[Bug target/104581] New: Huge compile-time regression building SPEC 2017 538.imagick_r with PGO

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104581

            Bug ID: 104581
           Summary: Huge compile-time regression building SPEC 2017
                    538.imagick_r with PGO
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

Building magick/enhance.c with -Ofast -march=znver2 -fprofile-generate spends
all compile time in mdreorg:

 machine dep reorg                  : 505.62 ( 93%)   0.03 (  5%) 509.15 ( 92%)
  193k (  0%)
 TOTAL                              : 543.25          0.63        551.52       
  236M

https://lnt.opensuse.org/db_default/v4/SPEC/graph?highlight_run=23626&plot.507=14.507.8

shows similar behavior on Kabylake