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From: "tkoenig at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug fortran/56937] Unnecessarily temporary with array-vector assignments Date: Tue, 30 Apr 2013 11:58:00 -0000 [thread overview] Message-ID: <bug-56937-4-3U9VupvGDA@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-56937-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56937 Thomas Koenig <tkoenig at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |tkoenig at gcc dot gnu.org --- Comment #7 from Thomas Koenig <tkoenig at gcc dot gnu.org> 2013-04-30 11:58:43 UTC --- (In reply to comment #6) > Apparently there is no dependency analysis for array-vector assignments. Correct, however... > The > following test create a temporary that is not needed > > integer :: r(10), idx(4), jdx(4) > r = [(i+10,i=1,10)] > idx = [1, 2, 3, 4] > jdx = [6, 7, 8, 9] > r(idx) = r(jdx) > print *, r > end > > r(idx) = r(jdx) > 1 > Warning: Creating array temporary at (1) Currently, we do not support assigning values to variables and then later using the values for dependency analysis. This would require forward propagation of values, which we don't do in the front end. Plus, a lot of dependency test cases where we used variables to hide them from the optimization would start failing ;-)
next prev parent reply other threads:[~2013-04-30 11:58 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-04-12 18:12 [Bug fortran/56937] New: " burnus at gcc dot gnu.org 2013-04-12 20:56 ` [Bug fortran/56937] " dominiq at lps dot ens.fr 2013-04-12 21:28 ` burnus at gcc dot gnu.org 2013-04-13 10:15 ` mikael at gcc dot gnu.org 2013-04-13 10:26 ` mikael at gcc dot gnu.org 2013-04-13 10:32 ` mikael at gcc dot gnu.org 2013-04-29 22:26 ` dominiq at lps dot ens.fr 2013-04-30 11:58 ` tkoenig at gcc dot gnu.org [this message] 2013-04-30 12:15 ` dominiq at lps dot ens.fr 2013-04-30 12:35 ` burnus at gcc dot gnu.org 2013-07-21 13:47 ` tkoenig at gcc dot gnu.org 2013-07-21 13:50 ` tkoenig at gcc dot gnu.org 2013-08-09 9:20 ` tkoenig at gcc dot gnu.org
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