archive/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2025-09-16 17:14:41 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

7092905: C2: Keep track of the number of dead nodes

Browse source 
Keep an (almost) accurate running count of the reachable (live) flow graph nodes.

Reviewed-by: kvn, twisti, jrose, vlivanov
This commit is contained in:
Bharadwaj Yadavalli 2012-11-27 17:24:15 -08:00
parent 96562be9e5
commit 2d2532e740
28 changed files with 306 additions and 120 deletions
Download patch file Download diff file Expand all files Collapse all files

8
hotspot/src/share/vm/opto/loopTransform.cpp
View file

@ -269,10 +269,10 @@ void IdealLoopTree::reassociate_invariants(PhaseIdealLoop *phase) {
bool IdealLoopTree::policy_peeling( PhaseIdealLoop *phase ) const {
Node *test = ((IdealLoopTree*)this)->tail();
int body_size = ((IdealLoopTree*)this)->_body.size();
int uniq = phase->C->unique();
int live_node_count = phase->C->live_nodes();
// Peeling does loop cloning which can result in O(N^2) node construction
if( body_size > 255 /* Prevent overflow for large body_size */
|| (body_size * body_size + uniq > MaxNodeLimit) ) {
|| (body_size * body_size + live_node_count > MaxNodeLimit) ) {
return false; // too large to safely clone
}
while( test != _head ) { // Scan till run off top of loop
@ -601,7 +601,7 @@ bool IdealLoopTree::policy_maximally_unroll( PhaseIdealLoop *phase ) const {
return false;
if (new_body_size > unroll_limit ||
// Unrolling can result in a large amount of node construction
new_body_size >= MaxNodeLimit - phase->C->unique()) {
new_body_size >= MaxNodeLimit - (uint) phase->C->live_nodes()) {
return false;
}
@ -2268,7 +2268,7 @@ bool IdealLoopTree::iteration_split_impl( PhaseIdealLoop *phase, Node_List &old_
// Skip next optimizations if running low on nodes. Note that
// policy_unswitching and policy_maximally_unroll have this check.
uint nodes_left = MaxNodeLimit - phase->C->unique();
uint nodes_left = MaxNodeLimit - (uint) phase->C->live_nodes();
if ((2 * _body.size()) > nodes_left) {
return true;
}