On Sat, Apr 21, 2018 at 2:16 AM, Jason Ekstrand <ja...@jlekstrand.net> wrote: > > I was thinking about this a bit this morning and it gets even more sticky. > What happens if you have > > bool e = (a < b) && (c < d); > > where a and b are 16-bit and c and d are 32-bit? In this case, one > comprison has a 32-bit value and one has a 16-bit value and you have to pick > one for the &&.
In OpenCL C, relational operators don't return a bool, but a signed integer type with the same size and number of components as the operands; so, comparing scalar 16-bit data to scalar 16-bit data (doesn't matter if short, ushort or half) would produce a short, and comparing scalar 64-bit data to scalar 64-bit data would produce a long (which in OpenCL C is always 64 bit); the same also holds for vector types (so e.g. comparing a half8 to a half8 produces a short8). So, in your example above, what would happen in OpenCL C would be this: (a < b) would return a short (which is 16-bit in OpenCL C); (c < d) would return an int (which is 32-bit in OpenCL C); their logical combination would return a bool, with appropriate type promotion. I don't suppose something like this could be implemented in NIR? -- Giuseppe "Oblomov" Bilotta _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
