as mentioned in the CP2K PR 29975, current trunk miscompiles CP2K at -O2. the
following illustrates the issue:
MODULE TEST
IMPLICIT NONE
INTEGER, PARAMETER :: dp=KIND(0.0D0)
TYPE mulliken_restraint_type
INTEGER :: ref_count
REAL(KIND = dp) :: strength
REAL(KIND = dp) :: TARGET
INTEGER :: natoms
INTEGER, POINTER, DIMENSION(:) :: atoms
END TYPE mulliken_restraint_type
CONTAINS
SUBROUTINE INIT(mulliken)
TYPE(mulliken_restraint_type), INTENT(INOUT) :: mulliken
ALLOCATE(mulliken%atoms(1))
mulliken%atoms(1)=1
mulliken%natoms=1
mulliken%target=0
mulliken%strength=0
END SUBROUTINE INIT
SUBROUTINE restraint_functional(mulliken_restraint_control,charges, &
charges_deriv,energy,order_p)
TYPE(mulliken_restraint_type), &
INTENT(IN) :: mulliken_restraint_control
REAL(KIND=dp), DIMENSION(:, :), POINTER :: charges, charges_deriv
REAL(KIND=dp), INTENT(OUT) :: energy, order_p
INTEGER :: I
REAL(KIND=dp) :: dum
charges_deriv=0.0_dp
order_p=0.0_dp
DO I=1,mulliken_restraint_control%natoms
order_p=order_p+charges(mulliken_restraint_control%atoms(I),1) &
-charges(mulliken_restraint_control%atoms(I),2)
ENDDO
energy=mulliken_restraint_control%strength*(order_p-mulliken_restraint_control%target)**2
dum=2*mulliken_restraint_control%strength*(order_p-mulliken_restraint_control%target)
DO I=1,mulliken_restraint_control%natoms
charges_deriv(mulliken_restraint_control%atoms(I),1)= dum
charges_deriv(mulliken_restraint_control%atoms(I),2)= -dum
ENDDO
END SUBROUTINE restraint_functional
END MODULE
USE TEST
IMPLICIT NONE
TYPE(mulliken_restraint_type) :: mulliken
REAL(KIND=dp), DIMENSION(:, :), POINTER :: charges, charges_deriv
REAL(KIND=dp) :: energy,order_p
ALLOCATE(charges(1,2),charges_deriv(1,2))
charges(1,1)=2.0_dp
charges(1,2)=1.0_dp
CALL INIT(mulliken)
CALL restraint_functional(mulliken,charges,charges_deriv,energy,order_p)
write(6,*) order_p
END
> gfortran -O2 test.f90
> ./a.out
0.00000000000000
> gfortran -O1 test.f90
> ./a.out
1.00000000000000
this is for:
Driving: gfortran -v -O2 test.f90 -lgfortranbegin -lgfortran -lm -shared-libgcc
Using built-in specs.
Target: x86_64-unknown-linux-gnu
Configured with: /data03/vondele/gcc_trunk/gcc/configure
--prefix=/data03/vondele/gcc_trunk/build --with-gmp=/data03/vondele/
--with-mpfr=/data03/vondele/ --enable-languages=c,fortran
Thread model: posix
gcc version 4.3.0 20070702 (experimental)
/data03/vondele/gcc_trunk/build/libexec/gcc/x86_64-unknown-linux-gnu/4.3.0/f951
test.f90 -quiet -dumpbase test.f90 -mtune=generic -auxbase test -O2 -version
-fintrinsic-modules-path
/data03/vondele/gcc_trunk/build/lib/gcc/x86_64-unknown-linux-gnu/4.3.0/finclude
-o /tmp/ccaqj3g7.s
GNU F95 version 4.3.0 20070702 (experimental) (x86_64-unknown-linux-gnu)
compiled by GNU C version 4.3.0 20070702 (experimental), GMP version
4.2.1, MPFR version 2.2.1.
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
as -V -Qy -o /tmp/cccJhUbb.o /tmp/ccaqj3g7.s
GNU assembler version 2.16.91.0.5 (x86_64-suse-linux) using BFD version
2.16.91.0.5 20051219 (SUSE Linux)
/data03/vondele/gcc_trunk/build/libexec/gcc/x86_64-unknown-linux-gnu/4.3.0/collect2
--eh-frame-hdr -m elf_x86_64 -dynamic-linker /lib64/ld-linux-x86-64.so.2
/usr/lib/../lib64/crt1.o /usr/lib/../lib64/crti.o
/data03/vondele/gcc_trunk/build/lib/gcc/x86_64-unknown-linux-gnu/4.3.0/crtbegin.o
-L/data03/vondele/gcc_trunk/build/lib/gcc/x86_64-unknown-linux-gnu/4.3.0
-L/data03/vondele/gcc_trunk/build/lib/gcc/x86_64-unknown-linux-gnu/4.3.0/../../../../lib64
-L/lib/../lib64 -L/usr/lib/../lib64
-L/data03/vondele/gcc_trunk/build/lib/gcc/x86_64-unknown-linux-gnu/4.3.0/../../..
/tmp/cccJhUbb.o -lgfortranbegin -lgfortran -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc
/data03/vondele/gcc_trunk/build/lib/gcc/x86_64-unknown-linux-gnu/4.3.0/crtend.o
/usr/lib/../lib64/crtn.o
--
Summary: miscompilation at -O2
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jv244 at cam dot ac dot uk
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32604
