Turns out we are not doing this correctly in SM1, because the rounding
should be to the number that is closer to zero and lower_casts_to_int()
doesn't do that.
A vertex shader test is added since in SM1 they must rely on the SLT
operation instead of the CMP operation.
fxc compiles this method even without the backcompat option.
Furthermore, it even does it on ps_2_0 despite the fact that it maps to
a texldd instruction, which is not available on plain ps_2_0, nor ps_2_b,
only on ps_2_a and ps_3_0 according to documentation.
It is worth mentioning that the additional offset parameter is not
supported when lowering.
Otherwise ubsan reports these errors on the bitwise.shader_test:
libs/vkd3d-shader/hlsl_constant_ops.c:970:50: runtime error: left shift of 1 by 31 places cannot be represented in type 'int'
libs/vkd3d-shader/hlsl_constant_ops.c:970:50: runtime error: left shift of negative value -12
We apply distributivity to applicable expressions, specifically with
the following rewrite rules:
(x OPL a) OPR (x OPL b) -> x OPL (a OPR b)
(y OPR (x OPL a)) OPR (x OPL b) -> y OPR (x OPL (a OPR b))
((x OPL a) OPR y) OPR (x OPL b) -> (x OPL (a OPR b)) OPR y
(x OPL a) OPR ((x OPL b) OPR y) -> (x OPL (a OPR b)) OPR y
(x OPL a) OPR (y OPR (x OPL b)) -> (x OPL (a OPR b)) OPR y
where a, b are constants.
Like we did before commit 067e6deee4aba447c6627ce02b58c6bdcd90470e.
These skips aren't all that interesting; it's entirely intentional that
e.g. a 2.0-3.0 run wouldn't run 4.0 shaders.
Adjust the algorithm for deciding for which profiles to test compilation.
We first ensure that if the compilation result changes (most often as the result
of a feature introduced in a specific version), we test the versions immediately
on either side of the change, to validate that vkd3d-shader is emulating the
same version behaviour.
We then ensure that we are testing at least one version from each set of sm1,
sm4, and sm6.
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.
