Populate member_type_index_redirection as reverse lookup, not forward lookup.
Move use of member_type_index_redirection from CompilerMSL::to_member_reference()
to CompilerGLSL::access_chain_internal() to access all redirected type info,
not just name.
When gl_Position is defined by SPIR-V, but neither used nor initialized,
it appeared twice in the MSL output, as gl_Position and glPosition_1.
The existing tests for whether an output is active check only that it is
used by an op, or initialized. Adding the implicit gl_Position also marked
the existing gl_Position as active, duplicating the output variable.
Fix is that when checking for the need to add an implicit gl_Position
output, also check if the var is already defined in the shader,
and just needs to be marked as active.
Add test shader.
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.
This should hopefully reduce underutilization of the GPU, especially on
GPUs where the thread execution width is greater than the number of
control points.
This also simplifies initialization by reading the buffer directly
instead of using Metal's vertex-attribute-in-compute support. It turns
out the only way in which shader stages are allowed to differ in their
interfaces is in the number of components per vector; the base type must
be the same. Since we are using the raw buffer instead of attributes, we
can now also emit arrays and matrices directly into the buffer, instead
of flattening them and then unpacking them. Structs are still flattened,
however; this is due to the need to handle vectors with fewer components
than were output, and I think handling this while also directly emitting
structs could get ugly.
Another advantage of this scheme is that the extra invocations needed to
read the attributes when there were more input than output points are
now no more. The number of threads per workgroup is now lcm(SIMD-size,
output control points). This should ensure we always process a whole
number of patches per workgroup.
To avoid complexity handling indices in the tessellation control shader,
I've also changed the way vertex shaders for tessellation are handled.
They are now compute kernels using Metal's support for vertex-style
stage input. This lets us always emit vertices into the buffer in order
of vertex shader execution. Now we no longer have to deal with indexing
in the tessellation control shader. This also fixes a long-standing
issue where if an index were greater than the number of vertices to
draw, the vertex shader would wind up writing outside the buffer, and
the vertex would be lost.
This is a breaking change, and I know SPIRV-Cross has other clients, so
I've hidden this behind an option for now. In the future, I want to
remove this option and make it the default.
Metal is picky about interface matching. If the types don't match
exactly, down to the number of vector components, Metal fails pipline
compilation. To support pipelines where the number of components
consumed by the fragment shader is less than that produced by the vertex
shader, we have to fix up the fragment shader to accept all the
components produced.
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.
Atomics are not supported on images or texture_buffers in MSL.
Properly throw an error if OpImageTexelPointer is used (since it can
only be used for atomic operations anyways).
Even as of Metal 2.1, MSL still doesn't support arrays of buffers
directly. Therefore, we must manually expand them. In the prologue, we
define arrays holding the argument pointers; these arrays are what the
transpiled code ends up referencing. We might be able to do similar
things for textures and samplers prior to MSL 2.0.
Speaking of which, also enable texture arrays on iOS MSL 1.2.
This requires MSL 2.0+.
Also, force `ViewportIndex` and `Layer` to be defined as the correct
type, which is always `uint` in MSL.
Since Metal doesn't yet have geometry shaders, the vertex shader (or
tessellation evaluation shader == "post-tessellation vertex shader" in
Metal jargon) is the only kind of shader that can set this output. This
currently requires an extension to Vulkan, which causes validation of
the SPIR-V binaries for the test cases to fail. Therefore, the test
cases are marked "invalid", even though they're actually perfectly valid
SPIR-V--they just won't work without the
`SPV_EXT_shader_viewport_index_layer` extension.
In MSL, these only have an effect on fragment `[[stage_in]]` members.
They have no effect in vertex shaders. The Khronos front end doesn't
even emit the SPIR-V decorations for them.
Add CompilerMSL::Options::disable_rasterization input/output API flag.
Disable rasterization via API flag or when writing to textures.
Disable rasterization when shader declares no output.
Add test shaders for vertex no output and write texture forcing void output.
Support flattening StorageOutput & StorageInput matrices and arrays.
No longer move matrix & array inputs to separate buffer.
Add separate SPIRFunction::fixup_statements_in & SPIRFunction::fixup_statements_out
instead of just SPIRFunction::fixup_statements.
Emit SPIRFunction::fixup_statements at beginning of functions.
CompilerMSL track vars_needing_early_declaration.
Pass global output variables as variables to functions that access them.
Sort input structs by location, same as output structs.
Emit struct declarations in order output, input, uniforms.
Regenerate reference shaders to new formats defined by above.
Support MSL typedefs to declare 3-row row-major matrices as 3-column matrices.
Allow those matrices to be decorated as packed.
Support transposing those matrices when used.
Modify how member alignments are calculated.
Add bool members is_read and is_written to SPIRType::Image.
Output correct texture read/write access by marking whether textures
are read from and written to by the shader.
Override bitcast_glsl_op() to use Metal as_type<type> functions.
Add implementations of SPIR-V functions inverse(), degrees() & radians().
Map inverseSqrt() to rsqrt().
Map roundEven() to rint().
GLSL functions imageSize() and textureSize() map to equivalent
expression using MSL get_width() & get_height() functions.
Map several SPIR-V integer bitfield functions to MSL equivalents.
Map SPIR-V atomic functions to MSL equivalents.
Map texture packing and unpacking functions to MSL equivalents.
Refactor existing, and add new, image query functions.
Reorganize header lines into includes and pragmas.
Simplify type_to_glsl() logic.
Add MSL test case vert/functions.vert for added function implementations.
Add MSL test case comp/atomic.comp for added function implementations.
test_shaders.py use macOS compilation for MSL shader compilation validations.
CompilerMSL accesses options using same design pattern as CompilerGLSL and CompilerHLSL.
CompilerMSL support setting VA & rez binding specs via either constructor or compile() method overload.
CompilerMSL support single UBO packing and padding in single pass.
spriv_cross app (main.cpp) supports turning off UBO packing and padding via command line option.
Add MSL UBO alignment test shader.
In some cases, the compiler decided to emit continue block first,
which invalidated the expressions used by the condition.
Parameters to functions can be evaluated in any order which caused
"random" behavior.
Add to suite of MSL tests and references any existing GLSL tests
that successfully convert GLSL->SPIRV->MSL and compile as MSL.
test_shaders_helper() ignores hidden files that start with '.',
to avoid accidentally finding hidden OSX files such as .DS_Store.
Use xcrun to compile MSL shaders instead of hard-coded path to Metal compiler.
Wrap calls to xcrun in exception handling to ignore if Xcode not installed.
For MSL tests, move call to validate_shader_msl() to after call to
regression_check() to allow a converted MSL shader to be saved for
manual review even if it doesn't successfully compile as MSL.
If we run on a system with Xcode installed to a default path, run Xcode
Metal shader compiler to validate the generated MSL shader.
This uncovers an issue in the existing MSL test - MSL backend currently
does not auto-assign attribute locations, which means that translating
GLSL shader without location layout produces an invalid MSL which
generates "error: 'attribute' index '0' is used more than once".
