diff options
Diffstat (limited to 'compiler/optimizing/nodes.cc')
| -rw-r--r-- | compiler/optimizing/nodes.cc | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc index 2d3dcf746b..7a8b463d13 100644 --- a/compiler/optimizing/nodes.cc +++ b/compiler/optimizing/nodes.cc @@ -383,19 +383,27 @@ void HGraph::ComputeTryBlockInformation() { } void HGraph::SimplifyCFG() { - // Simplify the CFG for future analysis, and code generation: +// Simplify the CFG for future analysis, and code generation: // (1): Split critical edges. - // (2): Simplify loops by having only one back edge, and one preheader. + // (2): Simplify loops by having only one preheader. // NOTE: We're appending new blocks inside the loop, so we need to use index because iterators // can be invalidated. We remember the initial size to avoid iterating over the new blocks. for (size_t block_id = 0u, end = blocks_.size(); block_id != end; ++block_id) { HBasicBlock* block = blocks_[block_id]; if (block == nullptr) continue; - if (block->NumberOfNormalSuccessors() > 1) { - for (size_t j = 0; j < block->GetSuccessors().size(); ++j) { + if (block->GetSuccessors().size() > 1) { + // Only split normal-flow edges. We cannot split exceptional edges as they + // are synthesized (approximate real control flow), and we do not need to + // anyway. Moves that would be inserted there are performed by the runtime. + for (size_t j = 0, e = block->NumberOfNormalSuccessors(); j < e; ++j) { HBasicBlock* successor = block->GetSuccessors()[j]; DCHECK(!successor->IsCatchBlock()); - if (successor->GetPredecessors().size() > 1) { + if (successor == exit_block_) { + // Throw->TryBoundary->Exit. Special case which we do not want to split + // because Goto->Exit is not allowed. + DCHECK(block->IsSingleTryBoundary()); + DCHECK(block->GetSinglePredecessor()->GetLastInstruction()->IsThrow()); + } else if (successor->GetPredecessors().size() > 1) { SplitCriticalEdge(block, successor); --j; } |