Re: [PATCH v1] Match: Refactor unsigned SAT_MUL form 1 mul and widen-mul by for [NFC]

[Richard Biener]

On Thu, Sep 25, 2025 at 7:02 AM <pan2...@intel.com> wrote:
>
> From: Pan Li <pan2...@intel.com>
>
> Inspired by the previous patch, the form 1 of unsigned SAT_MUL
> can be mul or widen-mul based.  So we can leverage the keyword
> for to group it, and avoid the pattern duplication.
>
> The below test suites are passed for this patch:
> 1. The rv64gcv fully regression tests.
> 2. The x86 bootstrap tests.
> 3. The x86 fully regression tests.

OK.

Thanks,
Richard.

> gcc/ChangeLog:
>
>         * match.pd: Refactor the form 1 of SAT_MUL by keyword for.
>
> Signed-off-by: Pan Li <pan2...@intel.com>
> ---
>  gcc/match.pd | 29 ++++++++++-------------------
>  1 file changed, 10 insertions(+), 19 deletions(-)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index b3fd26e18dd..870d2caafd1 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -3620,6 +3620,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>
>  /* Saturation mult for unsigned integer.  */
>  (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type))
> + (for mult_op (mult widen_mult)
>    (match (unsigned_integer_sat_mul @0 @1)
>     /* SAT_U_MUL (X, Y) = {
>         WT x = (WT)a * (WT)b;
> @@ -3630,9 +3631,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>           return (T)x;
>        }
>        while WT is uint128_t, T is uint8_t, uint16_t, uint32_t or uint64_t.  
> */
> -   (convert (min (widen_mult:c@3 (convert@4 @0)
> -                                (convert@5 @1))
> -                  INTEGER_CST@2))
> +   (convert (min (mult_op:c@3 (convert@4 @0) (convert@5 @1)) INTEGER_CST@2))
>     (if (types_match (type, @0, @1))
>      (with
>       {
> @@ -3640,24 +3639,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
>        unsigned widen_prec = TYPE_PRECISION (TREE_TYPE (@3));
>        unsigned cvt4_prec = TYPE_PRECISION (TREE_TYPE (@4));
>        unsigned cvt5_prec = TYPE_PRECISION (TREE_TYPE (@5));
> -      wide_int c2 = wi::to_wide (@2);
> -      wide_int max = wi::mask (prec, false, widen_prec);
> -      bool c2_is_max_p = wi::eq_p (c2, max);
> -      bool widen_mult_p = cvt4_prec == cvt5_prec && widen_prec == cvt5_prec 
> * 2;
> -     }
> -     (if (widen_prec > prec && c2_is_max_p && widen_mult_p)))))
> -  (match (unsigned_integer_sat_mul @0 @1)
> -   (convert (min (mult:c@3 (convert @0) (convert @1)) INTEGER_CST@2))
> -   (if (types_match (type, @0, @1))
> -    (with
> -     {
> -      unsigned prec = TYPE_PRECISION (type);
> -      unsigned widen_prec = TYPE_PRECISION (TREE_TYPE (@3));
> -      wide_int c2 = wi::to_wide (@2);
> +
>        wide_int max = wi::mask (prec, false, widen_prec);
> -      bool c2_is_max_p = wi::eq_p (c2, max);
> +      bool c2_is_max_p = wi::eq_p (wi::to_wide (@2), max);
> +
> +      bool widen_mult_p = mult_op == WIDEN_MULT_EXPR && cvt4_prec == 
> cvt5_prec
> +       && widen_prec == cvt5_prec * 2 && widen_prec > prec;
> +      bool mult_p = mult_op == MULT_EXPR && cvt4_prec == cvt5_prec
> +       && cvt4_prec == widen_prec && widen_prec > prec;
>       }
> -     (if (widen_prec > prec && c2_is_max_p)))))
> +     (if (c2_is_max_p && (widen_mult_p || mult_p)))))))
>    (match (unsigned_integer_sat_mul @0 @1)
>     /* SAT_U_MUL (X, Y) = {
>         T result;
> --
> 2.43.0
>