On Mon, Dec 31, 2012 at 6:03 AM, Dan Nicholson <[email protected]> wrote: > On Sun, Dec 23, 2012 at 3:41 AM, Johannes Obermayr > <[email protected]> wrote: >> Am Samstag, 22. Dezember 2012, 16:34:48 schrieben Sie: >>> On Sat, Dec 22, 2012 at 10:47 AM, Johannes Obermayr >>> <[email protected]> wrote: >>> > Am Samstag, 22. Dezember 2012, 09:21:33 schrieb Matt Turner: >>> >> On Sat, Dec 22, 2012 at 9:16 AM, Johannes Obermayr >>> >> <[email protected]> wrote: >>> >> > This way the user has the privilege of last decision and so the option >>> >> > to build an optimized debug build again. >>> >> > --- >>> >> >>> >> You can just do CFLAGS="-g -O2" ./configure can't you? >>> > >>> > Nope. >>> > >>> > CXXFLAGS='-fmessage-length=0 -O2 -Wall -D_FORTIFY_SOURCE=2 >>> > -fstack-protector -funwind-tables -fasynchronous-unwind-tables -g' >>> > CFLAGS='-fmessage-length=0 -O2 -Wall -D_FORTIFY_SOURCE=2 >>> > -fstack-protector -funwind-tables -fasynchronous-unwind-tables -g' >>> > ./autogen.sh --host=x86_64-suse-linux-gnu --build=x86_64-suse-linux-gnu >>> > --program-prefix= --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin >>> > --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share >>> > --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/lib >>> > --localstatedir=/var --sharedstatedir=/usr/com --mandir=/usr/share/man >>> > --infodir=/usr/share/info --disable-dependency-tracking --enable-xvmc >>> > --enable-vdpau --enable-texture-float --enable-debug >>> > --with-dri-drivers=i915,i965,nouveau,r200,radeon,swrast >>> > --with-gallium-drivers=i915,nouveau,r300,r600,svga,swrast --enable-dri >>> > --enable-glx --enable-osmesa --enable-gles1 --enable-gles2 >>> > --enable-openvg --enable-shared-glapi --enable-shared-gallium >>> > --enable-gbm --enable-xa --ena >>> > ble-gallium-egl --enable-gallium-llvm --enable-gallium-gbm >>> > --enable-opencl --enable-r600-llvm-compiler --enable-gallium-g3dvl >>> > --enable-glx-tls >>> > >>> > Resulting Makefile: >>> > before: >>> > CFLAGS = -fmessage-length=0 -O2 -Wall -D_FORTIFY_SOURCE=2 >>> > -fstack-protector -funwind-tables -fasynchronous-unwind-tables -g -Wall >>> > -std=c99 -Werror=implicit-function-declaration -Werror=missing-prototypes >>> > -fno-strict-aliasing -fno-builtin-memcmp -g -O0 >>> > >>> > after: >>> > CFLAGS = -Wall -std=c99 -Werror=implicit-function-declaration >>> > -Werror=missing-prototypes -fno-strict-aliasing -fno-builtin-memcmp -g >>> > -O0 -fmessage-length=0 -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector >>> > -funwind-tables -fasynchronous-unwind-tables -g >>> > >>> > You see configure CFLAGS and initial CFLAGS are vice versa. >>> >>> The real fix here is not to have configure.ac touch CFLAGS at all like >>> any reasonable autotools project. That was an unfortunate shortcut >>> during the initial work. That would be a lot more effort, though. >> >> Initial work after ~ 5 years? >> http://cgit.freedesktop.org/mesa/mesa/commit/?id=122345876479cf5cf553e38162ab105658614ab7 > > Not sure what you mean by this. When I wrote configure.ac however many > years ago, I didn't cleanly split off CFLAGS set by mesa from the > user's CFLAGS as a shortcut. Looking back now, I should have just bit > the bullet and made something like MESA_CFLAGS/MESA_LDFLAGS and made > all the Makefiles use that. > >> Btw: >> http://cgit.freedesktop.org/mesa/mesa/commit/?id=ff2efdf5997d20b41f7a82b77118366e6fbd23bc >> http://cgit.freedesktop.org/mesa/mesa/commit/?id=33ae29c93b8f70a86dcedc495dd658a5d5679db3 >> >> This patch covers the motivation for commit 33ae29c. >> >>> >>> However, the typical convention is that the user's CFLAGS come first >>> (see any automake COMPILE or LTCOMPILE definition), mostly so that any >>> user specified -I paths take precedence. That's unfortunate when -O >>> options to gcc are last one wins, but that's how things have typically >>> been. I would make this change very cautiously. >>> >>> -- >>> Dan >> >> And here is the real reason for my request: >> >> /usr/lib64/mesa-demos/egl/opengl/xeglgears >> >> AMD Fusion (fps) Nvidia ION (fps) >> -O0 -O2 -O0 -O2 >> 562,7 750,778 0,33 641,851 921,464 0,44 >> 701,756 662,877 -0,06 693,752 1000,196 0,44 >> 571,566 665,052 0,16 692,196 936,147 0,35 >> 542,715 664,658 0,22 693,733 995,499 0,43 >> 542,935 664,78 0,22 692,702 992,634 0,43 >> 542,574 665,398 0,23 692,835 998,665 0,44 >> 542,945 663,087 0,22 691,353 998,319 0,44 >> 541,732 664,253 0,23 656,32 995,91 0,52 >> 543,392 665,078 0,22 691,084 994,037 0,44 >> 542,901 663,406 0,22 693,464 996,858 0,44 >> 5635,216 6729,367 0,19 6839,29 9829,729 0,44 >> (sum) >> >> -> Performance + 19 % on AMD Fusion, + 44 % on Nvidia ION on debug build >> with -O2. :-) >> >> Usual users should build Mesa with default FLAGS. Advanced users should be >> able to build it with their own FLAGS without modifying source. > > Right, --enable-debug is forcing you to have -O0. That's the problem. > Mesa should not be overriding user defined flags such as optimization > unless it's necessary to get Mesa to build. There are two issues here: > > 1. Adding -O0 in --enable-debug is a convenience, but as you see it > can conflicts with the user's flags. This is why I left -O out of > --enable-debug from the beginning. > > http://cgit.freedesktop.org/mesa/mesa/commit/?id=23656c47 > > That said, the whole option is just a helper. If you know what you're > doing, you can easily build with CFLAGS='-g -O2 -DDEBUG' and have all > the control you want. --enable-32-bit/--enable-64-bit are the same > way. They're convenience options I added that fiddle with your CFLAGS > so you don't have to, but they clearly have to make compromises about > "the right thing". All three options should have their help text > updated to indicate that they're just passing flags to the compiler > and not doing anything special to the code. That way people that know > what they're doing can set things up the way they want. > > An alternate fix would be to check if CFLAGS contains -O already and > leave out -O0 in that case.
The following two patches provide a short term fix by only adding '-g -O0' for --enable-debug when CFLAGS/CXXFLAGS have not been set by the user. I think that's the simplest way to still get the functionality from -DDEBUG while respecting the user's preferences. It doesn't try to fix the general issue of configure overriding the user's flags, though. -- Dan _______________________________________________ mesa-dev mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-dev
