On 11/14/2011 10:36 PM, Christoph Bumiller wrote: > On 11/14/2011 10:13 PM, Jose Fonseca wrote: >> .... >> >> My other reply was about this particular case. >> >> But I'm not convinced we can ignore this case at all. I'm fine with drivers >> cutting corners. By I can't accept an interface that's broken by design for >> all drivers. >> >> The argument from TGSI_OPCODE_IF may very well come from the >> application/state tracker as CONSTs. This means that state tracker would >> need to sanitize every const -0.0f => 0.0f, or emit code that did that >> before passing the TGSI_OPCODE_IF. >> > > If it comes from CONST, it will be either a uniform of type boolean, and > thus not a degenerate case, or > for if ((float)), the compiler / TGSI converter will emit a cast too > bool first (i.e. an (F/I/U)SET).
Also, from GL_ARB_uniform_buffer_object: Members of type "bool" are extracted from a buffer object by reading a single uint-typed value at the specified offset. All non-zero values correspond to true, and zero corresponds to false. > > It's not as messy as it sounds, we just need to define the exact > behaviour of IF, and making its source a float (the *only* other choice > to zero/non-zero) seems awkward (since I'm strongly against representing > booleans as 1.0f/0.0f if integers are supported.) > > The only way where we differ from SM4 is that our float comparison ops > return floats, and with NativeIntegers, these are always followed by a > conversion to our current boolean representation (~0/0). > > We already have to make a distinction, if integers are not supported, > glsl-to-tgsi has to turn all glsl-ir integer operations into float > operations. > >> Take a pick, but please keep this consistent. >> >> Jose > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
