From: Richard Henderson <rth@redhat.com>
To: "Sanjiv Kumar Gupta, Noida" <sanjivg@noida.hcltech.com>
Cc: David Edelsohn <dje@watson.ibm.com>,
Daniel Berlin <dberlin@dberlin.org>,
Dale Johannesen <dalej@apple.com>,
gcc@gcc.gnu.org
Subject: Re: possible gcse failure: not able to eliminate redundant loads
Date: Fri, 13 Dec 2002 02:42:00 -0000 [thread overview]
Message-ID: <20021213093054.GA29293@redhat.com> (raw)
In-Reply-To: <E04CF3F88ACBD5119EFE00508BBB2121061C3264@exch-01.noida.hcltech.com>
On Fri, Dec 13, 2002 at 11:26:34AM +0530, Sanjiv Kumar Gupta, Noida wrote:
> b[2] = a[1];
> for (j = 0; j < i; j++)
> {
> if (i)
> b[3] = a[1];
Yes, this requires more knowledge than is present in loop.
Ignoring the first statement, we cannot hoist a[1] because
it is only conditionally executed and might trap. But we
don't have any code that knows how to propagate the fact
that we've already loaded from a earlier.
This case needs some form of gcse to work.
r~
next prev parent reply other threads:[~2002-12-13 9:31 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-13 0:39 Sanjiv Kumar Gupta, Noida
2002-12-13 2:42 ` Richard Henderson [this message]
2002-12-13 13:10 ` Toon Moene
2002-12-16 10:15 ` Richard Henderson
2002-12-16 11:32 ` Andrew Haley
2002-12-16 13:13 ` Toon Moene
2002-12-16 13:32 ` Richard Henderson
2002-12-16 14:44 ` Toon Moene
2002-12-16 14:48 ` Toon Moene
2002-12-16 15:29 ` Richard Henderson
2002-12-17 15:20 ` Toon Moene
2002-12-16 15:38 ` Jan Hubicka
2002-12-16 16:40 ` Alex Rosenberg
-- strict thread matches above, loose matches on Subject: below --
2002-12-21 20:36 Robert Dewar
2002-12-19 7:08 Richard Kenner
2002-12-18 18:39 Robert Dewar
2002-12-19 3:02 ` Richard Henderson
2002-12-21 19:49 ` Alexandre Oliva
2002-12-12 23:42 Sanjiv Kumar Gupta, Noida
2002-12-12 21:35 Sanjiv Kumar Gupta, Noida
2002-12-12 21:44 ` Dan Nicolaescu
2002-12-11 22:00 Sanjiv Kumar Gupta, Noida
2002-12-11 22:18 ` Daniel Berlin
2002-12-11 20:32 Sanjiv Kumar Gupta, Noida
2002-12-11 3:30 Sanjiv Kumar Gupta, Noida
2002-12-11 14:53 ` Dale Johannesen
2002-12-11 20:02 ` Daniel Berlin
2002-12-11 20:03 ` Daniel Berlin
2002-12-12 12:25 ` Richard Henderson
2002-12-12 12:28 ` Daniel Berlin
2002-12-12 13:03 ` Richard Henderson
2002-12-12 13:04 ` David Edelsohn
2002-12-12 14:32 ` Richard Henderson
2002-12-12 14:42 ` David Edelsohn
2002-12-12 14:58 ` Richard Henderson
2002-12-12 15:28 ` Daniel Berlin
2002-12-13 3:41 ` Richard Henderson
2002-12-12 20:30 ` David Edelsohn
2002-12-12 15:29 ` Geoff Keating
2002-12-11 3:27 Sanjiv Kumar Gupta, Noida
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