| Message ID | 20240521090109.2436971-1-haochen.jiang@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] i386: Disable ix86_expand_vecop_qihi2 when !TARGET_AVX512BW | expand |
On Tue, May 21, 2024 at 11:01 AM Haochen Jiang <haochen.jiang@intel.com> wrote: > > Hi all, > > This is the v3 patch to fix PR115069. The new testcase has passed. > > Changes in v3: > - Simplify the testcase. > > Changes in v2: > - Add a testcase. > - Change the comment for the early exit. > > Thx, > Haochen > > Since vpermq is really slow, we should avoid using it for permutation > when vpmovwb is not available (needs AVX512BW) for ix86_expand_vecop_qihi2 > and fall back to ix86_expand_vecop_qihi. > > gcc/ChangeLog: > > PR target/115069 > * config/i386/i386-expand.cc (ix86_expand_vecop_qihi2): > Do not enable the optimization when AVX512BW is not enabled. > > gcc/testsuite/ChangeLog: > > PR target/115069 > * gcc.target/i386/pr115069.c: New. LGTM, with a nit below. Thanks, Uros. > --- > gcc/config/i386/i386-expand.cc | 7 +++++++ > gcc/testsuite/gcc.target/i386/pr115069.c | 10 ++++++++++ > 2 files changed, 17 insertions(+) > create mode 100644 gcc/testsuite/gcc.target/i386/pr115069.c > > diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc > index a6132911e6a..f7939761879 100644 > --- a/gcc/config/i386/i386-expand.cc > +++ b/gcc/config/i386/i386-expand.cc > @@ -24323,6 +24323,13 @@ ix86_expand_vecop_qihi2 (enum rtx_code code, rtx dest, rtx op1, rtx op2) > bool op2vec = GET_MODE_CLASS (GET_MODE (op2)) == MODE_VECTOR_INT; > bool uns_p = code != ASHIFTRT; > > + /* Without VPMOVWB (provided by AVX512BW ISA), the expansion uses the > + generic permutation to merge the data back into the right place. This > + permutation results in VPERMQ, which is slow, so better fall back to > + ix86_expand_vecop_qihi. */ > + if (!TARGET_AVX512BW) > + return false; > + > if ((qimode == V16QImode && !TARGET_AVX2) > || (qimode == V32QImode && (!TARGET_AVX512BW || !TARGET_EVEX512)) > /* There are no V64HImode instructions. */ > diff --git a/gcc/testsuite/gcc.target/i386/pr115069.c b/gcc/testsuite/gcc.target/i386/pr115069.c > new file mode 100644 > index 00000000000..7f1ff209f26 > --- /dev/null > +++ b/gcc/testsuite/gcc.target/i386/pr115069.c > @@ -0,0 +1,10 @@ > +/* { dg-do compile } */ > +/* { dg-options "-O2 -mavx2" } */ > +/* { dg-final { scan-assembler-not "vpermq" } } */ > + > +typedef char v16qi __attribute__((vector_size(16))); > + > +v16qi foo (v16qi a, v16qi b) { > + return a * b; > +} > + Please remove the trailing line. > -- > 2.31.1 >
> -----Original Message----- > From: Uros Bizjak <ubizjak@gmail.com> > Sent: Tuesday, May 21, 2024 9:04 PM > To: Jiang, Haochen <haochen.jiang@intel.com> > Cc: gcc-patches@gcc.gnu.org; Liu, Hongtao <hongtao.liu@intel.com> > Subject: Re: [PATCH v3] i386: Disable ix86_expand_vecop_qihi2 > when !TARGET_AVX512BW > > On Tue, May 21, 2024 at 11:01 AM Haochen Jiang > <haochen.jiang@intel.com> wrote: > > > > Hi all, > > > > This is the v3 patch to fix PR115069. The new testcase has passed. > > > > Changes in v3: > > - Simplify the testcase. > > > > Changes in v2: > > - Add a testcase. > > - Change the comment for the early exit. > > > > Thx, > > Haochen > > > > Since vpermq is really slow, we should avoid using it for permutation > > when vpmovwb is not available (needs AVX512BW) for > ix86_expand_vecop_qihi2 > > and fall back to ix86_expand_vecop_qihi. > > > > gcc/ChangeLog: > > > > PR target/115069 > > * config/i386/i386-expand.cc (ix86_expand_vecop_qihi2): > > Do not enable the optimization when AVX512BW is not enabled. > > > > gcc/testsuite/ChangeLog: > > > > PR target/115069 > > * gcc.target/i386/pr115069.c: New. > > LGTM, with a nit below. Ok and I will also backport the patch to GCC14. Thx, Haochen > > Thanks, > Uros.
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc index a6132911e6a..f7939761879 100644 --- a/gcc/config/i386/i386-expand.cc +++ b/gcc/config/i386/i386-expand.cc @@ -24323,6 +24323,13 @@ ix86_expand_vecop_qihi2 (enum rtx_code code, rtx dest, rtx op1, rtx op2) bool op2vec = GET_MODE_CLASS (GET_MODE (op2)) == MODE_VECTOR_INT; bool uns_p = code != ASHIFTRT; + /* Without VPMOVWB (provided by AVX512BW ISA), the expansion uses the + generic permutation to merge the data back into the right place. This + permutation results in VPERMQ, which is slow, so better fall back to + ix86_expand_vecop_qihi. */ + if (!TARGET_AVX512BW) + return false; + if ((qimode == V16QImode && !TARGET_AVX2) || (qimode == V32QImode && (!TARGET_AVX512BW || !TARGET_EVEX512)) /* There are no V64HImode instructions. */ diff --git a/gcc/testsuite/gcc.target/i386/pr115069.c b/gcc/testsuite/gcc.target/i386/pr115069.c new file mode 100644 index 00000000000..7f1ff209f26 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr115069.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -mavx2" } */ +/* { dg-final { scan-assembler-not "vpermq" } } */ + +typedef char v16qi __attribute__((vector_size(16))); + +v16qi foo (v16qi a, v16qi b) { + return a * b; +} +
Hi all, This is the v3 patch to fix PR115069. The new testcase has passed. Changes in v3: - Simplify the testcase. Changes in v2: - Add a testcase. - Change the comment for the early exit. Thx, Haochen Since vpermq is really slow, we should avoid using it for permutation when vpmovwb is not available (needs AVX512BW) for ix86_expand_vecop_qihi2 and fall back to ix86_expand_vecop_qihi. gcc/ChangeLog: PR target/115069 * config/i386/i386-expand.cc (ix86_expand_vecop_qihi2): Do not enable the optimization when AVX512BW is not enabled. gcc/testsuite/ChangeLog: PR target/115069 * gcc.target/i386/pr115069.c: New. --- gcc/config/i386/i386-expand.cc | 7 +++++++ gcc/testsuite/gcc.target/i386/pr115069.c | 10 ++++++++++ 2 files changed, 17 insertions(+) create mode 100644 gcc/testsuite/gcc.target/i386/pr115069.c