From: Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz>
To: Devang Patel <dpatel@apple.com>
Cc: "gcc@gcc.gnu.org list" <gcc@gcc.gnu.org>,
Jason Merrill <jason@redhat.com>,
Dorit Naishlos <DORIT@il.ibm.com>,
Richard Henderson <rth@redhat.com>,
Diego Novillo <dnovillo@redhat.com>
Subject: Re: [lno] [RFC] if-conversion and auto vectorizer
Date: Sat, 13 Mar 2004 09:24:00 -0000 [thread overview]
Message-ID: <20040313092438.GA6767@atrey.karlin.mff.cuni.cz> (raw)
In-Reply-To: <415253BF-7455-11D8-A347-000393A91CAA@apple.com>
Hello,
> OK. So far I have coded transformation to transform
>
> bar ()
> {
> int A[N+1], B[N+1], C[N+1], D[N+1];
> int i;
>
> for (i = 1; i<N; i++)
> {
> if (A[i] > 0)
> {
> A[i] = A[i] + C[i];
> B[i] = A[i] + 1;
> }
> else
> {
> A[i] = D[i];
> B[i] = D[i] + 1;
> }
> }
> ibar(A);
> ibar(B);
> }
>
> into :
>
> bar ()
> {
> int i;
> int D[17];
> int C[17];
> int B[17];
> int A[17];
> int T.5;
> int T.4;
> int T.3;
> int T.2;
> int T.1;
> int T.0;
>
> # BLOCK 0
> # PRED: ENTRY [100.0%] (fallthru,exec)
> # SUCC: 1 [100.0%] (fallthru,exec)
>
> # BLOCK 1
> # PRED: 6 [100.0%] (fallthru) 0 [100.0%] (fallthru,exec)
> # i_1 = PHI <1(0), i_15(6)>;
> <L0>:;
> T.0_3 = if (1)
> {
> A[i_1];
> };
> if (T.0_3 > 0) goto <L1>; else goto <L2>;
> # SUCC: 3 [21.0%] (false,exec) 2 [79.0%] (true,exec)
>
> # BLOCK 2
> # PRED: 1 [79.0%] (true,exec)
> <L1>:;
> T.1_9 = if (1 && T.0_3 > 0)
why this "1 &&" part?
> {
> C[i_1];
> };
> T.2_10 = if (1 && T.0_3 > 0)
> {
> T.0_3 + T.1_9;
> };
> A[i_1] = if (1 && T.0_3 > 0)
> {
> T.2_10
> };
> T.3_12 = if (1 && T.0_3 > 0)
> {
> T.2_10 + 1;
> };
> B[i_1] = if (1 && T.0_3 > 0)
> {
> T.3_12
> };
> goto <bb 4> (<L3>);
> # SUCC: 4 [100.0%] (fallthru,exec)
>
> # BLOCK 3
> # PRED: 1 [21.0%] (false,exec)
> <L2>:;
> T.4_5 = if (1 && !(T.0_3 > 0))
> {
> D[i_1];
> };
> A[i_1] = if (1 && !(T.0_3 > 0))
> {
> T.4_5
> };
> T.5_7 = if (1 && !(T.0_3 > 0))
> {
> T.4_5 + 1;
> };
> B[i_1] = if (1 && !(T.0_3 > 0))
> {
> T.5_7
> };
> # SUCC: 4 [100.0%] (fallthru,exec)
>
> # BLOCK 4
> # PRED: 3 [100.0%] (fallthru,exec) 2 [100.0%] (fallthru,exec)
> <L3>:;
> i_15 = i_1 + 1;
> if (i_15 <= 15) goto <L8>; else goto <L5>;
> # SUCC: 5 [11.0%] (false,exec) 6 [89.0%] (true,exec)
>
> # BLOCK 6
> # PRED: 4 [89.0%] (true,exec)
> <L8>:;
> goto <bb 1> (<L0>);
> # SUCC: 1 [100.0%] (fallthru)
>
> # BLOCK 5
> # PRED: 4 [11.0%] (false,exec)
> <L5>:;
> ibar (&A);
> ibar (&B);
> return;
> # SUCC: EXIT [100.0%]
>
> }
>
> I spent lot of time unnecessary to create super block inside loop by
> merging block 2 and 3 into block 1.
>
> If vectorizer can not vectorize this loop then it will be reverted to
> original form using loop versioning. Am I on the right track ?
I am not at all sure what you want to achieve with this transformation;
it seems to me that you haven't done anything that could possibly make
vectorizer's work easier.
Zdenek
next prev parent reply other threads:[~2004-03-13 9:24 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-04 19:59 Devang Patel
2004-03-04 20:12 ` Andrew Pinski
2004-03-04 20:39 ` Devang Patel
2004-03-04 21:03 ` Richard Henderson
2004-03-05 19:06 ` Devang Patel
2004-03-05 19:17 ` Diego Novillo
2004-03-05 19:22 ` Diego Novillo
2004-03-05 19:28 ` Devang Patel
2004-03-05 19:41 ` Diego Novillo
2004-03-05 19:44 ` Diego Novillo
2004-03-12 18:45 ` Devang Patel
2004-03-13 9:24 ` Zdenek Dvorak [this message]
2004-03-13 22:41 ` Devang Patel
2004-03-14 10:59 ` Dorit Naishlos
2004-03-14 10:57 Fw: " Dorit Naishlos
2004-03-14 19:22 ` Andrew Pinski
2004-03-14 22:31 ` Daniel Berlin
2004-03-15 2:29 ` Alex Rosenberg
2004-03-15 22:38 ` Richard Henderson
2004-03-15 23:08 ` Devang Patel
2004-03-15 23:20 ` Richard Henderson
2004-03-16 0:02 ` Devang Patel
2004-03-16 0:07 ` Diego Novillo
2004-03-16 0:45 ` Richard Henderson
2004-03-16 3:02 ` Diego Novillo
2004-03-16 3:33 ` Richard Henderson
2004-03-16 6:33 ` Devang Patel
2004-03-15 22:42 Robert Dewar
2004-03-15 23:08 ` Richard Henderson
2004-03-16 3:46 Chris Lattner
2004-03-16 5:33 Robert Dewar
2004-03-16 6:54 ` Richard Henderson
2004-03-16 12:27 Robert Dewar
2004-03-16 18:32 ` Richard Henderson
2004-03-16 22:51 ` Toon Moene
2004-03-16 23:10 ` Joseph S. Myers
2004-03-16 23:28 ` Toon Moene
2004-03-16 23:37 ` Richard Henderson
2004-03-16 23:42 ` Toon Moene
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=20040313092438.GA6767@atrey.karlin.mff.cuni.cz \
--to=rakdver@atrey.karlin.mff.cuni.cz \
--cc=DORIT@il.ibm.com \
--cc=dnovillo@redhat.com \
--cc=dpatel@apple.com \
--cc=gcc@gcc.gnu.org \
--cc=jason@redhat.com \
--cc=rth@redhat.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).