I've had no problem with debugging even with -O2. Yeah, gdb cannot show some variables sometimes, but I rarely had to force CFLAGS to -O0 to debug an issue. That said, I can continue overriding CFLAGS and CXXFLAGS like I do now if the majority of people think that --disable-optimizations would be useless.
Right now I use: CFLAGS="-DDEBUG -O2 -g -fno-omit-frame-pointer" CXXFLAGS="$CFLAGS" Marek On Tue, Jan 8, 2013 at 6:31 PM, Brian Paul <bri...@vmware.com> wrote: > On 01/08/2013 08:38 AM, Marek Olšák wrote: >> >> This reverts commit 122345876479cf5cf553e38162ab105658614ab7. >> >> Some distributions use --enable-debug for testing packages and the commit >> results in terrible CPU performance. It can be embarrassing for us. > > > Surely people should understand that enabling debugging code/flags can > adversely effect performance. > > > >> Those who do not want optimizations should set the CFLAGS and CXXFLAGS >> environment variables. In my opinion, --enable-debug should only set >> -DDEBUG. > > > Previously, if we set --enable-debug we got -g -O2 which was pretty much > useless if you planned to use gdb (and why else would you use > --enable-debug?). That's why I advocated -g -O0. > > Just setting -DDEBUG can lead to reduced performance too (in Mesa or in any > other project). For example in the past I've done stuff like: > > #ifdef DEBUG > do extra validation, error checking etc. > #endif > > which could significantly impact performance, regardless of -g or -O. > > -Brian _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
