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| author | Alon Zakai <alonzakai@gmail.com> | 2017-09-25 14:36:32 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2017-09-25 14:36:32 -0700 |
| commit | c69253378014ffc451adf916d017d8f21faae77c (patch) | |
| tree | ade468593470d27672d6caed4057fee653c6b67d /src/passes/DeadCodeElimination.cpp | |
| parent | 23d015b159e6805022cfac1797030fbec42aa8d1 (diff) | |
| download | binaryen-c69253378014ffc451adf916d017d8f21faae77c.tar.gz binaryen-c69253378014ffc451adf916d017d8f21faae77c.tar.bz2 binaryen-c69253378014ffc451adf916d017d8f21faae77c.zip | |
fix dce bug with not updating the parent when turning a node unreachable (#1198)
Diffstat (limited to 'src/passes/DeadCodeElimination.cpp')
| -rw-r--r-- | src/passes/DeadCodeElimination.cpp | 43 |
1 files changed, 23 insertions, 20 deletions
diff --git a/src/passes/DeadCodeElimination.cpp b/src/passes/DeadCodeElimination.cpp index 5017569aa..bca898e25 100644 --- a/src/passes/DeadCodeElimination.cpp +++ b/src/passes/DeadCodeElimination.cpp @@ -48,6 +48,7 @@ struct DeadCodeElimination : public WalkerPass<PostWalker<DeadCodeElimination>> Expression* replaceCurrent(Expression* expression) { auto* old = getCurrent(); + if (old == expression) return expression; WalkerPass<PostWalker<DeadCodeElimination>>::replaceCurrent(expression); // also update the type updater typeUpdater.noteReplacement(old, expression); @@ -219,14 +220,17 @@ struct DeadCodeElimination : public WalkerPass<PostWalker<DeadCodeElimination>> } static void scan(DeadCodeElimination* self, Expression** currp) { + auto* curr = *currp; if (!self->reachable) { - // convert to an unreachable. do this without UB, even though we have no destructors on AST nodes + // convert to an unreachable safely #define DELEGATE(CLASS_TO_VISIT) { \ - self->typeUpdater.noteRecursiveRemoval(*currp); \ - ExpressionManipulator::convert<CLASS_TO_VISIT, Unreachable>(static_cast<CLASS_TO_VISIT*>(*currp)); \ + auto* parent = self->typeUpdater.parents[curr]; \ + self->typeUpdater.noteRecursiveRemoval(curr); \ + ExpressionManipulator::convert<CLASS_TO_VISIT, Unreachable>(static_cast<CLASS_TO_VISIT*>(curr)); \ + self->typeUpdater.noteAddition(curr, parent); \ break; \ } - switch ((*currp)->_id) { + switch (curr->_id) { case Expression::Id::BlockId: DELEGATE(Block); case Expression::Id::IfId: DELEGATE(If); case Expression::Id::LoopId: DELEGATE(Loop); @@ -256,7 +260,6 @@ struct DeadCodeElimination : public WalkerPass<PostWalker<DeadCodeElimination>> #undef DELEGATE return; } - auto* curr =* currp; if (curr->is<If>()) { self->pushTask(DeadCodeElimination::doVisitIf, currp); if (curr->cast<If>()->ifFalse) { @@ -328,18 +331,18 @@ struct DeadCodeElimination : public WalkerPass<PostWalker<DeadCodeElimination>> for (size_t i = 0; i < list.size(); ++i) { auto* elem = list[i]; if (isUnreachable(elem)) { - auto* replacement = elem; - if (i > 0) { - auto* block = getModule()->allocator.alloc<Block>(); - for (size_t j = 0; j < i; ++j) { - block->list.push_back(drop(list[j])); - } - block->list.push_back(list[i]); - block->finalize(type); - replacement = block; - } - replaceCurrent(replacement); - return; + auto* replacement = elem; + if (i > 0) { + auto* block = getModule()->allocator.alloc<Block>(); + for (size_t j = 0; j < i; ++j) { + block->list.push_back(drop(list[j])); + } + block->list.push_back(list[i]); + block->finalize(type); + replacement = block; + } + replaceCurrent(replacement); + return; } } } @@ -349,7 +352,7 @@ struct DeadCodeElimination : public WalkerPass<PostWalker<DeadCodeElimination>> } void visitLoad(Load* curr) { - blockifyReachableOperands({ curr->ptr}, curr->type); + blockifyReachableOperands({ curr->ptr }, curr->type); } void visitStore(Store* curr) { @@ -369,11 +372,11 @@ struct DeadCodeElimination : public WalkerPass<PostWalker<DeadCodeElimination>> } void visitBinary(Binary* curr) { - blockifyReachableOperands({ curr->left, curr->right}, curr->type); + blockifyReachableOperands({ curr->left, curr->right }, curr->type); } void visitSelect(Select* curr) { - blockifyReachableOperands({ curr->ifTrue, curr->ifFalse, curr->condition}, curr->type); + blockifyReachableOperands({ curr->ifTrue, curr->ifFalse, curr->condition }, curr->type); } void visitDrop(Drop* curr) { |