Jason Ekstrand
88a2a2e053
Unlike the current CSE pass, global value numbering is capable of detecting
common values even if one does not dominate the other. For instance, in
you have
if (...) {
ssa_1 = ssa_0 + 7;
/* use ssa_1 */
} else {
ssa_2 = ssa_0 + 7;
/* use ssa_2 */
}
Global value numbering doesn't care about dominance relationships so it
figures out that ssa_1 and ssa_2 are the same and converts this to
if (...) {
ssa_1 = ssa_0 + 7;
/* use ssa_1 */
} else {
/* use ssa_1 */
}
Obviously, we just broke SSA form which is bad. Global code motion,
however, will repair this for us by turning this into
ssa_1 = ssa_0 + 7;
if (...) {
/* use ssa_1 */
} else {
/* use ssa_1 */
}
This intended to eventually mostly replace CSE. However, conventional CSE
may still be useful because it's less of a scorched-earth approach and
doesn't require GCM. This makes it a bit more appropriate for use as a
clean-up in a late optimization run.
Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
File: docs/README.WIN32 Last updated: 21 June 2013 Quick Start ----- ----- Windows drivers are build with SCons. Makefiles or Visual Studio projects are no longer shipped or supported. Run scons libgl-gdi to build gallium based GDI driver. This will work both with MSVS or Mingw. Windows Drivers ------- ------- At this time, only the gallium GDI driver is known to work. Source code also exists in the tree for other drivers in src/mesa/drivers/windows, but the status of this code is unknown. Recipe ------ Building on windows requires several open-source packages. These are steps that work as of this writing. - install python 2.7 - install scons (latest) - install mingw, flex, and bison - install pywin32 from here: http://www.lfd.uci.edu/~gohlke/pythonlibs get pywin32-218.4.win-amd64-py2.7.exe - install git - download mesa from git see http://www.mesa3d.org/repository.html - run scons General ------- After building, you can copy the above DLL files to a place in your PATH such as $SystemRoot/SYSTEM32. If you don't like putting things in a system directory, place them in the same directory as the executable(s). Be careful about accidentially overwriting files of the same name in the SYSTEM32 directory. The DLL files are built so that the external entry points use the stdcall calling convention. Static LIB files are not built. The LIB files that are built with are the linker import files associated with the DLL files. The si-glu sources are used to build the GLU libs. This was done mainly to get the better tessellator code. If you have a Windows-related build problem or question, please post to the mesa-dev or mesa-users list.