code review 8102044: 8a/8l: add PCMPEQB and PMOVMSKB to 386.

8a/8l: add PCMPEQB and PMOVMSKB to 386.

Used by CL 8056043 for fast string equals.

[khr, 2013-03-29 07:05:29]

Hello bradfitz@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://khr%40golang.org@code.google.com/p/go/

[bradfitz, 2013-03-29 07:13:42]

LGTM

The Google confirms the opcode on at least the first one.  I'll trust you
on the second one.  I assume the plan9 naming is what makes it hard to
search for.      The "PMOVMSKB" at least ends in 0xd7, so I'll assume you
know what you're doing and it works.

</duediligence>

On Fri, Mar 29, 2013 at 12:05 AM, <khr@golang.org> wrote:

> Reviewers: bradfitz,
>
> Message:
> Hello bradfitz@golang.org (cc: golang-dev@googlegroups.com),
>
> I'd like you to review this change to
>
https://khr%40golang.org@code.**google.com/p/go/<http://40golang.org@code.goo...
>
>
> Description:
> 8a/8l: add PCMPEQB and PMOVMSKB to 386.
>
> Used by CL 8056043 for fast string equals.
>
> Please review this at
https://codereview.appspot.**com/8102044/<https://codereview.appspot.com/8102...
>
> Affected files:
>   M src/cmd/8a/lex.c
>   M src/cmd/8l/8.out.h
>   M src/cmd/8l/optab.c
>
>
> Index: src/cmd/8a/lex.c
> ==============================**==============================**=======
> --- a/src/cmd/8a/lex.c
> +++ b/src/cmd/8a/lex.c
> @@ -760,10 +760,12 @@
>         "ORPS",         LTYPE3, AORPS,
>         "PADDQ",        LTYPE3, APADDQ,
>         "PAND",         LTYPE3, APAND,
> +       "PCMPEQB",      LTYPE3, APCMPEQB,
>         "PMAXSW",       LTYPE3, APMAXSW,
>         "PMAXUB",       LTYPE3, APMAXUB,
>         "PMINSW",       LTYPE3, APMINSW,
>         "PMINUB",       LTYPE3, APMINUB,
> +       "PMOVMSKB",     LTYPE3, APMOVMSKB,
>         "PSADBW",       LTYPE3, APSADBW,
>         "PSHUFB",       LTYPE3, APSHUFB,
>         "PSUBB",        LTYPE3, APSUBB,
> Index: src/cmd/8l/8.out.h
> ==============================**==============================**=======
> --- a/src/cmd/8l/8.out.h
> +++ b/src/cmd/8l/8.out.h
> @@ -534,10 +534,12 @@
>         AORPS,
>         APADDQ,
>         APAND,
> +       APCMPEQB,
>         APMAXSW,
>         APMAXUB,
>         APMINSW,
>         APMINUB,
> +       APMOVMSKB,
>         APSADBW,
>         APSUBB,
>         APSUBL,
> Index: src/cmd/8l/optab.c
> ==============================**==============================**=======
> --- a/src/cmd/8l/optab.c
> +++ b/src/cmd/8l/optab.c
> @@ -364,6 +364,12 @@
>         Ym,     Ynone,  Zm_o,   2,
>         0
>  };
> +uchar  ymskb[] =
> +{
> +       Yxr,    Yrl,    Zm_r_xm,        2,
> +       Ymr,    Yrl,    Zm_r_xm,        1,
> +       0
> +};
>  uchar  yxm[] =
>  {
>         Yxm,    Yxr,    Zm_r_xm,        1,
> @@ -950,10 +956,12 @@
>         { AORPS,        yxm,    Pm, 0x56 },
>         { APADDQ,       yxm,    Pe, 0xd4 },
>         { APAND,        yxm,    Pe, 0xdb },
> +       { APCMPEQB,     yxmq,   Pe ,0x74 },
>         { APMAXSW,      yxm,    Pe, 0xee },
>         { APMAXUB,      yxm,    Pe, 0xde },
>         { APMINSW,      yxm,    Pe, 0xea },
>         { APMINUB,      yxm,    Pe, 0xda },
> +       { APMOVMSKB,    ymskb,  Px, Pe,0xd7,0xd7 },
>         { APSADBW,      yxm,    Pq, 0xf6 },
>         { APSUBB,       yxm,    Pe, 0xf8 },
>         { APSUBL,       yxm,    Pe, 0xfa },
>
>
>

[khr, 2013-03-29 07:34:07]

*** Submitted as https://code.google.com/p/go/source/detail?r=7505bf6d8988 ***

8a/8l: add PCMPEQB and PMOVMSKB to 386.

Used by CL 8056043 for fast string equals.

R=bradfitz
CC=golang-dev
https://codereview.appspot.com/8102044