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removeDeadNodes is called, only call it at the end of the pass being run. This saves 1.3 seconds running DSA on 177.mesa (5.3->4.0s), which is pretty big. This is only possible because of the automatic garbage collection done on forwarding nodes. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@11178 91177308-0d34-0410-b5e6-96231b3b80d8
1848 lines
69 KiB
C++
1848 lines
69 KiB
C++
//===- DataStructure.cpp - Implement the core data structure analysis -----===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file was developed by the LLVM research group and is distributed under
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// the University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the core data structure functionality.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/Analysis/DSGraph.h"
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#include "llvm/Function.h"
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#include "llvm/iOther.h"
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#include "llvm/DerivedTypes.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Assembly/Writer.h"
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#include "Support/CommandLine.h"
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#include "Support/Debug.h"
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#include "Support/STLExtras.h"
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#include "Support/Statistic.h"
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#include "Support/Timer.h"
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#include <algorithm>
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using namespace llvm;
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namespace {
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Statistic<> NumFolds ("dsa", "Number of nodes completely folded");
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Statistic<> NumCallNodesMerged("dsa", "Number of call nodes merged");
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Statistic<> NumNodeAllocated ("dsa", "Number of nodes allocated");
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Statistic<> NumDNE ("dsa", "Number of nodes removed by reachability");
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Statistic<> NumTrivialDNE ("dsa", "Number of nodes trivially removed");
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Statistic<> NumTrivialGlobalDNE("dsa", "Number of globals trivially removed");
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cl::opt<bool>
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EnableDSNodeGlobalRootsHack("enable-dsa-globalrootshack", cl::Hidden,
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cl::desc("Make DSA less aggressive when cloning graphs"));
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};
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#if 1
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#define TIME_REGION(VARNAME, DESC) \
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NamedRegionTimer VARNAME(DESC)
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#else
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#define TIME_REGION(VARNAME, DESC)
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#endif
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using namespace DS;
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DSNode *DSNodeHandle::HandleForwarding() const {
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assert(N->isForwarding() && "Can only be invoked if forwarding!");
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// Handle node forwarding here!
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DSNode *Next = N->ForwardNH.getNode(); // Cause recursive shrinkage
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Offset += N->ForwardNH.getOffset();
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if (--N->NumReferrers == 0) {
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// Removing the last referrer to the node, sever the forwarding link
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N->stopForwarding();
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}
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N = Next;
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N->NumReferrers++;
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if (N->Size <= Offset) {
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assert(N->Size <= 1 && "Forwarded to shrunk but not collapsed node?");
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Offset = 0;
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}
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return N;
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}
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//===----------------------------------------------------------------------===//
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// DSNode Implementation
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//===----------------------------------------------------------------------===//
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DSNode::DSNode(const Type *T, DSGraph *G)
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: NumReferrers(0), Size(0), ParentGraph(G), Ty(Type::VoidTy), NodeType(0) {
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// Add the type entry if it is specified...
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if (T) mergeTypeInfo(T, 0);
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if (G) G->addNode(this);
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++NumNodeAllocated;
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}
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// DSNode copy constructor... do not copy over the referrers list!
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DSNode::DSNode(const DSNode &N, DSGraph *G, bool NullLinks)
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: NumReferrers(0), Size(N.Size), ParentGraph(G),
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Ty(N.Ty), Globals(N.Globals), NodeType(N.NodeType) {
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if (!NullLinks)
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Links = N.Links;
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else
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Links.resize(N.Links.size()); // Create the appropriate number of null links
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G->addNode(this);
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++NumNodeAllocated;
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}
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/// getTargetData - Get the target data object used to construct this node.
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///
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const TargetData &DSNode::getTargetData() const {
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return ParentGraph->getTargetData();
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}
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void DSNode::assertOK() const {
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assert((Ty != Type::VoidTy ||
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Ty == Type::VoidTy && (Size == 0 ||
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(NodeType & DSNode::Array))) &&
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"Node not OK!");
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assert(ParentGraph && "Node has no parent?");
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const DSScalarMap &SM = ParentGraph->getScalarMap();
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for (unsigned i = 0, e = Globals.size(); i != e; ++i) {
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assert(SM.count(Globals[i]));
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assert(SM.find(Globals[i])->second.getNode() == this);
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}
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}
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/// forwardNode - Mark this node as being obsolete, and all references to it
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/// should be forwarded to the specified node and offset.
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///
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void DSNode::forwardNode(DSNode *To, unsigned Offset) {
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assert(this != To && "Cannot forward a node to itself!");
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assert(ForwardNH.isNull() && "Already forwarding from this node!");
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if (To->Size <= 1) Offset = 0;
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assert((Offset < To->Size || (Offset == To->Size && Offset == 0)) &&
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"Forwarded offset is wrong!");
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ForwardNH.setNode(To);
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ForwardNH.setOffset(Offset);
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NodeType = DEAD;
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Size = 0;
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Ty = Type::VoidTy;
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// Remove this node from the parent graph's Nodes list.
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ParentGraph->unlinkNode(this);
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ParentGraph = 0;
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}
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// addGlobal - Add an entry for a global value to the Globals list. This also
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// marks the node with the 'G' flag if it does not already have it.
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//
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void DSNode::addGlobal(GlobalValue *GV) {
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// Keep the list sorted.
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std::vector<GlobalValue*>::iterator I =
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std::lower_bound(Globals.begin(), Globals.end(), GV);
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if (I == Globals.end() || *I != GV) {
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//assert(GV->getType()->getElementType() == Ty);
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Globals.insert(I, GV);
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NodeType |= GlobalNode;
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}
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}
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/// foldNodeCompletely - If we determine that this node has some funny
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/// behavior happening to it that we cannot represent, we fold it down to a
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/// single, completely pessimistic, node. This node is represented as a
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/// single byte with a single TypeEntry of "void".
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///
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void DSNode::foldNodeCompletely() {
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if (isNodeCompletelyFolded()) return; // If this node is already folded...
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++NumFolds;
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// If this node has a size that is <= 1, we don't need to create a forwarding
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// node.
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if (getSize() <= 1) {
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NodeType |= DSNode::Array;
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Ty = Type::VoidTy;
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Size = 1;
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assert(Links.size() <= 1 && "Size is 1, but has more links?");
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Links.resize(1);
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} else {
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// Create the node we are going to forward to. This is required because
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// some referrers may have an offset that is > 0. By forcing them to
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// forward, the forwarder has the opportunity to correct the offset.
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DSNode *DestNode = new DSNode(0, ParentGraph);
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DestNode->NodeType = NodeType|DSNode::Array;
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DestNode->Ty = Type::VoidTy;
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DestNode->Size = 1;
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DestNode->Globals.swap(Globals);
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// Start forwarding to the destination node...
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forwardNode(DestNode, 0);
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if (!Links.empty()) {
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DestNode->Links.reserve(1);
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DSNodeHandle NH(DestNode);
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DestNode->Links.push_back(Links[0]);
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// If we have links, merge all of our outgoing links together...
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for (unsigned i = Links.size()-1; i != 0; --i)
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NH.getNode()->Links[0].mergeWith(Links[i]);
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Links.clear();
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} else {
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DestNode->Links.resize(1);
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}
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}
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}
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/// isNodeCompletelyFolded - Return true if this node has been completely
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/// folded down to something that can never be expanded, effectively losing
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/// all of the field sensitivity that may be present in the node.
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///
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bool DSNode::isNodeCompletelyFolded() const {
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return getSize() == 1 && Ty == Type::VoidTy && isArray();
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}
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namespace {
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/// TypeElementWalker Class - Used for implementation of physical subtyping...
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///
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class TypeElementWalker {
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struct StackState {
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const Type *Ty;
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unsigned Offset;
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unsigned Idx;
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StackState(const Type *T, unsigned Off = 0)
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: Ty(T), Offset(Off), Idx(0) {}
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};
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std::vector<StackState> Stack;
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const TargetData &TD;
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public:
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TypeElementWalker(const Type *T, const TargetData &td) : TD(td) {
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Stack.push_back(T);
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StepToLeaf();
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}
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bool isDone() const { return Stack.empty(); }
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const Type *getCurrentType() const { return Stack.back().Ty; }
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unsigned getCurrentOffset() const { return Stack.back().Offset; }
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void StepToNextType() {
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PopStackAndAdvance();
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StepToLeaf();
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}
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private:
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/// PopStackAndAdvance - Pop the current element off of the stack and
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/// advance the underlying element to the next contained member.
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void PopStackAndAdvance() {
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assert(!Stack.empty() && "Cannot pop an empty stack!");
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Stack.pop_back();
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while (!Stack.empty()) {
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StackState &SS = Stack.back();
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if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
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++SS.Idx;
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if (SS.Idx != ST->getElementTypes().size()) {
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const StructLayout *SL = TD.getStructLayout(ST);
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SS.Offset += SL->MemberOffsets[SS.Idx]-SL->MemberOffsets[SS.Idx-1];
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return;
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}
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Stack.pop_back(); // At the end of the structure
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} else {
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const ArrayType *AT = cast<ArrayType>(SS.Ty);
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++SS.Idx;
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if (SS.Idx != AT->getNumElements()) {
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SS.Offset += TD.getTypeSize(AT->getElementType());
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return;
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}
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Stack.pop_back(); // At the end of the array
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}
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}
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}
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/// StepToLeaf - Used by physical subtyping to move to the first leaf node
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/// on the type stack.
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void StepToLeaf() {
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if (Stack.empty()) return;
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while (!Stack.empty() && !Stack.back().Ty->isFirstClassType()) {
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StackState &SS = Stack.back();
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if (const StructType *ST = dyn_cast<StructType>(SS.Ty)) {
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if (ST->getElementTypes().empty()) {
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assert(SS.Idx == 0);
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PopStackAndAdvance();
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} else {
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// Step into the structure...
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assert(SS.Idx < ST->getElementTypes().size());
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const StructLayout *SL = TD.getStructLayout(ST);
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Stack.push_back(StackState(ST->getElementTypes()[SS.Idx],
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SS.Offset+SL->MemberOffsets[SS.Idx]));
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}
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} else {
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const ArrayType *AT = cast<ArrayType>(SS.Ty);
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if (AT->getNumElements() == 0) {
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assert(SS.Idx == 0);
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PopStackAndAdvance();
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} else {
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// Step into the array...
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assert(SS.Idx < AT->getNumElements());
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Stack.push_back(StackState(AT->getElementType(),
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SS.Offset+SS.Idx*
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TD.getTypeSize(AT->getElementType())));
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}
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}
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}
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}
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};
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} // end anonymous namespace
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/// ElementTypesAreCompatible - Check to see if the specified types are
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/// "physically" compatible. If so, return true, else return false. We only
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/// have to check the fields in T1: T2 may be larger than T1. If AllowLargerT1
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/// is true, then we also allow a larger T1.
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///
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static bool ElementTypesAreCompatible(const Type *T1, const Type *T2,
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bool AllowLargerT1, const TargetData &TD){
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TypeElementWalker T1W(T1, TD), T2W(T2, TD);
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while (!T1W.isDone() && !T2W.isDone()) {
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if (T1W.getCurrentOffset() != T2W.getCurrentOffset())
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return false;
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const Type *T1 = T1W.getCurrentType();
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const Type *T2 = T2W.getCurrentType();
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if (T1 != T2 && !T1->isLosslesslyConvertibleTo(T2))
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return false;
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T1W.StepToNextType();
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T2W.StepToNextType();
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}
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return AllowLargerT1 || T1W.isDone();
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}
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/// mergeTypeInfo - This method merges the specified type into the current node
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/// at the specified offset. This may update the current node's type record if
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/// this gives more information to the node, it may do nothing to the node if
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/// this information is already known, or it may merge the node completely (and
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/// return true) if the information is incompatible with what is already known.
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///
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/// This method returns true if the node is completely folded, otherwise false.
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///
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bool DSNode::mergeTypeInfo(const Type *NewTy, unsigned Offset,
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bool FoldIfIncompatible) {
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const TargetData &TD = getTargetData();
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// Check to make sure the Size member is up-to-date. Size can be one of the
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// following:
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// Size = 0, Ty = Void: Nothing is known about this node.
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// Size = 0, Ty = FnTy: FunctionPtr doesn't have a size, so we use zero
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// Size = 1, Ty = Void, Array = 1: The node is collapsed
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// Otherwise, sizeof(Ty) = Size
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//
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assert(((Size == 0 && Ty == Type::VoidTy && !isArray()) ||
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(Size == 0 && !Ty->isSized() && !isArray()) ||
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(Size == 1 && Ty == Type::VoidTy && isArray()) ||
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(Size == 0 && !Ty->isSized() && !isArray()) ||
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(TD.getTypeSize(Ty) == Size)) &&
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"Size member of DSNode doesn't match the type structure!");
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assert(NewTy != Type::VoidTy && "Cannot merge void type into DSNode!");
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if (Offset == 0 && NewTy == Ty)
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return false; // This should be a common case, handle it efficiently
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// Return true immediately if the node is completely folded.
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if (isNodeCompletelyFolded()) return true;
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// If this is an array type, eliminate the outside arrays because they won't
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// be used anyway. This greatly reduces the size of large static arrays used
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// as global variables, for example.
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//
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bool WillBeArray = false;
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while (const ArrayType *AT = dyn_cast<ArrayType>(NewTy)) {
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// FIXME: we might want to keep small arrays, but must be careful about
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// things like: [2 x [10000 x int*]]
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NewTy = AT->getElementType();
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WillBeArray = true;
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}
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// Figure out how big the new type we're merging in is...
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unsigned NewTySize = NewTy->isSized() ? TD.getTypeSize(NewTy) : 0;
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// Otherwise check to see if we can fold this type into the current node. If
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// we can't, we fold the node completely, if we can, we potentially update our
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// internal state.
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//
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if (Ty == Type::VoidTy) {
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// If this is the first type that this node has seen, just accept it without
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// question....
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assert(Offset == 0 && !isArray() &&
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"Cannot have an offset into a void node!");
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Ty = NewTy;
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NodeType &= ~Array;
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if (WillBeArray) NodeType |= Array;
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Size = NewTySize;
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// Calculate the number of outgoing links from this node.
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Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
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return false;
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}
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// Handle node expansion case here...
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if (Offset+NewTySize > Size) {
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// It is illegal to grow this node if we have treated it as an array of
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// objects...
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if (isArray()) {
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if (FoldIfIncompatible) foldNodeCompletely();
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return true;
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}
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if (Offset) { // We could handle this case, but we don't for now...
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std::cerr << "UNIMP: Trying to merge a growth type into "
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<< "offset != 0: Collapsing!\n";
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if (FoldIfIncompatible) foldNodeCompletely();
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return true;
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}
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// Okay, the situation is nice and simple, we are trying to merge a type in
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// at offset 0 that is bigger than our current type. Implement this by
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// switching to the new type and then merge in the smaller one, which should
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// hit the other code path here. If the other code path decides it's not
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// ok, it will collapse the node as appropriate.
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//
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const Type *OldTy = Ty;
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Ty = NewTy;
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NodeType &= ~Array;
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if (WillBeArray) NodeType |= Array;
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Size = NewTySize;
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// Must grow links to be the appropriate size...
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Links.resize((Size+DS::PointerSize-1) >> DS::PointerShift);
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// Merge in the old type now... which is guaranteed to be smaller than the
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// "current" type.
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return mergeTypeInfo(OldTy, 0);
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}
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assert(Offset <= Size &&
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"Cannot merge something into a part of our type that doesn't exist!");
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// Find the section of Ty that NewTy overlaps with... first we find the
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// type that starts at offset Offset.
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//
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unsigned O = 0;
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const Type *SubType = Ty;
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while (O < Offset) {
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assert(Offset-O < TD.getTypeSize(SubType) && "Offset out of range!");
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switch (SubType->getPrimitiveID()) {
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case Type::StructTyID: {
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const StructType *STy = cast<StructType>(SubType);
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const StructLayout &SL = *TD.getStructLayout(STy);
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unsigned i = 0, e = SL.MemberOffsets.size();
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for (; i+1 < e && SL.MemberOffsets[i+1] <= Offset-O; ++i)
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/* empty */;
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// The offset we are looking for must be in the i'th element...
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SubType = STy->getElementTypes()[i];
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O += SL.MemberOffsets[i];
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break;
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}
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case Type::ArrayTyID: {
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SubType = cast<ArrayType>(SubType)->getElementType();
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unsigned ElSize = TD.getTypeSize(SubType);
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unsigned Remainder = (Offset-O) % ElSize;
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O = Offset-Remainder;
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break;
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}
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default:
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if (FoldIfIncompatible) foldNodeCompletely();
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return true;
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}
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}
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assert(O == Offset && "Could not achieve the correct offset!");
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// If we found our type exactly, early exit
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if (SubType == NewTy) return false;
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// Differing function types don't require us to merge. They are not values anyway.
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if (isa<FunctionType>(SubType) &&
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isa<FunctionType>(NewTy)) return false;
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unsigned SubTypeSize = SubType->isSized() ? TD.getTypeSize(SubType) : 0;
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// Ok, we are getting desperate now. Check for physical subtyping, where we
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// just require each element in the node to be compatible.
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if (NewTySize <= SubTypeSize && NewTySize && NewTySize < 256 &&
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SubTypeSize && SubTypeSize < 256 &&
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ElementTypesAreCompatible(NewTy, SubType, !isArray(), TD))
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return false;
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// Okay, so we found the leader type at the offset requested. Search the list
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// of types that starts at this offset. If SubType is currently an array or
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// structure, the type desired may actually be the first element of the
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// composite type...
|
|
//
|
|
unsigned PadSize = SubTypeSize; // Size, including pad memory which is ignored
|
|
while (SubType != NewTy) {
|
|
const Type *NextSubType = 0;
|
|
unsigned NextSubTypeSize = 0;
|
|
unsigned NextPadSize = 0;
|
|
switch (SubType->getPrimitiveID()) {
|
|
case Type::StructTyID: {
|
|
const StructType *STy = cast<StructType>(SubType);
|
|
const StructLayout &SL = *TD.getStructLayout(STy);
|
|
if (SL.MemberOffsets.size() > 1)
|
|
NextPadSize = SL.MemberOffsets[1];
|
|
else
|
|
NextPadSize = SubTypeSize;
|
|
NextSubType = STy->getElementTypes()[0];
|
|
NextSubTypeSize = TD.getTypeSize(NextSubType);
|
|
break;
|
|
}
|
|
case Type::ArrayTyID:
|
|
NextSubType = cast<ArrayType>(SubType)->getElementType();
|
|
NextSubTypeSize = TD.getTypeSize(NextSubType);
|
|
NextPadSize = NextSubTypeSize;
|
|
break;
|
|
default: ;
|
|
// fall out
|
|
}
|
|
|
|
if (NextSubType == 0)
|
|
break; // In the default case, break out of the loop
|
|
|
|
if (NextPadSize < NewTySize)
|
|
break; // Don't allow shrinking to a smaller type than NewTySize
|
|
SubType = NextSubType;
|
|
SubTypeSize = NextSubTypeSize;
|
|
PadSize = NextPadSize;
|
|
}
|
|
|
|
// If we found the type exactly, return it...
|
|
if (SubType == NewTy)
|
|
return false;
|
|
|
|
// Check to see if we have a compatible, but different type...
|
|
if (NewTySize == SubTypeSize) {
|
|
// Check to see if this type is obviously convertible... int -> uint f.e.
|
|
if (NewTy->isLosslesslyConvertibleTo(SubType))
|
|
return false;
|
|
|
|
// Check to see if we have a pointer & integer mismatch going on here,
|
|
// loading a pointer as a long, for example.
|
|
//
|
|
if (SubType->isInteger() && isa<PointerType>(NewTy) ||
|
|
NewTy->isInteger() && isa<PointerType>(SubType))
|
|
return false;
|
|
} else if (NewTySize > SubTypeSize && NewTySize <= PadSize) {
|
|
// We are accessing the field, plus some structure padding. Ignore the
|
|
// structure padding.
|
|
return false;
|
|
}
|
|
|
|
Module *M = 0;
|
|
if (getParentGraph()->getReturnNodes().size())
|
|
M = getParentGraph()->getReturnNodes().begin()->first->getParent();
|
|
DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: ";
|
|
WriteTypeSymbolic(std::cerr, Ty, M) << "\n due to:";
|
|
WriteTypeSymbolic(std::cerr, NewTy, M) << " @ " << Offset << "!\n"
|
|
<< "SubType: ";
|
|
WriteTypeSymbolic(std::cerr, SubType, M) << "\n\n");
|
|
|
|
if (FoldIfIncompatible) foldNodeCompletely();
|
|
return true;
|
|
}
|
|
|
|
|
|
|
|
// addEdgeTo - Add an edge from the current node to the specified node. This
|
|
// can cause merging of nodes in the graph.
|
|
//
|
|
void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
|
|
if (NH.isNull()) return; // Nothing to do
|
|
|
|
DSNodeHandle &ExistingEdge = getLink(Offset);
|
|
if (!ExistingEdge.isNull()) {
|
|
// Merge the two nodes...
|
|
ExistingEdge.mergeWith(NH);
|
|
} else { // No merging to perform...
|
|
setLink(Offset, NH); // Just force a link in there...
|
|
}
|
|
}
|
|
|
|
|
|
// MergeSortedVectors - Efficiently merge a vector into another vector where
|
|
// duplicates are not allowed and both are sorted. This assumes that 'T's are
|
|
// efficiently copyable and have sane comparison semantics.
|
|
//
|
|
static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
|
|
const std::vector<GlobalValue*> &Src) {
|
|
// By far, the most common cases will be the simple ones. In these cases,
|
|
// avoid having to allocate a temporary vector...
|
|
//
|
|
if (Src.empty()) { // Nothing to merge in...
|
|
return;
|
|
} else if (Dest.empty()) { // Just copy the result in...
|
|
Dest = Src;
|
|
} else if (Src.size() == 1) { // Insert a single element...
|
|
const GlobalValue *V = Src[0];
|
|
std::vector<GlobalValue*>::iterator I =
|
|
std::lower_bound(Dest.begin(), Dest.end(), V);
|
|
if (I == Dest.end() || *I != Src[0]) // If not already contained...
|
|
Dest.insert(I, Src[0]);
|
|
} else if (Dest.size() == 1) {
|
|
GlobalValue *Tmp = Dest[0]; // Save value in temporary...
|
|
Dest = Src; // Copy over list...
|
|
std::vector<GlobalValue*>::iterator I =
|
|
std::lower_bound(Dest.begin(), Dest.end(), Tmp);
|
|
if (I == Dest.end() || *I != Tmp) // If not already contained...
|
|
Dest.insert(I, Tmp);
|
|
|
|
} else {
|
|
// Make a copy to the side of Dest...
|
|
std::vector<GlobalValue*> Old(Dest);
|
|
|
|
// Make space for all of the type entries now...
|
|
Dest.resize(Dest.size()+Src.size());
|
|
|
|
// Merge the two sorted ranges together... into Dest.
|
|
std::merge(Old.begin(), Old.end(), Src.begin(), Src.end(), Dest.begin());
|
|
|
|
// Now erase any duplicate entries that may have accumulated into the
|
|
// vectors (because they were in both of the input sets)
|
|
Dest.erase(std::unique(Dest.begin(), Dest.end()), Dest.end());
|
|
}
|
|
}
|
|
|
|
void DSNode::mergeGlobals(const std::vector<GlobalValue*> &RHS) {
|
|
MergeSortedVectors(Globals, RHS);
|
|
}
|
|
|
|
// 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.
|
|
//
|
|
// ***WARNING***
|
|
// Since merging may cause either node to go away, we must always
|
|
// use the node-handles to refer to the nodes. These node handles are
|
|
// automatically updated during merging, so will always provide access
|
|
// to the correct node after a merge.
|
|
//
|
|
void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
|
|
assert(CurNodeH.getOffset() >= NH.getOffset() &&
|
|
"This should have been enforced in the caller.");
|
|
|
|
// Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
|
|
// respect to NH.Offset) is now zero. NOffset is the distance from the base
|
|
// of our object that N starts from.
|
|
//
|
|
unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
|
|
unsigned NSize = NH.getNode()->getSize();
|
|
|
|
// If the two nodes are of different size, and the smaller node has the array
|
|
// bit set, collapse!
|
|
if (NSize != CurNodeH.getNode()->getSize()) {
|
|
if (NSize < CurNodeH.getNode()->getSize()) {
|
|
if (NH.getNode()->isArray())
|
|
NH.getNode()->foldNodeCompletely();
|
|
} else if (CurNodeH.getNode()->isArray()) {
|
|
NH.getNode()->foldNodeCompletely();
|
|
}
|
|
}
|
|
|
|
// Merge the type entries of the two nodes together...
|
|
if (NH.getNode()->Ty != Type::VoidTy)
|
|
CurNodeH.getNode()->mergeTypeInfo(NH.getNode()->Ty, NOffset);
|
|
assert(!CurNodeH.getNode()->isDeadNode());
|
|
|
|
// If we are merging a node with a completely folded node, then both nodes are
|
|
// now completely folded.
|
|
//
|
|
if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
|
|
if (!NH.getNode()->isNodeCompletelyFolded()) {
|
|
NH.getNode()->foldNodeCompletely();
|
|
assert(NH.getNode() && NH.getOffset() == 0 &&
|
|
"folding did not make offset 0?");
|
|
NOffset = NH.getOffset();
|
|
NSize = NH.getNode()->getSize();
|
|
assert(NOffset == 0 && NSize == 1);
|
|
}
|
|
} else if (NH.getNode()->isNodeCompletelyFolded()) {
|
|
CurNodeH.getNode()->foldNodeCompletely();
|
|
assert(CurNodeH.getNode() && CurNodeH.getOffset() == 0 &&
|
|
"folding did not make offset 0?");
|
|
NOffset = NH.getOffset();
|
|
NSize = NH.getNode()->getSize();
|
|
assert(NOffset == 0 && NSize == 1);
|
|
}
|
|
|
|
DSNode *N = NH.getNode();
|
|
if (CurNodeH.getNode() == N || N == 0) return;
|
|
assert(!CurNodeH.getNode()->isDeadNode());
|
|
|
|
// Merge the NodeType information.
|
|
CurNodeH.getNode()->NodeType |= N->NodeType;
|
|
|
|
// Start forwarding to the new node!
|
|
N->forwardNode(CurNodeH.getNode(), NOffset);
|
|
assert(!CurNodeH.getNode()->isDeadNode());
|
|
|
|
// Make all of the outgoing links of N now be outgoing links of CurNodeH.
|
|
//
|
|
for (unsigned i = 0; i < N->getNumLinks(); ++i) {
|
|
DSNodeHandle &Link = N->getLink(i << DS::PointerShift);
|
|
if (Link.getNode()) {
|
|
// 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 = CurNodeH.getNode();
|
|
if (CN->Size != 1)
|
|
MergeOffset = ((i << DS::PointerShift)+NOffset) % CN->getSize();
|
|
CN->addEdgeTo(MergeOffset, Link);
|
|
}
|
|
}
|
|
|
|
// Now that there are no outgoing edges, all of the Links are dead.
|
|
N->Links.clear();
|
|
|
|
// Merge the globals list...
|
|
if (!N->Globals.empty()) {
|
|
CurNodeH.getNode()->mergeGlobals(N->Globals);
|
|
|
|
// Delete the globals from the old node...
|
|
std::vector<GlobalValue*>().swap(N->Globals);
|
|
}
|
|
}
|
|
|
|
|
|
// mergeWith - Merge this node and the specified node, moving all links to and
|
|
// from the argument node into the current node, deleting the node argument.
|
|
// 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, we update it to
|
|
// point to this node).
|
|
//
|
|
void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
|
|
DSNode *N = NH.getNode();
|
|
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!");
|
|
|
|
if (N == this) {
|
|
// We cannot merge two pieces of the same node together, collapse the node
|
|
// completely.
|
|
DEBUG(std::cerr << "Attempting to merge two chunks of"
|
|
<< " the same node together!\n");
|
|
foldNodeCompletely();
|
|
return;
|
|
}
|
|
|
|
// If both nodes are not at offset 0, make sure that we are merging the node
|
|
// at an later offset into the node with the zero offset.
|
|
//
|
|
if (Offset < NH.getOffset()) {
|
|
N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
|
|
return;
|
|
} else if (Offset == NH.getOffset() && getSize() < N->getSize()) {
|
|
// If the offsets are the same, merge the smaller node into the bigger node
|
|
N->mergeWith(DSNodeHandle(this, Offset), NH.getOffset());
|
|
return;
|
|
}
|
|
|
|
// Ok, now we can merge the two nodes. Use a static helper that works with
|
|
// two node handles, since "this" may get merged away at intermediate steps.
|
|
DSNodeHandle CurNodeH(this, Offset);
|
|
DSNodeHandle NHCopy(NH);
|
|
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()+SrcGNH.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());
|
|
|
|
// If the source node contained any globals, make sure to create entries
|
|
// in the scalar map for them!
|
|
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");
|
|
assert(SrcGNH.getNode() == SN && "Global mapping inconsistent");
|
|
Dest.getNodeForValue(GV).mergeWith(DSNodeHandle(DestGNH.getNode(),
|
|
DestGNH.getOffset()+SrcGNH.getOffset()));
|
|
|
|
if (CloneFlags & DSGraph::UpdateInlinedGlobals)
|
|
Dest.getInlinedGlobals().insert(GV);
|
|
}
|
|
}
|
|
|
|
|
|
// 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
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// Define here to avoid including iOther.h and BasicBlock.h in DSGraph.h
|
|
Function &DSCallSite::getCaller() const {
|
|
return *Site.getInstruction()->getParent()->getParent();
|
|
}
|
|
|
|
void DSCallSite::InitNH(DSNodeHandle &NH, const DSNodeHandle &Src,
|
|
ReachabilityCloner &RC) {
|
|
NH = RC.getClonedNH(Src);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// DSGraph Implementation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// getFunctionNames - Return a space separated list of the name of the
|
|
/// functions in this graph (if any)
|
|
std::string DSGraph::getFunctionNames() const {
|
|
switch (getReturnNodes().size()) {
|
|
case 0: return "Globals graph";
|
|
case 1: return getReturnNodes().begin()->first->getName();
|
|
default:
|
|
std::string Return;
|
|
for (DSGraph::ReturnNodesTy::const_iterator I = getReturnNodes().begin();
|
|
I != getReturnNodes().end(); ++I)
|
|
Return += I->first->getName() + " ";
|
|
Return.erase(Return.end()-1, Return.end()); // Remove last space character
|
|
return Return;
|
|
}
|
|
}
|
|
|
|
|
|
DSGraph::DSGraph(const DSGraph &G) : GlobalsGraph(0), TD(G.TD) {
|
|
PrintAuxCalls = false;
|
|
NodeMapTy NodeMap;
|
|
cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
|
|
}
|
|
|
|
DSGraph::DSGraph(const DSGraph &G, NodeMapTy &NodeMap)
|
|
: GlobalsGraph(0), TD(G.TD) {
|
|
PrintAuxCalls = false;
|
|
cloneInto(G, ScalarMap, ReturnNodes, NodeMap);
|
|
}
|
|
|
|
DSGraph::~DSGraph() {
|
|
FunctionCalls.clear();
|
|
AuxFunctionCalls.clear();
|
|
InlinedGlobals.clear();
|
|
ScalarMap.clear();
|
|
ReturnNodes.clear();
|
|
|
|
// Drop all intra-node references, so that assertions don't fail...
|
|
for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
|
|
(*NI)->dropAllReferences();
|
|
|
|
// Free all of the nodes.
|
|
Nodes.clear();
|
|
}
|
|
|
|
// dump - Allow inspection of graph in a debugger.
|
|
void DSGraph::dump() const { print(std::cerr); }
|
|
|
|
|
|
/// remapLinks - Change all of the Links in the current node according to the
|
|
/// specified mapping.
|
|
///
|
|
void DSNode::remapLinks(DSGraph::NodeMapTy &OldNodeMap) {
|
|
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 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");
|
|
ReachabilityCloner RC(*this, *GlobalsGraph, 0);
|
|
|
|
// 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
|
|
DSScalarMap::iterator It = GlobalsGraph->ScalarMap.find(*I);
|
|
if (It != GlobalsGraph->ScalarMap.end())
|
|
RC.merge(getNodeForValue(*I), It->second);
|
|
}
|
|
}
|
|
|
|
/// cloneInto - Clone the specified DSGraph into the current graph. The
|
|
/// translated ScalarMap for the old function is filled into the OldValMap
|
|
/// member, and the translated ReturnNodes map is returned into ReturnNodes.
|
|
///
|
|
/// The CloneFlags member controls various aspects of the cloning process.
|
|
///
|
|
void DSGraph::cloneInto(const DSGraph &G, DSScalarMap &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!");
|
|
|
|
// Remember the last node that existed before, or node_end() if there are no
|
|
// nodes.
|
|
node_iterator FN = node_end();
|
|
if (FN != node_begin()) --FN;
|
|
|
|
// 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...
|
|
for (node_iterator I = G.node_begin(), E = G.node_end(); I != E; ++I)
|
|
if (!(*I)->isForwarding()) {
|
|
DSNode *New = new DSNode(**I, this);
|
|
New->maskNodeTypes(~BitsToClear);
|
|
OldNodeMap[*I] = New;
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
Timer::addPeakMemoryMeasurement();
|
|
#endif
|
|
|
|
// Move FN to the first newly added node.
|
|
if (FN != node_end())
|
|
++FN;
|
|
else
|
|
FN = node_begin();
|
|
|
|
// Rewrite the links in the new nodes to point into the current graph now.
|
|
for (; FN != node_end(); ++FN)
|
|
(*FN)->remapLinks(OldNodeMap);
|
|
|
|
// Copy the scalar map... merging all of the global nodes...
|
|
for (DSScalarMap::const_iterator I = G.ScalarMap.begin(),
|
|
E = G.ScalarMap.end(); I != E; ++I) {
|
|
DSNodeHandle &MappedNode = OldNodeMap[I->second.getNode()];
|
|
DSNodeHandle &H = OldValMap[I->first];
|
|
H.mergeWith(DSNodeHandle(MappedNode.getNode(),
|
|
I->second.getOffset()+MappedNode.getOffset()));
|
|
|
|
// 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);
|
|
if (CloneFlags & DSGraph::UpdateInlinedGlobals)
|
|
InlinedGlobals.insert(GV);
|
|
}
|
|
}
|
|
|
|
if (!(CloneFlags & DontCloneCallNodes)) {
|
|
// Copy the function calls list...
|
|
unsigned FC = FunctionCalls.size(); // FirstCall
|
|
FunctionCalls.reserve(FC+G.FunctionCalls.size());
|
|
for (unsigned i = 0, ei = G.FunctionCalls.size(); i != ei; ++i)
|
|
FunctionCalls.push_back(DSCallSite(G.FunctionCalls[i], OldNodeMap));
|
|
}
|
|
|
|
if (!(CloneFlags & DontCloneAuxCallNodes)) {
|
|
// Copy the auxiliary function calls list...
|
|
unsigned FC = AuxFunctionCalls.size(); // FirstCall
|
|
AuxFunctionCalls.reserve(FC+G.AuxFunctionCalls.size());
|
|
for (unsigned i = 0, ei = G.AuxFunctionCalls.size(); i != ei; ++i)
|
|
AuxFunctionCalls.push_back(DSCallSite(G.AuxFunctionCalls[i], OldNodeMap));
|
|
}
|
|
|
|
// Map the return node pointers over...
|
|
for (ReturnNodesTy::const_iterator I = G.getReturnNodes().begin(),
|
|
E = G.getReturnNodes().end(); I != E; ++I) {
|
|
const DSNodeHandle &Ret = I->second;
|
|
DSNodeHandle &MappedRet = OldNodeMap[Ret.getNode()];
|
|
OldReturnNodes.insert(std::make_pair(I->first,
|
|
DSNodeHandle(MappedRet.getNode(),
|
|
MappedRet.getOffset()+Ret.getOffset())));
|
|
}
|
|
}
|
|
|
|
|
|
/// 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
|
|
/// graph.
|
|
///
|
|
void DSGraph::mergeInGraph(const DSCallSite &CS, Function &F,
|
|
const DSGraph &Graph, unsigned CloneFlags) {
|
|
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.
|
|
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 // FIXME: We should merge vararg arguments!
|
|
if (AI == F.aend() && !F.getFunctionType()->isVarArg())
|
|
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));
|
|
}
|
|
|
|
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 (node_iterator NI = Graph.node_begin(), E = Graph.node_end();
|
|
NI != E; ++NI)
|
|
if (!(*NI)->getGlobals().empty())
|
|
RC.getClonedNH(*NI);
|
|
|
|
} else {
|
|
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;
|
|
#ifndef NDEBUG // FIXME: We should merge varargs arguments!!
|
|
if (AI == F.aend() && !F.getFunctionType()->isVarArg())
|
|
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));
|
|
}
|
|
}
|
|
}
|
|
|
|
/// getCallSiteForArguments - Get the arguments and return value bindings for
|
|
/// the specified function in the current graph.
|
|
///
|
|
DSCallSite DSGraph::getCallSiteForArguments(Function &F) const {
|
|
std::vector<DSNodeHandle> Args;
|
|
|
|
for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
|
|
if (isPointerType(I->getType()))
|
|
Args.push_back(getNodeForValue(I));
|
|
|
|
return DSCallSite(CallSite(), getReturnNodeFor(F), &F, Args);
|
|
}
|
|
|
|
|
|
|
|
// markIncompleteNodes - Mark the specified node as having contents that are not
|
|
// known with the current analysis we have performed. Because a node makes all
|
|
// of the nodes it can reach incomplete if the node itself is incomplete, we
|
|
// must recursively traverse the data structure graph, marking all reachable
|
|
// nodes as incomplete.
|
|
//
|
|
static void markIncompleteNode(DSNode *N) {
|
|
// Stop recursion if no node, or if node already marked...
|
|
if (N == 0 || N->isIncomplete()) return;
|
|
|
|
// Actually mark the node
|
|
N->setIncompleteMarker();
|
|
|
|
// Recursively process children...
|
|
for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
|
|
if (DSNode *DSN = N->getLink(i).getNode())
|
|
markIncompleteNode(DSN);
|
|
}
|
|
|
|
static void markIncomplete(DSCallSite &Call) {
|
|
// Then the return value is certainly incomplete!
|
|
markIncompleteNode(Call.getRetVal().getNode());
|
|
|
|
// All objects pointed to by function arguments are incomplete!
|
|
for (unsigned i = 0, e = Call.getNumPtrArgs(); i != e; ++i)
|
|
markIncompleteNode(Call.getPtrArg(i).getNode());
|
|
}
|
|
|
|
// markIncompleteNodes - Traverse the graph, identifying nodes that may be
|
|
// modified by other functions that have not been resolved yet. This marks
|
|
// nodes that are reachable through three sources of "unknownness":
|
|
//
|
|
// Global Variables, Function Calls, and Incoming Arguments
|
|
//
|
|
// For any node that may have unknown components (because something outside the
|
|
// scope of current analysis may have modified it), the 'Incomplete' flag is
|
|
// added to the NodeType.
|
|
//
|
|
void DSGraph::markIncompleteNodes(unsigned Flags) {
|
|
// Mark any incoming arguments as incomplete...
|
|
if (Flags & DSGraph::MarkFormalArgs)
|
|
for (ReturnNodesTy::iterator FI = ReturnNodes.begin(), E =ReturnNodes.end();
|
|
FI != E; ++FI) {
|
|
Function &F = *FI->first;
|
|
if (F.getName() != "main")
|
|
for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I)
|
|
if (isPointerType(I->getType()))
|
|
markIncompleteNode(getNodeForValue(I).getNode());
|
|
}
|
|
|
|
// Mark stuff passed into functions calls as being incomplete...
|
|
if (!shouldPrintAuxCalls())
|
|
for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
|
|
markIncomplete(FunctionCalls[i]);
|
|
else
|
|
for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
|
|
markIncomplete(AuxFunctionCalls[i]);
|
|
|
|
|
|
// Mark all global nodes as incomplete...
|
|
if ((Flags & DSGraph::IgnoreGlobals) == 0)
|
|
for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
|
|
if ((*NI)->isGlobalNode() && (*NI)->getNumLinks())
|
|
markIncompleteNode(*NI);
|
|
}
|
|
|
|
static inline void killIfUselessEdge(DSNodeHandle &Edge) {
|
|
if (DSNode *N = Edge.getNode()) // Is there an edge?
|
|
if (N->getNumReferrers() == 1) // Does it point to a lonely node?
|
|
// No interesting info?
|
|
if ((N->getNodeFlags() & ~DSNode::Incomplete) == 0 &&
|
|
N->getType() == Type::VoidTy && !N->isNodeCompletelyFolded())
|
|
Edge.setNode(0); // Kill the edge!
|
|
}
|
|
|
|
static inline bool nodeContainsExternalFunction(const DSNode *N) {
|
|
const std::vector<GlobalValue*> &Globals = N->getGlobals();
|
|
for (unsigned i = 0, e = Globals.size(); i != e; ++i)
|
|
if (Globals[i]->isExternal())
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
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;
|
|
unsigned NumDuplicateCalls = 0;
|
|
bool LastCalleeContainsExternalFunction = false;
|
|
for (unsigned i = 0; i != Calls.size(); ++i) {
|
|
DSCallSite &CS = Calls[i];
|
|
|
|
// If the Callee is a useless edge, this must be an unreachable call site,
|
|
// 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 {
|
|
// If the return value or any arguments point to a void node with no
|
|
// information at all in it, and the call node is the only node to point
|
|
// to it, remove the edge to the node (killing the node).
|
|
//
|
|
killIfUselessEdge(CS.getRetVal());
|
|
for (unsigned a = 0, e = CS.getNumPtrArgs(); a != e; ++a)
|
|
killIfUselessEdge(CS.getPtrArg(a));
|
|
|
|
// If this call site calls the same function as the last call site, and if
|
|
// the function pointer contains an external function, this node will
|
|
// never be resolved. Merge the arguments of the call node because no
|
|
// information will be lost.
|
|
//
|
|
if ((CS.isDirectCall() && CS.getCalleeFunc() == LastCalleeFunc) ||
|
|
(CS.isIndirectCall() && CS.getCalleeNode() == LastCalleeNode)) {
|
|
++NumDuplicateCalls;
|
|
if (NumDuplicateCalls == 1) {
|
|
if (LastCalleeNode)
|
|
LastCalleeContainsExternalFunction =
|
|
nodeContainsExternalFunction(LastCalleeNode);
|
|
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 0
|
|
||
|
|
// This should be more than enough context sensitivity!
|
|
// FIXME: Evaluate how many times this is tripped!
|
|
NumDuplicateCalls > 20
|
|
#endif
|
|
) {
|
|
DSCallSite &OCS = Calls[i-1];
|
|
OCS.mergeWith(CS);
|
|
|
|
// The node will now be eliminated as a duplicate!
|
|
if (CS.getNumPtrArgs() < OCS.getNumPtrArgs())
|
|
CS = OCS;
|
|
else if (CS.getNumPtrArgs() > OCS.getNumPtrArgs())
|
|
OCS = CS;
|
|
}
|
|
#endif
|
|
} else {
|
|
if (CS.isDirectCall()) {
|
|
LastCalleeFunc = CS.getCalleeFunc();
|
|
LastCalleeNode = 0;
|
|
} else {
|
|
LastCalleeNode = CS.getCalleeNode();
|
|
LastCalleeFunc = 0;
|
|
}
|
|
NumDuplicateCalls = 0;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
Calls.erase(std::unique(Calls.begin(), Calls.end()), Calls.end());
|
|
|
|
// Track the number of call nodes merged away...
|
|
NumCallNodesMerged += NumFns-Calls.size();
|
|
|
|
DEBUG(if (NumFns != Calls.size())
|
|
std::cerr << "Merged " << (NumFns-Calls.size()) << " call nodes.\n";);
|
|
}
|
|
|
|
|
|
// removeTriviallyDeadNodes - After the graph has been constructed, this method
|
|
// removes all unreachable nodes that are created because they got merged with
|
|
// other nodes in the graph. These nodes will all be trivially unreachable, so
|
|
// we don't have to perform any non-trivial analysis here.
|
|
//
|
|
void DSGraph::removeTriviallyDeadNodes() {
|
|
TIME_REGION(X, "removeTriviallyDeadNodes");
|
|
|
|
// Loop over all of the nodes in the graph, calling getNode on each field.
|
|
// This will cause all nodes to update their forwarding edges, causing
|
|
// forwarded nodes to be delete-able.
|
|
for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI) {
|
|
DSNode *N = *NI;
|
|
for (unsigned l = 0, e = N->getNumLinks(); l != e; ++l)
|
|
N->getLink(l*N->getPointerSize()).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 (DSScalarMap::iterator I = ScalarMap.begin(),E = ScalarMap.end();I != E;){
|
|
I->second.getNode();
|
|
++I;
|
|
}
|
|
}
|
|
#endif
|
|
bool isGlobalsGraph = !GlobalsGraph;
|
|
|
|
for (NodeListTy::iterator NI = Nodes.begin(), E = Nodes.end(); NI != E; ) {
|
|
DSNode &Node = *NI;
|
|
|
|
// Do not remove *any* global nodes in the globals graph.
|
|
// This is a special case because such nodes may not have I, M, R flags set.
|
|
if (Node.isGlobalNode() && isGlobalsGraph) {
|
|
++NI;
|
|
continue;
|
|
}
|
|
|
|
if (Node.isComplete() && !Node.isModified() && !Node.isRead()) {
|
|
// This is a useless node if it has no mod/ref info (checked above),
|
|
// outgoing edges (which it cannot, as it is not modified in this
|
|
// context), and it has no incoming edges. If it is a global node it may
|
|
// have all of these properties and still have incoming edges, due to the
|
|
// scalar map, so we check those now.
|
|
//
|
|
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 = getNodeForValue(Globals[j]).getNode();
|
|
assert(N == &Node && "ScalarMap doesn't match globals list!");
|
|
}
|
|
|
|
// Make sure NumReferrers still agrees, if so, the node is truly dead.
|
|
if (Node.getNumReferrers() == Globals.size()) {
|
|
for (unsigned j = 0, e = Globals.size(); j != e; ++j)
|
|
ScalarMap.erase(Globals[j]);
|
|
Node.makeNodeDead();
|
|
++NumTrivialGlobalDNE;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (Node.getNodeFlags() == 0 && Node.hasNoReferrers()) {
|
|
// This node is dead!
|
|
NI = Nodes.erase(NI); // Erase & remove from node list.
|
|
++NumTrivialDNE;
|
|
} else {
|
|
++NI;
|
|
}
|
|
}
|
|
|
|
removeIdenticalCalls(FunctionCalls);
|
|
removeIdenticalCalls(AuxFunctionCalls);
|
|
}
|
|
|
|
|
|
/// markReachableNodes - This method recursively traverses the specified
|
|
/// DSNodes, marking any nodes which are reachable. All reachable nodes it adds
|
|
/// to the set, which allows it to only traverse visited nodes once.
|
|
///
|
|
void DSNode::markReachableNodes(hash_set<DSNode*> &ReachableNodes) {
|
|
if (this == 0) return;
|
|
assert(getForwardNode() == 0 && "Cannot mark a forwarded node!");
|
|
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) {
|
|
getRetVal().getNode()->markReachableNodes(Nodes);
|
|
if (isIndirectCall()) getCalleeNode()->markReachableNodes(Nodes);
|
|
|
|
for (unsigned i = 0, e = getNumPtrArgs(); i != e; ++i)
|
|
getPtrArg(i).getNode()->markReachableNodes(Nodes);
|
|
}
|
|
|
|
// CanReachAliveNodes - Simple graph walker that recursively traverses the graph
|
|
// looking for a node that is marked alive. If an alive node is found, return
|
|
// true, otherwise return false. If an alive node is reachable, this node is
|
|
// marked as alive...
|
|
//
|
|
static bool CanReachAliveNodes(DSNode *N, hash_set<DSNode*> &Alive,
|
|
hash_set<DSNode*> &Visited,
|
|
bool IgnoreGlobals) {
|
|
if (N == 0) return false;
|
|
assert(N->getForwardNode() == 0 && "Cannot mark a forwarded node!");
|
|
|
|
// If this is a global node, it will end up in the globals graph anyway, so we
|
|
// don't need to worry about it.
|
|
if (IgnoreGlobals && N->isGlobalNode()) return false;
|
|
|
|
// If we know that this node is alive, return so!
|
|
if (Alive.count(N)) return true;
|
|
|
|
// Otherwise, we don't think the node is alive yet, check for infinite
|
|
// recursion.
|
|
if (Visited.count(N)) return false; // Found a cycle
|
|
Visited.insert(N); // No recursion, insert into Visited...
|
|
|
|
for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
|
|
if (CanReachAliveNodes(N->getLink(i).getNode(), Alive, Visited,
|
|
IgnoreGlobals)) {
|
|
N->markReachableNodes(Alive);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// CallSiteUsesAliveArgs - Return true if the specified call site can reach any
|
|
// alive nodes.
|
|
//
|
|
static bool CallSiteUsesAliveArgs(DSCallSite &CS, hash_set<DSNode*> &Alive,
|
|
hash_set<DSNode*> &Visited,
|
|
bool IgnoreGlobals) {
|
|
if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited,
|
|
IgnoreGlobals))
|
|
return true;
|
|
if (CS.isIndirectCall() &&
|
|
CanReachAliveNodes(CS.getCalleeNode(), Alive, Visited, IgnoreGlobals))
|
|
return true;
|
|
for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
|
|
if (CanReachAliveNodes(CS.getPtrArg(i).getNode(), Alive, Visited,
|
|
IgnoreGlobals))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
// removeDeadNodes - Use a more powerful reachability analysis to eliminate
|
|
// subgraphs that are unreachable. This often occurs because the data
|
|
// structure doesn't "escape" into it's caller, and thus should be eliminated
|
|
// from the caller's graph entirely. This is only appropriate to use when
|
|
// inlining graphs.
|
|
//
|
|
void DSGraph::removeDeadNodes(unsigned Flags) {
|
|
DEBUG(AssertGraphOK(); if (GlobalsGraph) GlobalsGraph->AssertGraphOK());
|
|
|
|
// Reduce the amount of work we have to do... remove dummy nodes left over by
|
|
// merging...
|
|
removeTriviallyDeadNodes();
|
|
|
|
TIME_REGION(X, "removeDeadNodes");
|
|
|
|
// FIXME: Merge non-trivially identical call nodes...
|
|
|
|
// Alive - a set that holds all nodes found to be reachable/alive.
|
|
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 (DSScalarMap::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
|
|
// NOT used as a pointer, we can delete the node. We will be able to
|
|
// detect this situation if the node pointed to ONLY has Unknown bit set
|
|
// in the node. In this case, the node is not incomplete, does not point
|
|
// to any other nodes (no mod/ref bits set), and is therefore
|
|
// uninteresting for data structure analysis. If we run across one of
|
|
// these, prune the scalar pointing to it.
|
|
//
|
|
if (N->getNodeFlags() == DSNode::UnknownNode && !isa<Argument>(I->first))
|
|
ScalarMap.erase(I++);
|
|
else {
|
|
#endif
|
|
N->markReachableNodes(Alive);
|
|
++I;
|
|
//}
|
|
}
|
|
}
|
|
|
|
// The return values are alive as well.
|
|
for (ReturnNodesTy::iterator I = ReturnNodes.begin(), E = ReturnNodes.end();
|
|
I != E; ++I)
|
|
I->second.getNode()->markReachableNodes(Alive);
|
|
|
|
// Mark any nodes reachable by primary calls as alive...
|
|
for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
|
|
FunctionCalls[i].markReachableNodes(Alive);
|
|
|
|
|
|
// 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.
|
|
//
|
|
bool Iterate;
|
|
hash_set<DSNode*> Visited;
|
|
std::vector<unsigned char> AuxFCallsAlive(AuxFunctionCalls.size());
|
|
do {
|
|
Visited.clear();
|
|
// If any global node points to a non-global that is "alive", the global is
|
|
// "alive" as well... Remove it from the GlobalNodes list so we only have
|
|
// unreachable globals in the list.
|
|
//
|
|
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;
|
|
}
|
|
|
|
// Mark only unresolvable call nodes for moving to the GlobalsGraph since
|
|
// call nodes that get resolved will be difficult to remove from that graph.
|
|
// The final unresolved call nodes must be handled specially at the end of
|
|
// the BU pass (i.e., in main or other roots of the call graph).
|
|
for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
|
|
if (!AuxFCallsAlive[i] &&
|
|
(AuxFunctionCalls[i].isIndirectCall()
|
|
|| CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited,
|
|
Flags & DSGraph::RemoveUnreachableGlobals))) {
|
|
AuxFunctionCalls[i].markReachableNodes(Alive);
|
|
AuxFCallsAlive[i] = true;
|
|
Iterate = true;
|
|
}
|
|
} while (Iterate);
|
|
|
|
// Move dead aux function calls to the end of the list
|
|
unsigned CurIdx = 0;
|
|
for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
|
|
if (AuxFCallsAlive[i])
|
|
AuxFunctionCalls[CurIdx++].swap(AuxFunctionCalls[i]);
|
|
|
|
// Copy and merge all global nodes and dead aux call nodes into the
|
|
// GlobalsGraph, and all nodes reachable from those nodes
|
|
//
|
|
if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
|
|
// 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],
|
|
GGCloner));
|
|
}
|
|
// Crop all the useless ones out...
|
|
AuxFunctionCalls.erase(AuxFunctionCalls.begin()+CurIdx,
|
|
AuxFunctionCalls.end());
|
|
|
|
// We are finally done with the GGCloner so we can destroy it.
|
|
GGCloner.destroy();
|
|
|
|
// At this point, any nodes which are visited, but not alive, are nodes
|
|
// which can be removed. Loop over all nodes, eliminating completely
|
|
// unreachable nodes.
|
|
//
|
|
std::vector<DSNode*> DeadNodes;
|
|
DeadNodes.reserve(Nodes.size());
|
|
for (NodeListTy::iterator NI = Nodes.begin(), E = Nodes.end(); NI != E;)
|
|
if (!Alive.count(NI)) {
|
|
++NumDNE;
|
|
DSNode *N = Nodes.remove(NI++);
|
|
DeadNodes.push_back(N);
|
|
N->dropAllReferences();
|
|
} else {
|
|
assert(NI->getForwardNode() == 0 && "Alive forwarded node?");
|
|
++NI;
|
|
}
|
|
|
|
// 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)
|
|
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)
|
|
delete DeadNodes[i];
|
|
|
|
DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
|
|
}
|
|
|
|
void DSGraph::AssertGraphOK() const {
|
|
for (node_iterator NI = node_begin(), E = node_end(); NI != E; ++NI)
|
|
(*NI)->assertOK();
|
|
|
|
for (ScalarMapTy::const_iterator I = ScalarMap.begin(),
|
|
E = ScalarMap.end(); I != E; ++I) {
|
|
assert(I->second.getNode() && "Null node in scalarmap!");
|
|
AssertNodeInGraph(I->second.getNode());
|
|
if (GlobalValue *GV = dyn_cast<GlobalValue>(I->first)) {
|
|
assert(I->second.getNode()->isGlobalNode() &&
|
|
"Global points to node, but node isn't global?");
|
|
AssertNodeContainsGlobal(I->second.getNode(), GV);
|
|
}
|
|
}
|
|
AssertCallNodesInGraph();
|
|
AssertAuxCallNodesInGraph();
|
|
}
|
|
|
|
/// 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.
|
|
///
|
|
void DSGraph::computeNodeMapping(const DSNodeHandle &NH1,
|
|
const DSNodeHandle &NH2, NodeMapTy &NodeMap,
|
|
bool StrictChecking) {
|
|
DSNode *N1 = NH1.getNode(), *N2 = NH2.getNode();
|
|
if (N1 == 0 || N2 == 0) return;
|
|
|
|
DSNodeHandle &Entry = NodeMap[N1];
|
|
if (Entry.getNode()) {
|
|
// Termination of recursion!
|
|
assert(!StrictChecking ||
|
|
(Entry.getNode() == N2 &&
|
|
Entry.getOffset() == (NH2.getOffset()-NH1.getOffset())) &&
|
|
"Inconsistent mapping detected!");
|
|
return;
|
|
}
|
|
|
|
Entry.setNode(N2);
|
|
Entry.setOffset(NH2.getOffset()-NH1.getOffset());
|
|
|
|
// Loop over all of the fields that N1 and N2 have in common, recursively
|
|
// mapping the edges together now.
|
|
int N2Idx = NH2.getOffset()-NH1.getOffset();
|
|
unsigned N2Size = N2->getSize();
|
|
for (unsigned i = 0, e = N1->getSize(); i < e; i += DS::PointerSize)
|
|
if (unsigned(N2Idx)+i < N2Size)
|
|
computeNodeMapping(N1->getLink(i), N2->getLink(N2Idx+i), NodeMap);
|
|
}
|