Use and implement API for graph traversals

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5431 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-01-29 21:10:20 +00:00
parent 9e4b15b1a1
commit 5c7380e567

View File

@ -13,7 +13,6 @@
#include "Support/Statistic.h"
#include "Support/Timer.h"
#include <algorithm>
#include <set>
using std::vector;
@ -938,17 +937,27 @@ void DSGraph::removeTriviallyDeadNodes() {
}
// markAlive - Simple graph walker that recursively traverses the graph, marking
// stuff to be alive.
//
static void markAlive(DSNode *N, std::set<DSNode*> &Alive) {
if (N == 0) return;
std::set<DSNode*>::iterator I = Alive.lower_bound(N);
if (I != Alive.end() && *I == N) return; // Already marked alive
Alive.insert(I, N); // Is alive now
/// 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(std::set<DSNode*> &ReachableNodes) {
if (this == 0) return;
std::set<DSNode*>::iterator I = ReachableNodes.lower_bound(this);
if (I != ReachableNodes.end() && *I == this)
return; // Already marked reachable
ReachableNodes.insert(I, this); // Is reachable now
for (unsigned i = 0, e = N->getSize(); i < e; i += DS::PointerSize)
markAlive(N->getLink(i).getNode(), Alive);
for (unsigned i = 0, e = getSize(); i < e; i += DS::PointerSize)
getLink(i).getNode()->markReachableNodes(ReachableNodes);
}
void DSCallSite::markReachableNodes(std::set<DSNode*> &Nodes) {
getRetVal().getNode()->markReachableNodes(Nodes);
getCallee().getNode()->markReachableNodes(Nodes);
for (unsigned j = 0, e = getNumPtrArgs(); j != e; ++j)
getPtrArg(j).getNode()->markReachableNodes(Nodes);
}
// markAliveIfCanReachAlive - Simple graph walker that recursively traverses the
@ -981,7 +990,7 @@ static bool markAliveIfCanReachAlive(DSNode *N, std::set<DSNode*> &Alive,
ChildrenAreAlive |= markAliveIfCanReachAlive(N->getLink(i).getNode(),
Alive, Visited);
if (ChildrenAreAlive)
markAlive(N, Alive);
N->markReachableNodes(Alive);
return ChildrenAreAlive;
}
@ -996,14 +1005,6 @@ static bool CallSiteUsesAliveArgs(DSCallSite &CS, std::set<DSNode*> &Alive,
return false;
}
static void markAlive(DSCallSite &CS, std::set<DSNode*> &Alive) {
markAlive(CS.getRetVal().getNode(), Alive);
markAlive(CS.getCallee().getNode(), Alive);
for (unsigned j = 0, e = CS.getNumPtrArgs(); j != e; ++j)
markAlive(CS.getPtrArg(j).getNode(), Alive);
}
// 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
@ -1025,12 +1026,12 @@ void DSGraph::removeDeadNodes(unsigned Flags) {
E = ScalarMap.end(); I != E; ++I)
if (!(Flags & DSGraph::RemoveUnreachableGlobals) ||
!isa<GlobalValue>(I->first)) // Don't mark globals!
markAlive(I->second.getNode(), Alive);
I->second.getNode()->markReachableNodes(Alive);
else // Keep track of global nodes
GlobalNodes.push_back(std::make_pair(I->first, I->second.getNode()));
// The return value is alive as well...
markAlive(RetNode.getNode(), Alive);
RetNode.getNode()->markReachableNodes(Alive);
// If any global nodes points to a non-global that is "alive", the global is
// "alive" as well...
@ -1042,14 +1043,14 @@ void DSGraph::removeDeadNodes(unsigned Flags) {
std::vector<bool> FCallsAlive(FunctionCalls.size());
for (unsigned i = 0, e = FunctionCalls.size(); i != e; ++i)
if (CallSiteUsesAliveArgs(FunctionCalls[i], Alive, Visited)) {
markAlive(FunctionCalls[i], Alive);
FunctionCalls[i].markReachableNodes(Alive);
FCallsAlive[i] = true;
}
std::vector<bool> AuxFCallsAlive(AuxFunctionCalls.size());
for (unsigned i = 0, e = AuxFunctionCalls.size(); i != e; ++i)
if (CallSiteUsesAliveArgs(AuxFunctionCalls[i], Alive, Visited)) {
markAlive(AuxFunctionCalls[i], Alive);
AuxFunctionCalls[i].markReachableNodes(Alive);
AuxFCallsAlive[i] = true;
}