[Bug tree-optimization/86702] [9 Regression] SPEC CPU2006 400.perlbench, CPU2017 500.perlbench_r ~3% performance drop after r262247
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86702 Martin Liška changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #6 from Martin Liška --- Should be fixed now, please reopen it it still exists.
[Bug tree-optimization/86702] [9 Regression] SPEC CPU2006 400.perlbench, CPU2017 500.perlbench_r ~3% performance drop after r262247
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86702 --- Comment #5 from Martin Liška --- Author: marxin Date: Mon Aug 27 12:17:54 2018 New Revision: 263877 URL: https://gcc.gnu.org/viewcvs?rev=263877&root=gcc&view=rev Log: Fix probabilities for jump table (PR tree-optimization/86702). 2018-08-27 Martin Liska PR tree-optimization/86702 * tree-switch-conversion.c (jump_table_cluster::emit): Make probabilities even for values in jump table according to number of cases handled. (switch_decision_tree::compute_cases_per_edge): Pass argument to reset_out_edges_aux function. (switch_decision_tree::analyze_switch_statement): Likewise. * tree-switch-conversion.h (switch_decision_tree::reset_out_edges_aux): Make it static. Modified: trunk/gcc/ChangeLog trunk/gcc/tree-switch-conversion.c trunk/gcc/tree-switch-conversion.h
[Bug tree-optimization/86702] [9 Regression] SPEC CPU2006 400.perlbench, CPU2017 500.perlbench_r ~3% performance drop after r262247
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86702 --- Comment #4 from Alexander Nesterovskiy --- I've noticed performance regressions on different targets and with different compilation options, not only highly optimized like "-march=skylake-avx512 -Ofast -flto -funroll-loops" but with "-O2" too. The simplest case is 500.perlbench_r with "-O2" on Broadwell executed in one copy. Performance drop is not in a particular place but "spread" over whole S_regmatch function which is really big. My guess was that loosing of these probabilities affects passes that follows tree-switchlower1. And it is what I see in generated assembly - some different spilling/filling and different order of blocks.
[Bug tree-optimization/86702] [9 Regression] SPEC CPU2006 400.perlbench, CPU2017 500.perlbench_r ~3% performance drop after r262247
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86702 --- Comment #3 from Martin Liška --- I must confirm that probabilities are lost, but as the switch will end up as jump table, so they are not used..
[Bug tree-optimization/86702] [9 Regression] SPEC CPU2006 400.perlbench, CPU2017 500.perlbench_r ~3% performance drop after r262247
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86702 --- Comment #2 from Martin Liška --- Can you please provide info about affected target and precise options used?
[Bug tree-optimization/86702] [9 Regression] SPEC CPU2006 400.perlbench, CPU2017 500.perlbench_r ~3% performance drop after r262247
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86702 Richard Biener changed: What|Removed |Added Version|unknown |9.0 Target Milestone|--- |9.0
[Bug tree-optimization/86702] [9 Regression] SPEC CPU2006 400.perlbench, CPU2017 500.perlbench_r ~3% performance drop after r262247
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86702 Martin Liška changed: What|Removed |Added Status|UNCONFIRMED |ASSIGNED Last reconfirmed||2018-07-27 CC||marxin at gcc dot gnu.org Blocks||26163 Assignee|unassigned at gcc dot gnu.org |marxin at gcc dot gnu.org Summary|[8/9 Regression] SPEC |[9 Regression] SPEC CPU2006 |CPU2006 400.perlbench, |400.perlbench, CPU2017 |CPU2017 500.perlbench_r ~3% |500.perlbench_r ~3% |performance drop after |performance drop after |r262247 |r262247 Ever confirmed|0 |1 --- Comment #1 from Martin Liška --- Thanks for the report, I'll take a look. If it's really caused by the revision, then it's only 9 regression. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=26163 [Bug 26163] [meta-bug] missed optimization in SPEC (2k17, 2k and 2k6 and 95)
