Valid stream output objects must be single-element containing a
PointStream/LineStream/TriangleStream object.
Moreover, stream output objects cannot be declared globally.
Sometimes SM1-3 shaders contain write masks that exceed the
signature element masks. That happens because SM1-3 shaders do not
have a concept of signature and signature masks, and OTOH aren't
always able to express any given write mask.
In VSIR we don't want to deal with I/O register masks exceeding the
corresponding signature element mask or usage mask, because, for
instance, for higher shader models it can complicate dealing with
DCL_INDEX_RANGE. In order to have uniform rules for all shader
models we normalise masks coming from SM1-3 shaders.
We don't do that normalisation when disassembling, in order to
preserve the expected output.
The previous names "not normalised" and "fully normalised" have meanings
which are likely to change with time. OTOH including a description of the
normalisation level in the enumerant seems excessive. Relating
normalisation levels to shader model versions might be a reasonable
compromise.
The alternative to adding the vsir_program->tess_output_primitive and
vsir_program->tess_partitioning fields would be to emit the vsir
DCL_TESSELLATOR_OUTPUT_PRIMITIVE and DCL_TESSELLATOR_PARTITIONING
instructions, like DXIL does, but I think that the preference is to store
these kind of data directly in the vsir_program.
