Commit Graph

7 Commits

Author SHA1 Message Date
Alastair Donaldson
fcb22ecf0f
spirv-fuzz: Report fresh ids in transformations (#3856)
Adds a virtual method, GetFreshIds(), to Transformation. Every
transformation uses this to indicate which ids in its protobuf message
are fresh ids. This means that when replaying a sequence of
transformations the replayer can obtain a smallest id that is not in
use by the module already and that will not be used by any
transformation by necessity. Ids greater than or equal to this id
can be used as overflow ids.

Fixes #3851.
2020-09-29 22:12:49 +01:00
Alastair Donaldson
8d4261bc44
spirv-fuzz: Introduce TransformationContext (#3272)
Some transformations (e.g. TransformationAddFunction) rely on running
the validator to decide whether the transformation is applicable.  A
recent change allowed spirv-fuzz to take validator options, to cater
for the case where a module should be considered valid under
particular conditions.  However, validation during the checking of
transformations had no access to these validator options.

This change introduced TransformationContext, which currently consists
of a fact manager and a set of validator options, but could in the
future have other fields corresponding to other objects that it is
useful to have access to when applying transformations.  Now, instead
of checking and applying transformations in the context of a
FactManager, a TransformationContext is used.  This gives access to
the fact manager as before, and also access to the validator options
when they are needed.
2020-04-02 15:54:46 +01:00
Alastair Donaldson
27238bcca0
spirv-fuzz: preserve some analyses when permuting blocks (#2918)
The performance of the fuzzer was unacceptable in the 'permute blocks'
transformation, due to dominator analysis being repeatedly invalidated
and recomputed.  This change preserves the dominator analysis,
together with the CFG analysis, when a block is moved down.
2019-09-26 10:56:43 +01:00
Alastair Donaldson
958f7e72a7
Employ the "swarm testing" idea in spirv-fuzz (#2890)
This change to spirv-fuzz uses ideas from "Swarm Testing" (Groce et al. 2012), so that a random subset of fuzzer passes are enabled. These passes are then applied repeatedly in a randomized fashion, with the aggression with which they are applied being randomly chosen per pass.

There is plenty of scope for refining the probabilities introduce in this change; this is just meant to be a reasonable first effort.
2019-09-23 16:29:19 +01:00
Alastair Donaldson
efde682369
Disallow movement of unreachable blocks. (#2700)
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.
2019-06-26 15:32:25 +01:00
Alastair Donaldson
dfcb5a1e10
Refactor fuzzer transformations (#2694)
Introduced abstract class for transformations, and refactored all transformations to inherit from this abstract class.
2019-06-25 20:49:46 +01:00
Alastair Donaldson
209ff0ce90
Add spirv-fuzz pass to permute blocks. (#2642)
The blocks within each function in the module will be permuted in a
randomized manner that respects dominance.
2019-05-31 09:59:06 +01:00