3 files changed, 28 insertions, 8 deletions
diff --git a/compiler/optimizing/gvn.cc b/compiler/optimizing/gvn.cc
index 813772e9af..71c394ec1f 100644
--- a/compiler/optimizing/gvn.cc
+++ b/compiler/optimizing/gvn.cc
@@ -301,8 +301,11 @@ class ValueSet : public ArenaObject<kArenaAllocGvn> {
     // Pure instructions are put into odd buckets to speed up deletion. Note that in the
     // case of irreducible loops, we don't put pure instructions in odd buckets, as we
     // need to delete them when entering the loop.
-    if (instruction->GetSideEffects().HasDependencies() ||
-        instruction->GetBlock()->GetGraph()->HasIrreducibleLoops()) {
+    // ClinitCheck is treated as a pure instruction since it's only executed
+    // once.
+    bool pure = !instruction->GetSideEffects().HasDependencies() ||
+                instruction->IsClinitCheck();
+    if (!pure || instruction->GetBlock()->GetGraph()->HasIrreducibleLoops()) {
       return (hash_code << 1) | 0;
     } else {
       return (hash_code << 1) | 1;
diff --git a/compiler/optimizing/licm.cc b/compiler/optimizing/licm.cc
index 7af1a20f98..d3a0376e9c 100644
--- a/compiler/optimizing/licm.cc
+++ b/compiler/optimizing/licm.cc
@@ -129,10 +129,25 @@ void LICM::Run() {
            !inst_it.Done();
            inst_it.Advance()) {
         HInstruction* instruction = inst_it.Current();
-        if (instruction->CanBeMoved()
-            && (!instruction->CanThrow() || !found_first_non_hoisted_visible_instruction_in_loop)
-            && !instruction->GetSideEffects().MayDependOn(loop_effects)
-            && InputsAreDefinedBeforeLoop(instruction)) {
+        bool can_move = false;
+        if (instruction->CanBeMoved() && InputsAreDefinedBeforeLoop(instruction)) {
+          if (instruction->CanThrow()) {
+            if (!found_first_non_hoisted_visible_instruction_in_loop) {
+              DCHECK(instruction->GetBlock()->IsLoopHeader());
+              if (instruction->IsClinitCheck()) {
+                // clinit is only done once, and since all visible instructions
+                // in the loop header so far have been hoisted out, we can hoist
+                // the clinit check out also.
+                can_move = true;
+              } else if (!instruction->GetSideEffects().MayDependOn(loop_effects)) {
+                can_move = true;
+              }
+            }
+          } else if (!instruction->GetSideEffects().MayDependOn(loop_effects)) {
+            can_move = true;
+          }
+        }
+        if (can_move) {
           // We need to update the environment if the instruction has a loop header
           // phi in it.
           if (instruction->NeedsEnvironment()) {
@@ -142,7 +157,9 @@ void LICM::Run() {
           }
           instruction->MoveBefore(pre_header->GetLastInstruction());
           MaybeRecordStat(stats_, MethodCompilationStat::kLoopInvariantMoved);
-        } else if (instruction->CanThrow() || instruction->DoesAnyWrite()) {
+        }
+
+        if (!can_move && (instruction->CanThrow() || instruction->DoesAnyWrite())) {
           // If `instruction` can do something visible (throw or write),
           // we cannot move further instructions that can throw.
           found_first_non_hoisted_visible_instruction_in_loop = true;
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 42a9d95b9a..d33f2f1d65 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -6259,7 +6259,7 @@ class HClinitCheck FINAL : public HExpression<1> {
   HClinitCheck(HLoadClass* constant, uint32_t dex_pc)
       : HExpression(
             DataType::Type::kReference,
-            SideEffects::AllChanges(),  // Assume write/read on all fields/arrays.
+            SideEffects::AllExceptGCDependency(),  // Assume write/read on all fields/arrays.
             dex_pc) {
     SetRawInputAt(0, constant);
   }