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.
The following changes are introduced:
1. Entry block might have more than one predecessor, even if it is not
a selection/loop merge block. However Apply method asserts that
there is only one predecessor. Now, IsApplicable method ensures
that there is only one predecessor.
2. In fuzzer pass we exclude both loop headers and selection headers
as potential exit blocks.
Fixes#3827.
Before this change, the replayer would return a SPIR-V binary. This
did not allow further transforming the resulting module: it would need
to be re-parsed, and the transformation context arising from the
replayed transformations was not available. This change makes it so
that after replay an IR context and transformation context are
returned instead; the IR context can subsequently be turned into a
binary if desired.
This change paves the way for an upcoming PR to integrate spirv-reduce
with the spirv-fuzz shrinker.
TransformationContext now holds a std::unique_ptr to a FactManager,
rather than a plain pointer. This makes it easier for clients of
TransformationContext to work with heap-allocated instances of
TransformationContext, which is needed in some upcoming work.
This transformation, given a constant integer (scalar or vector) C,
constants I and S of compatible type and scalar 32-bit integer constant
N, such that C = I - S*N, adds a loop which subtracts S from I, N
times, creating a synonym for C.
The related fuzzer pass randomly chooses constants to which to add
synonyms using this transformation, and the location where they should
be added.
Fixes#3616.
In preparation for some upcoming work on the shrinker, this PR changes
the interfaces of Fuzzer, Replayer and Shrinker so that all data
relevant to each class is provided on construction, meaning that the
"Run" method can become a zero-argument method that returns a status,
transformed binary and sequence of applied transformations via a
struct.
This makes greater use of fields, so that -- especially in Fuzzer --
there is a lot less parameter passing.
This change introduces various strategies for controlling the manner
in which fuzzer passes are applied repeatedly, including infrastructure
to allow fuzzer passes to be recommended based on which passes ran
previously.
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.
Introduces two changes:
- duplicated_exit_region refers to a correct block, regardless of the order
of the blocks in the enclosing function.
- Exclude the case where the continue target is the exit block.
This PR implements part of the add bit instruction synonym transformation.
For now, the implementation covers the OpBitwiseOr, OpBitwiseXor and
OpBitwiseAnd cases.
This PR changes the fact manager so that, when calling some of the
functions in submanagers, passes references to other submanagers if
necessary (e.g. to make consistency checks).
In particular:
- DataSynonymAndIdEquationFacts is passed to the AddFactIdIsIrrelevant
function of IrrelevantValueFacts
- IrrelevantValueFacts is passed to the AddFact functions of
DataSynonymAndIdEquationFacts
The IRContext is also passed when necessary and the calls to the
corresponding functions in FactManager were updated to be valid and
always use an updated context.
Fixes#3550.
This transformation, given the header of a selection construct with
branching instruction OpBranchConditional, flattens it.
Side-effecting operations such as OpLoad, OpStore and OpFunctionCall
are enclosed within smaller conditionals.
It is applicable if the construct does not contain inner selection
constructs or loops, or atomic or barrier instructions.
The corresponding fuzzer pass looks for selection headers and
tries to flatten them.
Needed for the issue #3544, but it does not fix it completely.
Adds a transformation that inserts a conditional statement with a
boolean expression of arbitrary value and duplicates a given
single-entry, single-exit region, so that it is present in each
conditional branch and will be executed regardless of which branch will
be taken.
Fixes#3614.
This transformation takes an OpSelect instruction and replaces it with
a conditional branch, selecting the correct value using an OpPhi
instruction.
Fixes part of the issue #3544.
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.
This transformation takes the id of an OpPhi instruction, of a dead
predecessor of the block containing it and a replacement id of
available to use and of the same type as the OpPhi, and changes
the id in the OpPhi corresponding to the given predecessor.
For example, %id = OpPhi %type %v1 %p1 %v2 %p2
becomes %id = OpPhi %type %v3 %p1 %v2 %p2
if the transformation is given %id, %p1 and %v3, %p1 is a dead block,
%v3 is type type and it is available to use at the end of %p1.
The fuzzer pass randomly decides to apply the transformation to OpPhi
instructions for which at least one of the predecessors is dead
Fixes#3726.
A transformation that replaces the use of an irrelevant id with
another id of the same type.
The related fuzzer pass, for every use of an irrelevant id,
checks whether the id can be replaced in that use by another
id of the same type and randomly decides whether to replace
it.
Fixes#3503.
This PR extends CallGraph with functions to return:
- a list of functions in lexicographical order, with respect to
function calls
- the maximum loop nesting depth that a function can be called from
(computed interprocedurally, e.g. if foo() calls bar() at depth 2
and bar() calls baz() at depth 1, the maximum depth of baz() will
be 3).
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 .
This change adds the notion of "overflow ids", which can be used
during shrinking to facilitate applying transformations that would
otherwise have become inapplicable due to earlier transformations
being removed.
Adds FuzzerPassAddCompositeInserts, which randomly adds new
OpCompositeInsert instructions. Each OpCompositeInsert instruction
yields a copy of an original composite with one subcomponent replaced
with an existing or newly added object. Synonym facts are added for the
unchanged components in the original and added composite, and for the
replaced subcomponent and the object, if possible.
Fixes#2859
For FuzzerPassAddParameters, adds pointer types (that have the storage
class Function or Private) to the pool of available types for new
parameters. If there are no variables of the chosen pointer type, it
invokes TransformationAddLocalVariable / TransformationAddGlobalVariable
to add one.
Part of #3403
`TransformationAddDeadBlock` did not check whether the existing block
(that will become a selection header) dominates its successor block (that
will become its merge block).
This change adds the check.
Fixes#3690.
Improves the code coverage of tests for the following transformations:
1. TransformationAddRelaxedDecoration
2. TransformationReplaceCopyMemoryWithLoadStore
3. TransformationReplaceCopyObjectWithStoreLoad
4. TransformationReplaceLoadStoreWithCopyMemory
5. TransformationReplaceAddSubMulWithCarryingExtended
Support identical predecessors in TransformationPropagateInstructionUp.
A basic block may have multiple identical predecessors as follows:
%1 = OpLabel
OpSelectionMerge %2 None
OpBranchConditional %true %2 %2
%2 = OpLabel
...
This case wasn't supported before.
`TransformationAddTypeFloat` and `TransformationAddTypeInt` did not check whether the required capabilities were present when adding 16-bit, 64-bit, and 8-bit types.
This change adds these checks in the `IsApplicable` method of each transformation.
Fixes#3669.
`TransformationReplaceIdWithSynonym` is careful to avoid replacing id uses that index into a struct with synonyms because the indices must only be `OpConstant` instructions. However, the check only considered `OpAccessChain` instructions, even though the same restriction applies to `OpInBoundsAccessChain`, `OpPtrAccessChain`, etc.
This change extends the check to include all access chain instructions.
Fixes#3671.
Given an instruction (that may use an OpPhi result from the same block as an input operand), try to clone the instruction into each predecessor block, replacing the input operand with the corresponding OpPhi input operand in each case, if necessary.
Fixes#3458.
Replaces OpIAdd with OpIAddCarry, OpISub with OpISubBorrow, OpIMul with
OpUMulExtended or OpSMulExtended and stores the result into a fresh_id
representing a structure. Extracts the first element of the result into
the original result_id. This value is the same as the result of the
original instruction.
Fixes#3577
This PR changes FuzzerPassOutlineFunctions so that it uses some
transformation that make the TransformationOutlineFunction
transformation applicable in more cases. See the discussion in
#3095 for more details.
Fixes#3095.
