Adds a new transformation that rewrites a scalar operation (like
OpFAdd, opISub) as an equivalent vector operation, adding a synonym
between the scalar result and an appropriate component of the vector
result.
Fixes#4195.
The following implementations are introduced:
- Transformation and fuzzer pass for expanding vector reduction.
- Unit tests to cover the instructions with different vector sizes.
Fixes#3768.
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.
This PR implements part of the add bit instruction synonym transformation.
For now, the implementation covers the OpBitwiseOr, OpBitwiseXor and
OpBitwiseAnd cases.
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.
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.
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 .
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
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 introduces TransformationAddLoopPreheader, which, given
a loop header and enough fresh ids, adds a loop preheader, updating
all the references so that this new block is the only out-of-loop
predecessor of the header, which branches unconditionally to the
header.
See the discussion in #3095.
Adds a transformation that takes a pair of instruction descriptors to
OpLoad and OpStore that have the same intermediate value and replaces
the OpStore with an equivalent OpCopyMemory.
Fixes#3353.
Adds a transformation that replaces instruction OpCopyMemory with
loading the source variable to an intermediate value and storing this
value into the target variable of the original OpCopyMemory instruction.
Fixes#3352
Adds a transformation that replaces instruction OpCopyObject with
storing into a new variable and immediately loading this variable to
|result_id| of the original OpCopyObject instruction.
Fixes#3351.
Add TransformationAddRelaxedDecoration, which adds the RelaxedPrecision decoration to ids of numeric instructions (those yielding 32-bit ints or floats) in dead blocks.
Fixes#3502
In this PR, the classes that represent the adjust branch weights
transformation and fuzzer pass were implemented. This transformation
adjusts the branch weights of a OpBranchConditional instruction.
The fact manager maintains an equivalence relation on data descriptors
that tracks when one data descriptor could be used in place of
another. An algorithm to compute the closure of such facts allows
deducing new synonym facts from existing facts. E.g., for two 2D
vectors u and v it is known that u.x is synonymous with v.x and u.y is
synonymous with v.y, it can be deduced that u and v are synonymous.
The closure computation algorithm is very expensive if we get large
equivalence relations.
This change addresses this in three ways:
- The size of equivalence relations is reduced by limiting the extent
to which the components of a composite are recursively noted as
being equivalent, so that when we have large synonymous arrays we do
not record all array elements as being pairwise equivalent.
- When computing the closure of facts, equivalence classes above a
certain size are simply skipped (which can lead to missed facts)
- The closure computation is performed less frequently - it is invoked
explicitly before fuzzer passes that will benefit from data synonym
facts. A new transformation is used to control its invocation, so
that fuzzing and replaying do not get out of sync.
The change also tidies up the order in which some getters are declared
in FuzzerContext.
wangshi