The previous logic for detection of incompatible PHINodes was broken in
various different ways.
1. `return true` and `return false` were flipped, so it effectively did
the opposite of what it was expected to do
2. `std::numeri_limits<Value *>::max()` yielded 0, breaking the lookup.
This commit fixes the condition for incompatible PHINodes and adds a lot
of logging.
Before this commit, the code never put in the same group two PHINodes if
one of them had a non-phi User. This condition was wrong and was
unnecessarily preventing valig PHINodes to be put in the same group.
This caused the generation of a lot more local variables than necessary.
Before this commit we were replacing all uses of a PHI that were not
used by other PHIs with llvm::UndefValue. That was wrong. The
replacement is valid only if the use is used by a PHINode that is in the
same group. This commit fixes the condition for such a replacement to
take place.
Replace the stable_sort that ordered (block, value) entries by raw
BasicBlock* address in getIncomingUsesOfValuesFromBlocks with a
MapVector that groups entries by block in first-encountered
insertion order, and add a per-block stable_sort by use count
(descending). Same-block contiguity is now structural rather than
enforced by a sort, and the order in which the split basic blocks
are created and appended to the function no longer depends on
pointer values that vary across runs. The within-block ordering,
the use-count tie-breaking, and the rest of the edge-splitting
algorithm are preserved.
Before this commit, the insertion point for load instructions was being
set before a PHINode, causing the IR to temporarily fail verification.
The effect of this logic bug did not propagate outside the pass, because
all PHINodes are removed at the end of the pass, but it made debugging
harder.
This commit fixes the problem by always setting the insert point after
all the PHINodes.
* Make the following private headers public:
* Lift/CPUStateAccessAnalysisPass.h
* Lift/CSVOffsets.h
* Lift/PTCDump.h
* Lift/VariableManager.h
* Move from revngSupport to revngLift:
* IRAnnotators.{h,cpp}
* SelfReferencingDbgAnnotationWriter.{h,cpp}
* Move from revngSupport to revngModel:
* FunctionTags.{h,cpp}
* ProgramCounterHandler.{h,cpp}
* Move from revngSupport to revngRecompile:
* OriginalAssemblyAnnotationWriter.{h,cpp}
Before this commit, many passes in revng-c were skipping over
non-isolated functions.
Now revng-pipeline takes care of removing non-isolated functions so that
check can be omitted everywhere.
This commits changes the ExitSSAPass to ensure that StoreInst are placed
ASAP, close to the computation of the incoming Values of the replaced
PHINode.
This generates IR that typically yields less local variables in
SwitchToStatements.
Pietro Fezzardi