Games using D3D idioms can join images and samplers when a shader
executes, instead of baking them into a combined sampler image. This is
also possible on Vulkan.
One approach to this solution would be to use separate samplers on
Vulkan and leave this unimplemented on OpenGL, but we can't do this
because there's no consistent way of determining which constant buffer
holds a sampler and which one an image. We could in theory find the
first bit and if it's in the TIC area, it's an image; but this falls
apart when an image or sampler handle use an index of zero.
The used approach is to track for a LOP.OR operation (this is done at an
IR level, not at an ISA level), track again the constant buffers used as
source and store this pair. Then, outside of shader execution, join
the sample and image pair with a bitwise or operation.
This approach won't work on games that truly use separate samplers in a
meaningful way. For example, pooling textures in a 2D array and
determining at runtime what sampler to use.
This invalidates OpenGL's disk shader cache :)
- Used mostly by D3D ports to Switch
Allows reporting more cases where logic errors may exist, such as
implicit fallthrough cases, etc.
We currently ignore unused parameters, since we currently have many
cases where this is intentional (virtual interfaces).
While we're at it, we can also tidy up any existing code that causes
warnings. This also uncovered a few bugs as well.
These are std::shared_ptr instances underneath the hood, which means
copying them isn't as cheap as a regular pointer. Particularly so on
weakly-ordered systems.
This avoids atomic reference count increments and decrements where they
aren't necessary for the core set of operations.
While changing this code, simplify tracking code to allow returning
the base address node, this way callers don't have to manually rebuild
it on each invocation.
Instead of having a vector of unique_ptr stored in a vector and
returning star pointers to this, use shared_ptr. While changing
initialization code, move it to a separate file when possible.
This is a first step to allow code analysis and node generation beyond
the ShaderIR class.
Some games search conditionally use global memory instructions. This
allows the heuristic to search inside conditional nodes for the source
constant buffer.