public inbox for gcc@gcc.gnu.org
 help / color / mirror / Atom feed
From: "Qian, Jianhua" <qianjh@cn.fujitsu.com>
To: "gcc@gcc.gnu.org" <gcc@gcc.gnu.org>
Subject: A problem with one instruction multiple latencies and pipelines
Date: Mon, 7 Sep 2020 06:08:50 +0000	[thread overview]
Message-ID: <d005a34135eb46e185aaaa38cc8d30b7@G08CNEXMBPEKD06.g08.fujitsu.local> (raw)

Hi

I'm adding a new machine model. I have a problem when writing the "define_insn_reservation" for instruction scheduling.
How to write the "define_insn_reservation" for one instruction that there are different latencies and pipelines according to parameter.

For example, the ADD (shifted register) instruction in a64fx

Instruction            Option                             Latency    Pipeline
ADD (shifted register)  <amount> = 0                     1          EX* | EAG*
                      <amount> = [1-4] && <shift>=LSL  1+1       (EXA + EXA) | (EXB + EXB)
                                                         2+1       (EXA + EXA) | (EXB + EXB)

In aarch64.md ADD (shifted register) instruction is defined as following.
 (define_insn "*add_<shift>_<mode>"
  [(set (match_operand:GPI 0 "register_operand" "=r")
        (plus:GPI (ASHIFT:GPI (match_operand:GPI 1 "register_operand" "r")
                              (match_operand:QI 2 "aarch64_shift_imm_<mode>" "n"))
                  (match_operand:GPI 3 "register_operand" "r")))]
  ""
  "add\\t%<w>0, %<w>3, %<w>1, <shift> %2"
  [(set_attr "type" "alu_shift_imm")]
)

It could not be distinguished by the type "alu_shift_imm" when writing "define_insn_reservation" for ADD (shifted register). 
What should I do?

Regards
Qian




             reply	other threads:[~2020-09-07  6:09 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-07  6:08 Qian, Jianhua [this message]
2020-09-07  7:40 ` Richard Biener
2020-09-07  8:45   ` Qian, Jianhua
2020-09-07 11:58     ` Richard Biener
2020-09-07 20:20 ` Richard Sandiford
2020-09-08  5:34   ` Qian, Jianhua
2020-09-09 21:22   ` Segher Boessenkool
2020-09-10  5:01     ` Qian, Jianhua
2020-09-10 10:04     ` Richard Sandiford
2020-09-10 23:00       ` Segher Boessenkool
2020-09-11  7:44         ` Richard Sandiford
2020-09-11 13:58           ` Segher Boessenkool
2020-09-14  5:41             ` Qian, Jianhua
2020-09-14  9:55               ` Richard Sandiford
2020-09-14 18:41                 ` Segher Boessenkool
2020-09-14 19:35                   ` Richard Sandiford
2020-09-14 22:14                     ` Segher Boessenkool
2020-09-11 13:30 ` Richard Earnshaw
2020-09-14  2:53   ` Qian, Jianhua
2020-09-14  9:08     ` Richard Earnshaw

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=d005a34135eb46e185aaaa38cc8d30b7@G08CNEXMBPEKD06.g08.fujitsu.local \
    --to=qianjh@cn.fujitsu.com \
    --cc=gcc@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).