Without this patch, `gl_FragCoord` is not output for subpass reads in certain cases where `gl_FragCoord` is not used elsewhere in the shader.
I'm not sure why this isn't caught by existing tests (e.g. [input-attachment.frag](shaders-msl/frag/input-attachment.frag)), but I encountered this issue in code generated by DXC and passed through spire-opt.
I cannot find any reference to this flag ever having existed in older
MSL spec documents, and it breaks compilation on any recent SDK for any
iOS/macOS Metal version. Just remove it.
Limit inline blocks to one per descriptor set.
This should avoid the need for complicated code to calculate the
argument buffer ID stride of an inline uniform block. If there's demand
for more inline blocks, we can revisit this.
Here, the inline uniform block is explicit: we instantiate the buffer
block itself in the argument buffer, instead of a pointer to the buffer.
I just hope this will work with the `MTLArgumentDescriptor` API...
Note that Metal recursively assigns individual members of embedded
structs IDs. This means for automatic assignment that we have to
calculate the binding stride for a given buffer block. For MoltenVK,
we'll simply increment the ID by the size of the inline uniform block.
Then the later IDs will never conflict with the inline uniform block. We
can get away with this because Metal doesn't require that IDs be
contiguous, only monotonically increasing.
- Fixes issue with clip_distance flattening in MSL where member to
flatten from would come from to_member_name, where it should have used
the builtin name directly. This member name was modified by this patch
and broke clip distance test shaders.
- Some cleanups with ir.meta, use ir.find_meta instead to not create
unnecessary hashmap nodes.
MSL does not support this, so we have to emulate it by passing it around
as a varying between stages. We use a special "user(clipN)" attribute
for this rather than locN which is used for user varyings.
From UE4 review, does not cause any changes in test output, and should
only change output if we were unpacking arrays or something like that,
which we don't support.
There was a hack to workaround a bug in DXC where control point -> patch
constant phase was passed in Function storage, but we have to use
Workgroup here. We will not support these kinds of hacks for invalid
SPIR-V, so hack the reference files to use the "proper" fix and remove
the hack for time being.
To support loading array of array properly in tessellation, we need a
rewrite of how tessellation access chains are handled.
The major change is to remove the implicit unflatten step inside
access_chain which does not take into account the case where you load
directly from a control point array variable.
We defer unflatten step until OpLoad time instead.
This fixes cases where we load array of {array,matrix,struct}.
Removes the hacky path for MSL access chain index workaround.
Hoist out some conditionals and make it clear that we go into this path
if strip_array is used when declaring resources, i.e. there was no
explicit unflatten step.
Non-patch arrays of IO variables in tesc/tese have their array index
stripped, and access chains are specially handled, we shouldn't attempt
to create "normal" arrays of these.
