Eric Anholt
80ecb8f15b
By making a bool fs_reg only have a defined low bit (matching CMP
output), instead of being a full 0 or 1 value, we reduce the ANDs
generated in logic chains like:
if (v_texcoord.x < 0.0 || v_texcoord.x > texwidth ||
v_texcoord.y < 0.0 || v_texcoord.y > 1.0)
discard;
My concern originally when writing this code was that we would end up
generating unnecessary ANDs on bool uniforms, so I put the ANDs right
at the point of doing the CMPs that otherwise set only the low bit.
However, in order to use a bool, we're generating some instruction
anyway (e.g. moving it so as to produce a condition code update), and
those instructions can often be turned into an AND at that point. It
turns out in the shaders I have on hand, none of them regress in
instruction count:
Total instructions: 262649 -> 262545
39/2148 programs affected (1.8%)
14253 -> 14149 instructions in affected programs (0.7% reduction)
File: docs/README.WIN32 Last updated: 23 April 2011 Quick Start ----- ----- Windows drivers are build with SCons. Makefiles or Visual Studio projects are no longer shipped or supported. Run scons osmesa mesagdi to build classic mesa Windows GDI drivers; or 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. 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.