Vertex shaders do not have CMP, so we use SLT and MAD.
For example, this vertex shader:
uniform float4 f;
void main(inout float4 pos : position, out float4 t1 : TEXCOORD1)
{
t1 = (int4)f;
}
results in:
vs_2_0
dcl_position v0
slt r0, c0, -c0
frc r1, c0
add r2, -r1, c0
slt r1, -r1, r1
mad oT1, r0, r1, r2
mov oPos, v0
while we have the lower_cmp() pass, each time it is applied many
instructions are generated, so this patch introduces a specialized
version of the cast-to-int lowering for efficiency.
Otherwise ubsan reports runtime errors such as:
libs/vkd3d-shader/ir.c:4731:5: runtime error: null pointer passed as argument 1, which is declared to never be null
Since we have -Wswitch, this forces the developer to update all relevant
switches when an enum case is added.
Places where the default is just a FIXME are left alone.
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.
