On Tue, Aug 20, 2024 at 9:52 AM <pan2...@intel.com> wrote:
>
> From: Pan Li <pan2...@intel.com>
>
> This patch would like to support the form 4 of the unsigned integer
> .SAT_TRUNC. Aka below example:
>
> Form 4:
> #define DEF_SAT_U_TRUC_FMT_4(NT, WT) \
> NT __attribute__((noinline)) \
> sat_u_truc_##WT##_to_##NT##_fmt_4 (WT x) \
> { \
> bool not_overflow = x <= (WT)(NT)(-1); \
> return ((NT)x) | (NT)((NT)not_overflow - 1); \
> }
>
> DEF_SAT_U_TRUC_FMT_4(uint32_t, uint64_t)
>
> Before this patch:
> 4 │ __attribute__((noinline))
> 5 │ uint8_t sat_u_truc_uint32_t_to_uint8_t_fmt_4 (uint32_t x)
> 6 │ {
> 7 │ _Bool not_overflow;
> 8 │ unsigned char _1;
> 9 │ unsigned char _2;
> 10 │ unsigned char _3;
> 11 │ uint8_t _6;
> 12 │
> 13 │ ;; basic block 2, loop depth 0
> 14 │ ;; pred: ENTRY
> 15 │ not_overflow_5 = x_4(D) <= 255;
> 16 │ _1 = (unsigned char) x_4(D);
> 17 │ _2 = (unsigned char) not_overflow_5;
> 18 │ _3 = _2 + 255;
> 19 │ _6 = _1 | _3;
> 20 │ return _6;
> 21 │ ;; succ: EXIT
> 22 │
> 23 │ }
>
> After this patch:
> 4 │ __attribute__((noinline))
> 5 │ uint8_t sat_u_truc_uint32_t_to_uint8_t_fmt_4 (uint32_t x)
> 6 │ {
> 7 │ uint8_t _6;
> 8 │
> 9 │ ;; basic block 2, loop depth 0
> 10 │ ;; pred: ENTRY
> 11 │ _6 = .SAT_TRUNC (x_4(D)); [tail call]
> 12 │ return _6;
> 13 │ ;; succ: EXIT
> 14 │
> 15 │ }
OK.
Richard.
> The below test suites are passed for this patch.
> * The rv64gcv fully regression test.
> * The x86 bootstrap test.
> * The x86 fully regression test.
>
> gcc/ChangeLog:
>
> * match.pd: Add form 4 for unsigned .SAT_TRUNC matching.
>
> Signed-off-by: Pan Li <pan2...@intel.com>
> ---
> gcc/match.pd | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index c9c8478d286..5a2f777e65f 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -3311,6 +3311,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> }
> (if (otype_precision < itype_precision && wi::eq_p (trunc_max,
> int_cst))))))
>
> +/* Unsigned saturation truncate, case 3, sizeof (WT) > sizeof (NT).
> + SAT_U_TRUNC = (NT)X | ((NT)(X <= (WT)-1) + (NT)-1). */
> +(match (unsigned_integer_sat_trunc @0)
> + (bit_ior:c (plus:c (convert (le @0 INTEGER_CST@1)) INTEGER_CST@2)
> + (convert @0))
> + (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
> + && TYPE_UNSIGNED (TREE_TYPE (@0)))
> + (with
> + {
> + unsigned itype_precision = TYPE_PRECISION (TREE_TYPE (@0));
> + unsigned otype_precision = TYPE_PRECISION (type);
> + wide_int trunc_max = wi::mask (otype_precision, false, itype_precision);
> + wide_int max = wi::mask (otype_precision, false, otype_precision);
> + wide_int int_cst_1 = wi::to_wide (@1);
> + wide_int int_cst_2 = wi::to_wide (@2);
> + }
> + (if (wi::eq_p (trunc_max, int_cst_1) && wi::eq_p (max, int_cst_2))))))
> +
> /* x > y && x != XXX_MIN --> x > y
> x > y && x == XXX_MIN --> false . */
> (for eqne (eq ne)
> --
> 2.43.0
>
