ATOM operates atomically on global memory. For now only add ATOM.ADD
since that's what was found in commercial games.
This asserts for ATOM.ADD.S32 (handling the others as unimplemented),
although ATOM.ADD.U32 shouldn't be any different.
This change forces us to change the default type on SPIR-V storage
buffers from float to uint. We could also alias the buffers, but it's
simpler for now to just use uint. While we are at it, abstract the code
to avoid repetition.
Using the same technique we used for u8 on LDG, implement u16.
In the case of STG, load memory and insert the value we want to set
into it with bitfieldInsert. Then set that value.
LDG can load single bytes instead of full integers or packs of integers.
These have the advantage of loading bytes that are not aligned to 4
bytes.
To emulate these this commit gets the byte being referenced (by doing
"address & 3" and then using that to extract the byte from the loaded
integer:
result = bitfieldExtract(loaded_integer, (address % 4) * 8, 8)
Ignore global memory operations instead of invoking undefined behaviour
when constant buffer tracking fails and we are blasting through asserts,
ignore the operation.
In the case of LDG this means filling the destination registers with
zeroes; for STG this means ignore the instruction as a whole.
The default behaviour is still to abort execution on failure.
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.
This was originally included because texture operations returned a vec4.
These operations now return a single float and the F4 prefix doesn't
mean anything.
Previous code relied on GLSL parameter order (something that's always
ill-formed on an IR design). This approach passes spatial coordiantes
through operation nodes and array and depth compare values in the the
texture metadata. It still contains an "extra" vector containing generic
nodes for bias and component index (for example) which is still a bit
ill-formed but it should be better than the previous approach.
Some games call LDG at the top of a basic block, making the tracking
heuristic to fail. This commit lets the heuristic the decoded nodes as a
whole instead of per basic blocks.
This may lead to some false positives but allows it the heuristic to
track cases it previously couldn't.