This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: should sync builtins be full optimization barriers?

From: Paolo Bonzini <bonzini at gnu dot org>
To: "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
Cc: Richard Henderson <rth at redhat dot com>
Date: Tue, 20 Sep 2011 09:56:36 +0200
Subject: Re: should sync builtins be full optimization barriers?
References: <4E7225AF.3060800@redhat.com> <4E722733.3010003@gnu.org>

On 09/15/2011 06:26 PM, Paolo Bonzini wrote:

There's no reference to a GCC bug report about this in the thread.
Did the folks over at the libdispatch project never think to file one?


I asked them to attach a preprocessed testcase somewhere, but they
haven't done so yet. :(

They now attached it, and the bug turns out to be a missing parenthesis in an #ifdef. This made libdispatch compile the xchg as an asm rather than a sync builtin. And of course the asm was wrong.

Apparently, Apple people on the mailing list were looking at the Apple trunk, but the reporter was obviously compiling from the public trunk.

Paolo

References:
- Re: should sync builtins be full optimization barriers?
  - From: Richard Henderson
- Re: should sync builtins be full optimization barriers?
  - From: Paolo Bonzini

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]