[Bug tree-optimization/114281] New: [14 Regression] Multiple 2-10% exec time regressions of 465.tonto since r14-9193-ga0b1798042d033

[pheeck at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114281

            Bug ID: 114281
           Summary: [14 Regression] Multiple 2-10% exec time regressions
                    of 465.tonto since r14-9193-ga0b1798042d033
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pheeck at gcc dot gnu.org
            Blocks: 26163
  Target Milestone: ---
              Host: aarch64-gnu-linux, x86_64-linux
            Target: aarch64-gnu-linux, x86_64-linux

Our LNT instance has detected that runtime of benchmark 465.tonto from the SPEC
2006 suite regressed on all of our machines (aarch64 ampere altra, intel
skylake, amd zen{2,3,4}) on most configurations by 2-10%.

One example: Zen4 -Ofast -flto -march=native (regressed by 10%)
https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=992.230.0

I've bisected the example configuration to r14-9193-ga0b1798042d033 (Richard
Biener: tree-optimization/114074 - CHREC multiplication and undefined
overflow).

There have been two other SPEC benchmarks regressions reported that also got
bisected to this commit -- pr114269, pr114238. I assume that all of these have
the same cause.


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)