On Tue, Aug 8, 2017 at 4:25 PM, Scott D Phillips <scott.d.phill...@intel.com> wrote: >> + [BRW_HW_IMM_TYPE_UV] = 2, >> + [BRW_HW_IMM_TYPE_VF] = 4, >> + [BRW_HW_IMM_TYPE_V] = 2, > > Is this right? I see it was there before, and perhaps I'm being dense, > but it seems like V and UV should be size 4 from the PRM.
Yes. The encoded immediates themselves are 4 bytes, but this table captures the size of the individual components once expanded. That's admittedly a little weird. A V/UV immediate consists of 8x 4-bit integer values. A restriction documented in "Gen Graphics » BSpec » 3D and Compute Engine » 3D and GPGPU Programs » EU Overview » Registers and Register Regions » Immediate" states "When an immediate vector is used in an instruction, the destination must be 128-bit aligned with destination horizontal stride equivalent to a word for an immediate integer vector (v) and equivalent to a DWord for an immediate float vector (vf).". So we consider the individual components of the V/UV immediate to really be words, of size 2. Thanks for the good question! _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
