[Bug middle-end/45422] [4.6 Regression] compile time increases 8x.

["rguenth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #5 from rguenth at gcc dot gnu dot org  2010-08-27 12:06 -------
MODULE hfx_contract_block
  INTEGER, PARAMETER :: dp=KIND(0.0D0)
CONTAINS
  SUBROUTINE
block_9_2(mc_max,md_max,kbd,kbc,kad,kac,pbd,pbc,pad,pac,prim,scale)
    INTEGER                                  :: mc_max, md_max
    REAL(KIND=dp) :: kbd(2*md_max), kbc(2*mc_max), kad(9*md_max), &
      kac(9*mc_max), pbd(2*md_max), pbc(2*mc_max), pad(9*md_max), &
      pac(9*mc_max), prim(9*2*mc_max*md_max), scale

    INTEGER                                  :: ma, mb, mc, md, p_index
    REAL(KIND=dp)                            :: ks_bc, ks_bd, p_bc, p_bd, tmp

      kbd(1:2*md_max) = 0.0_dp
      kbc(1:2*mc_max) = 0.0_dp
      kad(1:9*md_max) = 0.0_dp
      kac(1:9*mc_max) = 0.0_dp
      p_index = 0
      DO md = 1,md_max
        DO mc = 1,mc_max
          DO mb = 1,2
            ks_bd = 0.0_dp
            ks_bc = 0.0_dp
            p_bd = pbd((md-1)*2+mb)
            p_bc = pbc((mc-1)*2+mb)
            DO ma = 1,9
              p_index=p_index+1
              tmp = scale*prim(p_index)
              ks_bc = ks_bc + tmp* pad((md-1)*9+ma)
              ks_bd = ks_bd + tmp* pac((mc-1)*9+ma)
              kad((md-1)*9+ma) =  kad((md-1)*9+ma)-tmp*p_bc
              kac((mc-1)*9+ma) = kac((mc-1)*9+ma)-tmp*p_bd
            END DO
            kbd((md-1)*2+mb) = kbd((md-1)*2+mb) - ks_bd
            kbc((mc-1)*2+mb) = kbc((mc-1)*2+mb) - ks_bc
          END DO
        END DO
      END DO
  END SUBROUTINE block_9_2
END MODULE

gfortran -S -O3 -ffree-form -fbounds-check t.f90 -ftime-report

 tree iv optimization  :   3.49 (94%) usr   0.00 ( 0%) sys   3.52 (94%) wall   
2272 kB (36%) ggc

can someone try to track down revisions that slowed that testcase down?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45422