On Thu, Apr 21, 2016 at 1:54 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
> On Thu, Apr 21, 2016 at 3:18 AM, Uros Bizjak <ubiz...@gmail.com> wrote:
>> On Thu, Apr 21, 2016 at 9:42 AM, Uros Bizjak <ubiz...@gmail.com> wrote:
>>> On Thu, Apr 21, 2016 at 9:37 AM, Uros Bizjak <ubiz...@gmail.com> wrote:
>>>> On Wed, Apr 20, 2016 at 9:53 PM, H.J. Lu <hongjiu...@intel.com> wrote:
>>>>> Since all 1s in TImode is standard SSE2 constants, all 1s in OImode is
>>>>> standard AVX2 constants and all 1s in XImode is standard AVX512F
>>>>> constants,
>>>>> pass mode to standard_sse_constant_p and standard_sse_constant_opcode
>>>>> to check if all 1s is available for target.
>>>>>
>>>>> Tested on Linux/x86-64. OK for master?
>>>>
>>>> No.
>>>>
>>>> This patch should use "isa" attribute instead of adding even more
>>>> similar patterns. Also, please leave MEM_P checks, the rare C->m move
>>>> can be easily resolved by IRA.
>>>
>>> Actually, register_operand checks are indeed better, please disregard
>>> MEM_P recommendation.
>>
>> So, something like attached untested RFC proto-patch, that lacks
>> wide-int handling.
>>
>> Uros.
>
> +
> + else if (CONST_INT_P (x))
> + {
> + if (INTVAL (X) == HOST_WIDE_INT_M1
> + && TARGET_SSE2)
> + return 2;
> + }
> + else if (CONST_WIDE_INT_P (x))
> + {
> + if (.... something involving wi::minus-one ....
> + && TARGET_AVX2)
> + return 2;
> + if (....
> + && TARGET_AVX512F)
> + return 2;
> + }
> + else if (vector_all_ones_operand (x, mode))
>
> All 1s may not use winde_int. It has VOIDmode.
> The mode is passed by
>
> @@ -18758,7 +18771,7 @@ ix86_expand_vector_move (machine_mode mode,
> rtx operands[])
> && (CONSTANT_P (op1)
> || (SUBREG_P (op1)
> && CONSTANT_P (SUBREG_REG (op1))))
> - && !standard_sse_constant_p (op1))
> + && !standard_sse_constant_p (op1, mode))
> op1 = validize_mem (force_const_mem (mode, op1));
>
> This is why I have
>
> -standard_sse_constant_p (rtx x)
> +standard_sse_constant_p (rtx x, machine_mode mode)
> {
> - machine_mode mode;
> -
> if (!TARGET_SSE)
> return 0;
>
> - mode = GET_MODE (x);
> -
> + if (mode == VOIDmode)
> + mode = GET_MODE (x);
> +
>
> since all 1s `x' may have VOIDmode when called from
> ix86_expand_vector_move if mode isn't passed.
We know, that const_int (-1) is allowed with TARGET_SSE2 and that
const_wide_int (-1) is allowed with TARGET_AVX2. Probably we don't
have to check AVX512F in standard_sse_constant_p, as it implies
TARGET_AVX2.
As said, it is the job of insn mode attributes to emit correct instruction.
Based on the above observations, mode checks for -1 are not needed in
standard_sse_constant_p.
Uros.
