From: Jim Wilson <wilson@codesourcery.com>
To: fanqifei@gmail.com
Cc: gcc@gcc.gnu.org
Subject: Re: Fwd: constant hoisting out of loops
Date: Sun, 21 Mar 2010 10:42:00 -0000 [thread overview]
Message-ID: <1269114229.4064.18.camel@localhost> (raw)
In-Reply-To: <f94afa701003201240u1129e4f9t5764c43de8af25ac@mail.gmail.com>
On Sun, 2010-03-21 at 03:40 +0800, fanqifei wrote:
> foor_expand_move is changed and it works now.
> However, I still don't understand why there was no such error if below
> condition was used and foor_expand_move was not changed.
> Both below condition and "(register_operand(operands[0], SImode) ||
> register_operand(operands[1],SImode)) ..." does not accept mem&&mem.
The define_expand is used for generating RTL. The RTL expander calls
the define_expand, which checks for MEM&CONST, and then falls through
generating the mem copy insn.
The define_insn is used for matching RTL. After it has been generated,
we look at the movsi define_insn, and see that MEM&MEM doesn't match, so
you get an error for unrecognized RTL.
The define_expand must always match the define_insn(s). They are used
in different phases, and they aren't checked against each other when gcc
is built. If there is a mismatch, then you get a run-time error for
unrecognized rtl.
Jim
next prev parent reply other threads:[~2010-03-20 19:44 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-11 6:48 fanqifei
2010-03-14 21:39 ` Jim Wilson
2010-03-17 12:55 ` fanqifei
2010-03-17 19:16 ` Jim Wilson
2010-03-18 17:10 ` fanqifei
[not found] ` <f94afa701003190704l6a8a97bfs66817322dc1eb8f7@mail.gmail.com>
2010-03-19 14:51 ` Fwd: " fanqifei
2010-03-19 22:30 ` Jim Wilson
2010-03-20 16:40 ` fanqifei
2010-03-20 19:40 ` Jim Wilson
2010-03-20 19:44 ` fanqifei
2010-03-21 10:42 ` Jim Wilson [this message]
2010-03-21 22:46 ` fanqifei
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=1269114229.4064.18.camel@localhost \
--to=wilson@codesourcery.com \
--cc=fanqifei@gmail.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).