mirror of
https://github.com/revng/revng
synced 2026-06-21 14:07:57 +00:00
Alessandro Di Federico
125 lines
3.7 KiB
C++
125 lines
3.7 KiB
C++
//
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// This file is distributed under the MIT License. See LICENSE.md for details.
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//
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#include "llvm/ADT/DepthFirstIterator.h"
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#include "llvm/ADT/GraphTraits.h"
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#include "llvm/ADT/PostOrderIterator.h"
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#include "llvm/ADT/STLExtras.h"
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#include "revng/ADT/FilteredGraphTraits.h"
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#include "DLAStep.h"
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namespace dla {
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using GT = llvm::GraphTraits<LayoutTypeSystemNode *>;
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static bool isInstanceAtOffset0(const GT::EdgeRef &E) {
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if (not isInstanceEdge(E))
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return false;
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return not E.second->getOffsetExpr().Offset;
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}
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using Instance0Graph = EdgeFilteredGraph<dla::LayoutTypeSystemNode *,
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isInstanceEdge>;
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using CInstance0Graph = EdgeFilteredGraph<const dla::LayoutTypeSystemNode *,
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isInstanceAtOffset0>;
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using Instance0Inverse = llvm::Inverse<Instance0Graph>;
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using CInstance0Inverse = llvm::Inverse<CInstance0Graph>;
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using DFVisitSet = llvm::df_iterator_default_set<const LayoutTypeSystemNode *,
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8>;
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static DFVisitSet getGrandParentsAtOffset0(const LayoutTypeSystemNode *N) {
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DFVisitSet Result;
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for ([[maybe_unused]] const auto *_ :
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llvm::depth_first_ext(CInstance0Inverse(N), Result))
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;
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return Result;
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}
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static DFVisitSet getChildrenAtOffset0(const LayoutTypeSystemNode *Parent) {
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DFVisitSet Children;
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const auto
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&Instance0SuccessorsRange = llvm::make_filter_range(Parent->Successors,
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isInstanceAtOffset0);
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for (const LayoutTypeSystemNode *Child :
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llvm::make_first_range(Instance0SuccessorsRange))
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Children.insert(Child);
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return Children;
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}
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static uint64_t getNumChildrenAtOffset0(const LayoutTypeSystemNode *Parent) {
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return getChildrenAtOffset0(Parent).size();
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}
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bool PushDownPointers::runOnTypeSystem(LayoutTypeSystem &TS) {
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bool Changed = false;
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if (VerifyLog.isEnabled())
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revng_assert(TS.verifyDAG());
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for (LayoutTypeSystemNode *Parent : llvm::nodes(&TS)) {
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if (isInstanceLeaf(Parent))
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continue;
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revng_assert(not isPointerNode(Parent));
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DFVisitSet GrandParentsAtOffset0 = getGrandParentsAtOffset0(Parent);
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llvm::SmallVector<LayoutTypeSystemNode *, 8> PointersToGrandParents;
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{
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llvm::SmallPtrSet<LayoutTypeSystemNode *, 8> Visited;
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for (LayoutTypeSystemNode *Child :
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llvm::make_first_range(Parent->Successors)) {
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for (LayoutTypeSystemNode *Pointer :
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llvm::post_order_ext(Child, Visited)) {
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if (not isPointerNode(Pointer))
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continue;
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revng_assert(Pointer->Successors.size() == 1);
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LayoutTypeSystemNode *Pointee = Pointer->Successors.begin()->first;
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if (Pointee != Parent and GrandParentsAtOffset0.count(Pointee))
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PointersToGrandParents.push_back(Pointer);
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}
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}
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}
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for (LayoutTypeSystemNode *Pointer : PointersToGrandParents) {
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revng_assert(isPointerNode(Pointer) and Pointer->Successors.size() == 1);
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auto PointerEdgeIt = Pointer->Successors.begin();
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LayoutTypeSystemNode *Pointee = PointerEdgeIt->first;
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LayoutTypeSystemNode *NewPointee = nullptr;
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DFVisitSet Visited = getChildrenAtOffset0(Parent);
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for (LayoutTypeSystemNode *N :
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llvm::depth_first_ext(Instance0Graph(Pointee), Visited)) {
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if (getNumChildrenAtOffset0(N) > 1) {
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NewPointee = N;
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break;
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}
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}
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if (not NewPointee)
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NewPointee = Parent;
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TS.eraseEdge(Pointer, PointerEdgeIt);
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TS.addPointerLink(Pointer, NewPointee);
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Changed = true;
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}
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}
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if (VerifyLog.isEnabled())
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revng_assert(TS.verifyDAG());
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return Changed;
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}
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} // end namespace dla
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