> Am 22.12.2023 um 09:26 schrieb Jakub Jelinek <ja...@redhat.com>:
>
> Hi!
>
> Large/huge _BitInt types are returned in memory and the bitint lowering
> pass right now relies on that.
> The gimplification etc. use aggregate_value_p to see if it should be
> returned in memory or not and use
> <retval> = _123;
> return <retval>;
> rather than
> return _123;
> But expand_thunk used e.g. by IPA-ICF was performing an optimization,
> assuming is_gimple_reg_type is always passed in registers and not calling
> aggregate_value_p in that case. The following patch changes it to match
> what the gimplification etc. are doing.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok
Richard
> 2023-12-22 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/112941
> * symtab-thunks.cc (expand_thunk): Check aggregate_value_p regardless
> of whether is_gimple_reg_type (restype) or not.
>
> * gcc.dg/bitint-60.c: New test.
>
> --- gcc/symtab-thunks.cc.jj 2023-08-24 15:37:28.698418172 +0200
> +++ gcc/symtab-thunks.cc 2023-12-21 16:42:41.406127267 +0100
> @@ -479,21 +479,15 @@ expand_thunk (cgraph_node *node, bool ou
> resdecl,
> build_int_cst (TREE_TYPE (resdecl), 0));
> }
> - else if (!is_gimple_reg_type (restype))
> + else if (aggregate_value_p (resdecl, TREE_TYPE (thunk_fndecl)))
> {
> - if (aggregate_value_p (resdecl, TREE_TYPE (thunk_fndecl)))
> - {
> - restmp = resdecl;
> + restmp = resdecl;
>
> - if (VAR_P (restmp))
> - {
> - add_local_decl (cfun, restmp);
> - BLOCK_VARS (DECL_INITIAL (current_function_decl))
> - = restmp;
> - }
> + if (VAR_P (restmp))
> + {
> + add_local_decl (cfun, restmp);
> + BLOCK_VARS (DECL_INITIAL (current_function_decl)) = restmp;
> }
> - else
> - restmp = create_tmp_var (restype, "retval");
> }
> else
> restmp = create_tmp_reg (restype, "retval");
> --- gcc/testsuite/gcc.dg/bitint-60.c.jj 2023-12-21 16:49:41.289298560 +0100
> +++ gcc/testsuite/gcc.dg/bitint-60.c 2023-12-21 16:49:09.061746003 +0100
> @@ -0,0 +1,20 @@
> +/* PR tree-optimization/112941 */
> +/* { dg-do compile { target bitint575 } } */
> +/* { dg-options "-O2 -std=c23" } */
> +
> +unsigned _BitInt(495) f1 (signed _BitInt(381) x) { unsigned _BitInt(539) y =
> x; return y; }
> +unsigned _BitInt(495) f2 (unsigned _BitInt(381) x) { unsigned _BitInt(539) y
> = x; return y; }
> +unsigned _BitInt(495) f3 (signed _BitInt(381) x) { _BitInt(539) y = x;
> return y; }
> +unsigned _BitInt(495) f4 (unsigned _BitInt(381) x) { _BitInt(539) y = x;
> return y; }
> +_BitInt(495) f5 (signed _BitInt(381) x) { unsigned _BitInt(539) y = x;
> return y; }
> +_BitInt(495) f6 (unsigned _BitInt(381) x) { unsigned _BitInt(539) y = x;
> return y; }
> +_BitInt(495) f7 (signed _BitInt(381) x) { _BitInt(539) y = x; return y; }
> +_BitInt(495) f8 (unsigned _BitInt(381) x) { _BitInt(539) y = x; return y; }
> +unsigned _BitInt(495) f9 (signed _BitInt(381) x) { return (unsigned
> _BitInt(539)) x; }
> +unsigned _BitInt(495) f10 (unsigned _BitInt(381) x) { return (unsigned
> _BitInt(539)) x; }
> +unsigned _BitInt(495) f11 (signed _BitInt(381) x) { return (_BitInt(539)) x;
> }
> +unsigned _BitInt(495) f12 (unsigned _BitInt(381) x) { return (_BitInt(539))
> x; }
> +_BitInt(495) f13 (signed _BitInt(381) x) { return (unsigned _BitInt(539)) x;
> }
> +_BitInt(495) f14 (unsigned _BitInt(381) x) { return (unsigned _BitInt(539))
> x; }
> +_BitInt(495) f15 (signed _BitInt(381) x) { return (_BitInt(539)) x; }
> +_BitInt(495) f16 (unsigned _BitInt(381) x) { return (_BitInt(539)) x; }
>
> Jakub
>
