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* Add #define to enabled debug messages

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* Move removeEdgesTo to be a member of DSNode
* Implement (but #ifdef out) the new, spiffier, method of determining
  shadow node equivalence.  This cannot be enabled until more is
  implemented.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2004 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-03-27 19:48:03 +00:00
parent 6088c4f55e
commit 2ba3a72c3a
1 changed files with 15 additions and 12 deletions
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27
lib/Analysis/DataStructure/EliminateNodes.cpp
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@ -19,6 +19,8 @@
#include "Support/STLExtras.h"
#include <algorithm>
//#define DEBUG_NODE_ELIMINATE 1
// NodesAreEquivalent - Check to see if the nodes are equivalent in all ways
// except node type. Since we know N1 is a shadow node, N2 is allowed to be
// any type.
@ -27,8 +29,13 @@ static bool NodesAreEquivalent(const ShadowDSNode *N1, const DSNode *N2) {
assert(N1 != N2 && "A node is always equivalent to itself!");
// Perform simple, fast checks first...
if (N1->getType() != N2->getType()) return false;
assert(N1->getNumLinks() == N2->getNumLinks() && "Same type, diff # links?");
if (N1->getType() != N2->getType() || // Must have same type...
N1->isCriticalNode()) // Must not be a critical node...
return false;
#if 0
return true;
#else
// The shadow node is considered equivalent if it has a subset of the incoming
// edges that N2 does...
@ -51,6 +58,7 @@ static bool NodesAreEquivalent(const ShadowDSNode *N1, const DSNode *N2) {
}
return i1 == e1 && i2 <= e2;
#endif
}
// IndistinguishableShadowNode - A shadow node is indistinguishable if some
@ -77,13 +85,6 @@ static bool IndistinguishableShadowNode(const ShadowDSNode *SN) {
return false;
}
// removeEdgesTo - Erase all edges in the graph that point to the specified node
static void removeEdgesTo(DSNode *Node) {
while (!Node->getReferrers().empty()) {
PointerValSet *PVS = Node->getReferrers().back();
PVS->removePointerTo(Node);
}
}
// UnlinkUndistinguishableShadowNodes - Eliminate shadow nodes that are not
// distinguishable from some other node in the graph...
@ -96,10 +97,12 @@ bool FunctionDSGraph::UnlinkUndistinguishableShadowNodes() {
for (vector<ShadowDSNode*>::iterator I = ShadowNodes.begin();
I != ShadowNodes.end(); )
if (IndistinguishableShadowNode(*I)) {
#ifdef DEBUG_NODE_ELIMINATE
cerr << "Found Indistinguishable Shadow Node:\n";
(*I)->print(cerr);
removeEdgesTo(*I);
// Don't need to dropAllRefs, because nothing can poitn to it now
#endif
(*I)->removeAllIncomingEdges();
// Don't need to dropAllRefs, because nothing can point to it now
delete *I;
I = ShadowNodes.erase(I);
@ -180,7 +183,7 @@ bool FunctionDSGraph::RemoveUnreachableShadowNodes() {
for (unsigned i = 0; i != ShadowNodes.size(); ++i)
if (!Reachable[i]) {
// Track all unreachable nodes...
#if 0
#if DEBUG_NODE_ELIMINATE
cerr << "Unreachable node eliminated:\n";
ShadowNodes[i]->print(cerr);
#endif