Mercurial > hg > graal-jvmci-8

comparison src/share/vm/opto/loopTransform.cpp @ 12027:bcc4f6f54d83

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
8022993: Convert MAX_UNROLL constant to LoopMaxUnroll C2 flag Summary: Replace MAX_UNROLL constant with new C2 LoopMaxUnroll flag. Reviewed-by: roland
author kvn
date Wed, 14 Aug 2013 10:21:26 -0700
parents a59625d96f71
children c9ccd7b85f20 cfd05ec74089
comparison
equal deleted inserted replaced
12026:11237ee74aae 12027:bcc4f6f54d83
622 622
623 return true; // Do maximally unroll 623 return true; // Do maximally unroll
624 } 624 }
625 625
626 626
627 #define MAX_UNROLL 16 // maximum number of unrolls for main loop
628
629 //------------------------------policy_unroll---------------------------------- 627 //------------------------------policy_unroll----------------------------------
630 // Return TRUE or FALSE if the loop should be unrolled or not. Unroll if 628 // Return TRUE or FALSE if the loop should be unrolled or not. Unroll if
631 // the loop is a CountedLoop and the body is small enough. 629 // the loop is a CountedLoop and the body is small enough.
632 bool IdealLoopTree::policy_unroll( PhaseIdealLoop *phase ) const { 630 bool IdealLoopTree::policy_unroll( PhaseIdealLoop *phase ) const {
633 631
640 // Protect against over-unrolling. 638 // Protect against over-unrolling.
641 // After split at least one iteration will be executed in pre-loop. 639 // After split at least one iteration will be executed in pre-loop.
642 if (cl->trip_count() <= (uint)(cl->is_normal_loop() ? 2 : 1)) return false; 640 if (cl->trip_count() <= (uint)(cl->is_normal_loop() ? 2 : 1)) return false;
643 641
644 int future_unroll_ct = cl->unrolled_count() * 2; 642 int future_unroll_ct = cl->unrolled_count() * 2;
645 if (future_unroll_ct > MAX_UNROLL) return false; 643 if (future_unroll_ct > LoopMaxUnroll) return false;
646 644
647 // Check for initial stride being a small enough constant 645 // Check for initial stride being a small enough constant
648 if (abs(cl->stride_con()) > (1<<2)*future_unroll_ct) return false; 646 if (abs(cl->stride_con()) > (1<<2)*future_unroll_ct) return false;
649 647
650 // Don't unroll if the next round of unrolling would push us 648 // Don't unroll if the next round of unrolling would push us