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.
We normalize binary expressions by attempting to group constants
together, in order to facilitate further simplification of the
expressions.
For any binary operator OP, non-constants x, y, and constants a, b, we
apply the following rewrite rules:
a OP x -> x OP a, if OP is commutative.
(x OP a) OP b -> x OP (a OP b), if OP is associative.
(x OP a) OP y -> (x OP y) OP a, if OP is associative and commutative.
x OP (y OP a) -> (x OP y) OP a, if OP is associative.
Note that we consider floating point operations to be
non-associative.
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.
The combined sampler is created as a SAMPLER instead of a TEXTURE
because that fits all our current infrastructure. The only problem is
that in the CTAB it must appear as a Texture, so the new field
hlsl_type.is_combined_sampler is added.
Co-authored-by: Elizabeth Figura <zfigura@codeweavers.com>
Looking at the implementation of shader_sm4_read_dcl_sampler(), vsir
stores the resource index range both in
vkd3d_shader_instruction.declaration.sampler.range
and in the
vkd3d_shader_instruction.declaration.sampler.src.reg.idx[1-2]
indexes, so we do the same.
It is also worth noting that for shader models lower than 5.1, vsir
has a normalization on the ins->declaration src register indexes.
Refer to the following comment:
/* SM5.1 places a symbol identifier in idx[0] and moves
* other values up one slot. Normalize to SM5.1. */
on shader_sm4_read_param().
This normalization is also added to the generated vsir instructions.
