| Message ID | c643ed57-cdba-5487-1781-47904dbe6208@suse.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] x86: make better use of VBROADCASTSS / VPBROADCASTD | expand |
On Wed, Jun 21, 2023 at 2:06 PM Jan Beulich via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > ... 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 > possible need for VEX3 in the broadcast ones. When EVEX encoding is > required the broadcast insns are always shorter. > > Add new alternatives to cover the AVX2 and AVX512 cases as appropriate. > > 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. > --- > 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. > > Is there a reason why vec_dupv4sf uses sseshuf1 for its shuffle > alternatives, but *vec_dupv4si uses sselog1? I'd be happy to correct > this in whichever is the appropriate direction, while touching this > anyway. It should be sseshuf1(or sseshuf depending on input operands number in the pattern) for shufps, sselog means logical instructions. I think it comes from Intel SDM Vlolumes1: 5.6.1 Intel® SSE2 Packed and Scalar Double Precision Floating-Point Instructions there're descriptions for different kinds of instructions. > > 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. > > Isn't prefix_extra use bogus here? What extra prefix does vbroadcastss According to comments, yes, no extra prefix is needed. ;; There are also additional prefixes in 3DNOW, SSSE3. ;; ssemuladd,sse4arg default to 0f24/0f25 and DREX byte, ;; sseiadd1,ssecvt1 to 0f7a with no DREX byte. ;; 3DNOW has 0f0f prefix, SSSE3 and SSE4_{1,2} 0f38/0f3a. > use? (Same further down in *vec_dupv4si and avx2_vbroadcasti128_<mode> > and elsewhere.) > --- > 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 > @@ -26141,41 +26141,64 @@ > (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" "0,0,1,*") > + (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,sselog1,ssemov,sselog1") > + (set_attr "length_immediate" "0,0,1,0,1") > + (set_attr "prefix_extra" "0,0,0,1,*") > + (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") Could you write a testcase for the newly added constraint? You can use an inline assembly to explicitly use an evex xmm register. .i.e. typedef float v4sf __attribute__((vector_size(16))); typedef int v4si __attribute__((vector_size(16))); v4sf foo (float a) { register float c __asm("xmm16") = a; asm volatile ("": "+v"(c)); return __extension__(v4sf) {c, c, c, c}; } v4si foo1 (int a) { register int c __asm("xmm16") = a; asm volatile ("": "+v"(c)); return __extension__(v4si) {c, c, c, c}; } with your patch, the above testcase should generate vbroadcastss/vpbroadcastd %xmm16, %zmm0 with -mavx512f -mno-avx512vl -mprefer-vector-width=512. Refer to gcc/testsuite/gcc.target/i386/avx512bw-pack-2.c Otherwise LGTM. -- BR, Hongtao
On 21.06.2023 09:37, Hongtao Liu wrote: > On Wed, Jun 21, 2023 at 2:06 PM Jan Beulich via Gcc-patches > <gcc-patches@gcc.gnu.org> wrote: >> >> Is there a reason why vec_dupv4sf uses sseshuf1 for its shuffle >> alternatives, but *vec_dupv4si uses sselog1? I'd be happy to correct >> this in whichever is the appropriate direction, while touching this >> anyway. > It should be sseshuf1(or sseshuf depending on input operands number in > the pattern) for shufps, sselog means logical instructions. Would you be okay for me to fold in that adjustment, or do you insist on a separate patch? >> 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. >> >> Isn't prefix_extra use bogus here? What extra prefix does vbroadcastss > According to comments, yes, no extra prefix is needed. > > ;; There are also additional prefixes in 3DNOW, SSSE3. > ;; ssemuladd,sse4arg default to 0f24/0f25 and DREX byte, > ;; sseiadd1,ssecvt1 to 0f7a with no DREX byte. > ;; 3DNOW has 0f0f prefix, SSSE3 and SSE4_{1,2} 0f38/0f3a. Right, that's what triggered my question. I guess dropping these "prefix_extra" really wants to be a separate patch (or maybe even multiple, but it's hard to see how to split), dealing with all of the instances which likely have accumulated simply via copy-and-paste. >> --- a/gcc/config/i386/sse.md >> +++ b/gcc/config/i386/sse.md >> @@ -26141,41 +26141,64 @@ >> (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" "0,0,1,*") >> + (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,sselog1,ssemov,sselog1") >> + (set_attr "length_immediate" "0,0,1,0,1") >> + (set_attr "prefix_extra" "0,0,0,1,*") >> + (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") > Could you write a testcase for the newly added constraint? > > You can use an inline assembly to explicitly use an evex xmm register. > .i.e. > > typedef float v4sf __attribute__((vector_size(16))); > typedef int v4si __attribute__((vector_size(16))); > v4sf > foo (float a) > { > register float c __asm("xmm16") = a; > asm volatile ("": "+v"(c)); > return __extension__(v4sf) {c, c, c, c}; > } > > > v4si > foo1 (int a) > { > register int c __asm("xmm16") = a; > asm volatile ("": "+v"(c)); > return __extension__(v4si) {c, c, c, c}; > } > > with your patch, the above testcase should generate > vbroadcastss/vpbroadcastd %xmm16, %zmm0 with -mavx512f -mno-avx512vl > -mprefer-vector-width=512. > > Refer to gcc/testsuite/gcc.target/i386/avx512bw-pack-2.c I can certainly do that. Not having had a need to adjust any existing tests made me conclude that the earlier alternatives also don't (all) have a corresponding testcase. Jan
On 21.06.2023 09:44, Jan Beulich wrote: > On 21.06.2023 09:37, Hongtao Liu wrote: >> On Wed, Jun 21, 2023 at 2:06 PM Jan Beulich via Gcc-patches >> <gcc-patches@gcc.gnu.org> wrote: >>> >>> Isn't prefix_extra use bogus here? What extra prefix does vbroadcastss >> According to comments, yes, no extra prefix is needed. >> >> ;; There are also additional prefixes in 3DNOW, SSSE3. >> ;; ssemuladd,sse4arg default to 0f24/0f25 and DREX byte, >> ;; sseiadd1,ssecvt1 to 0f7a with no DREX byte. >> ;; 3DNOW has 0f0f prefix, SSSE3 and SSE4_{1,2} 0f38/0f3a. > > Right, that's what triggered my question. I guess dropping these > "prefix_extra" really wants to be a separate patch (or maybe even > multiple, but it's hard to see how to split), dealing with all of the > instances which likely have accumulated simply via copy-and-paste. Or wait - I'm altering those lines anyway, so I could as well drop them right away (and slightly shrink patch size), if that's okay with you. Of course I should then not forget to also mention this in the changelog entry. Jan
> -----Original Message----- > From: Jan Beulich <jbeulich@suse.com> > Sent: Wednesday, June 21, 2023 8:40 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 v2] x86: make better use of VBROADCASTSS / > VPBROADCASTD > > On 21.06.2023 09:44, Jan Beulich wrote: > > On 21.06.2023 09:37, Hongtao Liu wrote: > >> On Wed, Jun 21, 2023 at 2:06 PM Jan Beulich via Gcc-patches > >> <gcc-patches@gcc.gnu.org> wrote: > >>> > >>> Isn't prefix_extra use bogus here? What extra prefix does > >>> vbroadcastss > >> According to comments, yes, no extra prefix is needed. > >> > >> ;; There are also additional prefixes in 3DNOW, SSSE3. > >> ;; ssemuladd,sse4arg default to 0f24/0f25 and DREX byte, ;; > >> sseiadd1,ssecvt1 to 0f7a with no DREX byte. > >> ;; 3DNOW has 0f0f prefix, SSSE3 and SSE4_{1,2} 0f38/0f3a. > > > > Right, that's what triggered my question. I guess dropping these > > "prefix_extra" really wants to be a separate patch (or maybe even > > multiple, but it's hard to see how to split), dealing with all of the > > instances which likely have accumulated simply via copy-and-paste. > > Or wait - I'm altering those lines anyway, so I could as well drop them right > away (and slightly shrink patch size), if that's okay with you. Of course I > should then not forget to also mention this in the changelog entry. > Yes. > Jan
On Sun, Jun 25, 2023 at 9:17 AM Liu, Hongtao <hongtao.liu@intel.com> wrote: > > > > > -----Original Message----- > > From: Jan Beulich <jbeulich@suse.com> > > Sent: Wednesday, June 21, 2023 8:40 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 v2] x86: make better use of VBROADCASTSS / > > VPBROADCASTD > > > > On 21.06.2023 09:44, Jan Beulich wrote: > > > On 21.06.2023 09:37, Hongtao Liu wrote: > > >> On Wed, Jun 21, 2023 at 2:06 PM Jan Beulich via Gcc-patches > > >> <gcc-patches@gcc.gnu.org> wrote: > > >>> > > >>> Isn't prefix_extra use bogus here? What extra prefix does > > >>> vbroadcastss > > >> According to comments, yes, no extra prefix is needed. > > >> > > >> ;; There are also additional prefixes in 3DNOW, SSSE3. > > >> ;; ssemuladd,sse4arg default to 0f24/0f25 and DREX byte, ;; > > >> sseiadd1,ssecvt1 to 0f7a with no DREX byte. > > >> ;; 3DNOW has 0f0f prefix, SSSE3 and SSE4_{1,2} 0f38/0f3a. > > > > > > Right, that's what triggered my question. I guess dropping these > > > "prefix_extra" really wants to be a separate patch (or maybe even > > > multiple, but it's hard to see how to split), dealing with all of the > > > instances which likely have accumulated simply via copy-and-paste. > > > > Or wait - I'm altering those lines anyway, so I could as well drop them right > > away (and slightly shrink patch size), if that's okay with you. Of course I > > should then not forget to also mention this in the changelog entry. > > > Yes. >Would you be okay for me to fold in that adjustment, or do you >insist on a separate patch? Also for this, no need for a separate patch. > > Jan
--- a/gcc/config/i386/sse.md +++ b/gcc/config/i386/sse.md @@ -26141,41 +26141,64 @@ (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" "0,0,1,*") + (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,sselog1,ssemov,sselog1") + (set_attr "length_immediate" "0,0,1,0,1") + (set_attr "prefix_extra" "0,0,0,1,*") + (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")
... 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 possible need for VEX3 in the broadcast ones. When EVEX encoding is required the broadcast insns are always shorter. Add new alternatives to cover the AVX2 and AVX512 cases as appropriate. 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. --- 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. Is there a reason why vec_dupv4sf uses sseshuf1 for its shuffle alternatives, but *vec_dupv4si uses sselog1? I'd be happy to correct this in whichever is the appropriate direction, while touching this anyway. 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. Isn't prefix_extra use bogus here? What extra prefix does vbroadcastss use? (Same further down in *vec_dupv4si and avx2_vbroadcasti128_<mode> and elsewhere.) --- v2: Correct operand constraints. Respect -mprefer-vector-width=. Fold two alternatives of vec_dupv4sf.