[Bug tree-optimization/84037] New: [8 Regression] Speed regression of polyhedron benchmark since r256643

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84037

            Bug ID: 84037
           Summary: [8 Regression] Speed regression of polyhedron
                    benchmark since r256643
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---
              Host: x86_64-linux-gnu
            Target: x86_64-linux-gnu

Polyhedron benchmark:
https://www.polyhedron.com/web_images/documents/pb11.zip

Running:
$ gfortran -march=native -Ofast capacita.f90 && ./a.out

is now slower from 0m16.227s to 0m21.610s.

Verbose options:
 /home/marxin/bin/gcc/lib/gcc/x86_64-pc-linux-gnu/8.0.1/f951 capacita.f90
-march=haswell -mmmx -mno-3dnow -msse -msse2 -msse3 -mssse3 -mno-sse4a -mcx16
-msahf -mmovbe -maes -mno-sha -mpclmul -mpopcnt -mabm -mno-lwp -mfma -mno-fma4
-mno-xop -mbmi -mno-sgx -mbmi2 -mno-tbm -mavx -mavx2 -msse4.2 -msse4.1 -mlzcnt
-mno-rtm -mno-hle -mrdrnd -mf16c -mfsgsbase -mno-rdseed -mno-prfchw -mno-adx
-mfxsr -mxsave -mxsaveopt -mno-avx512f -mno-avx512er -mno-avx512cd
-mno-avx512pf -mno-prefetchwt1 -mno-clflushopt -mno-xsavec -mno-xsaves
-mno-avx512dq -mno-avx512bw -mno-avx512vl -mno-avx512ifma -mno-avx512vbmi
-mno-avx5124fmaps -mno-avx5124vnniw -mno-clwb -mno-mwaitx -mno-clzero -mno-pku
-mno-rdpid -mno-gfni -mno-ibt -mno-shstk -mno-avx512vbmi2 -mno-avx512vnni
-mno-vaes -mno-vpclmulqdq -mno-avx512bitalg --param l1-cache-size=32 --param
l1-cache-line-size=64 --param l2-cache-size=8192 -mtune=haswell -quiet
-dumpbase capacita.f90 -auxbase capacita -Ofast -version
-fintrinsic-modules-path
/home/marxin/bin/gcc/lib64/gcc/x86_64-pc-linux-gnu/8.0.1/finclude -o
/tmp/ccRwPBvh.s