Re: [PATCH 08/43] i386: Emulate MMX ashr<mode>3/<shift_insn><mode>3 with SSE

[Uros Bizjak <ubizjak@gmail.com>]

On Sun, Feb 10, 2019 at 9:38 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Sun, Feb 10, 2019 at 2:26 AM Uros Bizjak <ubizjak@gmail.com> wrote:
> >
> > On 2/10/19, H.J. Lu <hjl.tools@gmail.com> wrote:
> > > Emulate MMX ashr<mode>3/<shift_insn><mode>3 with SSE.  Only SSE register
> > > source operand is allowed.
> > >
> > >       PR target/89021
> > >       * config/i386/mmx.md (mmx_ashr<mode>3): Disallow with
> > >       TARGET_MMX_WITH_SSE.
> > >       (mmx_<shift_insn><mode>3): Likewise.
> > >       (ashr<mode>3): New.
> > >       (<shift_insn><mode>3): Likewise.
> >
> > Please merge patterns use mmx_isa attribute.
>
> Currently, MMX pattern names have a "mmx_" prefix.  For SSE emulation, we
> don't want such a prefix so that the middle-end can detect and use them.  If we
> remove the "mmx_" prefix from MMX pattern names, won't the middle-end
> generate MMX instructions in this case?  It it safe to do so?

I meant to create a merged "*ashr<mode>3" pattern, and introduce
ashr<mode>3 expander. The intention from maintainability point of view
is for instruction patterns to follow an unified approach as much as
possible, and minimise deviations between patterns of the same family.

Uros.

>
>
> > Uros.
> >
> > > ---
> > >  gcc/config/i386/mmx.md | 38 ++++++++++++++++++++++++++++++++++++--
> > >  1 file changed, 36 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/gcc/config/i386/mmx.md b/gcc/config/i386/mmx.md
> > > index 2024c75fa78..9e07bf31f81 100644
> > > --- a/gcc/config/i386/mmx.md
> > > +++ b/gcc/config/i386/mmx.md
> > > @@ -995,7 +995,7 @@
> > >          (ashiftrt:MMXMODE24
> > >         (match_operand:MMXMODE24 1 "register_operand" "0")
> > >         (match_operand:DI 2 "nonmemory_operand" "yN")))]
> > > -  "TARGET_MMX"
> > > +  "TARGET_MMX && !TARGET_MMX_WITH_SSE"
> > >    "psra<mmxvecsize>\t{%2, %0|%0, %2}"
> > >    [(set_attr "type" "mmxshft")
> > >     (set (attr "length_immediate")
> > > @@ -1009,7 +1009,7 @@
> > >          (any_lshift:MMXMODE248
> > >         (match_operand:MMXMODE248 1 "register_operand" "0")
> > >         (match_operand:DI 2 "nonmemory_operand" "yN")))]
> > > -  "TARGET_MMX"
> > > +  "TARGET_MMX && !TARGET_MMX_WITH_SSE"
> > >    "p<vshift><mmxvecsize>\t{%2, %0|%0, %2}"
> > >    [(set_attr "type" "mmxshft")
> > >     (set (attr "length_immediate")
> > > @@ -1018,6 +1018,40 @@
> > >         (const_string "0")))
> > >     (set_attr "mode" "DI")])
> > >
> > > +(define_insn "ashr<mode>3"
> > > +  [(set (match_operand:MMXMODE24 0 "register_operand" "=x,Yv")
> > > +        (ashiftrt:MMXMODE24
> > > +       (match_operand:MMXMODE24 1 "register_operand" "0,Yv")
> > > +       (match_operand:DI 2 "nonmemory_operand" "xN,YvN")))]
> > > +  "TARGET_MMX_WITH_SSE"
> > > +  "@
> > > +   psra<mmxvecsize>\t{%2, %0|%0, %2}
> > > +   vpsra<mmxvecsize>\t{%2, %1, %0|%0, %1, %2}"
> > > +  [(set_attr "isa" "noavx,avx")
> > > +   (set_attr "type" "sseishft,sseishft")
> > > +   (set (attr "length_immediate")
> > > +     (if_then_else (match_operand 2 "const_int_operand")
> > > +       (const_string "1")
> > > +       (const_string "0")))
> > > +   (set_attr "mode" "TI")])
> > > +
> > > +(define_insn "<shift_insn><mode>3"
> > > +  [(set (match_operand:MMXMODE248 0 "register_operand" "=x,Yv")
> > > +        (any_lshift:MMXMODE248
> > > +       (match_operand:MMXMODE248 1 "register_operand" "0,Yv")
> > > +       (match_operand:DI 2 "nonmemory_operand" "xN,YvN")))]
> > > +  "TARGET_MMX_WITH_SSE"
> > > +  "@
> > > +   p<vshift><mmxvecsize>\t{%2, %0|%0, %2}
> > > +   vp<vshift><mmxvecsize>\t{%2, %1, %0|%0, %1, %2}"
> > > +  [(set_attr "isa" "noavx,avx")
> > > +   (set_attr "type" "sseishft,sseishft")
> > > +   (set (attr "length_immediate")
> > > +     (if_then_else (match_operand 2 "const_int_operand")
> > > +       (const_string "1")
> > > +       (const_string "0")))
> > > +   (set_attr "mode" "TI")])
> > > +
> > >  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> > >  ;;
> > >  ;; Parallel integral comparisons
> > > --
> > > 2.20.1
> > >
> > >
>
>
>
> --
> H.J.