On Thu, 5 Aug 2021 at 18:05, Christophe Lyon <christophe.lyon....@gmail.com> wrote: > > > > On Thu, Aug 5, 2021 at 2:28 PM Prathamesh Kulkarni > <prathamesh.kulka...@linaro.org> wrote: >> >> On Tue, 3 Aug 2021 at 20:52, Christophe Lyon >> <christophe.lyon....@gmail.com> wrote: >> > >> > >> > >> > On Tue, Aug 3, 2021 at 12:57 PM Prathamesh Kulkarni >> > <prathamesh.kulka...@linaro.org> wrote: >> >> >> >> On Tue, 3 Aug 2021 at 14:59, Christophe Lyon >> >> <christophe.lyon....@gmail.com> wrote: >> >> > >> >> > >> >> > >> >> > On Tue, Jul 6, 2021 at 11:26 AM Prathamesh Kulkarni via Gcc-patches >> >> > <gcc-patches@gcc.gnu.org> wrote: >> >> >> >> >> >> On Tue, 6 Jul 2021 at 13:33, Kyrylo Tkachov <kyrylo.tkac...@arm.com> >> >> >> wrote: >> >> >> > >> >> >> > >> >> >> > >> >> >> > > -----Original Message----- >> >> >> > > From: Prathamesh Kulkarni <prathamesh.kulka...@linaro.org> >> >> >> > > Sent: 06 July 2021 08:06 >> >> >> > > To: Christophe LYON <christophe.l...@foss.st.com> >> >> >> > > Cc: Kyrylo Tkachov <kyrylo.tkac...@arm.com>; gcc Patches <gcc- >> >> >> > > patc...@gcc.gnu.org> >> >> >> > > Subject: Re: [ARM] PR98435: Missed optimization in expanding vector >> >> >> > > constructor >> >> >> > > >> >> >> > > On Thu, 1 Jul 2021 at 16:26, Prathamesh Kulkarni >> >> >> > > <prathamesh.kulka...@linaro.org> wrote: >> >> >> > > > >> >> >> > > > On Wed, 30 Jun 2021 at 20:51, Christophe LYON >> >> >> > > > <christophe.l...@foss.st.com> wrote: >> >> >> > > > > >> >> >> > > > > >> >> >> > > > > On 29/06/2021 12:46, Prathamesh Kulkarni wrote: >> >> >> > > > > > On Mon, 28 Jun 2021 at 14:48, Christophe LYON >> >> >> > > > > > <christophe.l...@foss.st.com> wrote: >> >> >> > > > > >> >> >> >> > > > > >> On 28/06/2021 10:40, Kyrylo Tkachov via Gcc-patches wrote: >> >> >> > > > > >>>> -----Original Message----- >> >> >> > > > > >>>> From: Prathamesh Kulkarni <prathamesh.kulka...@linaro.org> >> >> >> > > > > >>>> Sent: 28 June 2021 09:38 >> >> >> > > > > >>>> To: Kyrylo Tkachov <kyrylo.tkac...@arm.com> >> >> >> > > > > >>>> Cc: Christophe Lyon <christophe.l...@linaro.org>; gcc >> >> >> > > > > >>>> Patches >> >> >> > > <gcc- >> >> >> > > > > >>>> patc...@gcc.gnu.org> >> >> >> > > > > >>>> Subject: Re: [ARM] PR98435: Missed optimization in >> >> >> > > > > >>>> expanding >> >> >> > > vector >> >> >> > > > > >>>> constructor >> >> >> > > > > >>>> >> >> >> > > > > >>>> On Thu, 24 Jun 2021 at 22:01, Kyrylo Tkachov >> >> >> > > <kyrylo.tkac...@arm.com> >> >> >> > > > > >>>> wrote: >> >> >> > > > > >>>>> >> >> >> > > > > >>>>>> -----Original Message----- >> >> >> > > > > >>>>>> From: Prathamesh Kulkarni >> >> >> > > > > >>>>>> <prathamesh.kulka...@linaro.org> >> >> >> > > > > >>>>>> Sent: 14 June 2021 09:02 >> >> >> > > > > >>>>>> To: Christophe Lyon <christophe.l...@linaro.org> >> >> >> > > > > >>>>>> Cc: gcc Patches <gcc-patches@gcc.gnu.org>; Kyrylo >> >> >> > > > > >>>>>> Tkachov >> >> >> > > > > >>>>>> <kyrylo.tkac...@arm.com> >> >> >> > > > > >>>>>> Subject: Re: [ARM] PR98435: Missed optimization in >> >> >> > > > > >>>>>> expanding >> >> >> > > vector >> >> >> > > > > >>>>>> constructor >> >> >> > > > > >>>>>> >> >> >> > > > > >>>>>> On Wed, 9 Jun 2021 at 15:58, Prathamesh Kulkarni >> >> >> > > > > >>>>>> <prathamesh.kulka...@linaro.org> wrote: >> >> >> > > > > >>>>>>> On Fri, 4 Jun 2021 at 13:15, Christophe Lyon >> >> >> > > > > >>>> <christophe.l...@linaro.org> >> >> >> > > > > >>>>>> wrote: >> >> >> > > > > >>>>>>>> On Fri, 4 Jun 2021 at 09:27, Prathamesh Kulkarni via >> >> >> > > > > >>>>>>>> Gcc- >> >> >> > > patches >> >> >> > > > > >>>>>>>> <gcc-patches@gcc.gnu.org> wrote: >> >> >> > > > > >>>>>>>>> Hi, >> >> >> > > > > >>>>>>>>> As mentioned in PR, for the following test-case: >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>>> #include <arm_neon.h> >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>>> bfloat16x4_t f1 (bfloat16_t a) >> >> >> > > > > >>>>>>>>> { >> >> >> > > > > >>>>>>>>> return vdup_n_bf16 (a); >> >> >> > > > > >>>>>>>>> } >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>>> bfloat16x4_t f2 (bfloat16_t a) >> >> >> > > > > >>>>>>>>> { >> >> >> > > > > >>>>>>>>> return (bfloat16x4_t) {a, a, a, a}; >> >> >> > > > > >>>>>>>>> } >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>>> Compiling with arm-linux-gnueabi -O3 -mfpu=neon >> >> >> > > > > >>>>>>>>> -mfloat- >> >> >> > > > > >>>> abi=softfp >> >> >> > > > > >>>>>>>>> -march=armv8.2-a+bf16+fp16 results in f2 not being >> >> >> > > vectorized: >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>>> f1: >> >> >> > > > > >>>>>>>>> vdup.16 d16, r0 >> >> >> > > > > >>>>>>>>> vmov r0, r1, d16 @ v4bf >> >> >> > > > > >>>>>>>>> bx lr >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>>> f2: >> >> >> > > > > >>>>>>>>> mov r3, r0 @ __bf16 >> >> >> > > > > >>>>>>>>> adr r1, .L4 >> >> >> > > > > >>>>>>>>> ldrd r0, [r1] >> >> >> > > > > >>>>>>>>> mov r2, r3 @ __bf16 >> >> >> > > > > >>>>>>>>> mov ip, r3 @ __bf16 >> >> >> > > > > >>>>>>>>> bfi r1, r2, #0, #16 >> >> >> > > > > >>>>>>>>> bfi r0, ip, #0, #16 >> >> >> > > > > >>>>>>>>> bfi r1, r3, #16, #16 >> >> >> > > > > >>>>>>>>> bfi r0, r2, #16, #16 >> >> >> > > > > >>>>>>>>> bx lr >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>>> This seems to happen because vec_init pattern in >> >> >> > > > > >>>>>>>>> neon.md >> >> >> > > has VDQ >> >> >> > > > > >>>>>> mode >> >> >> > > > > >>>>>>>>> iterator, which doesn't include V4BF. In attached >> >> >> > > > > >>>>>>>>> patch, I >> >> >> > > changed >> >> >> > > > > >>>>>>>>> mode >> >> >> > > > > >>>>>>>>> to VDQX which seems to work for the test-case, and >> >> >> > > > > >>>>>>>>> the >> >> >> > > compiler >> >> >> > > > > >>>> now >> >> >> > > > > >>>>>> generates: >> >> >> > > > > >>>>>>>>> f2: >> >> >> > > > > >>>>>>>>> vdup.16 d16, r0 >> >> >> > > > > >>>>>>>>> vmov r0, r1, d16 @ v4bf >> >> >> > > > > >>>>>>>>> bx lr >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>>> However, the pattern is also gated on TARGET_HAVE_MVE >> >> >> > > and I am >> >> >> > > > > >>>>>> not >> >> >> > > > > >>>>>>>>> sure if either VDQ or VDQX are correct modes for MVE >> >> >> > > > > >>>>>>>>> since >> >> >> > > MVE >> >> >> > > > > >>>> has >> >> >> > > > > >>>>>>>>> only 128-bit vectors ? >> >> >> > > > > >>>>>>>>> >> >> >> > > > > >>>>>>>> I think patterns common to both Neon and MVE should be >> >> >> > > moved to >> >> >> > > > > >>>>>>>> vec-common.md, I don't know why such patterns were >> >> >> > > > > >>>>>>>> left in >> >> >> > > > > >>>> neon.md. >> >> >> > > > > >>>>>>> Since we end up calling neon_expand_vector_init for >> >> >> > > > > >>>>>>> both >> >> >> > > NEON and >> >> >> > > > > >>>> MVE, >> >> >> > > > > >>>>>>> I am not sure if we should separate the pattern ? >> >> >> > > > > >>>>>>> Would it make sense to FAIL if the mode size isn't 16 >> >> >> > > > > >>>>>>> bytes for >> >> >> > > MVE as >> >> >> > > > > >>>>>>> in attached patch so >> >> >> > > > > >>>>>>> it will call neon_expand_vector_init only for 128-bit >> >> >> > > > > >>>>>>> vectors ? >> >> >> > > > > >>>>>>> Altho hard-coding 16 in the pattern doesn't seem a >> >> >> > > > > >>>>>>> good idea to >> >> >> > > me >> >> >> > > > > >>>> either. >> >> >> > > > > >>>>>> ping https://gcc.gnu.org/pipermail/gcc-patches/2021- >> >> >> > > June/572342.html >> >> >> > > > > >>>>>> (attaching patch as text). >> >> >> > > > > >>>>>> >> >> >> > > > > >>>>> --- a/gcc/config/arm/neon.md >> >> >> > > > > >>>>> +++ b/gcc/config/arm/neon.md >> >> >> > > > > >>>>> @@ -459,10 +459,12 @@ >> >> >> > > > > >>>>> ) >> >> >> > > > > >>>>> >> >> >> > > > > >>>>> (define_expand "vec_init<mode><V_elem_l>" >> >> >> > > > > >>>>> - [(match_operand:VDQ 0 "s_register_operand") >> >> >> > > > > >>>>> + [(match_operand:VDQX 0 "s_register_operand") >> >> >> > > > > >>>>> (match_operand 1 "" "")] >> >> >> > > > > >>>>> "TARGET_NEON || TARGET_HAVE_MVE" >> >> >> > > > > >>>>> { >> >> >> > > > > >>>>> + if (TARGET_HAVE_MVE && GET_MODE_SIZE (GET_MODE >> >> >> > > > > >>>> (operands[0])) != 16) >> >> >> > > > > >>>>> + FAIL; >> >> >> > > > > >>>>> neon_expand_vector_init (operands[0], operands[1]); >> >> >> > > > > >>>>> DONE; >> >> >> > > > > >>>>> }) >> >> >> > > > > >>>>> >> >> >> > > > > >>>>> I think we should move this to vec-common.md like >> >> >> > > > > >>>>> Christophe >> >> >> > > said. >> >> >> > > > > >>>>> Perhaps rather than making it FAIL for non-16 MVE sizes >> >> >> > > > > >>>>> we just >> >> >> > > disable it in >> >> >> > > > > >>>> the expander condition? >> >> >> > > > > >>>>> "TARGET_NEON || (TARGET_HAVE_MVE && GET_MODE_SIZE (< >> >> >> > > > > >>>> VDQ>mode) != 16)" >> >> >> > > > > >>>> Is it OK to use <MODE>mode ? Because using <VDQ>mode >> >> >> > > > > >>>> resulted >> >> >> > > in lot >> >> >> > > > > >>>> of build errors. >> >> >> > > > > >>>> Also, I think the comparison should be inverted, ie, >> >> >> > > > > >>>> GET_MODE_SIZE >> >> >> > > > > >>>> (<MODE>mode) == 16 since >> >> >> > > > > >>>> we want to make the pattern pass if target is MVE and >> >> >> > > > > >>>> vector size is >> >> >> > > 16 bytes ? >> >> >> > > > > >>>> Do these changes in attached patch look OK ? >> >> >> > > > > >>> Yes, you're right. >> >> >> > > > > >> >> >> >> > > > > >> Can't this be ARM_HAVE_<MODE>_ARITH like in most expanders >> >> >> > > > > >> in >> >> >> > > vec-common.md? >> >> >> > > > > >> >> >> >> > > > > >> (maybe with a && !TARGET_REALLY_IWMMXT if needed) >> >> >> > > > > > I wonder if this should be ARM_HAVE_<MODE>_LDST instead since >> >> >> > > we're >> >> >> > > > > > initializing the vector ? >> >> >> > > > > >> >> >> > > > > >> >> >> > > > > Well, it really depends on which modes you want to enable. >> >> >> > > > > >> >> >> > > > > >> >> >> > > > > Looks like your move VDQ -> VDQ adds V4BF, V8BF and DI. >> >> >> > > > > >> >> >> > > > > Are they all OK for Neon? >> >> >> > > > > >> >> >> > > > > They are not OK for MVE. >> >> >> > > > > >> >> >> > > > > Ideally you could add testcases to cover to the supported and >> >> >> > > > > unsupported modes for both Neon and MVE.\ >> >> >> > > > > >> >> >> > > > > Before your patch, the expander is enabled for MVE for 64 bit >> >> >> > > > > modes >> >> >> > > > > (V8QI, V4HI, V2SI): what happens in this case? Does the >> >> >> > > > > compiler crash >> >> >> > > > > or is there something else preventing the match? >> >> >> > > > Hi, >> >> >> > > > Apparently there is VALID_MVE_MODE macro, so is it better to use: >> >> >> > > > TARGET_NEON || (TARGET_HAVE_MVE && >> >> >> > > VALID_MVE_MODE(<MODE>mode)) >> >> >> > > > as in the attached patch ? >> >> >> > >> >> >> > The change is ok. I would like to see some testcases like Christophe >> >> >> > suggested, but this patch just moves the expander around rather than >> >> >> > introducing new functionality. >> >> >> Hi Kyrill, >> >> >> As mentioned in the first email, the patch improves code-gen for >> >> >> following test-case: >> >> >> >> >> >> bfloat16x4_t f (bfloat16_t a) >> >> >> { >> >> >> return (bfloat16x4_t) {a, a, a, a}; >> >> >> } >> >> >> >> >> >> Before patch: >> >> >> f: >> >> >> mov r3, r0 @ __bf16 >> >> >> adr r1, .L4 >> >> >> ldrd r0, [r1] >> >> >> mov r2, r3 @ __bf16 >> >> >> mov ip, r3 @ __bf16 >> >> >> bfi r1, r2, #0, #16 >> >> >> bfi r0, ip, #0, #16 >> >> >> bfi r1, r3, #16, #16 >> >> >> bfi r0, r2, #16, #16 >> >> >> bx lr >> >> >> >> >> >> After patch: >> >> >> f: >> >> >> vdup.16 d16, r0 >> >> >> vmov r0, r1, d16 @ v4bf >> >> >> bx lr >> >> >> >> >> >> because the patch changes mode from VDQ to VDQX to accommodate bf >> >> >> modes. >> >> >> I have included the test in the attached patch. >> >> >> I think Christophe's concerns were mainly about the right modes >> >> >> getting enabled for MVE. >> >> >> Unfortunately, I am not sure how to test for that because the FE >> >> >> catches invalid modes, and we don't >> >> >> end up hitting the pattern. >> >> >> >> >> > >> >> > Hi Prathamesh, >> >> > >> >> > The new testcase fails on arm-linux-gnueabihf: >> >> > FAIL: gcc.target/arm/simd/pr98435.c (test for excess errors) >> >> > Excess errors: >> >> > /aci-gcc-fsf/builds/gcc-fsf-gccsrc/sysroot-arm-none-linux-gnueabihf/usr/include/gnu/stubs.h:7:11: >> >> > fatal error: gnu/stubs-soft.h: No such file or directory >> >> > compilation terminated. >> >> > >> >> > Because you don't check whether -mfloat-abi=softfp is actually >> >> > supported. >> >> > >> >> > Can you fix that? >> >> Oops, sorry about that. >> >> The attached patch fixes the test by requiring arm_softfloat and makes >> >> it UNSUPPORTED on arm-linux-gnueabihf. >> >> Does it look OK ? >> >> >> > >> > I don't think that's right: it would make the test unsupported if softfp >> > is not the default even if the toolchain has the needed multilibs. >> > Did you check eg. with arm-eabi and multilibs enabled? >> Ah OK, thanks for pointing it out! >> Does the attached patch look correct ? >> > > I don't think: this would skip the test even if the toolchain has multilibs > enabled. > Did you check eg. with arm-eabi and multilibs enabled and the usual option > overrides? It showed 3 PASS with second patch: /* { dg-skip-if "skip test for hard float" { *-*-* } { "-mfloat-abi=hard" } { "" } } */
I ran it using make check-gcc RUNTESTFLAGS="simd.exp=pr98435.c" and built the toolchain using: abe.sh --target arm-eabi --build all --set multilib=aprofile gcc=gcc.git~master. I suppose that's correct ? gcc -v output: Configured with: '/home/prathamesh.kulkarni/abe-toolchain-2/snapshots/gcc.git~master/configure' SHELL=/bin/bash --with-mpc=/home/prathamesh.kulkarni/abe-toolchain-2/builds/destdir/x86_64-pc-linux-gnu --with-mpfr=/home/prathamesh.kulkarni/abe-toolchain-2/builds/destdir/x86_64-pc-linux-gnu --with-gmp=/home/prathamesh.kulkarni/abe-toolchain-2/builds/destdir/x86_64-pc-linux-gnu --with-gnu-as --with-gnu-ld --disable-libmudflap --enable-lto --enable-shared --without-included-gettext --enable-nls --with-system-zlib --disable-sjlj-exceptions --enable-gnu-unique-object --enable-linker-build-id --disable-libstdcxx-pch --enable-c99 --enable-clocale=gnu --enable-libstdcxx-debug --enable-long-long --with-cloog=no --with-ppl=no --with-isl=no --enable-multilib --with-multilib-list=aprofile --enable-threads=no --disable-multiarch --with-sysroot=/home/prathamesh.kulkarni/abe-toolchain-2/builds/destdir/x86_64-pc-linux-gnu/arm-eabi --with-newlib --enable-checking=yes --disable-bootstrap --enable-languages=c,c++,lto --prefix=/home/prathamesh.kulkarni/abe-toolchain-2/builds/destdir/x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --target=arm-eabi Thanks, Prathamesh > > > Christophe > >> Thanks, >> Prathamesh >> > >> > Christophe >> > >> >> >> >> Thanks, >> >> Prathamesh >> >> > >> >> > Thanks >> >> > >> >> > Christophe >> >> > >> >> > >> >> >> >> >> >> Thanks, >> >> >> Prathamesh >> >> >> > Thanks, >> >> >> > Kyrill >> >> >> > >> >> >> > > ping >> >> >> > > https://gcc.gnu.org/pipermail/gcc-patches/2021-July/574206.html >> >> >> > > >> >> >> > > Thanks, >> >> >> > > Prathamesh >> >> >> > > > >> >> >> > > > Thanks, >> >> >> > > > Prathamesh >> >> >> > > > > >> >> >> > > > > >> >> >> > > > > Thanks, >> >> >> > > > > >> >> >> > > > > >> >> >> > > > > Christophe >> >> >> > > > > >> >> >> > > > > >> >> >> > > > > > Thanks, >> >> >> > > > > > Prathamesh >> >> >> > > > > >> >> >> >> > > > > >> Christophe >> >> >> > > > > >> >> >> >> > > > > >> >> >> >> > > > > >>> Ok. >> >> >> > > > > >>> Thanks, >> >> >> > > > > >>> Kyrill >> >> >> > > > > >>> >> >> >> > > > > >>> >> >> >> > > > > >>>> Thanks, >> >> >> > > > > >>>> Prathamesh >> >> >> > > > > >>>>> Thanks, >> >> >> > > > > >>>>> Kyrill >> >> >> > > > > >>>>> >> >> >> > > > > >>>>>> Thanks, >> >> >> > > > > >>>>>> Prathamesh >> >> >> > > > > >>>>>>> Thanks, >> >> >> > > > > >>>>>>> Prathamesh >> >> >> > > > > >>>>>>>> That being said, I suggest you look at other similar >> >> >> > > > > >>>>>>>> patterns in >> >> >> > > > > >>>>>>>> vec-common.md, most of which are gated on >> >> >> > > > > >>>>>>>> ARM_HAVE_<MODE>_ARITH >> >> >> > > > > >>>>>>>> and possibly beware of issues with iwmmxt :-) >> >> >> > > > > >>>>>>>> >> >> >> > > > > >>>>>>>> Christophe >> >> >> > > > > >>>>>>>> >> >> >> > > > > >>>>>>>>> Thanks, >> >> >> > > > > >>>>>>>>> Prathamesh