From: Artur Skawina <skawina@geocities.com>
To: Richard Henderson <rth@cygnus.com>
Cc: Jamie Lokier <jamie.lokier@cern.ch>,
"Martin v. Loewis" <martin@mira.isdn.cs.tu-berlin.de>,
gcc@gcc.gnu.org
Subject: Re: what's required for builtin_memcpy to be inlined
Date: Fri, 10 Sep 1999 15:33:00 -0000 [thread overview]
Message-ID: <37D96F4D.452E72C@geocities.com> (raw)
In-Reply-To: <19990910121829.D5064@cygnus.com>
Richard Henderson wrote:
>
> On Fri, Sep 10, 1999 at 05:44:26PM +0200, Jamie Lokier wrote:
> > The size is variable, but known by dataflow inference at compile time.
> > I think GCC returns 1 from __builtin_constant_p in this case, nowadays.
>
> If it can -- we currently reduce __builtin_constant_p before
> gcse, so we'll not see a value set from a constant in another
> basic block, as the original example had.
My original "example" was cut&pasted from linux kernel sources, and
I noticed this problem because it prevented the kernel from building.
[I'm not complaing that __builtin_constant_p got smarter -- that's
a very good thing in itself, and I hope it gets even smarter. It's
just that a __builtin_constant_p that is smarter then a builtin
string routine makes the latter much less useful...]
WARNING: multiple messages have this Message-ID
From: Artur Skawina <skawina@geocities.com>
To: Richard Henderson <rth@cygnus.com>
Cc: Jamie Lokier <jamie.lokier@cern.ch>,
"Martin v. Loewis" <martin@mira.isdn.cs.tu-berlin.de>,
gcc@gcc.gnu.org
Subject: Re: what's required for builtin_memcpy to be inlined
Date: Thu, 30 Sep 1999 18:02:00 -0000 [thread overview]
Message-ID: <37D96F4D.452E72C@geocities.com> (raw)
Message-ID: <19990930180200.ihgTvjZgNjhMfAkuGK2xRg8ZnK39QGH0Vd89jDlhDaI@z> (raw)
In-Reply-To: <19990910121829.D5064@cygnus.com>
Richard Henderson wrote:
>
> On Fri, Sep 10, 1999 at 05:44:26PM +0200, Jamie Lokier wrote:
> > The size is variable, but known by dataflow inference at compile time.
> > I think GCC returns 1 from __builtin_constant_p in this case, nowadays.
>
> If it can -- we currently reduce __builtin_constant_p before
> gcse, so we'll not see a value set from a constant in another
> basic block, as the original example had.
My original "example" was cut&pasted from linux kernel sources, and
I noticed this problem because it prevented the kernel from building.
[I'm not complaing that __builtin_constant_p got smarter -- that's
a very good thing in itself, and I hope it gets even smarter. It's
just that a __builtin_constant_p that is smarter then a builtin
string routine makes the latter much less useful...]
next prev parent reply other threads:[~1999-09-10 15:33 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-09-08 19:21 Artur Skawina
1999-09-08 19:35 ` Joe Buck
1999-09-09 14:39 ` Artur Skawina
1999-09-30 18:02 ` Artur Skawina
1999-09-30 18:02 ` Joe Buck
1999-09-09 1:47 ` Martin v. Loewis
1999-09-10 8:45 ` Jamie Lokier
1999-09-10 12:20 ` Richard Henderson
1999-09-10 15:33 ` Artur Skawina [this message]
1999-09-10 16:12 ` Richard Henderson
1999-09-13 10:31 ` Joern Rennecke
1999-09-13 12:01 ` Richard Henderson
1999-09-13 16:43 ` Joern Rennecke
1999-09-30 18:02 ` Joern Rennecke
1999-09-30 18:02 ` Richard Henderson
1999-09-30 18:02 ` Joern Rennecke
1999-09-30 18:02 ` Richard Henderson
1999-09-30 18:02 ` Artur Skawina
1999-09-30 18:02 ` Richard Henderson
1999-09-10 13:47 ` Martin v. Loewis
1999-09-30 18:02 ` Martin v. Loewis
1999-09-30 18:02 ` Jamie Lokier
1999-09-30 18:02 ` Martin v. Loewis
1999-09-30 18:02 ` Artur Skawina
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