commit 293f1c006cc283345630ea38266f3ee38b624d5d
author Mingyao Yang <mingyao@google.com> Wed Nov 08 15:22:17 2017 -0800
committer Mingyao Yang <mingyao@google.com> Wed Nov 08 15:26:15 2017 -0800
tree 9560d72041ab5dfad71aa38030529997bc528bdc
parent 3b5df92d613bb72c8e6f8a766c60835d8313414f

Check invocation's side effects for LSE.

More optimization is allowed if an invocation doesn't do read/write.

Test: run-test on host.
Change-Id: Id80e2fa90b8c843afd852778e8f7e6c69c765ad5

compiler/optimizing/escape.cc

diff --git a/compiler/optimizing/escape.cc b/compiler/optimizing/escape.cc
index 9df5bf1..88e9326 100644
--- a/compiler/optimizing/escape.cc
+++ b/compiler/optimizing/escape.cc
@@ -51,7 +51,9 @@
       *is_singleton_and_not_returned = false;
       *is_singleton_and_not_deopt_visible = false;
       return;
-    } else if (user->IsPhi() || user->IsSelect() || user->IsInvoke() ||
+    } else if (user->IsPhi() ||
+               user->IsSelect() ||
+               (user->IsInvoke() && user->GetSideEffects().DoesAnyWrite()) ||
                (user->IsInstanceFieldSet() && (reference == user->InputAt(1))) ||
                (user->IsUnresolvedInstanceFieldSet() && (reference == user->InputAt(1))) ||
                (user->IsStaticFieldSet() && (reference == user->InputAt(1))) ||

compiler/optimizing/load_store_elimination.cc

diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc
index 7dff696..c041f56 100644
--- a/compiler/optimizing/load_store_elimination.cc
+++ b/compiler/optimizing/load_store_elimination.cc
@@ -528,15 +528,21 @@
     }
   }
 
-  void HandleInvoke(HInstruction* invoke) {
+  void HandleInvoke(HInstruction* instruction) {
+    SideEffects side_effects = instruction->GetSideEffects();
     ScopedArenaVector<HInstruction*>& heap_values =
-        heap_values_for_[invoke->GetBlock()->GetBlockId()];
+        heap_values_for_[instruction->GetBlock()->GetBlockId()];
     for (size_t i = 0; i < heap_values.size(); i++) {
       ReferenceInfo* ref_info = heap_location_collector_.GetHeapLocation(i)->GetReferenceInfo();
       if (ref_info->IsSingleton()) {
         // Singleton references cannot be seen by the callee.
       } else {
-        heap_values[i] = kUnknownHeapValue;
+        if (side_effects.DoesAnyRead()) {
+          KeepIfIsStore(heap_values[i]);
+        }
+        if (side_effects.DoesAnyWrite()) {
+          heap_values[i] = kUnknownHeapValue;
+        }
       }
     }
   }

test/530-checker-lse/src/Main.java

diff --git a/test/530-checker-lse/src/Main.java b/test/530-checker-lse/src/Main.java
index 7ae873a..58abbee 100644
--- a/test/530-checker-lse/src/Main.java
+++ b/test/530-checker-lse/src/Main.java
@@ -810,6 +810,23 @@
     return arr[0] + arr[1] + arr[2] + arr[3];
   }
 
+  /// CHECK-START: int Main.testNoSideEffects(int[]) load_store_elimination (before)
+  /// CHECK: ArraySet
+  /// CHECK: ArraySet
+  /// CHECK: ArrayGet
+
+  /// CHECK-START: int Main.testNoSideEffects(int[]) load_store_elimination (after)
+  /// CHECK: ArraySet
+  /// CHECK: ArraySet
+  /// CHECK-NOT: ArrayGet
+
+  private static int testNoSideEffects(int[] array) {
+    array[0] = 101;
+    int bitCount = Integer.bitCount(0x3456);
+    array[1] = array[0] + 1;
+    return array[0] + bitCount;
+  }
+
   /// CHECK-START: double Main.getCircleArea(double, boolean) load_store_elimination (before)
   /// CHECK: NewInstance
 
@@ -1017,6 +1034,11 @@
     assertIntEquals(testStoreStore().i, 41);
     assertIntEquals(testStoreStore().j, 43);
     assertIntEquals(testStoreStoreWithDeoptimize(new int[4]), 4);
+
+    int ret = testNoSideEffects(iarray);
+    assertIntEquals(iarray[0], 101);
+    assertIntEquals(iarray[1], 102);
+    assertIntEquals(ret, 108);
   }
 
   static boolean sFlag;