`DropMarkerCalls` used to take an `ArrayRef<StringRef>` as an argument,
however the `ArrayRef` was copied in a class field, leading to a
reference to a temporary array.
This commit switches from `ArrayRef` to `SmallVector`.
This commit improves the function isolation pass to fix references to
predecessor basic blocks in phi nodes.
The commit also improves handling of instruction operands to ensure no
unmapped Values are used.
The call to `exception_warning` in `support.c` is now performed
directly by the `raise_exception_helper` function defined in
`support.c`, so that we can avoid calling two different functions in the
translated and isolated module.
When loading a CSV, we sometimes need to mask part of the loaded
value. However, this happened also when the source and target types had
the same size, leading to complex code doing nothing.
This bug has been discovered due to a problem in i386: all the function
calls were identified as indirect.
Enhanced the `findReachableNodes` algorithm, with a new `StackSet`
parallel data structure which is used to quickly check if we are
encountering a node already on the visit stack.
Modified the `findReachableNodes` to include in the returned set of
nodes also nodes which are encountered on self loop paths and that
should consequently be included in this set.
Add a new dummy node as the source of each backedge found in the graph,
during the preprocessing.
This help in the semplification phase of the SCS, since the new dummy
node helps triggering merging of metaregions with have a non empty
intersection.
The new SCS merging criterion, checks that there are no abnormal
retreating nodes between SCS, meaning retreatings which exit from the
current SCS and do not point to the head of another SCS.
This kind of situation, if ignored could cause the introduction of some
cycles between outlined nodes and existing nodes, inserting new cycles
during the restructuring, which is a behavior which we aim to avoid.
When outlining nodes, we now include them in eventual parent metaregions
that included the nodes collapsed.
This should lead to minor duplication (as in the `cp` benchmark), since
we avoid duplicating two times nodes if also the external region causes
the first iteration outlining.
The method which computes the weight for a `BasicBlockNode` now relies
on a new `WeightTraits` which is specialized for `BasicBlock` and for
`DotNode`.
In this way, we can change the implementation of the `getWeight` method
without having to modify the implementation inside the `revng` project.
`CpuLoopFunctionPass` is a pass performing some changes to
`cpu_loop`. Among these, calls to `cpu_*_exec` are replaced with the
value of `exception_index`.
This commit does not directly loads it but computes its address as an
offset from `CPUState`. This commit goes in tandem with the
corresponding QEMU commit which provide `exception_index` as an offset
from `CPUState` instead than from `env`. All of this makes CSAA more
effective.
* Introduce `ShrinkInstructionOperandsPass`: a transformation shrinking
operands and the results of instructions if they are
zero/sign-extended immediately before and after the instruction.
* Introduce `ConstantRangeSet`: similar to `ConstantRange` but allows
disjoint ranges.
* Introduce `MaterializedValue`: a class that can represent a constant
value or a symbol plus offset pair.
* Introduce `DropHelperCallsPass`: a transformation removing calls to
helpers and replacing them with a function call reading the CSVs that
the helper reads and writing the CSVs that the helper writes
(according to CSAA).
* Introduce `DropRangeMetadataPass`: a transformation dropping the
`range` metadata, which, in certain situations, lowers the quality of
the results provided by `LazyValueInfo`.
* Introduce `AdvancedValueInfo`: an analysis exploiting results of
`LazyValueInfo` but collecting them as `ConstantRangeSet` with a
monotone framework. It produces `MaterializedValue`.
* Anticipate linking of helpers: `AVI` requires `CSAA`, which requires
helper functions to be linked in.
* Drop `--no-link`.
* Force x86-64 `DataLayout`.
* Reorganize harvesting to either collect simple literals or go with
(incremental) `AVI`.
* Drop `SET`, `OSRA`, the reaching definition analysis, the
`SimplifyComparisonsPass` and all the sumjump-related code: e now
clone `root`, optimize it and analyze it with `AVI`.
* Temporarily drop the `NoReturnAnalysis`.
* Link `libLLVMInstCombine`, `libLLVMCodeGen` and `libLLVMPasses`.
* Introduce tests for `AdvancedValueInfo`,
`ShrinkInstructionOperandsPass` and `ConstantRangeSet`.
* Fix test results.
* Add `llvm.bswap.i64` and `@pc` to the LLVM template module for unit
tests.
Any stack pointer value greater than or equal to the original one used
to be OK for stack analysis to recognize an instruction as a
return. This commit changes this policy by collecting the value of the
stack pointer on all the return points and, at the end, elect a final
stack pointer value. All non-compliant returns are marked a
`BranchType::BrokenReturn`. The function is now considered fake only if
all the return instructions agree on a specific value of the stack
pointer, and it's lower than the original one.
* Drop `BranchType::IndirectTail`.
* `s/BranchType::FunctionSummary/BranchType::RegularFunction/`.
A series of algorithms working on `llvm::GraphTraits`.
* `nodesBetween` computes the set of nodes on all the paths from a node
A to B.
* Factor out code to iterate over infinite loops into
`exitless_scc_range`.
* Introduce unit tests.
Let the user provide the list of the basic blocks to visit, in a
specific order. This is useful when the same graph has to be visited
multiple times to avoid having `MonotoneFramework` recompute the reverse
post order each time.
* Introduce `KeyContainer::compare` and drop the `getKey` method.
* Let users of ZipMapIterator specify a trait class instead of using the
default one.
* Handle SIGINT in children gracefully (`run` function).
* `run_translate`: return 0 on success.
* Move useful information about the `revng` installation from
`--version` to `--help`.
* Do not `execv` on external commands, otherwise the script will not
proceed.
* Print current directory-relative paths with `--verbose`.
To release memory of a `PTCInstructionList`, we used to call
`ptc_instruction_list_free` only. However, that function does not
release memory. This commit calls `delete` to actually release the
memory and prevent memory from leaking.
We know keep updated the RPOT during node removals (otherwise we have
situation of pointer clashes) instead of recomputing it at each
metaregion restructuring iteration.
CPUStateAccessAnalysisPass can now run lazily and accumulate partial
results. Actual fixes to the accesses to the CPU State (to make them
explicit) are only applied when the analysis is run in non-lazy mode.
* `GeneratedCodeBasicInfo::getCSVUsedByHelperCall` and
`GeneratedCodeBasicInfo::extractCSVs`: make the call argument an
`Instruction`.
* Introduce `blockByName`
* Introduce `getUniqueUser`.
* Fix linking issues.
Implement a new `getWeight` method for the `BasicBlockNode` class.
This method is later used in the `untangle` pass to obtain an estimate
of the weight in terms of original instructions of the node under
analysis.
In case of a collapsed node the method recursively explore all the
collapsed region and return the sum of the weights of the nodes
composing the collapsed region.
Improve the computation of the weight for the nodes between the
immediate postdominator and all the exits from the region.
To do this we exploit the `findReachableNodes` helper function, since at
this point all the exits from the region are connected to the `Sink`
node.
Alessandro Di Federico