Implement a FIXME, improving the efficiency of DSA on povray.

This reduces CBU time from 145s -> 122s (debug build), reduces # allocated nodes
from 129420 to 116477.

llvm-svn: 12125
This commit is contained in:
Chris Lattner 2004-03-04 19:47:04 +00:00
parent a24ac9bf8b
commit ac1eaa43fa

View File

@ -785,8 +785,22 @@ DSNodeHandle ReachabilityCloner::getClonedNH(const DSNodeHandle &SrcNH) {
if (!NH.isNull()) // Node already mapped?
return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
// FIXME if SrcNH has globals and the dest graph contains the same globals, we
// could use 'merge' to do this work more efficiently!
// If SrcNH has globals and the destination graph has one of the same globals,
// merge this node with the destination node, which is much more efficient.
if (SN->global_begin() != SN->global_end()) {
DSScalarMap &DestSM = Dest.getScalarMap();
for (DSNode::global_iterator I = SN->global_begin(), E = SN->global_end();
I != E; ++I) {
GlobalValue *GV = *I;
DSScalarMap::iterator GI = DestSM.find(GV);
if (GI != DestSM.end() && !GI->second.isNull()) {
// We found one, use merge instead!
merge(GI->second, Src.getNodeForValue(GV));
assert(!NH.isNull() && "Didn't merge node!");
return DSNodeHandle(NH.getNode(), NH.getOffset()+SrcNH.getOffset());
}
}
}
DSNode *DN = new DSNode(*SN, &Dest, true /* Null out all links */);
DN->maskNodeTypes(BitsToKeep);