From: Jeff Law <law@redhat.com>
To: Richard Biener <richard.guenther@gmail.com>,
Kugan Vivekanandarajah <kugan.vivekanandarajah@linaro.org>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [RFC][SSA] Iterator to visit SSA
Date: Tue, 06 Sep 2016 21:58:00 -0000 [thread overview]
Message-ID: <219955f1-4f6c-a328-e9fe-af9b429dbed1@redhat.com> (raw)
In-Reply-To: <CAFiYyc1cvTTphTbQh0+h=yKtnkJa1JSTLDFm5=nLUabC2indsw@mail.gmail.com>
On 09/05/2016 01:57 AM, Richard Biener wrote:
> On Mon, Sep 5, 2016 at 7:26 AM, Kugan Vivekanandarajah
> <kugan.vivekanandarajah@linaro.org> wrote:
>> Hi All,
>>
>> While looking at gcc source, I noticed that we are iterating over SSA
>> variable from 0 to num_ssa_names in some cases and 1 to num_ssa_names
>> in others. It seems that variable 0 is always NULL TREE.
>
> Yeah, that's artificial because we don't assign SSA name version 0 (for some
> unknown reason).
That might have been the global for aliasing purposes eons ago. Or it
might have been used for default defs early in the SSA development work.
I wouldn't be surprised if it doesn't need to be special anymore.
Jeff
prev parent reply other threads:[~2016-09-06 21:56 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-05 5:39 Kugan Vivekanandarajah
2016-09-05 7:58 ` Richard Biener
2016-09-06 6:00 ` Kugan Vivekanandarajah
2016-09-06 9:08 ` Richard Biener
2016-09-06 9:58 ` Kugan Vivekanandarajah
2016-09-06 10:07 ` Richard Biener
2016-09-06 10:07 ` Kugan Vivekanandarajah
2016-09-06 10:41 ` Richard Biener
2016-09-07 4:46 ` Kugan Vivekanandarajah
2016-09-07 8:03 ` Dominik Inführ
2016-09-07 11:37 ` Richard Biener
2016-09-08 5:57 ` Kugan Vivekanandarajah
2016-09-14 10:21 ` Richard Biener
2016-09-06 21:58 ` Jeff Law [this message]
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=219955f1-4f6c-a328-e9fe-af9b429dbed1@redhat.com \
--to=law@redhat.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=kugan.vivekanandarajah@linaro.org \
--cc=richard.guenther@gmail.com \
/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).