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.
Richard.
> 2021-05-19 Jakub Jelinek <ja...@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
