Mainly in order to not waste time compile-testing the same version
more than once [as we do with e.g. the d3d11 and d3d12 runners, or
d3d12, GL, and Vulkan].
When a shader fails to compile for a range of versions, we want to validate that
we are correctly implementing that behaviour. E.g. if a feature requires shader
model 5.0, we should validate that it compiles correctly with 5.0 (which we do),
but also that it *fails* to compile with 4.1 (which we do not).
The obvious and simple solution is to simply run compile tests for each version.
There are, however, at least 12 versions of HLSL up to and including 6.0, at
least 10 of which are known to introduce new features. Shader compilation takes
about 10-15% of the time that draw and dispatch does, both for native and
(currently) vkd3d. Testing every version for every shader would add a
noticeable amount of time to the tests.
In practice, the interesting versions to test for most shaders are:
* At least one from each range 1-3, 4-5, and 6. It's common enough for the
semantics of the HLSL to differ between bytecode formats, or for features to
be added or removed across those boundaries.
* If the shader requires a given feature, we want to test both sides of the cusp
to ensure we're requiring the same version for the feature.
In practice this is 3 or 4 versions, which is measurably less than the 12 we'd
otherwise be running.
In order to achieve this goal of testing only the 3 or 4 interesting versions
for a shader, we need to know what version is actually required for a feature.
This is encoded in the shader itself using e.g. [pixel shader fail(sm<5)].
This patch therefore implements the first step towards this goal, namely,
determining which versions succeed and fail, so we can figure out which ones are
interesting.
We could require the test writer to specify which versions are interesting ahead
of time (e.g. "for version in 2.0 4.1 5.0 6.0") but this is both redundant (and
there are a *lot* of tests that need some feature gate) and easy for a test
writer to get wrong by missing interesting versions.
We normalize binary expressions by attempting to group constants
together, in order to facilitate further simplification of the
expressions.
For any binary operator OP, non-constants x, y, and constants a, b, we
apply the following rewrite rules:
a OP x -> x OP a, if OP is commutative.
(x OP a) OP b -> x OP (a OP b), if OP is associative.
(x OP a) OP y -> (x OP y) OP a, if OP is associative and commutative.
x OP (y OP a) -> (x OP y) OP a, if OP is associative.
Note that we consider floating point operations to be
non-associative.
The combined sampler is created as a SAMPLER instead of a TEXTURE
because that fits all our current infrastructure. The only problem is
that in the CTAB it must appear as a Texture, so the new field
hlsl_type.is_combined_sampler is added.
Co-authored-by: Elizabeth Figura <zfigura@codeweavers.com>
Some test programs, particularly the shader runner, are built from
many different files nowadays, and a line number is relatively
cumbersome to use if you don't know which file that line comes from.
These are redundant either because we already have a broader tag like
"sm<6", or because the tests are never executed with the GLSL runner in
the first place.
