[Bug ipa/122096] New: [16 Regression] r16-4000 causing 523.xalancbmk_r codesize increase by 13-15% with "-Ofast -march=native -flto" on multiple platforms

[haochen.jiang at intel dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122096

            Bug ID: 122096
           Summary: [16 Regression] r16-4000 causing 523.xalancbmk_r
                    codesize increase by 13-15% with "-Ofast -march=native
                    -flto" on multiple platforms
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: haochen.jiang at intel dot com
  Target Milestone: ---

I have detected a codesize increase for 13.9% on GNR, 13.6% on SRF, 13.8% on
SPR, 13.8% on ICX, 14.5% for AWS Zen4 Server and 15.6% for AWS Graviton4 on
523.xalancbmk_r with -Ofast -march=native -flto.

However, no perf improvement detected for 523.xalancbmk_r.

My bisect points to r16-4000. I am not sure if it is a dup for PR122058 since
it also directs to r16-4000.