<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN"> <HTML> <HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8"> <META NAME="GENERATOR" CONTENT="GtkHTML/3.26.0"> </HEAD> <BODY> On Tue, 2010-02-02 at 14:00 -0800, Jeremy Huddleston wrote: <BLOCKQUOTE TYPE=CITE> <PRE> On Feb 2, 2010, at 13:18, Gaetan Nadon wrote: > I have not seen any compelling reasons to turn off this optimization. > Maybe 10 years ago when it was first introduced. I have seen reports of > large number of warnings, but from older gcc versions. As it is today, > we are losing some optimization that could be beneficial. > > This option has been there for so long (most likely copied along), I > doubt you will will get a clear answer for each of the 240 xorg modules. > It would take a few modules to try it out first. I see it in libX11 has historically used -fno-strict-aliasing: <A HREF="http://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=db7c6fdeeaef9475458498e4cf09d6b1329e9aa3">http://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=db7c6fdeeaef9475458498e4cf09d6b1329e9aa3</A> but adding XORG_CWARNFLAGS to XORG_DEFAULT_OPTIONS has caused this to change for other modules. Looking at historic versions of modules, I see it present in: libICE libSM libX11 libXau libXfont libXft libXpm libXres xorg-server of course most of these seem to have just copied the entire GCC_WARNINGS block and probably didn't actually need -fno-strict-aliasing </PRE> </BLOCKQUOTE> Of course. Whatever the reasons were, if anyone remembers, may not apply anymore. Devising a plan for it's removal will not be an easy task. I see 3 options: 1) take it out of macros, 1 patch 2) transfer it to all makefiles and then removing it gradually, that's 2*240 +1 patches 3) override in 'n' makefiles until proven safe. Then take it out macros. That's 2*n +1 patches. I am curious how you can about this. </BODY> </HTML>