hg: jdk/sandbox: 8223363: Bad node estimate assertion failure; ...

[chris.hegarty at oracle.com]

Changeset: ba171f871932
Author:    phedlin
Date:      2019-05-28 14:56 +0200
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/ba171f871932

8223363: Bad node estimate assertion failure
8223502: Node estimate for loop unswitching is not correct: assert(delta <= 2 * required) failed: Bad node estimate
8224648: assert(!exceeding_node_budget()) failed: Too many NODES required! failure with ctw
Summary: Tighten the node estimates. New est_loop_clone_sz() implementation that will compute a "fan-out" complexity estimate as part of the size estimate (to better estimate complex loop body size after cloning). New est_loop_unroll_sz() function, used to estimate the size of a loop body att full/maximal unrolling. Correction to node budget final tests and asserts.
Reviewed-by: neliasso, kvn

! src/hotspot/share/opto/loopTransform.cpp
! src/hotspot/share/opto/loopUnswitch.cpp
! src/hotspot/share/opto/loopnode.cpp
! src/hotspot/share/opto/loopnode.hpp
! src/hotspot/share/opto/loopopts.cpp
+ test/hotspot/jtreg/compiler/loopopts/LoopUnswitchingBadNodeBudget.java