There's no limit on the number of memory exports in a shader on the real
Xenos, and exports can be done anywhere, including in loops. Now, instead
of deferring the exports to the end of the shader, and assuming that export
allocs are executed only once, Xenia flushes exports when it reaches an
alloc (allocs terminate memory exports on Xenos, as well as individual ALU
instructions with `serialize`, but not handling this case for simplicity,
it's only truly mandatory to flush memory exports before starting a new
one), the end of the shader, or a pixel with outstanding exports is killed.
To know which eM# registers need to be flushed to the memory, traversing
the successors of each exec potentially writing any eM#, and specifying
that certain eM# registers might have potentially been written before each
reached control flow instruction, until a flush point or the end of the
shader is reached.
Also, some games export to sub-32bpp formats. These are now supported via
atomic AND clearing the bits of the dword to replace followed by an atomic
OR inserting the new byte/short.
Block members can be decorated with Invariant only since SPIR-V 1.5 Revision 2. In earlier versions, Invariant can be used only for variables. Mesa warns about this.
Previously, for mips, the dimensions of the texture weren't rounded to powers of two before calculating the mip tail extent, resulting in the mip tail for a 260 blocks tall texture, that contains mips ending at Y of up to 36, having the Y extent calculated as 32. With rounding to powers of two, it would have been 64.
However, with the GetTiledAddressUpperBound functions, none of this is necessary at all (and neither is rounding the extents in TextureGuestLayout::Level to 32x32x4 blocks) - using the same code for calculating the XYZ extents of tiled textures as for linear textures now, which, for the mip tail, calculates the actual maximum coordinates of the mips stored in it - and rounding to tiles is done internally by GetTiledAddressUpperBound.
Fixes the PIX validation warning about missing resource states on every guest draw. Also potentially prevents drivers from making assumptions about the shared memory buffer based on the bindings, though no such cases are currently known.
Also fixes addressing of MSAA samples 2 and 3 for 64bpp color render targets in the ROV RB implementation on Direct3D 12.
Additionally, with FSI/ROV, alpha test and alpha to coverage are done only if the render target 0 was dynamically written to (according to the Direct3D 9 rules for writing to color render targets, though not sure if they actually apply to the alpha tests on Direct3D 9, but for safety).
There is also some code cleanup for things spotted during the development of the feature.
For more optimal usage of exports and the parameter cache on the host regardless of how effective the optimizations in the host GPU driver are. Also reserve space for Vulkan/Metal/D3D11-specific HostVertexShaderTypes to use one more bit for the host vertex shader type in the shader modification bits, so that won't have to be done in the future as that would require invalidating shader storages (which are invalidated by this commit) again.
Put all descriptors used by translated shaders in up to 4 descriptor sets, which is the minimum required, and the most common on Android, `maxBoundDescriptorSets` device limit value
