We have to distinguish between the "bind count" and the "allocation size"
of variables.
The "allocation size" affects the starting register id for the resource to
be allocated next, while the "bind count" is determined by the last field
actually used. The former may be larger than the latter.
What we are currently calling hlsl_reg.bind_count is actually the
"allocation size", so a rename is in order.
The real "bind count", which will be introduced in following patches,
is important because it is what should be shown in the RDEF table and
some resource allocation rules depend on it.
For instance, for this shader:
texture2D texs[3];
texture2D tex;
float4 main() : sv_target
{
return texs[0].Load(int3(0, 0, 0)) + tex.Load(int3(0, 0, 0));
}
the variable "texs" has a "bind count" of 1, but an "allocation size" of
3:
// Resource Bindings:
//
// Name Type Format Dim HLSL Bind Count
// ------------------------------ ---------- ------- ----------- -------------- ------
// texs texture float4 2d t0 1
// tex texture float4 2d t3 1
We will add register information lookup tables on this struct later.
They will be used by sm4_encode_register(), and thus, they will be
required by write_sm4_instruction().
This struct is required for handling both whole-variable resources for
SM < 5 and single-component resources for SM 5 in the same way, when
writting the RDEF block and resource declarations within the shader.
After lowering the derefs path to a single offset node, there was no way
of knowing the type of the referenced part of the variable. This little
modification allows to avoid having to pass the data type everywhere and
it is required for supporting instructions that reference objects
components within struct types.
Since deref->data_type allows us to retrieve the type of the deref,
deref->offset_regset is no longer necessary.
Store it in the shader_desc, and declare temps from that when compiling SPIR-V,
instead of parsing dcl_instructions.
As part of this change, we declare a single, global temps array (with Private
scope instead of Function) which is as large as the maximum of all dcl_temps
instructions. It is not clear to me whether this will improve, hurt, or have no
significant effect on the lower-level compiler. An alternative is to still
redeclare a new temps array every time (although still with a smaller size).
Instead of modifying the swizzle after calling sm4_src_from_node().
This fixes the case where sm4_src_from_node() returns an immediate constant.
Fixes: a471c5567a
The new fixmes can be triggered in presence of object components within
structs (for SM5).
In shaders such as this one:
struct apple
{
Texture2D tex : TEX;
float4 color : COLOR;
};
float4 main(struct apple input) : sv_target
{
return input.tex.Load(int3(1, 2, 3));
}
Or this one:
struct
{
Texture2D tex;
float4 color;
} s;
float4 main() : sv_target
{
return s.tex.Load(int3(1, 2, 3));
}
Variables that contain more than one object (arrays or structs) require
the allocation of contiguous registers in the respective object
register spaces.
