[Bug tree-optimization/83232] fma3d spec2000 regression on zen with -Ofast (generic tuning) after r255268 by missed SLP oppurtunity

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83232

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Testcase:

      SUBROUTINE MATERIAL_41_INTEGRATION ( STRESS,YLDC,EFPS,                  
&
     &  DTnext,Dxx,Dyy,Dzz,Dxy,Dxz,Dyz,MatID,P1,P3 )
      REAL(KIND(0D0)), INTENT(INOUT) :: STRESS(6)
      REAL(KIND(0D0)), INTENT(IN)    :: DTnext
      REAL(KIND(0D0)), INTENT(IN)    :: Dxx,Dyy,Dzz,Dxy,Dxz,Dyz
      REAL(KIND(0D0)) :: Einc(6)
      REAL(KIND(0D0)) :: P1,P3

      Einc(1) = DTnext * Dxx
      Einc(2) = DTnext * Dyy
      Einc(3) = DTnext * Dzz
      Einc(4) = DTnext * Dxy
      Einc(5) = DTnext * Dxz
      Einc(6) = DTnext * Dyz
      DO i = 1,6
        STRESS(i) = STRESS(i) + P3*Einc(i)
      ENDDO
      STRESS(1) = STRESS(1) + (DTnext * P1 * (Dxx+Dyy+Dzz))
      STRESS(2) = STRESS(2) + (DTnext * P1 * (Dxx+Dyy+Dzz))
      STRESS(3) = 0.0
      Einc(5) = 0.0
      Einc(6) = 0.0
      WRITE (*,*) Einc
      END SUBROUTINE