Am 12.09.2018 um 08:31 schrieb Axel Davy: > On 9/12/18 8:17 AM, Axel Davy wrote: >> >> The goal is to catch inf and -inf and replace them by FLT_MAX and >> -FLT_MAX. >> >> Without, the NaN would appear when doing mul or mad. Ah I somehow completely missed this (but indeed this code will replace nans with flt_max, I guess though it's fine as long as you try to avoid getting nans as inputs there in the first place).
>> >> Axel >> >> >> > I small precision I want to add: This is not the only place clamping > makes a difference. > > Indeed else MUL_ZERO_WINS would be safe to use and remove all the clamping. > > > The rasterizers can produce NaN when given Inf in the vertex shader on > some devices for example, > > and I think on some devices inf and FLT_MAX give different color in the > pixel shader. > > > Thus why I want to test carefully what do the other vendors for all the > shader versions (we know already there are > > behaviour changes for some) and check with the behaviours mentionned > above, before removing the clamps when MUL_ZERO_WINS. Yes it's all quite a mess. d3d9 rules are awkward (if they are even documented), whereas gl may do whatever (personally I would consider at least for core contexts everything not following ieee754 rules a bug, well maybe not for gles...). Roland > > > > Axel > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
