On Thu, 14 Dec 2023, Jakub Jelinek wrote:
> Hi!
>
> As shown in the testcase, .{ADD,SUB,MUL}_OVERFLOW calls are another
> exception to the middle/large/huge _BitInt discovery through SSA_NAMEs
> next to stores of INTEGER_CSTs to memory and their conversions to
> floating point.
> The calls can have normal COMPLEX_TYPE with INTEGER_TYPE elts return type
> (or BITINT_TYPE with small precision) and one of the arguments can be
> SSA_NAME with an INTEGER_TYPE or small BITINT_TYPE as well; still, when
> there is an INTEGER_CST argument with large/huge BITINT_TYPE, we need to
> lower it that way.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
> trunk?
OK.
Richard.
> 2023-12-14 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/113003
> * gimple-lower-bitint.cc (arith_overflow_arg_kind): New function.
> (gimple_lower_bitint): Use it to catch .{ADD,SUB,MUL}_OVERFLOW
> calls with large/huge INTEGER_CST arguments.
>
> * gcc.dg/bitint-54.c: New test.
>
> --- gcc/gimple-lower-bitint.cc.jj 2023-12-13 11:36:21.636633517 +0100
> +++ gcc/gimple-lower-bitint.cc 2023-12-14 13:28:17.660737468 +0100
> @@ -5641,6 +5641,37 @@ build_bitint_stmt_ssa_conflicts (gimple
> def (live, lhs, graph);
> }
>
> +/* If STMT is .{ADD,SUB,MUL}_OVERFLOW with INTEGER_CST arguments,
> + return the largest bitint_prec_kind of them, otherwise return
> + bitint_prec_small. */
> +
> +static bitint_prec_kind
> +arith_overflow_arg_kind (gimple *stmt)
> +{
> + bitint_prec_kind ret = bitint_prec_small;
> + if (is_gimple_call (stmt) && gimple_call_internal_p (stmt))
> + switch (gimple_call_internal_fn (stmt))
> + {
> + case IFN_ADD_OVERFLOW:
> + case IFN_SUB_OVERFLOW:
> + case IFN_MUL_OVERFLOW:
> + for (int i = 0; i < 2; ++i)
> + {
> + tree a = gimple_call_arg (stmt, i);
> + if (TREE_CODE (a) == INTEGER_CST
> + && TREE_CODE (TREE_TYPE (a)) == BITINT_TYPE)
> + {
> + bitint_prec_kind kind = bitint_precision_kind (TREE_TYPE (a));
> + ret = MAX (ret, kind);
> + }
> + }
> + break;
> + default:
> + break;
> + }
> + return ret;
> +}
> +
> /* Entry point for _BitInt(N) operation lowering during optimization. */
>
> static unsigned int
> @@ -5657,7 +5688,12 @@ gimple_lower_bitint (void)
> continue;
> tree type = TREE_TYPE (s);
> if (TREE_CODE (type) == COMPLEX_TYPE)
> - type = TREE_TYPE (type);
> + {
> + if (arith_overflow_arg_kind (SSA_NAME_DEF_STMT (s))
> + != bitint_prec_small)
> + break;
> + type = TREE_TYPE (type);
> + }
> if (TREE_CODE (type) == BITINT_TYPE
> && bitint_precision_kind (type) != bitint_prec_small)
> break;
> @@ -5745,7 +5781,12 @@ gimple_lower_bitint (void)
> continue;
> tree type = TREE_TYPE (s);
> if (TREE_CODE (type) == COMPLEX_TYPE)
> - type = TREE_TYPE (type);
> + {
> + if (arith_overflow_arg_kind (SSA_NAME_DEF_STMT (s))
> + >= bitint_prec_large)
> + has_large_huge = true;
> + type = TREE_TYPE (type);
> + }
> if (TREE_CODE (type) == BITINT_TYPE
> && bitint_precision_kind (type) >= bitint_prec_large)
> {
> @@ -6245,8 +6286,7 @@ gimple_lower_bitint (void)
> {
> bitint_prec_kind this_kind
> = bitint_precision_kind (TREE_TYPE (t));
> - if (this_kind > kind)
> - kind = this_kind;
> + kind = MAX (kind, this_kind);
> }
> if (is_gimple_assign (stmt) && gimple_store_p (stmt))
> {
> @@ -6255,8 +6295,7 @@ gimple_lower_bitint (void)
> {
> bitint_prec_kind this_kind
> = bitint_precision_kind (TREE_TYPE (t));
> - if (this_kind > kind)
> - kind = this_kind;
> + kind = MAX (kind, this_kind);
> }
> }
> if (is_gimple_assign (stmt)
> @@ -6268,21 +6307,22 @@ gimple_lower_bitint (void)
> {
> bitint_prec_kind this_kind
> = bitint_precision_kind (TREE_TYPE (t));
> - if (this_kind > kind)
> - kind = this_kind;
> + kind = MAX (kind, this_kind);
> }
> }
> if (is_gimple_call (stmt))
> {
> t = gimple_call_lhs (stmt);
> - if (t
> - && TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE
> - && TREE_CODE (TREE_TYPE (TREE_TYPE (t))) == BITINT_TYPE)
> + if (t && TREE_CODE (TREE_TYPE (t)) == COMPLEX_TYPE)
> {
> - bitint_prec_kind this_kind
> - = bitint_precision_kind (TREE_TYPE (TREE_TYPE (t)));
> - if (this_kind > kind)
> - kind = this_kind;
> + bitint_prec_kind this_kind = arith_overflow_arg_kind (stmt);
> + kind = MAX (kind, this_kind);
> + if (TREE_CODE (TREE_TYPE (TREE_TYPE (t))) == BITINT_TYPE)
> + {
> + this_kind
> + = bitint_precision_kind (TREE_TYPE (TREE_TYPE (t)));
> + kind = MAX (kind, this_kind);
> + }
> }
> }
> if (kind == bitint_prec_small)
> --- gcc/testsuite/gcc.dg/bitint-54.c.jj 2023-12-14 13:47:46.683512224
> +0100
> +++ gcc/testsuite/gcc.dg/bitint-54.c 2023-12-14 13:47:20.191879500 +0100
> @@ -0,0 +1,21 @@
> +/* PR tree-optimization/113003 */
> +/* { dg-do compile { target bitint } } */
> +/* { dg-options "-std=c23 -O2" } */
> +
> +#if __BITINT_MAXWIDTH__ >= 131
> +int
> +foo (_BitInt(7) x)
> +{
> + return __builtin_mul_overflow_p (x,
> 1046555807606105294475452482332716433408wb, 0);
> +}
> +
> +#ifdef __SIZEOF_INT128__
> +int
> +bar (unsigned __int128 x)
> +{
> + return __builtin_sub_overflow_p
> (340282366920938463463374607431768211457uwb, x, 0);
> +}
> +#endif
> +#else
> +int i;
> +#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)
