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Re: [Patch, Fortran] CAF dep (1/3): PR62278 - improve dependency.c's gfc_check_dependency's check (missed-optimization)

Dear Tobias,

Given Dominques news that this fixes a golden oldie that drove me to
madness and PR60593 - OK for trunk, 4.8 and 4.9

Many thanks for the patch


On 27 August 2014 22:59, Tobias Burnus <> wrote:
> The current gfc_check_dependency check always looked at the pointer
> attribute - and assumed the worst, if either the LHS or the RHS was true.
> Thus, it claimed that "a" and "b" alias for the following definition:
> integer, pointer :: p;  integer :: a. However, as "a" has no target (or
> pointer) attribute, that's not possible. Additionally, "class(t) :: a" has
> internally the "pointer" attribute (but CLASS_DATA(sym)->attr.class_pointer
> == 0), however, in the Fortran sense, "a" is not a pointer and cannot alias.
> I do not have a good example for the test case, except for a similar one as
> above using "a[i] = p" and looking at the dump; but that requires patch 3/3
> of this series.
> Build and regtested on x86-64-gnu-linux. (I do get a failure for
> gfortran.dg/graphite/pr42393.f90, but only with -O1 -fgraphite-identity and
> also without the patch.)
> OK for the trunk?
> Tobias

The knack of flying is learning how to throw yourself at the ground and miss.
       --Hitchhikers Guide to the Galaxy

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