Commit Graph

9 Commits

Author SHA1 Message Date
Alastair Donaldson
bed84792f9
spirv-fuzz: Call by value and move in transformations (#4208)
Adapts all transformation classes so that their protobuf message is
passed by value and then moved into the message_ field.
2021-03-23 13:31:44 +00:00
Vasyl Teliman
e6a9f4e430
spirv-fuzz: Fix the bug in TransformationReplaceBranchFromDeadBlockWithExit (#4140)
Fixes #4136.
2021-03-05 14:27:37 +00:00
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
Vasyl Teliman
a3b0adc306
spirv-fuzz: Add is_irrelevant parameter (#3563)
Part of #3177.
Adjusts functions to create constants.
2020-07-21 08:59:13 +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
983b5b4fcc
spirv-fuzz: Use validator to check break/continue dominance conditions (#3089)
The passes that add dead breaks and continues suffer from the
challenge that a new control flow graph edge can change dominance
information, leading to the potenital for definitions to no longer
dominate their uses.  The attempt at guarding against this was known
to be incomplete.  This change calls on the SPIR-V validator to do the
necessary checking: in deciding whether adding such an edge would be
legitimate, we clone the module, add the edge, and use the validator
to check whether the transformed clone is valid.

This strategy is heavy-weight, and should be used sparingly, but seems
like a good option when the validity of transformations is intricate,
to avoid reimplementing swathes of validation logic in the fuzzer.

Fixes #2919.
2019-12-06 16:38:17 +00:00
Alastair Donaldson
c1e03834e3
spirv-fuzz: Fixes to preconditions for adding dead break/continue edges (#2904)
Issues #2898 and #2900 identify some cases where adding a dead
continue would lead to an invalid module, and these turned out to be
due to the lack of sensible dominance information when a continue
target is unreachable. This change requires that the header of a loop
dominates the loop's continue target if a dead continue is to be
added.

Furthermore, issue #2905 identified a shortcoming in the algorithm
being used to identify when it is OK, from a dominance point of view,
to add a new break/continue edge to a control flow graph. This change
replaces that algorithm with a simpler and more obviously correct
algorithm (that incidentally does not require the new edge to be a
break/continue edge in particular).

Fixes #2898.
Fixes #2900.
Fixes #2905.
2019-09-25 16:51:41 +01:00
Alastair Donaldson
7ee8f443ea
Fix add-dead-break and add-dead-continue passes to respect dominance (#2838)
The implementation of these passes had overlooked the fact that adding
a new edge to a control flow graph can change dominance information.
Adding a dead break/continue risks causing uses to no longer be
dominated by their definitions.  This change introduces various tests
to expose such scenarios, and augments the preconditions for these
transformations with checks to guard against the situation.
2019-09-10 14:48:27 +01:00
Alastair Donaldson
1a89ac8b28
Transformation and fuzzer pass to add dead continues (#2758)
Similar to the existing 'add dead breaks' pass, this adds a pass to
add dead continues to blocks in loops where such a transformation is
viable.  Various functionality common to this new pass and 'add dead
breaks' has been factored into 'fuzzer_util', and some small
improvements to 'add dead breaks' that were identified while reviewing
that code again have been applied.

Fixes #2719.
2019-07-25 13:50:33 +01:00