All of lore.kernel.org
 help / color / mirror / Atom feed
From: tugouxp <13824125580@163.com>
To: qemu-devel@nongnu.org
Subject: What this mean "dead: 1" and "dead: 0 1" on each tb block start?
Date: Wed, 29 Jul 2020 22:27:55 +0800 (CST)	[thread overview]
Message-ID: <6807386b.7ba3.1739af8fc12.Coremail.13824125580@163.com> (raw)

[-- Attachment #1: Type: text/plain, Size: 1264 bytes --]

HI folks:
  on each tb block start, there are following ir code, and the most confusing me is that  the postfix of each line "dead:" flag, what it is represent precisely?
i guess it may be related to the register or varible liveness for help generating tghe target machine code, but i cant get the precisely connection of the dead attrribute with qemu  internal varibles.
for example, why the line 61 use "dead:1" and the line 63 use "dead: 0, 1"?  what is the precisely meaning of the number after the "dead:" word?


thank you!     




    60 OP after optimization and liveness analysis:

     61  ld_i32 tmp5,env,$0xffffffffffffffec                 dead: 1

     62  movi_i32 tmp6,$0x0

     63  brcond_i32 tmp5,tmp6,lt,$L0                      dead: 0 1

     64  

     65  ---- 60000004 00000000 00000e04

     66  movi_i32 tmp5,$0x60000010

     67  mov_i32 tmp7,tmp5                                dead: 1

     68  qemu_ld_i32 tmp6,tmp7,leul,3                     dead: 1

     69  mov_i32 r1,tmp6                                  sync: 0  dead: 0 1

     70  goto_tb $0x1

     71  movi_i32 pc,$0x60000008                          sync: 0  dead: 0

     72  exit_tb $0x7f8e8ef58101

     73  set_label $L0

     74  exit_tb $0x7f8e8ef58103

     75  



[-- Attachment #2: Type: text/html, Size: 2947 bytes --]

             reply	other threads:[~2020-07-29 14:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-29 14:27 tugouxp [this message]
2020-07-29 16:16 ` What this mean "dead: 1" and "dead: 0 1" on each tb block start? Richard Henderson
2020-07-30  5:54   ` tugouxp

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=6807386b.7ba3.1739af8fc12.Coremail.13824125580@163.com \
    --to=13824125580@163.com \
    --cc=qemu-devel@nongnu.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.