On Mon, 11 Mar 2024, Jakub Jelinek wrote:
> On Sat, Mar 09, 2024 at 12:25:42PM +0100, Richard Biener wrote:
> > Ideally we?d clear TREE_ADDRESSABLE but set DECL_NOT_GIMPLE_REG,
> > I think the analysis where we check the base would be a more
> > appropriate place to enforce that.
>
> So like this?
Hm, I was thinking of non_rewritable_lvalue_p/non_rewritable_mem_ref_base
though that requires duplicating, so I guess handling in maybe_optimize_var
would work.
I do now wonder whether setting DECL_NOT_GIMPLE_REG_P in bitfield
lowering would prevail?
(sorry for approving the earlier patch now, I was too quick and didn't
remember the discussion)
Richard.
> Bootstrapped/regtested on x86_64-linux and i686-linux.
>
> 2024-03-11 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/114278
> * tree-ssa.cc (maybe_optimize_var): If large/huge _BitInt vars are no
> longer addressable, set DECL_NOT_GIMPLE_REG_P on them.
>
> * gcc.dg/bitint-99.c: New test.
>
> --- gcc/tree-ssa.cc.jj 2024-01-03 11:51:39.902615009 +0100
> +++ gcc/tree-ssa.cc 2024-03-09 23:34:12.469223987 +0100
> @@ -1785,6 +1785,20 @@ maybe_optimize_var (tree var, bitmap add
> fprintf (dump_file, "\n");
> }
> }
> + else if (TREE_CODE (TREE_TYPE (var)) == BITINT_TYPE
> + && (cfun->curr_properties & PROP_gimple_lbitint) != 0
> + && TYPE_PRECISION (TREE_TYPE (var)) > MAX_FIXED_MODE_SIZE)
> + {
> + /* Don't rewrite large/huge _BitInt vars after _BitInt lowering
> + into SSA form. */
> + DECL_NOT_GIMPLE_REG_P (var) = 1;
> + if (dump_file)
> + {
> + fprintf (dump_file, "_BitInt var after its lowering: ");
> + print_generic_expr (dump_file, var);
> + fprintf (dump_file, "\n");
> + }
> + }
> else if (DECL_NOT_GIMPLE_REG_P (var))
> {
> maybe_reg = true;
> --- gcc/testsuite/gcc.dg/bitint-99.c.jj 2024-03-08 14:26:17.658069942
> +0100
> +++ gcc/testsuite/gcc.dg/bitint-99.c 2024-03-08 14:25:36.292645965 +0100
> @@ -0,0 +1,26 @@
> +/* PR tree-optimization/114278 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-options "-O2 -fno-tree-dce -fno-tree-dse -fno-tree-ccp" } */
> +/* { dg-additional-options "-mavx2" { target i?86-*-* x86_64-*-* } } */
> +
> +void
> +foo (void *p)
> +{
> + _BitInt(64) b = *(_BitInt(64) *) __builtin_memmove (&b, p, sizeof
> (_BitInt(64)));
> +}
> +
> +#if __BITINT_MAXWIDTH__ >= 128
> +void
> +bar (void *p)
> +{
> + _BitInt(128) b = *(_BitInt(128) *) __builtin_memmove (&b, p, sizeof
> (_BitInt(128)));
> +}
> +#endif
> +
> +#if __BITINT_MAXWIDTH__ >= 256
> +void
> +baz (void *p)
> +{
> + _BitInt(256) b = *(_BitInt(256) *) __builtin_memmove (&b, p, sizeof
> (_BitInt(256)));
> +}
> +#endif
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
