Fix a compiler bug related to a catch-less try-finally statement.
Ensure a dead basic block produced in this case is properly
removed.
Change-Id: I7c88e26aaa6c6378892f7c7c299494fa42312db2
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 7584f1b..ba4dccf 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -30,6 +30,36 @@
VisitBlockForBackEdges(entry_block_, visited, &visiting);
}
+static void RemoveAsUser(HInstruction* instruction) {
+ for (size_t i = 0; i < instruction->InputCount(); i++) {
+ instruction->InputAt(i)->RemoveUser(instruction, i);
+ }
+
+ HEnvironment* environment = instruction->GetEnvironment();
+ if (environment != nullptr) {
+ for (size_t i = 0, e = environment->Size(); i < e; ++i) {
+ HInstruction* vreg = environment->GetInstructionAt(i);
+ if (vreg != nullptr) {
+ vreg->RemoveEnvironmentUser(environment, i);
+ }
+ }
+ }
+}
+
+void HGraph::RemoveInstructionsAsUsersFromDeadBlocks(const ArenaBitVector& visited) const {
+ for (size_t i = 0; i < blocks_.Size(); ++i) {
+ if (!visited.IsBitSet(i)) {
+ HBasicBlock* block = blocks_.Get(i);
+ for (HInstructionIterator it(block->GetPhis()); !it.Done(); it.Advance()) {
+ RemoveAsUser(it.Current());
+ }
+ for (HInstructionIterator it(block->GetInstructions()); !it.Done(); it.Advance()) {
+ RemoveAsUser(it.Current());
+ }
+ }
+ }
+}
+
void HGraph::RemoveDeadBlocks(const ArenaBitVector& visited) const {
for (size_t i = 0; i < blocks_.Size(); ++i) {
if (!visited.IsBitSet(i)) {
@@ -72,16 +102,21 @@
// (1) Find the back edges in the graph doing a DFS traversal.
FindBackEdges(&visited);
- // (2) Remove blocks not visited during the initial DFS.
- // Step (3) requires dead blocks to be removed from the
+ // (2) Remove instructions and phis from blocks not visited during
+ // the initial DFS as users from other instructions, so that
+ // users can be safely removed before uses later.
+ RemoveInstructionsAsUsersFromDeadBlocks(visited);
+
+ // (3) Remove blocks not visited during the initial DFS.
+ // Step (4) requires dead blocks to be removed from the
// predecessors list of live blocks.
RemoveDeadBlocks(visited);
- // (3) Simplify the CFG now, so that we don't need to recompute
+ // (4) Simplify the CFG now, so that we don't need to recompute
// dominators and the reverse post order.
SimplifyCFG();
- // (4) Compute the immediate dominator of each block. We visit
+ // (5) Compute the immediate dominator of each block. We visit
// the successors of a block only when all its forward branches
// have been processed.
GrowableArray<size_t> visits(arena_, blocks_.Size());
@@ -391,19 +426,7 @@
instruction->SetBlock(nullptr);
instruction_list->RemoveInstruction(instruction);
- for (size_t i = 0; i < instruction->InputCount(); i++) {
- instruction->InputAt(i)->RemoveUser(instruction, i);
- }
-
- HEnvironment* environment = instruction->GetEnvironment();
- if (environment != nullptr) {
- for (size_t i = 0, e = environment->Size(); i < e; ++i) {
- HInstruction* vreg = environment->GetInstructionAt(i);
- if (vreg != nullptr) {
- vreg->RemoveEnvironmentUser(environment, i);
- }
- }
- }
+ RemoveAsUser(instruction);
}
void HBasicBlock::RemoveInstruction(HInstruction* instruction) {
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 9d0b4a9..0054d25 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -173,6 +173,7 @@
void VisitBlockForBackEdges(HBasicBlock* block,
ArenaBitVector* visited,
ArenaBitVector* visiting);
+ void RemoveInstructionsAsUsersFromDeadBlocks(const ArenaBitVector& visited) const;
void RemoveDeadBlocks(const ArenaBitVector& visited) const;
ArenaAllocator* const arena_;