> -----Original Message-----
> From: Jan Beulich <jbeul...@suse.com>
> Sent: Tuesday, July 11, 2023 2:04 PM
> To: gcc-patches@gcc.gnu.org
> Cc: Kirill Yukhin <kirill.yuk...@gmail.com>; Liu, Hongtao
> <hongtao....@intel.com>
> Subject: [PATCH v3] x86: make better use of VBROADCASTSS /
> VPBROADCASTD
>
> ... in vec_dupv4sf / *vec_dupv4si. The respective broadcast insns are never
> longer (yet sometimes shorter) than the corresponding VSHUFPS / VPSHUFD,
> due to the immediate operand of the shuffle insns balancing the
> (uniform) need for VEX3 in the broadcast ones. When EVEX encoding is
> respective the broadcast insns are always shorter.
>
> Add new alternatives to cover the AVX2 and AVX512 cases as appropriate.
>
> While touching this anyway, switch to consistently using "sseshuf1" in the
> "type" attributes for all shuffle forms.
>
> gcc/
>
> * config/i386/sse.md (vec_dupv4sf): Make first alternative use
> vbroadcastss for AVX2. New AVX512F alternative.
> (*vec_dupv4si): New AVX2 and AVX512F alternatives using
> vpbroadcastd. Replace sselog1 by sseshuf1 in "type" attribute.
>
> gcc/testsuite/
>
> * gcc.target/i386/avx2-dupv4sf.c: New test.
> * gcc.target/i386/avx2-dupv4si.c: Likewise.
> * gcc.target/i386/avx512f-dupv4sf.c: Likewise.
> * gcc.target/i386/avx512f-dupv4si.c: Likewise.
> ---
> Note that unlike originally intended, "prefix_extra" isn't dropped:
> "length_vex" uses it to determine whether 2-byte VEX encoding is possible
> (which it isn't for VBROADCASTSS / VPBROADCASTD). "length"
> itself specifically does not use it for VEX/EVEX encoded insns.
>
> Especially with the added "enabled" attribute I didn't really see how to
> (further) fold alternatives 0 and 1. Instead *vec_dupv4si might benefit from
> using sse2_noavx2 instead of sse2 for alternative 2, except that there is no
> sse2_noavx2, only sse2_noavx.
>
> I'm working from the assumption that the isa attributes to the original 1st
> and
> 2nd alternatives don't need further restricting (to sse2_noavx2 or
> avx_noavx2 as applicable), as the new earlier alternatives cover all operand
> forms already when at least AVX2 is enabled.
Yes, the patch LGTM.
> ---
> v3: Testcases for new alternatives. "type" and "prefix_extra"
> adjustments.
> v2: Correct operand constraints. Respect -mprefer-vector-width=. Fold
> two alternatives of vec_dupv4sf.
>
> --- a/gcc/config/i386/sse.md
> +++ b/gcc/config/i386/sse.md
> @@ -25969,41 +25969,64 @@
> (const_int 1)))])
>
> (define_insn "vec_dupv4sf"
> - [(set (match_operand:V4SF 0 "register_operand" "=v,v,x")
> + [(set (match_operand:V4SF 0 "register_operand" "=v,v,v,x")
> (vec_duplicate:V4SF
> - (match_operand:SF 1 "nonimmediate_operand" "Yv,m,0")))]
> + (match_operand:SF 1 "nonimmediate_operand" "Yv,v,m,0")))]
> "TARGET_SSE"
> "@
> - vshufps\t{$0, %1, %1, %0|%0, %1, %1, 0}
> + * return TARGET_AVX2 ? \"vbroadcastss\t{%1, %0|%0, %1}\" :
> \"vshufps\t{$0, %d1, %0|%0, %d1, 0}\";
> + vbroadcastss\t{%1, %g0|%g0, %1}
> vbroadcastss\t{%1, %0|%0, %1}
> shufps\t{$0, %0, %0|%0, %0, 0}"
> - [(set_attr "isa" "avx,avx,noavx")
> - (set_attr "type" "sseshuf1,ssemov,sseshuf1")
> - (set_attr "length_immediate" "1,0,1")
> - (set_attr "prefix_extra" "0,1,*")
> - (set_attr "prefix" "maybe_evex,maybe_evex,orig")
> - (set_attr "mode" "V4SF")])
> + [(set_attr "isa" "avx,*,avx,noavx")
> + (set (attr "type")
> + (cond [(and (eq_attr "alternative" "0")
> + (match_test "!TARGET_AVX2"))
> + (const_string "sseshuf1")
> + (eq_attr "alternative" "3")
> + (const_string "sseshuf1")
> + ]
> + (const_string "ssemov")))
> + (set (attr "length_immediate")
> + (if_then_else (eq_attr "type" "sseshuf1")
> + (const_string "1")
> + (const_string "0")))
> + (set_attr "prefix_extra" "0,1,1,*")
> + (set_attr "prefix" "maybe_evex,evex,maybe_evex,orig")
> + (set_attr "mode" "V4SF,V16SF,V4SF,V4SF")
> + (set (attr "enabled")
> + (if_then_else (eq_attr "alternative" "1")
> + (symbol_ref "TARGET_AVX512F && !TARGET_AVX512VL
> + && !TARGET_PREFER_AVX256")
> + (const_string "*")))])
>
> (define_insn "*vec_dupv4si"
> - [(set (match_operand:V4SI 0 "register_operand" "=v,v,x")
> + [(set (match_operand:V4SI 0 "register_operand" "=v,v,v,v,x")
> (vec_duplicate:V4SI
> - (match_operand:SI 1 "nonimmediate_operand" "Yv,m,0")))]
> + (match_operand:SI 1 "nonimmediate_operand" "Yvm,v,Yv,m,0")))]
> "TARGET_SSE"
> "@
> + vpbroadcastd\t{%1, %0|%0, %1}
> + vpbroadcastd\t{%1, %g0|%g0, %1}
> %vpshufd\t{$0, %1, %0|%0, %1, 0}
> vbroadcastss\t{%1, %0|%0, %1}
> shufps\t{$0, %0, %0|%0, %0, 0}"
> - [(set_attr "isa" "sse2,avx,noavx")
> - (set_attr "type" "sselog1,ssemov,sselog1")
> - (set_attr "length_immediate" "1,0,1")
> - (set_attr "prefix_extra" "0,1,*")
> - (set_attr "prefix" "maybe_vex,maybe_evex,orig")
> - (set_attr "mode" "TI,V4SF,V4SF")
> + [(set_attr "isa" "avx2,*,sse2,avx,noavx")
> + (set_attr "type" "ssemov,ssemov,sseshuf1,ssemov,sseshuf1")
> + (set_attr "length_immediate" "0,0,1,0,1")
> + (set_attr "prefix_extra" "1,1,0,1,*")
> + (set_attr "prefix" "maybe_evex,evex,maybe_vex,maybe_evex,orig")
> + (set_attr "mode" "TI,XI,TI,V4SF,V4SF")
> (set (attr "preferred_for_speed")
> - (cond [(eq_attr "alternative" "1")
> + (cond [(eq_attr "alternative" "3")
> (symbol_ref "!TARGET_INTER_UNIT_MOVES_TO_VEC")
> ]
> - (symbol_ref "true")))])
> + (symbol_ref "true")))
> + (set (attr "enabled")
> + (if_then_else (eq_attr "alternative" "1")
> + (symbol_ref "TARGET_AVX512F && !TARGET_AVX512VL
> + && !TARGET_PREFER_AVX256")
> + (const_string "*")))])
>
> (define_insn "*vec_dupv2di"
> [(set (match_operand:V2DI 0 "register_operand" "=x,v,v,v,x")
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/avx2-dupv4sf.c
> @@ -0,0 +1,18 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mavx2 -O2" } */
> +/* { dg-final { scan-assembler-times "vbroadcastss" 2 } } */
> +
> +typedef float __attribute__ ((vector_size (16))) v4sf;
> +
> +v4sf bcst_reg (float f)
> +{
> + register float x asm ("xmm7") = f;
> +
> + asm ("" : "+v" (x));
> + return (v4sf) {x, x, x, x};
> +}
> +
> +v4sf bcst_mem (const float *f)
> +{
> + return (v4sf) {*f, *f, *f, *f};
> +}
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/avx2-dupv4si.c
> @@ -0,0 +1,18 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mavx2 -O2" } */
> +/* { dg-final { scan-assembler-times "vpbroadcastd" 2 } } */
> +
> +typedef int __attribute__ ((vector_size (16))) v4si;
> +
> +v4si bcst_reg (int i)
> +{
> + register int x asm ("xmm7") = i;
> +
> + asm ("" : "+v" (x));
> + return (v4si) {x, x, x, x};
> +}
> +
> +v4si bcst_mem (const int *i)
> +{
> + return (v4si) {*i, *i, *i, *i};
> +}
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/avx512f-dupv4sf.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile { target { ! ia32 } } } */
> +/* { dg-options "-mavx512f -mno-avx512vl -mprefer-vector-width=512 -O2"
> +} */
> +/* { dg-final { scan-assembler "vbroadcastss\[^\n\]*%xmm17, *%zmm" } }
> +*/
> +
> +typedef float __attribute__ ((vector_size (16))) v4sf;
> +
> +v4sf bcst (float f)
> +{
> + register float x asm ("xmm17") = f;
> +
> + asm ("" : "+v" (x));
> + return (v4sf) {x, x, x, x};
> +}
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/avx512f-dupv4si.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile { target { ! ia32 } } } */
> +/* { dg-options "-mavx512f -mno-avx512vl -mprefer-vector-width=512 -O2"
> +} */
> +/* { dg-final { scan-assembler "vpbroadcastd\[^\n\]*%xmm17, *%zmm" } }
> +*/
> +
> +typedef int __attribute__ ((vector_size (16))) v4si;
> +
> +v4si bcst (int i)
> +{
> + register int x asm ("xmm17") = i;
> +
> + asm ("" : "+v" (x));
> + return (v4si) {x, x, x, x};
> +}
RE: [PATCH v3] x86: make better use of VBROADCASTSS / VPBROADCASTD
Liu, Hongtao via Gcc-patches Mon, 10 Jul 2023 23:33:52 -0700
- [PATCH v3] x86: make better use of VBROADCAST... Jan Beulich via Gcc-patches
- RE: [PATCH v3] x86: make better use of V... Liu, Hongtao via Gcc-patches
