On Mon, Apr 27, 2015 at 11:45 AM, Thomas Koenig <tkoe...@netcologne.de> wrote: > Am 25.04.2015 um 20:12 schrieb Mikael Morin: > >> I've double-checked in the standard, and it seems it is not possible to >> simplify after all: >> >> If ARRAY is a whole array and either ARRAY is an assumed-size >> array of rank DIM or dimension DIM of ARRAY has nonzero extent, >> LBOUND (ARRAY, DIM) has a value equal to the lower bound for >> subscript DIM of ARRAY. Otherwise the result value is 1. >> >> We can't tell whether the array is zero-sized, so we can't tell the >> lbound value. > > So it is only possible to simplify LBOUND if the lower bound is > equal to one, both for assumed-shape and explicit-shape arrays... > OK. > > The attached patch does that, including a test case which catches > that particular case. > >> As you may want to simplify in the limited scope of the matmul inlining, >> I'm giving comments about the patch (otherwise you can ignore them): >> - No need to check for allocatable or pointer, it should be excluded by >> as->type == AS_ASSUMED_SHAPE (but does no harm either). > > Actually, no. You can have assumed-shape allocatable or pointer > dummy arguments which keep their original lbound; see the subroutine > 'bar' in the test case. > >> - Please modify the early return condition: >> if (as && (as->type == AS_DEFERRED || as->type == AS_ASSUMED_SHAPE >> || as->type == AS_ASSUMED_RANK)) >> return NULL; >> and let the existing code do the simplification work. > > That is not part of my patch. > >> Or drop the lbound simplification idea, and fetch the lbound "by hand" >> at matmul inline time. > > I will probably do so as a future optimization, but I think that most > people will see no reason for using different lower bounds, so it is > OK for the time being to (slightly) pessimize this case. > > So... here is the new patch. OK for trunk? > > Thomas > > 2015-04-25 Thomas Koenig <tkoe...@gcc.gnu.org> > > PR fortran/37131 > * simplify.c (simplify_bound): Get constant lower bounds of one > from array spec for assumed and explicit shape shape arrays if > the lower bounds are indeed one. > > 2015-04-25 Thomas Koenig <tkoe...@gcc.gnu.org> > > PR fortran/37131 > * gfortran.dg/coarray_lib_this_image_2.f90: Adjust > scan pattern. > * gfortran.dg/bound_9.f90: New test case. >
This caused: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65981 -- H.J.
