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-rw-r--r--compiler/optimizing/licm.cc16
1 files changed, 16 insertions, 0 deletions
diff --git a/compiler/optimizing/licm.cc b/compiler/optimizing/licm.cc
index 02befc011a..a6b4078f46 100644
--- a/compiler/optimizing/licm.cc
+++ b/compiler/optimizing/licm.cc
@@ -94,6 +94,16 @@ void LICM::Run() {
SideEffects loop_effects = side_effects_.GetLoopEffects(block);
HBasicBlock* pre_header = loop_info->GetPreHeader();
+ bool contains_irreducible_loop = false;
+ if (graph_->HasIrreducibleLoops()) {
+ for (HBlocksInLoopIterator it_loop(*loop_info); !it_loop.Done(); it_loop.Advance()) {
+ if (it_loop.Current()->GetLoopInformation()->IsIrreducible()) {
+ contains_irreducible_loop = true;
+ break;
+ }
+ }
+ }
+
for (HBlocksInLoopIterator it_loop(*loop_info); !it_loop.Done(); it_loop.Advance()) {
HBasicBlock* inner = it_loop.Current();
DCHECK(inner->IsInLoop());
@@ -104,6 +114,12 @@ void LICM::Run() {
}
visited.SetBit(inner->GetBlockId());
+ if (contains_irreducible_loop) {
+ // We cannot licm in an irreducible loop, or in a natural loop containing an
+ // irreducible loop.
+ continue;
+ }
+
// We can move an instruction that can throw only if it is the first
// throwing instruction in the loop. Note that the first potentially
// throwing instruction encountered that is not hoisted stops this