We were passing arrays by value which the compiler fails to optimize,
causing abyssal performance. To fix this, we need to consider that
descriptors can be in constant or const device address spaces.
Also, lone descriptors are passed by value, so we explicitly remove address
space qualifiers.
One failure case is when shader passes a texture/sampler array as an
argument. It's all UniformConstant in SPIR-V, but in MSL it might be
thread, const device or constant, so that won't work ...
Global variable use works fine though, and that should cover 99.9999999%
of use cases.
Fragment shaders that require explicit early fragment tests are incompatible
with specifying depth and stencil values within the shader. If explicit early
fragment tests is specified, remove the depth and stencil outputs from the
output structure, and replace them with dummy local variables.
Add CompilerMSL:uses_explicit_early_fragment_test() function to consolidate
testing for whether early fragment tests are required.
Add two unit tests for depth-out with, and without, early fragment tests.
Promote to short instead and do simple casts on load/store instead.
Not 100% complete fix since structs can contain booleans, but this is
getting into pretty ridiculously complicated territory.
Add spvQuantizeToF16() family of synthetic functions to convert
from float to half and back again, and add function attribute
[[clang::optnone]] to honor infinities during conversions.
Adjust SPIRV-Cross unit test reference shaders to accommodate these changes.
Matching output/input struct member types between shader stages could fail if
a location is shared between members, each using different components of that
location, because the member vecsize was only stored once for the location.
Add MSLShaderInput::component member.
Use LocationComponentPair to key inputs_by_location, instead of just location.
ensure_correct_input_type() pass component value as well as location.
Vulkan specifies that the Sample Mask Test occurs before fragment shading.
This means gl_SampleMaskIn should be influenced by both sample-shading and
VkPipelineMultisampleStateCreateInfo::pSampleMask.
CTS tests dEQP-VK.pipeline.multisample_shader_builtin.* bear this out.
For sample-shading, gl_SampleMaskIn should only have a single bit set,
Since Metal does not filter for this, apply a bitmask based on gl_SampleID.
For a fixed sample mask, since Metal is unaware of
VkPipelineMultisampleStateCreateInfo::pSampleMask, we need to ensure that
we apply it to both gl_SampleMaskIn and gl_SampleMask. This has the side
effect of a redundant application of pSampleMask if the shader already
includes gl_SampleMaskIn when setting gl_SampleMask, but I don't see an
easy way around this.
Also, simplify the logic for including the fixed sample mask in gl_ShaderMask,
and print the fixed sample mask as a hex value for readability of bits.
We'll need to force a temporary and mark it as precise.
MSL is a little weird here, but we can piggyback on top of the invariant
float math option here to force fma() operations everywhere.
Firstly, never flatten inputs or outputs in multi-patch mode.
The main scenario where we do need to care is Block IO.
In this case, we should only flatten the top-level member, and after
that we use access chains as normal.
Using structs in Input storage class is now possible as well. We don't
need to consider per-location fixups at all here. In Vulkan, IO structs
must match exactly. Only plain vectors can have smaller vector sizes as
a special case.
For buffers, support all MSLResourceBinding::basetype pointers, not just void*.
Rename MSLResourceBinding::base_type to basetype for consistent use in other structs.
Add lookup from argument buffer argument index to resource binding for efficiency.
Fix error in advancing padding counts with combined image samplers.
Run clang-format.
If CompilerMSL::Options::pad_argument_buffer_resources enabled, Metal argument buffer
struct members are positionally aligned to their argument indexes by adding synthetic
padding members when needed. The types and sizes of these synthetic members are
identified in the resource_bindings vector provided through the API.
Add CompilerMSL::Options::pad_argument_buffer_resources to enable padding
Metal argument buffer structs to positionally match members to argument indexes.
Add MSLResourceBinding::base_type to identify resource type through API.
We only considered invalid names, and overwrote the alias for the
function. The correct fix is to replace illegal names early, do the
reserved fixup, then copy back alias to entry point name.
In Metal, the `[[position]]` input to a fragment shader remains at
fragment center, even at sample rate, like OpenGL and Direct3D. In
Vulkan, however, when the fragment shader runs at sample rate, the
`FragCoord` builtin moves to the sample position in the framebuffer,
instead of the fragment center. To account for this difference, adjust
the `FragCoord`, if present, by the sample position. The -0.5 offset is
because the fragment center is at (0.5, 0.5).
Also, add an option to force sample-rate shading in a fragment shader.
Since Metal has no explicit control for this, this is done by adding a
dummy `[[sample_id]]` which is otherwise unused, if none is already
present. This is intended to be used from e.g. MoltenVK when a
pipeline's `minSampleShading` value is nonzero.
Instead of checking if any `Input` variables have `Sample`
interpolation, I've elected to check that the `SampleRateShading`
capability is present. Since `SampleId`, `SamplePosition`, and the
`Sample` interpolation decoration require this cap, this should be
equivalent for any valid SPIR-V module. If this isn't acceptable, let me
know.
Add support for declaring a fixed subgroup size. Metal, like Vulkan with
`VK_EXT_subgroup_size_control`, allows the thread execution width to
vary depending on factors such as register usage. Unfortunately, this
breaks several tests that depend on the subgroup size being what the
device says it is. So we'll fix the subgroup size at the size the device
declares. The extra invocations in the subgroup will appear to be
inactive. Because of this, the ballot mask builtins are now ANDed with
the active subgroup mask.
Add support for emulating a subgroup of size 1. This is intended to be
used by Vulkan Portability implementations (e.g. MoltenVK) when the
hardware/software combo provides insufficient support for subgroups.
Luckily for us, Vulkan 1.1 only requires that the subgroup size be at
least 1.
Add support for quadgroup and SIMD-group functions which were added to
iOS in Metal 2.2 and 2.3. This will allow clients to take advantage of
expanded quadgroup and SIMD-group support in recent Metal versions and
on recent Apple GPUs (families 6 and 7).
Gut emulation of subgroup builtins in fragment shaders. It turns out
codegen for the SIMD-group functions in fragment wasn't implemented for
AMD on Mojave; it's a safe bet that it wasn't implemented for the other
drivers either. Subgroup support in fragment shaders now requires Metal
2.2.