On Tue, May 21, 2024 at 2:16 PM Haochen Jiang <haochen.ji...@intel.com> wrote: > > Hi all, > > Since vpermq is really slow, we should avoid using it when it is > the only instruction could be used for ix86_expand_vecop_qihi2. > > Bootstrapped and regtested on x86_64-pc-linux-gnu. Ok for trunk? Please add a testcase for it. > > Thx, > Haochen > > 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/config/i386/i386-expand.cc | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc > index a6132911e6a..f24c800bb4f 100644 > --- a/gcc/config/i386/i386-expand.cc > +++ b/gcc/config/i386/i386-expand.cc > @@ -24323,6 +24323,11 @@ 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; > > + /* vpermq is slow and we should not fall into the optimization when > + it is the only instruction to be selected. */ > + if (!TARGET_AVX512BW) > + return false; > + > if ((qimode == V16QImode && !TARGET_AVX2) > || (qimode == V32QImode && (!TARGET_AVX512BW || !TARGET_EVEX512)) > /* There are no V64HImode instructions. */ > -- > 2.31.1 >
-- BR, Hongtao
