Dead branch elimination needs to know about the constructs that a block is contained it when determining what to do with its merge instruction. We currently fold branches in block as we see them, which is parent constructs before their children. This causes the struct cfg analysis to crash because it tries to get the parent construct for a block after the parent has been folded.
This can be fixed by folding the branch of the children before the parents.
Fixes#2667.
There are a couple spots where we are not looking at decorations when we should.
1. Value numbering is suppose to assign a different value number to ids if they have different decorations. However that is not being done for OpCopyObject and OpPhi.
1. Instruction simplification is propagating OpCopyObject instruction without checking for decorations. It should only do that if no decorations are being lost.
Add a new function to the decoration manager to check if the decorations of one id are a subset of the decorations of another.
Fixes#2715.
Fixes#2669
* Check capabilities when validating variables
* validate load and store types
* Constant check
* Don't checks pointers for stores, constants and loads
* Validate composite instructions
* Validate conversions for 8- and 16-bit limited types
* Unified tests and expanded them
* Disallow OpCopyMemory
* new tests and update old tests
Adds to spirv-fuzz the option to shrink a sequence of transformations
that lead to an interesting binary to be generated, to find a smaller
sub-sequence of transformations that still lead to an interesting (but
hopefully simpler) binary being generated. The notion of what counts
as "interesting" comes from a user-provided script, the
"interestingness function", similar to the way the spirv-reduce tool
works. The shrinking process will give up after a maximum number of
steps, which can be configured on the command line.
Tests for the combination of fuzzing and shrinking are included, using
a variety of interestingness functions.
Inlining does not inline functions that have a single return that is in a loop. This is because the return cannot be replaced by a branch outside of the loop easily. Merge return knows how to rewrite the function so the return is replaced by a branch.
Fixes#2038.
It is illegal to inline an OpKill instruction into a continue construct because the continue header will no longer dominate the backedge.
This commit adds a check for this, and does not inline.
If we still want to be able to inline a function that contains an OpKill, we can add a new pass that will wrap OpKill instructions into its own function with just the single instruction.
I do not believe that this is a common case right now, so I will not do that yet.
Fixes#2433.
When working on descriptor indexing validation for compute shaders, the
gl_GlobalInvocationID builtin was being loaded as uint which would cause
compute shaders instrumented by the bindless check pass to have:
%83 = OpLoad %uint %gl_GlobalInvocationID
%84 = OpCompositeExtract %uint %83 0
%85 = OpCompositeExtract %uint %83 1
%86 = OpCompositeExtract %uint %83 2
which results in validation failures:
error: line 127: Reached non-composite type while indexes still remain
to be traversed.
%84 = OpCompositeExtract %uint %83 0
for trying to extract a uint from a uint.
Fixes#2695. Allowing unreachable blocks to be moved can lead to an
unreachable block A getting placed after an unreachable successor B,
which is a problem if B uses ids that A generates.
* Represent uniform facts via descriptor set and binding.
Previously uniform facts were expressed with resepect to the id of a
uniform variable. Describing them with respect to a descriptor set
and binding is more convenient from the point of view of expressing
facts about a shader without requiring analysis of its SPIR-V.
* Fix equality testing for uniform buffer element descriptors.
The equality test now checks that the lengths of the index vectors
match. Added a test that exposes the previous omission.
Adds a new transformation that can replace a constant with a uniform known to have the same value, and adds a fuzzer pass that (a) replaces a boolean with a comparison of literals (e.g. replacing "true" with "42 > 24"), and then (b) obfuscates the literals appearing in this comparison by replacing them with identically-valued uniforms, if available.
The fuzzer_replayer test file has also been updated to allow initial facts to be provided, and to do error checking of the status results returned by the fuzzer and replayer components.
* Can only be used with Vulkan memory model
* Can only be used with atomics
* Bit setting must match for compare exchange opcodes
* Updated memory semantics checks to allow constant instructions
generally with CooperativeMatrixNV
The replayer takes an existing sequence of transformations and applies
them to a module. Replaying a sequence of transformations that were
obtained via fuzzing should lead to an identical module to the module
that was fuzzed. Tests have been added to check for this.
Adds a new (and first) kind of fact to the fact manager, which is that
a specific uniform value is guaranteed to be equal to a specific
constant. The point of this is that such information (if known to be
true by some external source) can be used by spirv-fuzz to transform
the module in interesting ways that a static compiler cannot reverse
via compile-time analysis.
This change introduces protobuf messages for the fact, and adds
capabilities to the fact manager to store this kind of fact and
provide information about it.
The transformation can, for example, replace "true" with "12.0 > 6.0",
if constants for those floating-point values are available.
This introduces a new 'id use descriptor' structure, which provides a
way to describe a particular use of an id, and which will be heavily
used in future transformations. Describing an id use is trivial if
the use occurs in an instruction that itself generates an id, but is
less straightforward if the id of interest is used by an instruction
such as OpStore that does not have a result id. The 'id use
descriptor' structure caters for such cases.
Also add a Builtin test generator variant that takes
capabilities and extensions.
Tests
- verify that the SMCountNV, SMIDNV, WarpsPerSMNV, and WarpIDNV Builtins are
accepted as Inputs in Vertex, Fragment, TessControl, TessEval, Geometry,
and Compute.
- verify that the SMCountNV, SMIDNV, WarpsPerSMNV, and WarpIDNV Builtins are
accepted as Inputs in MeshNV and TaskNV shaders.
- verify that the SMCountNV, SMIDNV, WarpsPerSMNV, and WarpIDNV Builtins are
accepted as Inputs in the 6 ray tracing stages
- verify that the SMCountNV, SMIDNV, WarpsPerSMNV, and WarpIDNV Builtins are
NOT accepted as Outputs.
- verify that the SMCountNV, SMIDNV, WarpsPerSMNV, and WarpIDNV Builtins are
NOT accepted as non-scalar integers (f32, uvec3)
- verify that the SMCountNV, SMIDNV, WarpsPerSMNV, and WarpIDNV Builtins are
NOT accepted as non-32-bit integers (u64)
There turned out to be a bug in the 'split blocks' transformation due
to blocks being split while they were being iterated over. This
change fixes that issue, and adds tests that were able to expose the
issue by running the fuzzer on some example shaders.
When it's an OpConstant or OpSpecConstant, then the literal
values are compared. If the OpSpecConstant also has a SpecId
decoration, then that's also compared.
Otherwise, it's an OpSpecConstantOp and we only compare the
ID of the OpSpecConstantOp instruction itself.
Fixes#2649
This new pass adds some basic ingredients to a module on which future
passes are likely to depend, such as boolean constants and some
specfic integer and floating-point values. This is not a fuzzer pass
in the true sense in that it does not employ randomization, but it
makes sense to define it as a fuzzer pass since it is the first of a
number of transformations passes that the fuzzer will run on a module.
* Types: Avoid comparing IDs for in Type::IsSameImpl
When linking, we end up with duplicate types for imported and exported
types, that needs to be removed. The current code would reject valid
import/export pairs of symbols due to IDs mismatch, even if the types or
constants behind those ID were the same.
Enabled remaining type_match_test
Fixes#2442
New version has additional word in stage-specific section. Also
some changes in content for tesselation and compute shaders. Either
version can be invoked at pass creation. This is done to ease integration
and updating of validation layers. Version 1 is deprecated and eventually
will go away.
Also sneaking in fix to version 1 compute shaders.
With this pass, the fuzzer can split blocks in the input module. This
is mainly useful in order to give other (future) transformations more
opportunities to apply.
* Handle nested breaks from switches.
There was a recent decision made to allow branches to the merge node of
a switch even if the switch is not the first enclosing construct. They
can be generated by glslang from break statements in switches.
Dead branch elimination seems to be the only optimization that will
break because of this change, so I will update that optimizations.
The change made are:
- Track switches in structured cfg analysis.
- In Dead branch elimination:
- Look for nested breaks that will require a switch instruction.
- Rewrite, but don't delete, switchs that are required even if it
could be replaced by an unconditional branch.
- When looking for the first break, consider the merge of a switch
as well.
See #2612.
* Fix variable names and comments.
* Add tests for the struct cfg analysis and switches.
* Fix typos in comments.
This adds a number of tests that check that all types will match to
identically written clones during linking, including nearly every Type
and some combinations (e.g. Functions of Arrays of Floats). Intent is
for use with https://github.com/KhronosGroup/SPIRV-Tools/pull/2580,
however that PR focuses on issues with TypeArray whereas these tests are
(more) comprehensive and test more subtle (and possibly incorrect)
cases.
A number of these tests fail, many are fixed by the aforementioned PR.
Some additional tests involving TypeForwardPointer are currently
disabled as they cause assertion failures.
