public inbox for cgen@sourceware.org
 help / color / mirror / Atom feed
From: Jean-Marc Saffroy <jean-marc.saffroy@joguin.com>
To: cgen@sourceware.org
Subject: problem with 64-bit arch
Date: Thu, 01 Oct 2009 14:41:00 -0000	[thread overview]
Message-ID: <4AC4BF97.8040302@joguin.com> (raw)

Hi,

I am trying to use CGEN for an experimental 64-bit architecture (ie. 
word-bitsize is 64), and in my case the generated arch-ibld.c file is 
incorrect.

I defined the following insn field:

(df f-disp24     "disp24"              (PCREL-ADDR) 8 24 INT
     ((value pc) (sra WI (sub WI value pc) (const 2)))
     ((value pc) (add WI (sll WI value (const 2)) pc))
)

(define-operand
   (name disp24)
   (comment "24 bit signed displacement")
   (type h-iaddr)
   (mode WI)
   (index f-disp24)
)

And arch-ibld.c contains the following code (in <arch>_cgen_insert_operand):

   switch (opindex)
     {
     case <ARCH>_OPERAND_DISP24 :
       {
         long value = fields->f_disp24;
         value = (() (((value) - (pc))) >> (2));
         errmsg = insert_normal (cd, value,
0|(1<<CGEN_IFLD_SIGNED)|(1<<CGEN_IFLD_PCREL_ADDR), 0, 8, 24, 32,
total_length, buffer);
       }
       break;

Note the missing type in the cast before assigning to value. Also using 
a long type for value will cause problems when running on a 32-bit host, 
since it operates on 64-bit values.

I had a quick look at the other two archs that use word-bitsize 64, ie. 
sparc64 and ia64, and it seems they use multi-ifields for this kind of 
PC-relative field, which may be an artificial way of avoiding the problem.

Is there an obvious fix to this problem?

Cheers,
JM

             reply	other threads:[~2009-10-01 14:41 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-01 14:41 Jean-Marc Saffroy [this message]
2009-10-01 15:57 ` Doug Evans
2009-10-01 16:34   ` Jean-Marc Saffroy
2009-10-02 17:58     ` Doug Evans

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=4AC4BF97.8040302@joguin.com \
    --to=jean-marc.saffroy@joguin.com \
    --cc=cgen@sourceware.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).