https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106265
Vineet Gupta <vineetg at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |vineetg at gcc dot gnu.org
--- Comment #11 from Vineet Gupta <vineetg at gcc dot gnu.org> ---
Revisited this with gcc-13.
The reduced test case no longer shows the extraneous LI 4096 (although the full
test still does).
The key here is -funroll-loops which is needed for original issue to show as
well.
The was with middle-end update:
commit 19295e8607da2f743368fe6f5708146616aafa91
Author: Richard Biener <rguent...@suse.de>
Date: Mon Oct 24 09:51:32 2022 +0200
tree-optimization/100756 - niter analysis and folding
niter analysis, specifically the part trying to simplify the computed
maybe_zero condition against the loop header copying condition, is
confused by us now simplifying
_15 = n_8(D) * 4;
if (_15 > 0)
to
_15 = n_8(D) * 4;
if (n_8(D) > 0)
which is perfectly sound at the point we do this transform. One
solution might be to involve ranger in this simplification, another
is to be more aggressive when expanding expressions - the condition
we try to simplify is _15 > 0, so all we need is expanding that
to n_8(D) * 4 > 0.
