Because dominance information becomes a bit unreliable when blocks are
unreachable, this change makes it so that the 'dead break'
transformation will not introduce a break to an unreachable block.
Fixes#2907.
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.
This change introduces a robust check for whether an index in an
access chain is indexing into a struct, in which case the index needs
to be an OpConstant and cannot be replaced with a synonym.
Fixes#2906.
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.
Before this change, spirv-fuzz would replace a pointer argument to a
function call with a synonym, which is problematic when the synonym is
not a memory object declaration, since function call arguments are
required to be memory object declarations. This change adds a check
to ensure that such a replacement is not made.
Fixes#2896.
Before this change, spirv-fuzz would replace a constant boolean
argument to an OpPhi with the result of a binary operation, inserting
the instruction to compute the binary operation right before the
OpPhi, leading to an invalid module. This change conservatively
disallows replacing OpPhi arguments. Issue #2902 notes that there is
scope for being less conservative.
Fixes#2897.
* Handle extract with no indexes
It is possible that OpCompositeExtract instructions will not have any
indexes. This is not handled well by scalar replacement and instruction
folding.
Fixes https://crbug.com/1006435
* Fix typo.
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.
* Use OpReturn* in wrap-opkill
The warp-opkill pass is generating incorrect code. It is placing an
OpUnreachable at the end of a basic block, when the block can be
reached. We can't reach the end of the block, but we can reach the end.
Instead we will add a return instruction.
Fixes#2875.
To aid in debugging issues in spirv-fuzz, this change adds an option whereby the SPIR-V module is validated after each transformation is applied during replay. This can assist in finding a transformation that erroneously makes the module invalid, so that said transformation can be debugged.
The warp-opkill pass is generating incorrect code. It is placing an
OpUnreachable at the end of a basic block, when the block can be
reached. We can't reach the end of the block, but we can reach the end.
Instead we will add a return instruction.
Fixes#2875.
Many of the places in copy propagate arrays assumes that integer constant will be defined by an OpConstant instruction. That is not always true. We fix these spots by allowing for an OpConstantNull.
spirv-fuzz generates protobuf sources in a 'protobuf' directory. When
building with Unix Makefiles, compilation would fail due to to this
directory not existing. This change causes the directory to be
created when the build is prepared.
If the fuzzer's fact manager knows that ids A and B are synonymous, it
can replace a use of A with a use of B, so long as various conditions
hold (e.g. the definition of B must dominate the use of A, and it is
not legal to replace a use of an OpConstant in a struct's access chain
with a synonym that is not an OpConstant).
This change adds a fuzzer pass to sprinke such synonym replacements
through the module.
* When input or result is a pointer type also allow 32-bit integer
vectors for the other type
* Relaxation only applies to SPIR-V 1.5 or in the presence of
SPV_KHR_physical_storage_buffer
* new tests
* Vulkan specific checks
* storage buffer variables must be structs or arrays of structs
* storage buffer struct must be Block decorated
* uniform struct must be Block or BufferBlock decorated
* new tests
* Ensure same enum values have consistent extension lists
* val: fix checking of capabilities
The operand for an OpCapability should only be
checked for the extension or core version.
The InstructionPass registers a capability, and all its implied
sub-capabilities before actually checking the operand to an
OpCapability.
* Add basic support for SPIR-V 1.5
- Adds SPV_ENV_UNIVERSAL_1_5
- Command line tools default to spv1.5 environment
- SPIR-V 1.5 incorporates several extensions. Now the disassembler
prefers outputing the non-EXT or non-KHR names. This requires
updates to many tests, to make strings match again.
- Command line tests: Expect SPIR-V 1.5 by default
* Test validation of SPIR-V 1.5 incorporated extensions
Starting with 1.5, incorporated features no longer require
the associated OpExtension instruction.
A new fuzzer pass that randomly introduces OpCopyObject instructions
that make copies of ids, and uses the fact manager to record the fact
that an id %id is synonymous with an id generated by an OpCopyObject
applied to %id. (A future pass will exploit such synonym facts.)
If an OpKill instruction is inlined into a continue construct, then the
spir-v is no longer valid. To avoid this issue, we do inline into an
OpKill at all. This method was chosen because it is difficult to keep
track of whether or not you are in a continue construct while changing
the function that is being inlined into. This will work well with wrap
OpKill because every will still be inlined except for the OpKill
instruction itself.
Fixes#2554Fixes#2433
This reverts commit aa9e8f5380.
Before this change there was quite a lot of duplication in the code
being used to choose random percentages, and some of it was incorrect
so that a percentage chance of (100-N)% instead of N% was being used.
Also there was a lot of duplicate code to choose a random index into a
vector. This change eliminates that duplication (fixing up the
percentage problem), and gets rid of direct access to the random
number generator being used for fuzzing, so that all randomization
requests must go through the FuzzerContext class, discouraging future
ad-hoc uses of the random number generator.
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.
* Handle id overflow in the ssa rewriter.
Remove LocalSSAElim pass at the same time. It does the same thing as the SSARewrite pass. Then even share almost all of the same code.
Fixes crbug.com/997246
As far as I know, it is legal to have multiple decoration adding the
same decoration to the same id. The validator registers all of these
decoration as if they were distinct decorations. This can cause poor
memory usage and performance in some cases.
This fix is to make sure that duplicates are not registers.
I keep the type of the decoration list as an std::vector because I
expect it to be small enough in most cases that the linear search will
still be faster that using some type of map.
No tests are added because we do not have a mechanism to test memory
usage in our unit tests.
Fixes#2837. The total memory usage drop to 14,236KB.
The first pass applies the RelaxedPrecision decoration to all executable
instructions with float32 based type results. The second pass converts
all executable instructions with RelaxedPrecision result to the equivalent
float16 type, inserting converts where necessary.
