Update CanTriggerGC flag for ArraySet
ArraySet instructions can trigger a GC only when perforing a type
check. When clearing the needs type check flag, we should also
clear the CanTriggerGC flag from the instruction's side effects.
Note that once we clear the needs type check flag, we never set
it again.
Add check in graph checker that the needs type check and the can
trigger GC flag are consistent.
Add can_trigger_gc property to graph visualizer that reflects
whether the ArraySet instruction can trigger a GC.
Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Change-Id: I4c74f902aabf2339bd292e9b24737f55d2737440
diff --git a/test/521-checker-array-set-null/src/Main.java b/test/521-checker-array-set-null/src/Main.java
index f166b92..12a1985 100644
--- a/test/521-checker-array-set-null/src/Main.java
+++ b/test/521-checker-array-set-null/src/Main.java
@@ -16,26 +16,64 @@
public class Main {
public static void main(String[] args) {
- testWithNull(new Object[2]);
- testWithUnknown(new Object[2], new Object());
- testWithSame(new Object[2]);
+ $noinline$testWithNull(new Object[2]);
+ $noinline$testWithUnknown(new Object[2], new Object());
+ $noinline$testWithSame(new Object[2]);
+ $noinline$testWithSameRTI();
}
- /// CHECK-START: void Main.testWithNull(java.lang.Object[]) disassembly (after)
- /// CHECK: ArraySet needs_type_check:false
- public static void testWithNull(Object[] o) {
+ // Known null can eliminate the type check in early stages.
+
+ /// CHECK-START: void Main.$noinline$testWithNull(java.lang.Object[]) instruction_simplifier (before)
+ /// CHECK: ArraySet needs_type_check:true can_trigger_gc:true
+
+ /// CHECK-START: void Main.$noinline$testWithNull(java.lang.Object[]) instruction_simplifier (after)
+ /// CHECK: ArraySet needs_type_check:false can_trigger_gc:false
+
+ /// CHECK-START: void Main.$noinline$testWithNull(java.lang.Object[]) disassembly (after)
+ /// CHECK: ArraySet needs_type_check:false can_trigger_gc:false
+ public static void $noinline$testWithNull(Object[] o) {
o[0] = null;
}
- /// CHECK-START: void Main.testWithUnknown(java.lang.Object[], java.lang.Object) disassembly (after)
- /// CHECK: ArraySet needs_type_check:true
- public static void testWithUnknown(Object[] o, Object obj) {
+ /// CHECK-START: void Main.$noinline$testWithUnknown(java.lang.Object[], java.lang.Object) disassembly (after)
+ /// CHECK: ArraySet needs_type_check:true can_trigger_gc:true
+ public static void $noinline$testWithUnknown(Object[] o, Object obj) {
o[0] = obj;
}
- /// CHECK-START: void Main.testWithSame(java.lang.Object[]) disassembly (after)
- /// CHECK: ArraySet needs_type_check:false
- public static void testWithSame(Object[] o) {
+ // After GVN we know that we are setting values from the same array so there's no need for a type
+ // check.
+
+ /// CHECK-START: void Main.$noinline$testWithSame(java.lang.Object[]) instruction_simplifier$after_gvn (before)
+ /// CHECK: ArraySet needs_type_check:true can_trigger_gc:true
+
+ /// CHECK-START: void Main.$noinline$testWithSame(java.lang.Object[]) instruction_simplifier$after_gvn (after)
+ /// CHECK: ArraySet needs_type_check:false can_trigger_gc:false
+
+ /// CHECK-START: void Main.$noinline$testWithSame(java.lang.Object[]) disassembly (after)
+ /// CHECK: ArraySet needs_type_check:false can_trigger_gc:false
+ public static void $noinline$testWithSame(Object[] o) {
o[0] = o[1];
}
+
+ // We know that the array and the static Object have the same RTI in early stages. No need for a
+ // type check.
+
+ /// CHECK-START: java.lang.Object[] Main.$noinline$testWithSameRTI() instruction_simplifier (before)
+ /// CHECK: ArraySet needs_type_check:true can_trigger_gc:true
+
+ /// CHECK-START: java.lang.Object[] Main.$noinline$testWithSameRTI() instruction_simplifier (after)
+ /// CHECK: ArraySet needs_type_check:false can_trigger_gc:false
+
+ /// CHECK-START: java.lang.Object[] Main.$noinline$testWithSameRTI() disassembly (after)
+ /// CHECK: ArraySet needs_type_check:false can_trigger_gc:false
+ public static Object[] $noinline$testWithSameRTI() {
+ Object[] arr = new Object[1];
+ arr[0] = static_obj;
+ // Return so that LSE doesn't eliminate the ArraySet.
+ return arr;
+ }
+
+ static Object static_obj;
}