On Fri, Feb 17, 2012 at 10:01 PM, Jose Fonseca <[email protected]> wrote: > Note that SSE doesn't have vectorized UI to FP. Only SI to FP. At one point > LLVM was breaking down the conversion to scalar, which is overkill. I think > that since I look at it, LLVM has been updated to generate better code. > Please take a look generated assembly for LLVMBuildUIToFP before commiting. > Otherwise put a XXX comment warning about this so that we don't forget about > this issue. > > > I'd prefer to have this one in lp_bld_conv.c . Because eventually this > function will be superseeded by lp_build_conv(). > > The reason I don't recommend you to simply use lp_build_conv() is that > lp_build_conv doesn't do the right thing with unsigned ints due to the issue > above, and in many places (e.g., texture sampling), it doesn't matter. This > needs to be cleaned up so that uint -> fp is done properly, and places that > don't need uints don't use them.
Well ideally we won't be doing any ui->fp conversion except we get an opcode instructing us to do it, anywhere else would be a bug that would need to be fixed. I don't accept at all that we should be allowing texture fetches from unsigned to end up as floats at any point in the pipeline. So I don't think this is going to be a problem going forward too much. Dave. _______________________________________________ mesa-dev mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-dev
