spirv-fuzz features transformations that should be applicable by
construction. Assertions are used to detect when such transformations
turn out to be inapplicable. Failures of such assertions indicate bugs
in the fuzzer. However, when using the fuzzer at scale (e.g. in
ClusterFuzz) reports of these assertion failures create noise, and
cause the fuzzer to exit early. This change adds an option whereby
inapplicable transformations can be ignored. This reduces noise and
allows fuzzing to continue even when a transformation that should be
applicable but is not has been erroneously created.
This PR modifies the FactManager methods IdIsIrrelevant and GetIrrelevantIds so
that an id is always considered irrelevant if it comes from a dead block.
Fixes#3733.
Pointer (if VariablePointers is enabled) to find sets of potential
synonyms.
However, some instructions with these types cannot be used in an OpPhi:
- OpFunction cannot be used as a value
- OpUndef should not be used, because it yields an undefined value for
each use
Fixes#3761.
A transformation that adds new OpPhi instructions to blocks with >=1
predecessors, so that its value depends on previously-defined ids of
the right type, which are all synonymous. This instruction is also
recorded as synonymous to the others.
The related fuzzer pass still needs to be implemented.
Fixes#3592 .
