[v3] x86: make VPTERNLOG* usable on less than 512-bit operands with just AVX512F

There's no reason to constrain this to AVX512VL, unless instructed so by
-mprefer-vector-width=, as the wider operation is unusable for more
narrow operands only when the possible memory source is a non-broadcast
one. This way even the scalar copysign<mode>3 can benefit from the
operation being a single-insn one (leaving aside moves which the
compiler decides to insert for unclear reasons, and leaving aside the
fact that bcst_mem_operand() is too restrictive for broadcast to be
embedded right into VPTERNLOG*).

While there also bring *<avx512>_vternlog<mode>_all's in sync with that
of the three splitters.

Along with this also request value duplication in
ix86_expand_copysign()'s call to ix86_build_signbit_mask(), eliminating
excess space allocation in .rodata.*, filled with zeros which are never
read.

gcc/

	* config/i386/i386-expand.cc (ix86_expand_copysign): Request
	value duplication by ix86_build_signbit_mask() when AVX512F and
	not HFmode.
	* config/i386/sse.md (*<avx512>_vternlog<mode>_all): Convert to
	2-alternative form. Adjust "mode" attribute. Add "enabled"
	attribute.
	(*<avx512>_vpternlog<mode>_1): Also permit when TARGET_AVX512F
	&& !TARGET_PREFER_AVX256.
	(*<avx512>_vpternlog<mode>_2): Likewise.
	(*<avx512>_vpternlog<mode>_3): Likewise.

gcc/testsuite/
	* gcc.target/i386/avx512f-copysign.c: New test.
---
I haven't been able to find documentation on the dejagnu(?) regex syntax
(?:...). With ordinary (...) failing (producing twice as many matches),
I could only derive this from other scan-assembler patterns.

I guess the underlying pattern, going along the lines of what
<mask_codefor>one_cmpl<mode>2<mask_name> uses, can be applied elsewhere
as well.

HFmode could use embedded broadcast too for copysign and alike, but that
would need to be V2HF -> V8HF (for which I don't think there are any
existing patterns).
---
v3: Adjust insn conditional as well. Add testcase.
v2: Respect -mprefer-vector-width=.

On Tue, Jun 20, 2023 at 3:07 PM Jan Beulich via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> There's no reason to constrain this to AVX512VL, unless instructed so by
> -mprefer-vector-width=, as the wider operation is unusable for more
> narrow operands only when the possible memory source is a non-broadcast
> one. This way even the scalar copysign<mode>3 can benefit from the
> operation being a single-insn one (leaving aside moves which the
> compiler decides to insert for unclear reasons, and leaving aside the
> fact that bcst_mem_operand() is too restrictive for broadcast to be
> embedded right into VPTERNLOG*).
>
> While there also bring *<avx512>_vternlog<mode>_all's in sync with that
> of the three splitters.
>
> Along with this also request value duplication in
> ix86_expand_copysign()'s call to ix86_build_signbit_mask(), eliminating
> excess space allocation in .rodata.*, filled with zeros which are never
> read.
>
> gcc/
>
>         * config/i386/i386-expand.cc (ix86_expand_copysign): Request
>         value duplication by ix86_build_signbit_mask() when AVX512F and
>         not HFmode.
>         * config/i386/sse.md (*<avx512>_vternlog<mode>_all): Convert to
>         2-alternative form. Adjust "mode" attribute. Add "enabled"
>         attribute.
>         (*<avx512>_vpternlog<mode>_1): Also permit when TARGET_AVX512F
>         && !TARGET_PREFER_AVX256.
>         (*<avx512>_vpternlog<mode>_2): Likewise.
>         (*<avx512>_vpternlog<mode>_3): Likewise.
>
> gcc/testsuite/
>         * gcc.target/i386/avx512f-copysign.c: New test.
> ---
> I haven't been able to find documentation on the dejagnu(?) regex syntax
> (?:...). With ordinary (...) failing (producing twice as many matches),
> I could only derive this from other scan-assembler patterns.
>
> I guess the underlying pattern, going along the lines of what
> <mask_codefor>one_cmpl<mode>2<mask_name> uses, can be applied elsewhere
> as well.
That should be guarded with !TARGET_PREFER_AVX256, let's handle that
in a separate patch.
>
> HFmode could use embedded broadcast too for copysign and alike, but that
> would need to be V2HF -> V8HF (for which I don't think there are any
> existing patterns).
> ---
> v3: Adjust insn conditional as well. Add testcase.
> v2: Respect -mprefer-vector-width=.
>
> --- a/gcc/config/i386/i386-expand.cc
> +++ b/gcc/config/i386/i386-expand.cc
> @@ -2266,7 +2266,7 @@ ix86_expand_copysign (rtx operands[])
>    else
>      dest = NULL_RTX;
>    op1 = lowpart_subreg (vmode, force_reg (mode, operands[2]), mode);
> -  mask = ix86_build_signbit_mask (vmode, 0, 0);
> +  mask = ix86_build_signbit_mask (vmode, TARGET_AVX512F && mode != HFmode, 0);
>
>    if (CONST_DOUBLE_P (operands[1]))
>      {
> --- a/gcc/config/i386/sse.md
> +++ b/gcc/config/i386/sse.md
> @@ -12399,22 +12399,35 @@
>     (set_attr "mode" "<sseinsnmode>")])
>
>  (define_insn "*<avx512>_vternlog<mode>_all"
> -  [(set (match_operand:V 0 "register_operand" "=v")
> +  [(set (match_operand:V 0 "register_operand" "=v,v")
>         (unspec:V
> -         [(match_operand:V 1 "register_operand" "0")
> -          (match_operand:V 2 "register_operand" "v")
> -          (match_operand:V 3 "bcst_vector_operand" "vmBr")
> +         [(match_operand:V 1 "register_operand" "0,0")
> +          (match_operand:V 2 "register_operand" "v,v")
> +          (match_operand:V 3 "bcst_vector_operand" "vBr,m")
>            (match_operand:SI 4 "const_0_to_255_operand")]
>           UNSPEC_VTERNLOG))]
> -  "TARGET_AVX512F
> +  "(<MODE_SIZE> == 64 || TARGET_AVX512VL
> +    || (TARGET_AVX512F && !TARGET_PREFER_AVX256))
>  /* Disallow embeded broadcast for vector HFmode since
>     it's not real AVX512FP16 instruction.  */
>    && (GET_MODE_SIZE (GET_MODE_INNER (<MODE>mode)) >= 4
>       || GET_CODE (operands[3]) != VEC_DUPLICATE)"
> -  "vpternlog<ternlogsuffix>\t{%4, %3, %2, %0|%0, %2, %3, %4}"
> +{
> +  if (TARGET_AVX512VL)
> +    return "vpternlog<ternlogsuffix>\t{%4, %3, %2, %0|%0, %2, %3, %4}";
> +  else
> +    return "vpternlog<ternlogsuffix>\t{%4, %g3, %g2, %g0|%g0, %g2, %g3, %4}";
> +}
>    [(set_attr "type" "sselog")
>     (set_attr "prefix" "evex")
> -   (set_attr "mode" "<sseinsnmode>")])
> +   (set (attr "mode")
> +        (if_then_else (match_test "TARGET_AVX512VL")
> +                     (const_string "<sseinsnmode>")
> +                     (const_string "XI")))
> +   (set (attr "enabled")
> +       (if_then_else (eq_attr "alternative" "1")
> +                     (symbol_ref "<MODE_SIZE> == 64 || TARGET_AVX512VL")
> +                     (const_string "*")))])
>
>  ;; There must be lots of other combinations like
>  ;;
> @@ -12443,7 +12456,8 @@
>           (any_logic2:V
>             (match_operand:V 3 "regmem_or_bitnot_regmem_operand")
>             (match_operand:V 4 "regmem_or_bitnot_regmem_operand"))))]
> -  "(<MODE_SIZE> == 64 || TARGET_AVX512VL)
> +  "(<MODE_SIZE> == 64 || TARGET_AVX512VL
> +    || (TARGET_AVX512F && !TARGET_PREFER_AVX256))
>     && ix86_pre_reload_split ()
>     && (rtx_equal_p (STRIP_UNARY (operands[1]),
>                     STRIP_UNARY (operands[4]))
> @@ -12527,7 +12541,8 @@
>               (match_operand:V 2 "regmem_or_bitnot_regmem_operand"))
>             (match_operand:V 3 "regmem_or_bitnot_regmem_operand"))
>           (match_operand:V 4 "regmem_or_bitnot_regmem_operand")))]
> -  "(<MODE_SIZE> == 64 || TARGET_AVX512VL)
> +  "(<MODE_SIZE> == 64 || TARGET_AVX512VL
> +    || (TARGET_AVX512F && !TARGET_PREFER_AVX256))
>     && ix86_pre_reload_split ()
>     && (rtx_equal_p (STRIP_UNARY (operands[1]),
>                     STRIP_UNARY (operands[4]))
> @@ -12610,7 +12625,8 @@
>             (match_operand:V 1 "regmem_or_bitnot_regmem_operand")
>             (match_operand:V 2 "regmem_or_bitnot_regmem_operand"))
>           (match_operand:V 3 "regmem_or_bitnot_regmem_operand")))]
> -  "(<MODE_SIZE> == 64 || TARGET_AVX512VL)
> +  "(<MODE_SIZE> == 64 || TARGET_AVX512VL
> +    || (TARGET_AVX512F && !TARGET_PREFER_AVX256))
>     && ix86_pre_reload_split ()"
>    "#"
>    "&& 1"
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
> @@ -0,0 +1,32 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mavx512f -mno-avx512vl -O2" } */
Please explicitly add -mprefer-vector-width=512, our tester will also
test unix{-m32 \-march=cascadelake,\ -march=cascadelake} which set the
- mprefer-vector-width=256, -mprefer-vector-width=512 in dg-options
can overwrite that.
Others LGTM.
> +/* { dg-final { scan-assembler-times "vpternlog\[dq\]\[ \\t\]+\\\$(?:216|228|0xd8|0xe4)," 5 } } */
> +
> +double cs_df (double x, double y)
> +{
> +  return __builtin_copysign (x, y);
> +}
> +
> +float cs_sf (float x, float y)
> +{
> +  return __builtin_copysignf (x, y);
> +}
> +
> +typedef double __attribute__ ((vector_size (16))) v2df;
> +typedef double __attribute__ ((vector_size (32))) v4df;
> +typedef double __attribute__ ((vector_size (64))) v8df;
> +
> +v2df cs_v2df (v2df x, v2df y)
> +{
> +  return __builtin_ia32_copysignpd (x, y);
> +}
> +
> +v4df cs_v4df (v4df x, v4df y)
> +{
> +  return __builtin_ia32_copysignpd256 (x, y);
> +}
> +
> +v8df cs_v8df (v8df x, v8df y)
> +{
> +  return __builtin_ia32_copysignpd512 (x, y);
> +}

On 20.06.2023 10:33, Hongtao Liu wrote:
> On Tue, Jun 20, 2023 at 3:07 PM Jan Beulich via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
>>
>> I guess the underlying pattern, going along the lines of what
>> <mask_codefor>one_cmpl<mode>2<mask_name> uses, can be applied elsewhere
>> as well.
> That should be guarded with !TARGET_PREFER_AVX256, let's handle that
> in a separate patch.

Sure, and as indicated there are more places where similar things could
be done.

>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
>> @@ -0,0 +1,32 @@
>> +/* { dg-do compile } */
>> +/* { dg-options "-mavx512f -mno-avx512vl -O2" } */
> Please explicitly add -mprefer-vector-width=512, our tester will also
> test unix{-m32 \-march=cascadelake,\ -march=cascadelake} which set the
> - mprefer-vector-width=256, -mprefer-vector-width=512 in dg-options
> can overwrite that.

Oh, I see. Will do. And I expect I then also need to adjust the newly
added avx512f-dupv2di.c from the earlier patch. I guess I could commit
that option addition there as obvious?

> Others LGTM.

May I take this as "okay with that change", or should I submit v4?

Jan

On Tue, Jun 20, 2023 at 5:03 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 20.06.2023 10:33, Hongtao Liu wrote:
> > On Tue, Jun 20, 2023 at 3:07 PM Jan Beulich via Gcc-patches
> > <gcc-patches@gcc.gnu.org> wrote:
> >>
> >> I guess the underlying pattern, going along the lines of what
> >> <mask_codefor>one_cmpl<mode>2<mask_name> uses, can be applied elsewhere
> >> as well.
> > That should be guarded with !TARGET_PREFER_AVX256, let's handle that
> > in a separate patch.
>
> Sure, and as indicated there are more places where similar things could
> be done.
>
> >> --- /dev/null
> >> +++ b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
> >> @@ -0,0 +1,32 @@
> >> +/* { dg-do compile } */
> >> +/* { dg-options "-mavx512f -mno-avx512vl -O2" } */
> > Please explicitly add -mprefer-vector-width=512, our tester will also
> > test unix{-m32 \-march=cascadelake,\ -march=cascadelake} which set the
> > - mprefer-vector-width=256, -mprefer-vector-width=512 in dg-options
> > can overwrite that.
>
> Oh, I see. Will do. And I expect I then also need to adjust the newly
> added avx512f-dupv2di.c from the earlier patch. I guess I could commit
> that option addition there as obvious?
Still need to send out the patch, and commit as an obvious fix.
>
> > Others LGTM.
>
> May I take this as "okay with that change", or should I submit v4?
Okay. no need for a v4 version.
>
> Jan

On Tue, Jun 20, 2023 at 5:34 PM Hongtao Liu <crazylht@gmail.com> wrote:
>
> On Tue, Jun 20, 2023 at 5:03 PM Jan Beulich <jbeulich@suse.com> wrote:
> >
> > On 20.06.2023 10:33, Hongtao Liu wrote:
> > > On Tue, Jun 20, 2023 at 3:07 PM Jan Beulich via Gcc-patches
> > > <gcc-patches@gcc.gnu.org> wrote:
> > >>
> > >> I guess the underlying pattern, going along the lines of what
> > >> <mask_codefor>one_cmpl<mode>2<mask_name> uses, can be applied elsewhere
> > >> as well.
> > > That should be guarded with !TARGET_PREFER_AVX256, let's handle that
> > > in a separate patch.
> >
> > Sure, and as indicated there are more places where similar things could
> > be done.
> >
> > >> --- /dev/null
> > >> +++ b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
> > >> @@ -0,0 +1,32 @@
> > >> +/* { dg-do compile } */
> > >> +/* { dg-options "-mavx512f -mno-avx512vl -O2" } */
> > > Please explicitly add -mprefer-vector-width=512, our tester will also
> > > test unix{-m32 \-march=cascadelake,\ -march=cascadelake} which set the
> > > - mprefer-vector-width=256, -mprefer-vector-width=512 in dg-options
> > > can overwrite that.
> >
> > Oh, I see. Will do. And I expect I then also need to adjust the newly
> > added avx512f-dupv2di.c from the earlier patch. I guess I could commit
> > that option addition there as obvious?
> Still need to send out the patch, and commit as an obvious fix.
> >
> > > Others LGTM.
> >
> > May I take this as "okay with that change", or should I submit v4?
> Okay. no need for a v4 version.
> >
avx512f-copysign.c failed for -m32, we need to add -mfpmath=sse to dg-options.

cs_df:
.LFB0:
        .cfi_startproc
        fldl    12(%esp)
        fxam
        fnstsw  %ax
        fstp    %st(0)
        fldl    4(%esp)
        fabs
        testb   $2, %ah
        je      .L1
        fchs
.L1:
        ret
        .cfi_endproc
.LFE0:
        .size   cs_df, .-cs_df
        .p2align 4
        .globl  cs_sf
        .type   cs_sf, @function
cs_sf:
.LFB1:
        .cfi_startproc
        flds    8(%esp)
        fxam
        fnstsw  %ax
        fstp    %st(0)
        flds    4(%esp)
        testb   $2, %ah
        fabs
        fld     %st(0)
        fchs
        fcmove  %st(1), %st
        fstp    %st(1)
        ret
        .cfi_endproc
.LFE1:
        .size   cs_sf, .-cs_sf
        .p2align 4
        .globl  cs_v2df
        .type   cs_v2df, @function

> > Jan
>
>
>
> --
> BR,
> Hongtao

On 27.06.2023 07:11, Hongtao Liu wrote:
> On Tue, Jun 20, 2023 at 5:34 PM Hongtao Liu <crazylht@gmail.com> wrote:
>>
>> On Tue, Jun 20, 2023 at 5:03 PM Jan Beulich <jbeulich@suse.com> wrote:
>>>
>>> On 20.06.2023 10:33, Hongtao Liu wrote:
>>>> On Tue, Jun 20, 2023 at 3:07 PM Jan Beulich via Gcc-patches
>>>> <gcc-patches@gcc.gnu.org> wrote:
>>>>>
>>>>> I guess the underlying pattern, going along the lines of what
>>>>> <mask_codefor>one_cmpl<mode>2<mask_name> uses, can be applied elsewhere
>>>>> as well.
>>>> That should be guarded with !TARGET_PREFER_AVX256, let's handle that
>>>> in a separate patch.
>>>
>>> Sure, and as indicated there are more places where similar things could
>>> be done.
>>>
>>>>> --- /dev/null
>>>>> +++ b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
>>>>> @@ -0,0 +1,32 @@
>>>>> +/* { dg-do compile } */
>>>>> +/* { dg-options "-mavx512f -mno-avx512vl -O2" } */
>>>> Please explicitly add -mprefer-vector-width=512, our tester will also
>>>> test unix{-m32 \-march=cascadelake,\ -march=cascadelake} which set the
>>>> - mprefer-vector-width=256, -mprefer-vector-width=512 in dg-options
>>>> can overwrite that.
>>>
>>> Oh, I see. Will do. And I expect I then also need to adjust the newly
>>> added avx512f-dupv2di.c from the earlier patch. I guess I could commit
>>> that option addition there as obvious?
>> Still need to send out the patch, and commit as an obvious fix.
>>>
>>>> Others LGTM.
>>>
>>> May I take this as "okay with that change", or should I submit v4?
>> Okay. no need for a v4 version.
>>>
> avx512f-copysign.c failed for -m32, we need to add -mfpmath=sse to dg-options.

Oh, of course. I will take care of this, but it may take me a couple of
days, as I just came back from a week of vacation. One question though:
Elsewhere such tests are simply suppressed for 32-bit. Personally I'd
prefer going that route, but if you think adding -mfpmath=sse is indeed
better, I'll follow your request.

Jan

> -----Original Message-----
> From: Jan Beulich <jbeulich@suse.com>
> Sent: Tuesday, July 4, 2023 11:30 PM
> To: Hongtao Liu <crazylht@gmail.com>
> Cc: gcc-patches@gcc.gnu.org; Kirill Yukhin <kirill.yukhin@gmail.com>; Liu,
> Hongtao <hongtao.liu@intel.com>
> Subject: Re: [PATCH v3] x86: make VPTERNLOG* usable on less than 512-bit
> operands with just AVX512F
> 
> On 27.06.2023 07:11, Hongtao Liu wrote:
> > On Tue, Jun 20, 2023 at 5:34 PM Hongtao Liu <crazylht@gmail.com> wrote:
> >>
> >> On Tue, Jun 20, 2023 at 5:03 PM Jan Beulich <jbeulich@suse.com> wrote:
> >>>
> >>> On 20.06.2023 10:33, Hongtao Liu wrote:
> >>>> On Tue, Jun 20, 2023 at 3:07 PM Jan Beulich via Gcc-patches
> >>>> <gcc-patches@gcc.gnu.org> wrote:
> >>>>>
> >>>>> I guess the underlying pattern, going along the lines of what
> >>>>> <mask_codefor>one_cmpl<mode>2<mask_name> uses, can be
> applied
> >>>>> elsewhere as well.
> >>>> That should be guarded with !TARGET_PREFER_AVX256, let's handle
> >>>> that in a separate patch.
> >>>
> >>> Sure, and as indicated there are more places where similar things
> >>> could be done.
> >>>
> >>>>> --- /dev/null
> >>>>> +++ b/gcc/testsuite/gcc.target/i386/avx512f-copysign.c
> >>>>> @@ -0,0 +1,32 @@
> >>>>> +/* { dg-do compile } */
> >>>>> +/* { dg-options "-mavx512f -mno-avx512vl -O2" } */
> >>>> Please explicitly add -mprefer-vector-width=512, our tester will
> >>>> also test unix{-m32 \-march=cascadelake,\ -march=cascadelake} which
> >>>> set the
> >>>> - mprefer-vector-width=256, -mprefer-vector-width=512 in dg-options
> >>>> can overwrite that.
> >>>
> >>> Oh, I see. Will do. And I expect I then also need to adjust the
> >>> newly added avx512f-dupv2di.c from the earlier patch. I guess I
> >>> could commit that option addition there as obvious?
> >> Still need to send out the patch, and commit as an obvious fix.
> >>>
> >>>> Others LGTM.
> >>>
> >>> May I take this as "okay with that change", or should I submit v4?
> >> Okay. no need for a v4 version.
> >>>
> > avx512f-copysign.c failed for -m32, we need to add -mfpmath=sse to dg-
> options.
> 
> Oh, of course. I will take care of this, but it may take me a couple of days, as I
> just came back from a week of vacation. One question though:
> Elsewhere such tests are simply suppressed for 32-bit. Personally I'd prefer
> going that route, but if you think adding -mfpmath=sse is indeed better, I'll
> follow your request.
Either is ok.
> 
> Jan