From: Christophe Lyon <christophe.lyon@linaro.org>
To: Richard Biener <rguenther@suse.de>
Cc: Jakub Jelinek <jakub@redhat.com>, gcc Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] phiopt: Simplify (X & Y) == X -> (X & ~Y) == 0 even in presence of integral conversions [PR94589]
Date: Wed, 19 May 2021 13:29:00 +0200 [thread overview]
Message-ID: <CAKdteOZn28_3YH-7PZxwBcsFtfcKKDtzoQpkvPYha=99uCRJig@mail.gmail.com> (raw)
In-Reply-To: <nycvar.YFH.7.76.2105191313020.9200@zhemvz.fhfr.qr>
On Wed, 19 May 2021 at 13:13, Richard Biener <rguenther@suse.de> wrote:
>
> On Wed, 19 May 2021, Jakub Jelinek wrote:
>
> > On Wed, May 19, 2021 at 11:09:19AM +0200, Jakub Jelinek via Gcc-patches wrote:
> > > On Wed, May 19, 2021 at 10:15:53AM +0200, Christophe Lyon via Gcc-patches wrote:
> > > > After this update, the test fails on arm and aarch64: according to the
> > > > logs, the optimization is still performed 14 times.
> > >
> > > Seems this is because
> > > if (change
> > > && !flag_syntax_only
> > > && (load_extend_op (TYPE_MODE (TREE_TYPE (and0)))
> > > == ZERO_EXTEND))
> > > {
> > > tree uns = unsigned_type_for (TREE_TYPE (and0));
> > > and0 = fold_convert_loc (loc, uns, and0);
> > > and1 = fold_convert_loc (loc, uns, and1);
> > > }
> > > in fold-const.c adds on these targets extra casts that prevent the
> > > optimizations.
> >
> > This patch seems to fix it (but I don't have an easy way to test on aarch64
> > or arm on the trunk and 11 branch would need numerous backports).
>
> OK if somebody manages to test on arm/aarch64.
>
I confirm it fixes the problem on arm. (aarch64 in progress)
Thanks!
> Richard.
>
> > 2021-05-19 Jakub Jelinek <jakub@redhat.com>
> >
> > PR tree-optimization/94589
> > * match.pd ((X & Y) == X -> (X & ~Y) == 0): Simplify even in presence
> > of integral conversions.
> >
> > --- gcc/match.pd.jj 2021-05-15 10:10:28.000000000 +0200
> > +++ gcc/match.pd 2021-05-19 11:34:42.130624557 +0200
> > @@ -4769,6 +4769,16 @@ (define_operator_list COND_TERNARY
> > (simplify
> > (cmp:c (bit_and:c @0 @1) @0)
> > (cmp (bit_and @0 (bit_not! @1)) { build_zero_cst (TREE_TYPE (@0)); }))
> > + (simplify
> > + (cmp:c (convert@3 (bit_and (convert@2 @0) INTEGER_CST@1)) (convert @0))
> > + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
> > + && INTEGRAL_TYPE_P (TREE_TYPE (@2))
> > + && INTEGRAL_TYPE_P (TREE_TYPE (@3))
> > + && TYPE_PRECISION (TREE_TYPE (@2)) == TYPE_PRECISION (TREE_TYPE (@0))
> > + && TYPE_PRECISION (TREE_TYPE (@3)) > TYPE_PRECISION (TREE_TYPE (@2))
> > + && !wi::neg_p (wi::to_wide (@1)))
> > + (cmp (bit_and @0 (convert (bit_not @1)))
> > + { build_zero_cst (TREE_TYPE (@0)); })))
> >
> > /* (X | Y) == Y becomes (X & ~Y) == 0. */
> > (simplify
> >
> >
> > Jakub
next prev parent reply other threads:[~2021-05-19 11:29 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-18 7:42 [PATCH] phiopt: Optimize partial_ordering spaceship >= 0 -ffinite-math-only [PR94589] Jakub Jelinek
2021-05-18 7:55 ` Richard Biener
2021-05-19 8:15 ` Christophe Lyon
2021-05-19 9:09 ` Jakub Jelinek
2021-05-19 9:51 ` [PATCH] phiopt: Simplify (X & Y) == X -> (X & ~Y) == 0 even in presence of integral conversions [PR94589] Jakub Jelinek
2021-05-19 11:13 ` Richard Biener
2021-05-19 11:29 ` Christophe Lyon [this message]
2021-05-19 12:19 ` Christophe Lyon
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