[Bug middle-end/82004] [8 Regression] SPEC CPU2017 628.pop2_s miscompare

["andrey.y.guskov at intel dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82004

--- Comment #2 from Andrey Guskov <andrey.y.guskov at intel dot com> ---
Approximately a hundred different variables and function calls, the majority of
which are raised to the second or third power, sometimes fourth or fifth. As
628.pop2_s is mostly written in Fortran 90, all of the cases look like c**x.
I`m not sure if this gets transformed into pow() when x is constant, though.

As for the cases where x is either not constant or non-integer, there are 22 of
them:

co2calc.F90:          x1(i) = c10 ** (-phhi(i))
co2calc.F90:          x2(i) = c10 ** (-phlo(i))

ecosys_mod.F90:       Tfunc = Q_10**(((TEMP + T0_Kelvin)-(Tref +
T0_Kelvin))/c10)
ecosys_mod.F90:       zoo_loss = z_mort2 * Zprime**1.4_r8 + z_mort * Zprime
ecosys_mod.F90:       TfuncS = 2.5_r8**(((TEMP + T0_Kelvin) - (Tref +
T0_Kelvin)) / c10)

hmix_del4.F90:        AMF(:,:,iblock) = (UAREA(:,:,iblock)/uarea_equator)**1.5
hmix_del4.F90:        AHF(:,:,iblock) = (TAREA(:,:,iblock)/uarea_equator)**1.5

hmix_gm.F90:          BOLUS_SP(:,:,bid) = 50.0_r8 * sqrt(U_ISOP**c2 +
V_ISOP**c2)

overflows.F90:        phi = c1-Fgeo**(-c2/c3)

seq_flux_mct.F90:     anidr = (.026_R8/(cosz**1.7_R8 + 0.065_R8))
shr_flux_mod.F90:     temp = (zkB*zkB)**(1.0_R8/a2) ! note: zkB < 0, zkB*zkB >
0
shr_flux_mod.F90:     temp = (zeta*zeta)**(1.0_R8/a2) ! note: zeta < 0,
zeta*zeta > 0

state_mod.F90:        st15 = salt**(1.5_r8)

sw_absorption.F90:    chlamnt = 10**(logchl)

time_management.F90:  ifact = 10**(string_length - n)

vmix_kpp.F90:         cg = cstar*vonkar*(c_s*vonkar*epssfc)**p33
vmix_kpp.F90:         bckgrnd_vdc_psis=
bckgrnd_vdc_psim*exp(-(0.4_r8*(tlatd+28.9_r8))**c2)
vmix_kpp.F90:         bckgrnd_vdc_psin=
bckgrnd_vdc_psim*exp(-(0.4_r8*(tlatd-28.9_r8))**c2)
vmix_kpp.F90:         bckgrnd_vdc1 * (tlatd/10.0_r8)**c2
vmix_kpp.F90:         WM(i,j) = vonkar*USTAR(i,j)*(c1 - c16*ZETA(i,j))**p25
vmix_kpp.F90:         WM(i,j) =
vonkar*(a_m*(USTAR(i,j)**3)-c_m*ZETAH(i,j))**p33
vmix_kpp.F90:         WS(i,j) =
vonkar*(a_s*(USTAR(i,j)**3)-c_s*ZETAH(i,j))**p33


...Something tells me I didn`t get the question.