Using the Intel Vulkan driver, we've found some cases where SpvOpSelect is returning -0.0 (negative zeros) instead of normal 0.0 depending on the arguments.
I'm wondering if "SpvOpSelect x, a, b" for floats is being implemented with something like "a*x + b*(1-x)" ? That might explain where the negative zeros are coming from.
Our work-around is to implement selection with bitwise operations: (a & x) | (b & ~x)
It seems to me that SpvOpSelect shouldn't interpret the bits and just return an exact copy of the argument.
-Brian _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
