mirror of
https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5684 91177308-0d34-0410-b5e6-96231b3b80d8
1202 lines
45 KiB
C++
1202 lines
45 KiB
C++
//===- DataStructure.cpp - Implement the core data structure analysis -----===//
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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 "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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namespace {
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Statistic<> NumFolds ("dsnode", "Number of nodes completely folded");
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Statistic<> NumCallNodesMerged("dsnode", "Number of call nodes merged");
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};
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namespace DS { // TODO: FIXME
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extern TargetData TD;
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}
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using namespace DS;
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DSNode *DSNodeHandle::HandleForwarding() const {
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assert(!N->ForwardNH.isNull() && "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(unsigned NT, const Type *T, DSGraph *G)
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: NumReferrers(0), Size(0), ParentGraph(G), Ty(Type::VoidTy), NodeType(NT) {
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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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G->getNodes().push_back(this);
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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)
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: NumReferrers(0), Size(N.Size), ParentGraph(G), Ty(N.Ty),
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Links(N.Links), Globals(N.Globals), NodeType(N.NodeType) {
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G->getNodes().push_back(this);
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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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}
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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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}
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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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assert(!hasNoReferrers() &&
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"Why would we collapse a node with no referrers?");
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if (isNodeCompletelyFolded()) return; // If this node is already folded...
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++NumFolds;
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// Create the node we are going to forward to...
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DSNode *DestNode = new DSNode(NodeType|DSNode::Array, 0, ParentGraph);
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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.size()) {
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DestNode->Links.push_back(Links[0]);
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DSNodeHandle NH(DestNode);
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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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/// 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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/// 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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// 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 && "Cannot have an offset into a void node!");
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assert(!isArray() && "This shouldn't happen!");
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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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DEBUG(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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// 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...
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//
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unsigned SubTypeSize = SubType->isSized() ? TD.getTypeSize(SubType) : 0;
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unsigned PadSize = SubTypeSize; // Size, including pad memory which is ignored
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while (SubType != NewTy) {
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const Type *NextSubType = 0;
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unsigned NextSubTypeSize = 0;
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unsigned NextPadSize = 0;
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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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if (SL.MemberOffsets.size() > 1)
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NextPadSize = SL.MemberOffsets[1];
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else
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NextPadSize = SubTypeSize;
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NextSubType = STy->getElementTypes()[0];
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NextSubTypeSize = TD.getTypeSize(NextSubType);
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break;
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}
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case Type::ArrayTyID:
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NextSubType = cast<ArrayType>(SubType)->getElementType();
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NextSubTypeSize = TD.getTypeSize(NextSubType);
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NextPadSize = NextSubTypeSize;
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break;
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default: ;
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// fall out
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}
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if (NextSubType == 0)
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break; // In the default case, break out of the loop
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if (NextPadSize < NewTySize)
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break; // Don't allow shrinking to a smaller type than NewTySize
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SubType = NextSubType;
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SubTypeSize = NextSubTypeSize;
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PadSize = NextPadSize;
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}
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// If we found the type exactly, return it...
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if (SubType == NewTy)
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return false;
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// Check to see if we have a compatible, but different type...
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if (NewTySize == SubTypeSize) {
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// Check to see if this type is obviously convertable... int -> uint f.e.
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if (NewTy->isLosslesslyConvertableTo(SubType))
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return false;
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// Check to see if we have a pointer & integer mismatch going on here,
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// loading a pointer as a long, for example.
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//
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if (SubType->isInteger() && isa<PointerType>(NewTy) ||
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NewTy->isInteger() && isa<PointerType>(SubType))
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return false;
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} else if (NewTySize > SubTypeSize && NewTySize <= PadSize) {
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// We are accessing the field, plus some structure padding. Ignore the
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// structure padding.
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return false;
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}
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DEBUG(std::cerr << "MergeTypeInfo Folding OrigTy: " << Ty
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<< "\n due to:" << NewTy << " @ " << Offset << "!\n"
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<< "SubType: " << SubType << "\n\n");
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if (FoldIfIncompatible) foldNodeCompletely();
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return true;
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}
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// addEdgeTo - Add an edge from the current node to the specified node. This
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// can cause merging of nodes in the graph.
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//
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void DSNode::addEdgeTo(unsigned Offset, const DSNodeHandle &NH) {
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if (NH.getNode() == 0) return; // Nothing to do
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DSNodeHandle &ExistingEdge = getLink(Offset);
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if (ExistingEdge.getNode()) {
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// Merge the two nodes...
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ExistingEdge.mergeWith(NH);
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} else { // No merging to perform...
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setLink(Offset, NH); // Just force a link in there...
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}
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}
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// MergeSortedVectors - Efficiently merge a vector into another vector where
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// duplicates are not allowed and both are sorted. This assumes that 'T's are
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// efficiently copyable and have sane comparison semantics.
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//
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static void MergeSortedVectors(std::vector<GlobalValue*> &Dest,
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const std::vector<GlobalValue*> &Src) {
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// By far, the most common cases will be the simple ones. In these cases,
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// avoid having to allocate a temporary vector...
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//
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if (Src.empty()) { // Nothing to merge in...
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return;
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} else if (Dest.empty()) { // Just copy the result in...
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Dest = Src;
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} else if (Src.size() == 1) { // Insert a single element...
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const GlobalValue *V = Src[0];
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std::vector<GlobalValue*>::iterator I =
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std::lower_bound(Dest.begin(), Dest.end(), V);
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if (I == Dest.end() || *I != Src[0]) // If not already contained...
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Dest.insert(I, Src[0]);
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} else if (Dest.size() == 1) {
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GlobalValue *Tmp = Dest[0]; // Save value in temporary...
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Dest = Src; // Copy over list...
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std::vector<GlobalValue*>::iterator I =
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std::lower_bound(Dest.begin(), Dest.end(), Tmp);
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if (I == Dest.end() || *I != Tmp) // If not already contained...
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Dest.insert(I, Tmp);
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} else {
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// Make a copy to the side of Dest...
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std::vector<GlobalValue*> Old(Dest);
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// Make space for all of the type entries now...
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Dest.resize(Dest.size()+Src.size());
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// Merge the two sorted ranges together... into Dest.
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std::merge(Old.begin(), Old.end(), Src.begin(), Src.end(), Dest.begin());
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// Now erase any duplicate entries that may have accumulated into the
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// vectors (because they were in both of the input sets)
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Dest.erase(std::unique(Dest.begin(), Dest.end()), Dest.end());
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}
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}
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// MergeNodes() - Helper function for DSNode::mergeWith().
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// This function does the hard work of merging two nodes, CurNodeH
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// and NH after filtering out trivial cases and making sure that
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// CurNodeH.offset >= NH.offset.
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//
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// ***WARNING***
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// Since merging may cause either node to go away, we must always
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// use the node-handles to refer to the nodes. These node handles are
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// automatically updated during merging, so will always provide access
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// to the correct node after a merge.
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//
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void DSNode::MergeNodes(DSNodeHandle& CurNodeH, DSNodeHandle& NH) {
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assert(CurNodeH.getOffset() >= NH.getOffset() &&
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"This should have been enforced in the caller.");
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// Now we know that Offset >= NH.Offset, so convert it so our "Offset" (with
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// respect to NH.Offset) is now zero. NOffset is the distance from the base
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// of our object that N starts from.
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//
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unsigned NOffset = CurNodeH.getOffset()-NH.getOffset();
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unsigned NSize = NH.getNode()->getSize();
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// Merge the type entries of the two nodes together...
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if (NH.getNode()->Ty != Type::VoidTy)
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CurNodeH.getNode()->mergeTypeInfo(NH.getNode()->Ty, NOffset);
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assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
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// If we are merging a node with a completely folded node, then both nodes are
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// now completely folded.
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//
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if (CurNodeH.getNode()->isNodeCompletelyFolded()) {
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if (!NH.getNode()->isNodeCompletelyFolded()) {
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NH.getNode()->foldNodeCompletely();
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assert(NH.getNode() && NH.getOffset() == 0 &&
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"folding did not make offset 0?");
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NOffset = NH.getOffset();
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NSize = NH.getNode()->getSize();
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assert(NOffset == 0 && NSize == 1);
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}
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} else if (NH.getNode()->isNodeCompletelyFolded()) {
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CurNodeH.getNode()->foldNodeCompletely();
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assert(CurNodeH.getNode() && CurNodeH.getOffset() == 0 &&
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"folding did not make offset 0?");
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NOffset = NH.getOffset();
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NSize = NH.getNode()->getSize();
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assert(NOffset == 0 && NSize == 1);
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}
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DSNode *N = NH.getNode();
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if (CurNodeH.getNode() == N || N == 0) return;
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assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
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|
// Start forwarding to the new node!
|
|
CurNodeH.getNode()->NodeType |= N->NodeType;
|
|
N->forwardNode(CurNodeH.getNode(), NOffset);
|
|
assert((CurNodeH.getNode()->NodeType & DSNode::DEAD) == 0);
|
|
|
|
// 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()) {
|
|
MergeSortedVectors(CurNodeH.getNode()->Globals, 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, nothing happens).
|
|
//
|
|
void DSNode::mergeWith(const DSNodeHandle &NH, unsigned Offset) {
|
|
DSNode *N = NH.getNode();
|
|
if (N == 0 || (N == this && NH.getOffset() == Offset))
|
|
return; // Noop
|
|
|
|
assert((N->NodeType & DSNode::DEAD) == 0);
|
|
assert((NodeType & DSNode::DEAD) == 0);
|
|
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);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// DSCallSite Implementation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
// Define here to avoid including iOther.h and BasicBlock.h in DSGraph.h
|
|
Function &DSCallSite::getCaller() const {
|
|
return *Inst->getParent()->getParent();
|
|
}
|
|
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// DSGraph Implementation
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
DSGraph::DSGraph(const DSGraph &G) : Func(G.Func), GlobalsGraph(0) {
|
|
PrintAuxCalls = false;
|
|
hash_map<const DSNode*, DSNodeHandle> NodeMap;
|
|
RetNode = cloneInto(G, ScalarMap, NodeMap);
|
|
}
|
|
|
|
DSGraph::DSGraph(const DSGraph &G,
|
|
hash_map<const DSNode*, DSNodeHandle> &NodeMap)
|
|
: Func(G.Func), GlobalsGraph(0) {
|
|
PrintAuxCalls = false;
|
|
RetNode = cloneInto(G, ScalarMap, NodeMap);
|
|
}
|
|
|
|
DSGraph::~DSGraph() {
|
|
FunctionCalls.clear();
|
|
AuxFunctionCalls.clear();
|
|
ScalarMap.clear();
|
|
RetNode.setNode(0);
|
|
|
|
// Drop all intra-node references, so that assertions don't fail...
|
|
std::for_each(Nodes.begin(), Nodes.end(),
|
|
std::mem_fun(&DSNode::dropAllReferences));
|
|
|
|
// Delete all of the nodes themselves...
|
|
std::for_each(Nodes.begin(), Nodes.end(), deleter<DSNode>);
|
|
}
|
|
|
|
// 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(hash_map<const DSNode*, DSNodeHandle> &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());
|
|
}
|
|
}
|
|
|
|
|
|
// cloneInto - Clone the specified DSGraph into the current graph, returning the
|
|
// Return node of the graph. The translated ScalarMap for the old function is
|
|
// filled into the OldValMap member. If StripAllocas is set to true, Alloca
|
|
// markers are removed from the graph, as the graph is being cloned into a
|
|
// calling function's graph.
|
|
//
|
|
DSNodeHandle DSGraph::cloneInto(const DSGraph &G,
|
|
hash_map<Value*, DSNodeHandle> &OldValMap,
|
|
hash_map<const DSNode*, DSNodeHandle> &OldNodeMap,
|
|
unsigned CloneFlags) {
|
|
assert(OldNodeMap.empty() && "Returned OldNodeMap should be empty!");
|
|
assert(&G != this && "Cannot clone graph into itself!");
|
|
|
|
unsigned FN = Nodes.size(); // First new node...
|
|
|
|
// Duplicate all of the nodes, populating the node map...
|
|
Nodes.reserve(FN+G.Nodes.size());
|
|
|
|
// Remove alloca or mod/ref bits as specified...
|
|
unsigned clearBits = (CloneFlags & StripAllocaBit ? DSNode::AllocaNode : 0)
|
|
| (CloneFlags & StripModRefBits ? (DSNode::Modified | DSNode::Read) : 0);
|
|
clearBits |= DSNode::DEAD; // Clear dead flag...
|
|
for (unsigned i = 0, e = G.Nodes.size(); i != e; ++i) {
|
|
DSNode *Old = G.Nodes[i];
|
|
DSNode *New = new DSNode(*Old, this);
|
|
New->NodeType &= ~clearBits;
|
|
OldNodeMap[Old] = New;
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
Timer::addPeakMemoryMeasurement();
|
|
#endif
|
|
|
|
// Rewrite the links in the new nodes to point into the current graph now.
|
|
for (unsigned i = FN, e = Nodes.size(); i != e; ++i)
|
|
Nodes[i]->remapLinks(OldNodeMap);
|
|
|
|
// Copy the scalar map... merging all of the global nodes...
|
|
for (hash_map<Value*, DSNodeHandle>::const_iterator I = G.ScalarMap.begin(),
|
|
E = G.ScalarMap.end(); I != E; ++I) {
|
|
DSNodeHandle &H = OldValMap[I->first];
|
|
DSNodeHandle &MappedNode = OldNodeMap[I->second.getNode()];
|
|
H.setOffset(I->second.getOffset()+MappedNode.getOffset());
|
|
H.setNode(MappedNode.getNode());
|
|
|
|
if (isa<GlobalValue>(I->first)) { // Is this a global?
|
|
hash_map<Value*, DSNodeHandle>::iterator GVI = ScalarMap.find(I->first);
|
|
if (GVI != ScalarMap.end()) // Is the global value in this fn already?
|
|
GVI->second.mergeWith(H);
|
|
else
|
|
ScalarMap[I->first] = H; // Add global pointer to this graph
|
|
}
|
|
}
|
|
|
|
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 auxillary 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));
|
|
}
|
|
|
|
// Return the returned node pointer...
|
|
DSNodeHandle &MappedRet = OldNodeMap[G.RetNode.getNode()];
|
|
return DSNodeHandle(MappedRet.getNode(),
|
|
MappedRet.getOffset()+G.RetNode.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(DSCallSite &CS, const DSGraph &Graph,
|
|
unsigned CloneFlags) {
|
|
hash_map<Value*, DSNodeHandle> OldValMap;
|
|
DSNodeHandle RetVal;
|
|
hash_map<Value*, DSNodeHandle> *ScalarMap = &OldValMap;
|
|
|
|
// 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.
|
|
hash_map<const DSNode*, DSNodeHandle> OldNodeMap;
|
|
|
|
// The clone call may invalidate any of the vectors in the data
|
|
// structure graph. Strip locals and don't copy the list of callers
|
|
RetVal = cloneInto(Graph, OldValMap, OldNodeMap, CloneFlags);
|
|
ScalarMap = &OldValMap;
|
|
} else {
|
|
RetVal = getRetNode();
|
|
ScalarMap = &getScalarMap();
|
|
}
|
|
|
|
// Merge the return value with the return value of the context...
|
|
RetVal.mergeWith(CS.getRetVal());
|
|
|
|
// Resolve all of the function arguments...
|
|
Function &F = Graph.getFunction();
|
|
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
|
|
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));
|
|
}
|
|
}
|
|
|
|
|
|
// 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 imcomplete 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->NodeType & DSNode::Incomplete)) return;
|
|
|
|
// Actually mark the node
|
|
N->NodeType |= DSNode::Incomplete;
|
|
|
|
// Recusively 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) && Func && Func->getName() != "main")
|
|
for (Function::aiterator I = Func->abegin(), E = Func->aend(); I != E; ++I)
|
|
if (isPointerType(I->getType()) && ScalarMap.find(I) != ScalarMap.end())
|
|
markIncompleteNode(ScalarMap[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 (unsigned i = 0, e = Nodes.size(); i != e; ++i)
|
|
if (Nodes[i]->NodeType & DSNode::GlobalNode && Nodes[i]->getNumLinks())
|
|
markIncompleteNode(Nodes[i]);
|
|
}
|
|
|
|
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?
|
|
if ((N->NodeType & ~DSNode::Incomplete) == 0 && // No interesting info?
|
|
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,
|
|
const std::string &where) {
|
|
// Remove trivially identical function calls
|
|
unsigned NumFns = Calls.size();
|
|
std::sort(Calls.begin(), Calls.end()); // Sort by callee as primary key!
|
|
|
|
// 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()->NodeType == 0) { // No useful info?
|
|
std::cerr << "WARNING: Useless call site found??\n";
|
|
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();
|
|
}
|
|
|
|
if (LastCalleeContainsExternalFunction ||
|
|
// This should be more than enough context sensitivity!
|
|
// FIXME: Evaluate how many times this is tripped!
|
|
NumDuplicateCalls > 20) {
|
|
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;
|
|
}
|
|
} else {
|
|
if (CS.isDirectCall()) {
|
|
LastCalleeFunc = CS.getCalleeFunc();
|
|
LastCalleeNode = 0;
|
|
} else {
|
|
LastCalleeNode = CS.getCalleeNode();
|
|
LastCalleeFunc = 0;
|
|
}
|
|
NumDuplicateCalls = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
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 in " << where << "\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() {
|
|
removeIdenticalCalls(FunctionCalls, Func ? Func->getName() : "");
|
|
removeIdenticalCalls(AuxFunctionCalls, Func ? Func->getName() : "");
|
|
|
|
for (unsigned i = 0; i != Nodes.size(); ++i) {
|
|
DSNode *Node = Nodes[i];
|
|
if (!(Node->NodeType & ~(DSNode::Composition | DSNode::Array |
|
|
DSNode::DEAD))) {
|
|
// 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()) {
|
|
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 truely dead.
|
|
if (Node->getNumReferrers() == Globals.size()) {
|
|
for (unsigned j = 0, e = Globals.size(); j != e; ++j)
|
|
ScalarMap.erase(Globals[j]);
|
|
|
|
Globals.clear();
|
|
assert(Node->hasNoReferrers() && "Shouldn't have refs now!");
|
|
|
|
Node->NodeType = DSNode::DEAD;
|
|
}
|
|
}
|
|
}
|
|
|
|
if ((Node->NodeType & ~DSNode::DEAD) == 0 && Node->hasNoReferrers()) {
|
|
// This node is dead!
|
|
delete Node; // Free memory...
|
|
Nodes[i--] = Nodes.back();
|
|
Nodes.pop_back(); // Remove from node list...
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/// 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.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);
|
|
}
|
|
|
|
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) {
|
|
if (N == 0) return false;
|
|
assert(N->getForwardNode() == 0 && "Cannot mark a forwarded node!");
|
|
|
|
// 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)) {
|
|
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) {
|
|
if (CanReachAliveNodes(CS.getRetVal().getNode(), Alive, Visited))
|
|
return true;
|
|
if (CS.isIndirectCall() &&
|
|
CanReachAliveNodes(CS.getCalleeNode(), Alive, Visited))
|
|
return true;
|
|
for (unsigned i = 0, e = CS.getNumPtrArgs(); i != e; ++i)
|
|
if (CanReachAliveNodes(CS.getPtrArg(i).getNode(), Alive, Visited))
|
|
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) {
|
|
// Reduce the amount of work we have to do... remove dummy nodes left over by
|
|
// merging...
|
|
removeTriviallyDeadNodes();
|
|
|
|
// FIXME: Merge nontrivially 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;
|
|
|
|
// Mark all nodes reachable by (non-global) scalar nodes as alive...
|
|
for (hash_map<Value*, DSNodeHandle>::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?");
|
|
GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
|
|
++I;
|
|
} else {
|
|
// 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.
|
|
//
|
|
DSNode *N = I->second.getNode();
|
|
if (N->NodeType == DSNode::UnknownNode && !isa<Argument>(I->first)) {
|
|
ScalarMap.erase(I++);
|
|
} else {
|
|
I->second.getNode()->markReachableNodes(Alive);
|
|
++I;
|
|
}
|
|
}
|
|
|
|
// The return value is alive as well...
|
|
RetNode.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);
|
|
|
|
bool Iterate;
|
|
hash_set<DSNode*> Visited;
|
|
std::vector<unsigned char> AuxFCallsAlive(AuxFunctionCalls.size());
|
|
do {
|
|
Visited.clear();
|
|
// If any global nodes 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;
|
|
for (unsigned i = 0; i != GlobalNodes.size(); ++i)
|
|
if (CanReachAliveNodes(GlobalNodes[i].second, Alive, Visited)) {
|
|
std::swap(GlobalNodes[i--], GlobalNodes.back()); // Move to end to erase
|
|
GlobalNodes.pop_back(); // Erase efficiently
|
|
Iterate = true;
|
|
}
|
|
|
|
for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
|
|
if (!AuxFCallsAlive[i] &&
|
|
CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited)) {
|
|
AuxFunctionCalls[i].markReachableNodes(Alive);
|
|
AuxFCallsAlive[i] = true;
|
|
Iterate = true;
|
|
}
|
|
} while (Iterate);
|
|
|
|
// Remove all dead aux function calls...
|
|
unsigned CurIdx = 0;
|
|
for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
|
|
if (AuxFCallsAlive[i])
|
|
AuxFunctionCalls[CurIdx++].swap(AuxFunctionCalls[i]);
|
|
if (!(Flags & DSGraph::RemoveUnreachableGlobals)) {
|
|
assert(GlobalsGraph && "No globals graph available??");
|
|
// Move the unreachable call nodes to the globals graph...
|
|
GlobalsGraph->AuxFunctionCalls.insert(GlobalsGraph->AuxFunctionCalls.end(),
|
|
AuxFunctionCalls.begin()+CurIdx,
|
|
AuxFunctionCalls.end());
|
|
}
|
|
// Crop all the useless ones out...
|
|
AuxFunctionCalls.erase(AuxFunctionCalls.begin()+CurIdx,
|
|
AuxFunctionCalls.end());
|
|
|
|
// At this point, any nodes which are visited, but not alive, are nodes which
|
|
// should be moved to the globals graph. Loop over all nodes, eliminating
|
|
// completely unreachable nodes, and moving visited nodes to the globals graph
|
|
//
|
|
std::vector<DSNode*> DeadNodes;
|
|
DeadNodes.reserve(Nodes.size());
|
|
for (unsigned i = 0; i != Nodes.size(); ++i)
|
|
if (!Alive.count(Nodes[i])) {
|
|
DSNode *N = Nodes[i];
|
|
Nodes[i--] = Nodes.back(); // move node to end of vector
|
|
Nodes.pop_back(); // Erase node from alive list.
|
|
if (!(Flags & DSGraph::RemoveUnreachableGlobals) && // Not in TD pass
|
|
Visited.count(N)) { // Visited but not alive?
|
|
GlobalsGraph->Nodes.push_back(N); // Move node to globals graph
|
|
N->setParentGraph(GlobalsGraph);
|
|
} else { // Otherwise, delete the node
|
|
assert(((N->NodeType & DSNode::GlobalNode) == 0 ||
|
|
(Flags & DSGraph::RemoveUnreachableGlobals))
|
|
&& "Killing a global?");
|
|
//std::cerr << "[" << i+1 << "/" << DeadNodes.size()
|
|
// << "] Node is dead: "; N->dump();
|
|
DeadNodes.push_back(N);
|
|
N->dropAllReferences();
|
|
}
|
|
} else {
|
|
assert(Nodes[i]->getForwardNode() == 0 && "Alive forwarded node?");
|
|
}
|
|
|
|
// Now that the nodes have either been deleted or moved to the globals graph,
|
|
// loop over the scalarmap, updating the entries for globals...
|
|
//
|
|
if (!(Flags & DSGraph::RemoveUnreachableGlobals)) { // Not in the TD pass?
|
|
// In this array we start the remapping, which can cause merging. Because
|
|
// of this, the DSNode pointers in GlobalNodes may be invalidated, so we
|
|
// must always go through the ScalarMap (which contains DSNodeHandles [which
|
|
// cannot be invalidated by merging]).
|
|
//
|
|
for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i) {
|
|
Value *G = GlobalNodes[i].first;
|
|
hash_map<Value*, DSNodeHandle>::iterator I = ScalarMap.find(G);
|
|
assert(I != ScalarMap.end() && "Global not in scalar map anymore?");
|
|
assert(I->second.getNode() && "Global not pointing to anything?");
|
|
assert(!Alive.count(I->second.getNode()) && "Node is alive??");
|
|
GlobalsGraph->ScalarMap[G].mergeWith(I->second);
|
|
assert(GlobalsGraph->ScalarMap[G].getNode() &&
|
|
"Global not pointing to anything?");
|
|
ScalarMap.erase(I);
|
|
}
|
|
|
|
// Merging leaves behind silly nodes, we remove them to avoid polluting the
|
|
// globals graph.
|
|
if (!GlobalNodes.empty())
|
|
GlobalsGraph->removeTriviallyDeadNodes();
|
|
} else {
|
|
// If we are in the top-down pass, remove all unreachable globals from the
|
|
// ScalarMap...
|
|
for (unsigned i = 0, e = GlobalNodes.size(); i != e; ++i)
|
|
ScalarMap.erase(GlobalNodes[i].first);
|
|
}
|
|
|
|
// Loop over all of the dead nodes now, deleting them since their referrer
|
|
// count is zero.
|
|
for (unsigned i = 0, e = DeadNodes.size(); i != e; ++i)
|
|
delete DeadNodes[i];
|
|
|
|
DEBUG(AssertGraphOK(); GlobalsGraph->AssertGraphOK());
|
|
}
|
|
|
|
void DSGraph::AssertGraphOK() const {
|
|
for (unsigned i = 0, e = Nodes.size(); i != e; ++i)
|
|
Nodes[i]->assertOK();
|
|
return; // FIXME: remove
|
|
for (hash_map<Value*, DSNodeHandle>::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()->NodeType & DSNode::GlobalNode) &&
|
|
"Global points to node, but node isn't global?");
|
|
AssertNodeContainsGlobal(I->second.getNode(), GV);
|
|
}
|
|
}
|
|
AssertCallNodesInGraph();
|
|
AssertAuxCallNodesInGraph();
|
|
}
|