrcNH) {
+ if (SrcNH.isNull()) return; // Noop
+ if (NH.isNull()) {
+ // If there is no destination node, just clone the source and assign the
+ // destination node to be it.
+ NH.mergeWith(getClonedNH(SrcNH));
+ return;
+ }
+
+ // Okay, at this point, we know that we have both a destination and a source
+ // node that need to be merged. Check to see if the source node has already
+ // been cloned.
+ const DSNode *SN = SrcNH.getNode();
+ DSNodeHandle &SCNH = NodeMap[SN]; // SourceClonedNodeHandle
+ if (SCNH.getNode()) { // Node already cloned?
+ NH.mergeWith(DSNodeHandle(SCNH.getNode(),
+ SCNH.getOffset()+SrcNH.getOffset()));
+
+ return; // Nothing to do!
+ }
+
+ // Okay, so the source node has not already been cloned. Instead of creating
+ // a new DSNode, only to merge it into the one we already have, try to perform
+ // the merge in-place. The only case we cannot handle here is when the offset
+ // into the existing node is less than the offset into the virtual node we are
+ // merging in. In this case, we have to extend the existing node, which
+ // requires an allocation anyway.
+ DSNode *DN = NH.getNode(); // Make sure the Offset is up-to-date
+ if (NH.getOffset() >= SrcNH.getOffset()) {
+
+ if (!DN->isNodeCompletelyFolded()) {
+ // Make sure the destination node is folded if the source node is folded.
+ if (SN->isNodeCompletelyFolded()) {
+ DN->foldNodeCompletely();
+ DN = NH.getNode();
+ } else if (SN->getSize() != DN->getSize()) {
+ // If the two nodes are of different size, and the smaller node has the
+ // array bit set, collapse!
+ if (SN->getSize() < DN->getSize()) {
+ if (SN->isArray()) {
+ DN->foldNodeCompletely();
+ DN = NH.getNode();
+ }
+ } else if (DN->isArray()) {
+ DN->foldNodeCompletely();
+ DN = NH.getNode();
+ }
+ }
+
+ // Merge the type entries of the two nodes together...
+ if (SN->getType() != Type::VoidTy && !DN->isNodeCompletelyFolded()) {
+ DN->mergeTypeInfo(SN->getType(), NH.getOffset()-SrcNH.getOffset());
+ DN = NH.getNode();
+ }
+ }
+
+ assert(!DN->isDeadNode());
+
+ // Merge the NodeType information.
+ DN->mergeNodeFlags(SN->getNodeFlags() & BitsToKeep);
+
+ // Before we start merging outgoing links and updating the scalar map, make
+ // sure it is known that this is the representative node for the src node.
+ SCNH = DSNodeHandle(DN, NH.getOffset()-SrcNH.getOffset());
+
+ // If the source node contains any globals, make sure they end up in the
+ // scalar map with the correct offset.
+ if (SN->global_begin() != SN->global_end()) {
+ // Update the globals in the destination node itself.
+ DN->mergeGlobals(SN->getGlobals());
+
+ // Update the scalar map for the graph we are merging the source node
+ // into.
+ for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
+ I != E; ++I) {
+ GlobalValue *GV = *I;
+ const DSNodeHandle &SrcGNH = Src.getNodeForValue(GV);
+ DSNodeHandle &DestGNH = NodeMap[SrcGNH.getNode()];
+ assert(DestGNH.getNode()==NH.getNode() &&"Global mapping inconsistent");
+ Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
+ DestGNH.getOffset()+NH.getOffset()));
+
+ if (CloneFlags & DSGraph::UpdateInlinedGlobals)
+ Dest.getInlinedGlobals().insert(GV);
+ }
+ }
+ } else {
+ // We cannot handle this case without allocating a temporary node. Fall
+ // back on being simple.
+
+ DSNode *NewDN = new DSNode(*SN, &Dest, true /* Null out all links */);
+ NewDN->maskNodeTypes(BitsToKeep);
+
+ unsigned NHOffset = NH.getOffset();
+ NH.mergeWith(DSNodeHandle(NewDN, SrcNH.getOffset()));
+ assert(NH.getNode() &&
+ (NH.getOffset() > NHOffset ||
+ (NH.getOffset() == 0 && NH.getNode()->isNodeCompletelyFolded())) &&
+ "Merging did not adjust the offset!");
+
+ // Before we start merging outgoing links and updating the scalar map, make
+ // sure it is known that this is the representative node for the src node.
+ SCNH = DSNodeHandle(NH.getNode(), NH.getOffset()-SrcNH.getOffset());
+ }
+
+
+ // Next, recursively merge all outgoing links as necessary. Note that
+ // adding these links can cause the destination node to collapse itself at
+ // any time, and the current node may be merged with arbitrary other nodes.
+ // For this reason, we must always go through NH.
+ DN = 0;
+ for (unsigned i = 0, e = SN->getNumLinks(); i != e; ++i) {
+ const DSNodeHandle &SrcEdge = SN->getLink(i << DS::PointerShift);
+ if (!SrcEdge.isNull()) {
+ // Compute the offset into the current node at which to
+ // merge this link. In the common case, this is a linear
+ // relation to the offset in the original node (with
+ // wrapping), but if the current node gets collapsed due to
+ // recursive merging, we must make sure to merge in all remaining
+ // links at offset zero.
+ unsigned MergeOffset = 0;
+ DSNode *CN = SCNH.getNode();
+ if (CN->getSize() != 1)
+ MergeOffset = ((i << DS::PointerShift)+SCNH.getOffset()) %CN->getSize();
+
+ // Perform the recursive merging. Make sure to create a temporary NH,
+ // because the Link can disappear in the process of recursive merging.
+ DSNodeHandle Tmp = CN->getLink(MergeOffset);
+ merge(Tmp, SrcEdge);
+ }
+ }
+}
+
+/// mergeCallSite - Merge the nodes reachable from the specified src call
+/// site into the nodes reachable from DestCS.
+void ReachabilityCloner::mergeCallSite(const DSCallSite &DestCS,
+ const DSCallSite &SrcCS) {
+ merge(DestCS.getRetVal(), SrcCS.getRetVal());
+ unsigned MinArgs = DestCS.getNumPtrArgs();
+ if (SrcCS.getNumPtrArgs() < MinArgs) MinArgs = SrcCS.getNumPtrArgs();
+
+ for (unsigned a = 0; a != MinArgs; ++a)
+ merge(DestCS.getPtrArg(a), SrcCS.getPtrArg(a));
+}
+
+
//===----------------------------------------------------------------------===//
// DSCallSite Implementation
//===----------------------------------------------------------------------===//
return *Site.getInstruction()->getParent()->getParent();
}
+void DSCallSite::InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
+ ReachabilityCloner &RC) {
+ NH = RC.getClonedNH(Src);
+}
//===----------------------------------------------------------------------===//
// DSGraph Implementation
PrintAuxCalls = false;
NodeMapTy NodeMap;
cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
- InlinedGlobals.clear(); // clear set of "up-to-date" globals
}
DSGraph::DSGraph(const DSGraph &G, NodeMapTy &NodeMap)
: GlobalsGraph(0), TD(G.TD) {
PrintAuxCalls = false;
cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
- InlinedGlobals.clear(); // clear set of "up-to-date" globals
}
DSGraph::~DSGraph() {
/// specified mapping.
///
void DSNode::remapLinks(DSGraph::NodeMapTy &OldNodeMap) {
- for (unsigned i = 0, e = Links.size(); i != e; ++i) {
- DSNodeHandle &H = OldNodeMap[Links[i].getNode()];
- Links[i].setNode(H.getNode());
- Links[i].setOffset(Links[i].getOffset()+H.getOffset());
- }
-}
-
-
-/// cloneReachableNodes - Clone all reachable nodes from *Node into the
-/// current graph. This is a recursive function. The map OldNodeMap is a
-/// map from the original nodes to their clones.
-///
-void DSGraph::cloneReachableNodes(const DSNode* Node,
- unsigned BitsToClear,
- NodeMapTy& OldNodeMap,
- NodeMapTy& CompletedNodeMap) {
- if (CompletedNodeMap.find(Node) != CompletedNodeMap.end())
- return;
-
- DSNodeHandle& NH = OldNodeMap[Node];
- if (NH.getNode() != NULL)
- return;
-
- // else Node has not yet been cloned: clone it and clear the specified bits
- NH = new DSNode(*Node, this); // enters in OldNodeMap
- NH.getNode()->maskNodeTypes(~BitsToClear);
-
- // now recursively clone nodes pointed to by this node
- for (unsigned i = 0, e = Node->getNumLinks(); i != e; ++i) {
- const DSNodeHandle &Link = Node->getLink(i << DS::PointerShift);
- if (const DSNode* nextNode = Link.getNode())
- cloneReachableNodes(nextNode, BitsToClear, OldNodeMap, CompletedNodeMap);
- }
-}
-
-void DSGraph::cloneReachableSubgraph(const DSGraph& G,
- const hash_set<const DSNode*>& RootNodes,
- NodeMapTy& OldNodeMap,
- NodeMapTy& CompletedNodeMap,
- unsigned CloneFlags) {
- if (RootNodes.empty())
- return;
-
- assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
- assert(&G != this && "Cannot clone graph into itself!");
- assert((*RootNodes.begin())->getParentGraph() == &G &&
- "Root nodes do not belong to this graph!");
-
- // Remove alloca or mod/ref bits as specified...
- unsigned BitsToClear = ((CloneFlags & StripAllocaBit)? DSNode::AllocaNode : 0)
- | ((CloneFlags & StripModRefBits)? (DSNode::Modified | DSNode::Read) : 0)
- | ((CloneFlags & StripIncompleteBit)? DSNode::Incomplete : 0);
- BitsToClear |= DSNode::DEAD; // Clear dead flag...
-
- // Clone all nodes reachable from each root node, using a recursive helper
- for (hash_set<const DSNode*>::const_iterator I = RootNodes.begin(),
- E = RootNodes.end(); I != E; ++I)
- cloneReachableNodes(*I, BitsToClear, OldNodeMap, CompletedNodeMap);
-
- // Merge the map entries in OldNodeMap and CompletedNodeMap to remap links
- NodeMapTy MergedMap(OldNodeMap);
- MergedMap.insert(CompletedNodeMap.begin(), CompletedNodeMap.end());
-
- // Rewrite the links in the newly created nodes (the nodes in OldNodeMap)
- // to point into the current graph. MergedMap gives the full mapping.
- for (NodeMapTy::iterator I=OldNodeMap.begin(), E=OldNodeMap.end(); I!= E; ++I)
- I->second.getNode()->remapLinks(MergedMap);
-
- // Now merge cloned global nodes with their copies in the current graph
- // Just look through OldNodeMap to find such nodes!
- for (NodeMapTy::iterator I=OldNodeMap.begin(), E=OldNodeMap.end(); I!= E; ++I)
- if (I->first->isGlobalNode()) {
- DSNodeHandle &GClone = I->second;
- assert(GClone.getNode() != NULL && "NULL node in OldNodeMap?");
- const std::vector<GlobalValue*> &Globals = I->first->getGlobals();
- for (unsigned gi = 0, ge = Globals.size(); gi != ge; ++gi) {
- DSNodeHandle &GH = ScalarMap[Globals[gi]];
- GH.mergeWith(GClone);
+ for (unsigned i = 0, e = Links.size(); i != e; ++i)
+ if (DSNode *N = Links[i].getNode()) {
+ DSGraph::NodeMapTy::const_iterator ONMI = OldNodeMap.find(N);
+ if (ONMI != OldNodeMap.end()) {
+ Links[i].setNode(ONMI->second.getNode());
+ Links[i].setOffset(Links[i].getOffset()+ONMI->second.getOffset());
}
}
}
-
/// updateFromGlobalGraph - This function rematerializes global nodes and
/// nodes reachable from them from the globals graph into the current graph.
-/// It invokes cloneReachableSubgraph, using the globals in the current graph
-/// as the roots. It also uses the vector InlinedGlobals to avoid cloning and
-/// merging globals that are already up-to-date in the current graph. In
-/// practice, in the TD pass, this is likely to be a large fraction of the
-/// live global nodes in each function (since most live nodes are likely to
-/// have been brought up-to-date in at _some_ caller or callee).
+/// It uses the vector InlinedGlobals to avoid cloning and merging globals that
+/// are already up-to-date in the current graph. In practice, in the TD pass,
+/// this is likely to be a large fraction of the live global nodes in each
+/// function (since most live nodes are likely to have been brought up-to-date
+/// in at _some_ caller or callee).
///
void DSGraph::updateFromGlobalGraph() {
+ TIME_REGION(X, "updateFromGlobalGraph");
- // Use a map to keep track of the mapping between nodes in the globals graph
- // and this graph for up-to-date global nodes, which do not need to be cloned.
- NodeMapTy CompletedMap;
+ ReachabilityCloner RC(*this, *GlobalsGraph, 0);
- // Put the live, non-up-to-date global nodes into a set and the up-to-date
- // ones in the map above, mapping node in GlobalsGraph to the up-to-date node.
- hash_set<const DSNode*> GlobalNodeSet;
- for (ScalarMapTy::const_iterator I = getScalarMap().begin(),
- E = getScalarMap().end(); I != E; ++I)
- if (GlobalValue* GV = dyn_cast<GlobalValue>(I->first)) {
- DSNode* GNode = I->second.getNode();
- assert(GNode && "No node for live global in current Graph?");
- if (const DSNode* GGNode = GlobalsGraph->ScalarMap[GV].getNode())
- if (InlinedGlobals.count(GV) == 0) // GNode is not up-to-date
- GlobalNodeSet.insert(GGNode);
- else { // GNode is up-to-date
- CompletedMap[GGNode] = I->second;
- assert(GGNode->getNumLinks() == GNode->getNumLinks() &&
- "Links dont match in a node that is supposed to be up-to-date?"
- "\nremapLinks() will not work if the links don't match!");
- }
+ // Clone the non-up-to-date global nodes into this graph.
+ for (DSScalarMap::global_iterator I = getScalarMap().global_begin(),
+ E = getScalarMap().global_end(); I != E; ++I)
+ if (InlinedGlobals.count(*I) == 0) { // GNode is not up-to-date
+ ScalarMapTy::iterator It = GlobalsGraph->ScalarMap.find(*I);
+ if (It != GlobalsGraph->ScalarMap.end())
+ RC.merge(getNodeForValue(*I), It->second);
}
-
- // Clone the subgraph reachable from the vector of nodes in GlobalNodes
- // and merge the cloned global nodes with the corresponding ones, if any.
- NodeMapTy OldNodeMap;
- cloneReachableSubgraph(*GlobalsGraph, GlobalNodeSet, OldNodeMap,CompletedMap);
-
+
// Merging global nodes leaves behind unused nodes: get rid of them now.
- OldNodeMap.clear(); // remove references before dead node cleanup
- CompletedMap.clear(); // remove references before dead node cleanup
removeTriviallyDeadNodes();
}
void DSGraph::cloneInto(const DSGraph &G, ScalarMapTy &OldValMap,
ReturnNodesTy &OldReturnNodes, NodeMapTy &OldNodeMap,
unsigned CloneFlags) {
+ TIME_REGION(X, "cloneInto");
assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
assert(&G != this && "Cannot clone graph into itself!");
New->maskNodeTypes(~BitsToClear);
OldNodeMap[Old] = New;
}
-
#ifndef NDEBUG
Timer::addPeakMemoryMeasurement();
#endif
// If this is a global, add the global to this fn or merge if already exists
if (GlobalValue* GV = dyn_cast<GlobalValue>(I->first)) {
ScalarMap[GV].mergeWith(H);
- InlinedGlobals.insert(GV);
+ if (CloneFlags & DSGraph::UpdateInlinedGlobals)
+ InlinedGlobals.insert(GV);
}
}
}
}
+
/// mergeInGraph - The method is used for merging graphs together. If the
/// argument graph is not *this, it makes a clone of the specified graph, then
/// merges the nodes specified in the call site with the formal arguments in the
///
void DSGraph::mergeInGraph(const DSCallSite &CS, Function &F,
const DSGraph &Graph, unsigned CloneFlags) {
- ScalarMapTy OldValMap, *ScalarMap;
- DSNodeHandle RetVal;
+ TIME_REGION(X, "mergeInGraph");
// If this is not a recursive call, clone the graph into this graph...
if (&Graph != this) {
- // Clone the callee's graph into the current graph, keeping
- // track of where scalars in the old graph _used_ to point,
- // and of the new nodes matching nodes of the old graph.
- NodeMapTy OldNodeMap;
+ // Clone the callee's graph into the current graph, keeping track of where
+ // scalars in the old graph _used_ to point, and of the new nodes matching
+ // nodes of the old graph.
+ ReachabilityCloner RC(*this, Graph, CloneFlags);
+
+ // Set up argument bindings
+ Function::aiterator AI = F.abegin();
+ for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
+ // Advance the argument iterator to the first pointer argument...
+ while (AI != F.aend() && !isPointerType(AI->getType())) {
+ ++AI;
+#ifndef NDEBUG
+ if (AI == F.aend())
+ std::cerr << "Bad call to Function: " << F.getName() << "\n";
+#endif
+ }
+ if (AI == F.aend()) break;
+
+ // Add the link from the argument scalar to the provided value.
+ RC.merge(CS.getPtrArg(i), Graph.getNodeForValue(AI));
+ }
+
+ // Map the return node pointer over.
+ if (CS.getRetVal().getNode())
+ RC.merge(CS.getRetVal(), Graph.getReturnNodeFor(F));
+
+ // If requested, copy the calls or aux-calls lists.
+ if (!(CloneFlags & DontCloneCallNodes)) {
+ // Copy the function calls list...
+ FunctionCalls.reserve(FunctionCalls.size()+Graph.FunctionCalls.size());
+ for (unsigned i = 0, ei = Graph.FunctionCalls.size(); i != ei; ++i)
+ FunctionCalls.push_back(DSCallSite(Graph.FunctionCalls[i], RC));
+ }
- // The clone call may invalidate any of the vectors in the data
- // structure graph. Strip locals and don't copy the list of callers
- ReturnNodesTy OldRetNodes;
- cloneInto(Graph, OldValMap, OldRetNodes, OldNodeMap, CloneFlags);
-
- // We need to map the arguments for the function to the cloned nodes old
- // argument values. Do this now.
- RetVal = OldRetNodes[&F];
- ScalarMap = &OldValMap;
+ if (!(CloneFlags & DontCloneAuxCallNodes)) {
+ // Copy the auxiliary function calls list...
+ AuxFunctionCalls.reserve(AuxFunctionCalls.size()+
+ Graph.AuxFunctionCalls.size());
+ for (unsigned i = 0, ei = Graph.AuxFunctionCalls.size(); i != ei; ++i)
+ AuxFunctionCalls.push_back(DSCallSite(Graph.AuxFunctionCalls[i], RC));
+ }
+
+ // If the user requested it, add the nodes that we need to clone to the
+ // RootNodes set.
+ if (!EnableDSNodeGlobalRootsHack)
+ for (unsigned i = 0, e = Graph.Nodes.size(); i != e; ++i)
+ if (!Graph.Nodes[i]->getGlobals().empty())
+ RC.getClonedNH(Graph.Nodes[i]);
+
} else {
- RetVal = getReturnNodeFor(F);
- ScalarMap = &getScalarMap();
- }
+ DSNodeHandle RetVal = getReturnNodeFor(F);
- // Merge the return value with the return value of the context...
- RetVal.mergeWith(CS.getRetVal());
-
- // Resolve all of the function arguments...
- Function::aiterator AI = F.abegin();
-
- for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
- // Advance the argument iterator to the first pointer argument...
- while (AI != F.aend() && !isPointerType(AI->getType())) {
- ++AI;
+ // Merge the return value with the return value of the context...
+ RetVal.mergeWith(CS.getRetVal());
+
+ // Resolve all of the function arguments...
+ Function::aiterator AI = F.abegin();
+
+ for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i, ++AI) {
+ // Advance the argument iterator to the first pointer argument...
+ while (AI != F.aend() && !isPointerType(AI->getType())) {
+ ++AI;
#ifndef NDEBUG
- if (AI == F.aend())
- std::cerr << "Bad call to Function: " << F.getName() << "\n";
+ if (AI == F.aend())
+ std::cerr << "Bad call to Function: " << F.getName() << "\n";
#endif
+ }
+ if (AI == F.aend()) break;
+
+ // Add the link from the argument scalar to the provided value
+ DSNodeHandle &NH = getNodeForValue(AI);
+ assert(NH.getNode() && "Pointer argument without scalarmap entry?");
+ NH.mergeWith(CS.getPtrArg(i));
}
- if (AI == F.aend()) break;
-
- // Add the link from the argument scalar to the provided value
- assert(ScalarMap->count(AI) && "Argument not in scalar map?");
- DSNodeHandle &NH = (*ScalarMap)[AI];
- assert(NH.getNode() && "Pointer argument without scalarmap entry?");
- NH.mergeWith(CS.getPtrArg(i));
}
}
for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
if (isPointerType(I->getType()))
- Args.push_back(getScalarMap().find(I)->second);
+ Args.push_back(getNodeForValue(I));
return DSCallSite(CallSite(), getReturnNodeFor(F), &F, Args);
}
Function &F = *FI->first;
if (F.getName() != "main")
for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
- if (isPointerType(I->getType()) &&
- ScalarMap.find(I) != ScalarMap.end())
- markIncompleteNode(ScalarMap[I].getNode());
+ if (isPointerType(I->getType()))
+ markIncompleteNode(getNodeForValue(I).getNode());
}
// Mark stuff passed into functions calls as being incomplete...
}
static void removeIdenticalCalls(std::vector<DSCallSite> &Calls) {
-
// Remove trivially identical function calls
unsigned NumFns = Calls.size();
std::sort(Calls.begin(), Calls.end()); // Sort by callee as primary key!
+#if 1
// Scan the call list cleaning it up as necessary...
DSNode *LastCalleeNode = 0;
Function *LastCalleeFunc = 0;
// eliminate it.
if (CS.isIndirectCall() && CS.getCalleeNode()->getNumReferrers() == 1 &&
CS.getCalleeNode()->getNodeFlags() == 0) { // No useful info?
+#ifndef NDEBUG
std::cerr << "WARNING: Useless call site found??\n";
+#endif
CS.swap(Calls.back());
Calls.pop_back();
--i;
else
LastCalleeContainsExternalFunction = LastCalleeFunc->isExternal();
}
-
+
+ // It is not clear why, but enabling this code makes DSA really
+ // sensitive to node forwarding. Basically, with this enabled, DSA
+ // performs different number of inlinings based on which nodes are
+ // forwarding or not. This is clearly a problem, so this code is
+ // disabled until this can be resolved.
#if 1
- if (LastCalleeContainsExternalFunction ||
+ if (LastCalleeContainsExternalFunction
+#if 0
+ ||
// This should be more than enough context sensitivity!
// FIXME: Evaluate how many times this is tripped!
- NumDuplicateCalls > 20) {
+ NumDuplicateCalls > 20
+#endif
+ ) {
DSCallSite &OCS = Calls[i-1];
OCS.mergeWith(CS);
}
}
}
-
- Calls.erase(std::unique(Calls.begin(), Calls.end()),
- Calls.end());
+#endif
+ Calls.erase(std::unique(Calls.begin(), Calls.end()), Calls.end());
// Track the number of call nodes merged away...
NumCallNodesMerged += NumFns-Calls.size();
// we don't have to perform any non-trivial analysis here.
//
void DSGraph::removeTriviallyDeadNodes() {
+ TIME_REGION(X, "removeTriviallyDeadNodes");
removeIdenticalCalls(FunctionCalls);
removeIdenticalCalls(AuxFunctionCalls);
N->getLink(l*N->getPointerSize()).getNode();
}
- // Likewise, forward any edges from the scalar nodes...
- for (ScalarMapTy::iterator I = ScalarMap.begin(), E = ScalarMap.end();
- I != E; ++I)
- I->second.getNode();
+ // NOTE: This code is disabled. Though it should, in theory, allow us to
+ // remove more nodes down below, the scan of the scalar map is incredibly
+ // expensive for certain programs (with large SCCs). In the future, if we can
+ // make the scalar map scan more efficient, then we can reenable this.
+#if 0
+ { TIME_REGION(X, "removeTriviallyDeadNodes:scalarmap");
+ // Likewise, forward any edges from the scalar nodes. While we are at it,
+ // clean house a bit.
+ for (ScalarMapTy::iterator I = ScalarMap.begin(),E = ScalarMap.end();I != E;){
+ I->second.getNode();
+ ++I;
+ }
+ }
+#endif
bool isGlobalsGraph = !GlobalsGraph;
for (unsigned i = 0; i != Nodes.size(); ++i) {
if (Node->getNumReferrers() == Node->getGlobals().size()) {
const std::vector<GlobalValue*> &Globals = Node->getGlobals();
- // Loop through and make sure all of the globals are referring directly
- // to the node...
- for (unsigned j = 0, e = Globals.size(); j != e; ++j) {
- DSNode *N = ScalarMap.find(Globals[j])->second.getNode();
- assert(N == Node && "ScalarMap doesn't match globals list!");
- }
-
// Make sure NumReferrers still agrees, if so, the node is truly dead.
+ // Remove the scalarmap entries, which will drop the actual referrer
+ // count to zero.
if (Node->getNumReferrers() == Globals.size()) {
for (unsigned j = 0, e = Globals.size(); j != e; ++j)
ScalarMap.erase(Globals[j]);
- Node->makeNodeDead();
- }
- }
-
-#ifdef SANER_CODE_FOR_CHECKING_IF_ALL_REFERRERS_ARE_FROM_SCALARMAP
- //
- // *** It seems to me that we should be able to simply check if
- // *** there are fewer or equal #referrers as #globals and make
- // *** sure that all those referrers are in the scalar map?
- //
- if (Node->getNumReferrers() <= Node->getGlobals().size()) {
- const std::vector<GlobalValue*> &Globals = Node->getGlobals();
-
-#ifndef NDEBUG
- // Loop through and make sure all of the globals are referring directly
- // to the node...
- for (unsigned j = 0, e = Globals.size(); j != e; ++j) {
- DSNode *N = ScalarMap.find(Globals[j])->second.getNode();
- assert(N == Node && "ScalarMap doesn't match globals list!");
+ if (Node->hasNoReferrers())
+ Node->makeNodeDead();
}
-#endif
-
- // Make sure NumReferrers still agrees. The node is truly dead.
- assert(Node->getNumReferrers() == Globals.size());
- for (unsigned j = 0, e = Globals.size(); j != e; ++j)
- ScalarMap.erase(Globals[j]);
- Node->makeNodeDead();
}
-#endif
}
if (Node->getNodeFlags() == 0 && Node->hasNoReferrers()) {
void DSNode::markReachableNodes(hash_set<DSNode*> &ReachableNodes) {
if (this == 0) return;
assert(getForwardNode() == 0 && "Cannot mark a forwarded node!");
- if (ReachableNodes.count(this)) return; // Already marked reachable
- ReachableNodes.insert(this); // Is reachable now
-
- for (unsigned i = 0, e = getSize(); i < e; i += DS::PointerSize)
- getLink(i).getNode()->markReachableNodes(ReachableNodes);
+ if (ReachableNodes.insert(this).second) // Is newly reachable?
+ for (unsigned i = 0, e = getSize(); i < e; i += DS::PointerSize)
+ getLink(i).getNode()->markReachableNodes(ReachableNodes);
}
void DSCallSite::markReachableNodes(hash_set<DSNode*> &Nodes) {
// Reduce the amount of work we have to do... remove dummy nodes left over by
// merging...
- removeTriviallyDeadNodes();
+ //removeTriviallyDeadNodes();
+
+ TIME_REGION(X, "removeDeadNodes");
// FIXME: Merge non-trivially identical call nodes...
hash_set<DSNode*> Alive;
std::vector<std::pair<Value*, DSNode*> > GlobalNodes;
+ // Copy and merge all information about globals to the GlobalsGraph if this is
+ // not a final pass (where unreachable globals are removed).
+ //
+ // Strip all alloca bits since the current function is only for the BU pass.
+ // Strip all incomplete bits since they are short-lived properties and they
+ // will be correctly computed when rematerializing nodes into the functions.
+ //
+ ReachabilityCloner GGCloner(*GlobalsGraph, *this, DSGraph::StripAllocaBit |
+ DSGraph::StripIncompleteBit);
+
// Mark all nodes reachable by (non-global) scalar nodes as alive...
+ { TIME_REGION(Y, "removeDeadNodes:scalarscan");
for (ScalarMapTy::iterator I = ScalarMap.begin(), E = ScalarMap.end(); I !=E;)
if (isa<GlobalValue>(I->first)) { // Keep track of global nodes
assert(I->second.getNode() && "Null global node?");
assert(I->second.getNode()->isGlobalNode() && "Should be a global node!");
GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
+
+ // Make sure that all globals are cloned over as roots.
+ if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
+ DSGraph::ScalarMapTy::iterator SMI =
+ GlobalsGraph->getScalarMap().find(I->first);
+ if (SMI != GlobalsGraph->getScalarMap().end())
+ GGCloner.merge(SMI->second, I->second);
+ else
+ GGCloner.getClonedNH(I->second);
+ }
++I;
} else {
+ DSNode *N = I->second.getNode();
+#if 0
// Check to see if this is a worthless node generated for non-pointer
// values, such as integers. Consider an addition of long types: A+B.
// Assuming we can track all uses of the value in this context, and it is
// uninteresting for data structure analysis. If we run across one of
// these, prune the scalar pointing to it.
//
- DSNode *N = I->second.getNode();
- if (N->getNodeFlags() == DSNode::UnknownNode && !isa<Argument>(I->first)){
+ if (N->getNodeFlags() == DSNode::UnknownNode && !isa<Argument>(I->first))
ScalarMap.erase(I++);
- } else {
- I->second.getNode()->markReachableNodes(Alive);
+ else {
+#endif
+ N->markReachableNodes(Alive);
++I;
- }
+ //}
}
+ }
- // The return value is alive as well...
+ // The return values are alive as well.
for (ReturnNodesTy::iterator I = ReturnNodes.begin(), E = ReturnNodes.end();
I != E; ++I)
I->second.getNode()->markReachableNodes(Alive);
for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
FunctionCalls[i].markReachableNodes(Alive);
- // Copy and merge all information about globals to the GlobalsGraph
- // if this is not a final pass (where unreachable globals are removed)
- NodeMapTy GlobalNodeMap;
- hash_set<const DSNode*> GlobalNodeSet;
-
- for (std::vector<std::pair<Value*, DSNode*> >::const_iterator
- I = GlobalNodes.begin(), E = GlobalNodes.end(); I != E; ++I)
- GlobalNodeSet.insert(I->second); // put global nodes into a set
// Now find globals and aux call nodes that are already live or reach a live
// value (which makes them live in turn), and continue till no more are found.
//
Iterate = false;
if (!(Flags & DSGraph::RemoveUnreachableGlobals))
- for (unsigned i = 0; i != GlobalNodes.size(); ++i)
- if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited,
- Flags & DSGraph::RemoveUnreachableGlobals)) {
- std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to...
- GlobalNodes.pop_back(); // erase efficiently
- Iterate = true;
- }
+ for (unsigned i = 0; i != GlobalNodes.size(); ++i)
+ if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited,
+ Flags & DSGraph::RemoveUnreachableGlobals)) {
+ std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to...
+ GlobalNodes.pop_back(); // erase efficiently
+ Iterate = true;
+ }
// Mark only unresolvable call nodes for moving to the GlobalsGraph since
// call nodes that get resolved will be difficult to remove from that graph.
// GlobalsGraph, and all nodes reachable from those nodes
//
if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
-
- // First, add the dead aux call nodes to the set of root nodes for cloning
- // -- return value at this call site, if any
- // -- actual arguments passed at this call site
- // -- callee node at this call site, if this is an indirect call
- for (unsigned i = CurIdx, e = AuxFunctionCalls.size(); i != e; ++i) {
- if (const DSNode* RetNode = AuxFunctionCalls[i].getRetVal().getNode())
- GlobalNodeSet.insert(RetNode);
- for (unsigned j=0, N=AuxFunctionCalls[i].getNumPtrArgs(); j < N; ++j)
- if (const DSNode* ArgTarget=AuxFunctionCalls[i].getPtrArg(j).getNode())
- GlobalNodeSet.insert(ArgTarget);
- if (AuxFunctionCalls[i].isIndirectCall())
- GlobalNodeSet.insert(AuxFunctionCalls[i].getCalleeNode());
- }
-
- // There are no "pre-completed" nodes so use any empty map for those.
- // Strip all alloca bits since the current function is only for the BU pass.
- // Strip all incomplete bits since they are short-lived properties and they
- // will be correctly computed when rematerializing nodes into the functions.
- //
- NodeMapTy CompletedMap;
- GlobalsGraph->cloneReachableSubgraph(*this, GlobalNodeSet,
- GlobalNodeMap, CompletedMap,
- (DSGraph::StripAllocaBit |
- DSGraph::StripIncompleteBit));
- }
-
- // Remove all dead aux function calls...
- if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
- assert(GlobalsGraph && "No globals graph available??");
-
- // Copy the unreachable call nodes to the globals graph, updating
- // their target pointers using the GlobalNodeMap
+ // Copy the unreachable call nodes to the globals graph, updating their
+ // target pointers using the GGCloner
for (unsigned i = CurIdx, e = AuxFunctionCalls.size(); i != e; ++i)
GlobalsGraph->AuxFunctionCalls.push_back(DSCallSite(AuxFunctionCalls[i],
- GlobalNodeMap));
+ GGCloner));
}
// Crop all the useless ones out...
AuxFunctionCalls.erase(AuxFunctionCalls.begin()+CurIdx,
AuxFunctionCalls.end());
- // We are finally done with the GlobalNodeMap so we can clear it and
- // then get rid of unused nodes in the GlobalsGraph produced by merging.
- GlobalNodeMap.clear();
- GlobalsGraph->removeTriviallyDeadNodes();
+ // We are finally done with the GGCloner so we can clear it and then get rid
+ // of unused nodes in the GlobalsGraph produced by merging.
+ if (GGCloner.clonedNode()) {
+ GGCloner.destroy();
+ GlobalsGraph->removeTriviallyDeadNodes();
+ }
// At this point, any nodes which are visited, but not alive, are nodes
// which can be removed. Loop over all nodes, eliminating completely
// Remove all unreachable globals from the ScalarMap.
// If flag RemoveUnreachableGlobals is set, GlobalNodes has only dead nodes.
// In either case, the dead nodes will not be in the set Alive.
- for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i) {
- assert(((Flags & DSGraph::RemoveUnreachableGlobals) ||
- !Alive.count(GlobalNodes[i].second)) && "huh? non-dead global");
+ for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i)
if (!Alive.count(GlobalNodes[i].second))
ScalarMap.erase(GlobalNodes[i].first);
- }
+ else
+ assert((Flags & DSGraph::RemoveUnreachableGlobals) && "non-dead global");
// Delete all dead nodes now since their referrer counts are zero.
for (unsigned i = 0, e = DeadNodes.size(); i != e; ++i)
AssertAuxCallNodesInGraph();
}
-/// mergeInGlobalsGraph - This method is useful for clients to incorporate the
-/// globals graph into the DS, BU or TD graph for a function. This code retains
-/// all globals, i.e., does not delete unreachable globals after they are
-/// inlined.
-///
-void DSGraph::mergeInGlobalsGraph() {
- NodeMapTy GlobalNodeMap;
- ScalarMapTy OldValMap;
- ReturnNodesTy OldRetNodes;
- cloneInto(*GlobalsGraph, OldValMap, OldRetNodes, GlobalNodeMap,
- DSGraph::KeepAllocaBit | DSGraph::DontCloneCallNodes |
- DSGraph::DontCloneAuxCallNodes);
-
- // Now merge existing global nodes in the GlobalsGraph with their copies
- for (ScalarMapTy::iterator I = ScalarMap.begin(), E = ScalarMap.end();
- I != E; ++I)
- if (isa<GlobalValue>(I->first)) { // Found a global node
- DSNodeHandle &GH = I->second;
- DSNodeHandle &GGNodeH = GlobalsGraph->getScalarMap()[I->first];
- GH.mergeWith(GlobalNodeMap[GGNodeH.getNode()]);
- }
-
- // Merging leaves behind unused nodes: get rid of them now.
- GlobalNodeMap.clear();
- OldValMap.clear();
- OldRetNodes.clear();
- removeTriviallyDeadNodes();
-}
-
-
/// computeNodeMapping - Given roots in two different DSGraphs, traverse the
/// nodes reachable from the two graphs, computing the mapping of nodes from
/// the first to the second graph.