Mercurial > hg > graal-compiler

comparison src/share/vm/opto/loopTransform.cpp @ 7196:2aff40cb4703

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
7092905: C2: Keep track of the number of dead nodes Summary: keep an (almost) accurate running count of the reachable (live) flow graph nodes. Reviewed-by: kvn, twisti, jrose, vlivanov
author bharadwaj
date Tue, 27 Nov 2012 17:24:15 -0800
parents d2582a08fa5d
children b30b3c2a0cf2
comparison
equal deleted inserted replaced
7195:2cd5e15048e6 7196:2aff40cb4703
267 // Return TRUE or FALSE if the loop should be peeled or not. Peel if we can 267 // Return TRUE or FALSE if the loop should be peeled or not. Peel if we can
268 // make some loop-invariant test (usually a null-check) happen before the loop. 268 // make some loop-invariant test (usually a null-check) happen before the loop.
269 bool IdealLoopTree::policy_peeling( PhaseIdealLoop *phase ) const { 269 bool IdealLoopTree::policy_peeling( PhaseIdealLoop *phase ) const {
270 Node *test = ((IdealLoopTree*)this)->tail(); 270 Node *test = ((IdealLoopTree*)this)->tail();
271 int body_size = ((IdealLoopTree*)this)->_body.size(); 271 int body_size = ((IdealLoopTree*)this)->_body.size();
272 int uniq = phase->C->unique(); 272 int live_node_count = phase->C->live_nodes();
273 // Peeling does loop cloning which can result in O(N^2) node construction 273 // Peeling does loop cloning which can result in O(N^2) node construction
274 if( body_size > 255 /* Prevent overflow for large body_size */ 274 if( body_size > 255 /* Prevent overflow for large body_size */
275 || (body_size * body_size + uniq > MaxNodeLimit) ) { 275 || (body_size * body_size + live_node_count > MaxNodeLimit) ) {
276 return false; // too large to safely clone 276 return false; // too large to safely clone
277 } 277 }
278 while( test != _head ) { // Scan till run off top of loop 278 while( test != _head ) { // Scan till run off top of loop
279 if( test->is_If() ) { // Test? 279 if( test->is_If() ) { // Test?
280 Node *ctrl = phase->get_ctrl(test->in(1)); 280 Node *ctrl = phase->get_ctrl(test->in(1));
599 uint tst_body_size = (new_body_size - EMPTY_LOOP_SIZE) / trip_count + EMPTY_LOOP_SIZE; 599 uint tst_body_size = (new_body_size - EMPTY_LOOP_SIZE) / trip_count + EMPTY_LOOP_SIZE;
600 if (body_size != tst_body_size) // Check for int overflow 600 if (body_size != tst_body_size) // Check for int overflow
601 return false; 601 return false;
602 if (new_body_size > unroll_limit || 602 if (new_body_size > unroll_limit ||
603 // Unrolling can result in a large amount of node construction 603 // Unrolling can result in a large amount of node construction
604 new_body_size >= MaxNodeLimit - phase->C->unique()) { 604 new_body_size >= MaxNodeLimit - (uint) phase->C->live_nodes()) {
605 return false; 605 return false;
606 } 606 }
607 607
608 // Do not unroll a loop with String intrinsics code. 608 // Do not unroll a loop with String intrinsics code.
609 // String intrinsics are large and have loops. 609 // String intrinsics are large and have loops.
2266 } 2266 }
2267 } 2267 }
2268 2268
2269 // Skip next optimizations if running low on nodes. Note that 2269 // Skip next optimizations if running low on nodes. Note that
2270 // policy_unswitching and policy_maximally_unroll have this check. 2270 // policy_unswitching and policy_maximally_unroll have this check.
2271 uint nodes_left = MaxNodeLimit - phase->C->unique(); 2271 uint nodes_left = MaxNodeLimit - (uint) phase->C->live_nodes();
2272 if ((2 * _body.size()) > nodes_left) { 2272 if ((2 * _body.size()) > nodes_left) {
2273 return true; 2273 return true;
2274 } 2274 }
2275 2275
2276 // Counted loops may be peeled, may need some iterations run up 2276 // Counted loops may be peeled, may need some iterations run up