# HG changeset patch # User Doug Simon # Date 1338560944 -7200 # Node ID 7a0d58000ae03d08edccefae3e2f1773e1f2cc34 # Parent 08620ddf859c76667a7bfea688392801010fe377 checkcasts against restricted primary types no longer use hints added checkcast snippet for a test against an exact (i.e. effectively final and unique) type diff -r 08620ddf859c -r 7a0d58000ae0 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/snippets/CheckCastSnippets.java --- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/snippets/CheckCastSnippets.java Fri Jun 01 16:25:01 2012 +0200 +++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/snippets/CheckCastSnippets.java Fri Jun 01 16:29:04 2012 +0200 @@ -59,10 +59,44 @@ public class CheckCastSnippets implements SnippetsInterface { /** - * Type test used when the type being tested against is a restricted primary type. + * Type test used when the type being tested against is a final type. */ @Snippet - public static Object checkcastPrimary(Object hub, Object object, Object[] hintHubs, boolean hintsAreExact, boolean checkNull, int superCheckOffset) { + public static Object checkcastExact(Object object, Object exactHub, boolean checkNull) { + if (checkNull && object == null) { + return object; + } + Object objectHub = UnsafeLoadNode.loadObject(object, 0, hubOffset(), true); + if (objectHub != exactHub) { + DeoptimizeNode.deopt(RiDeoptAction.InvalidateReprofile, RiDeoptReason.ClassCastException); + } + return object; + } + + /** + * Type test used when the type being tested against is a restricted primary type. + * + * This test ignores use of hints altogether as the display-based type check only + * involves one extra load where the second load should hit the same cache line as the + * first. + */ + @Snippet + public static Object checkcastPrimary(Object hub, Object object, boolean checkNull, int superCheckOffset) { + if (checkNull && object == null) { + return object; + } + Object objectHub = UnsafeLoadNode.loadObject(object, 0, hubOffset(), true); + if (UnsafeLoadNode.loadObject(objectHub, 0, superCheckOffset, true) != hub) { + DeoptimizeNode.deopt(RiDeoptAction.InvalidateReprofile, RiDeoptReason.ClassCastException); + } + return object; + } + + /** + * Type test used when the type being tested against is a restricted secondary type. + */ + @Snippet + public static Object checkcastSecondary(Object hub, Object object, Object[] hintHubs, boolean checkNull) { if (checkNull && object == null) { return object; } @@ -75,21 +109,18 @@ return object; } } - if (hintsAreExact) { + if (!checkSecondarySubType(hub, objectHub)) { DeoptimizeNode.deopt(RiDeoptAction.InvalidateReprofile, RiDeoptReason.ClassCastException); - } else { - if (UnsafeLoadNode.loadObject(objectHub, 0, superCheckOffset, true) != hub) { - DeoptimizeNode.deopt(RiDeoptAction.InvalidateReprofile, RiDeoptReason.ClassCastException); - } } return object; } /** - * Type test used when the type being tested against is a restricted secondary type. + * Type test used when the type being tested against is not known at compile time (e.g. the type test + * in an object array store check). */ @Snippet - public static Object checkcastSecondary(Object hub, Object object, Object[] hintHubs, boolean hintsAreExact, boolean checkNull) { + public static Object checkcastUnknown(Object hub, Object object, Object[] hintHubs, boolean checkNull) { if (checkNull && object == null) { return object; } @@ -102,40 +133,8 @@ return object; } } - if (hintsAreExact) { + if (!checkUnknownSubType(hub, objectHub)) { DeoptimizeNode.deopt(RiDeoptAction.InvalidateReprofile, RiDeoptReason.ClassCastException); - } else { - if (!checkSecondarySubType(hub, objectHub)) { - DeoptimizeNode.deopt(RiDeoptAction.InvalidateReprofile, RiDeoptReason.ClassCastException); - } - } - return object; - } - - /** - * Type test used when the type being tested against is not known at compile time (e.g. the type test - * in an object array store check). - */ - @Snippet - public static Object checkcastUnknown(Object hub, Object object, Object[] hintHubs, boolean hintsAreExact, boolean checkNull) { - if (checkNull && object == null) { - return object; - } - Object objectHub = UnsafeLoadNode.loadObject(object, 0, hubOffset(), true); - // if we get an exact match: succeed immediately - ExplodeLoopNode.explodeLoop(); - for (int i = 0; i < hintHubs.length; i++) { - Object hintHub = hintHubs[i]; - if (hintHub == objectHub) { - return object; - } - } - if (hintsAreExact) { - DeoptimizeNode.deopt(RiDeoptAction.InvalidateReprofile, RiDeoptReason.ClassCastException); - } else { - if (!checkUnknownSubType(hub, objectHub)) { - DeoptimizeNode.deopt(RiDeoptAction.InvalidateReprofile, RiDeoptReason.ClassCastException); - } } return object; } @@ -206,7 +205,7 @@ public enum Counter { hintsHit("hit a hint type"), hintsMissed("missed the hint types"), - exact("tested type is (statically) final"), + exactType("tested type is (statically) final"), noHints("profile information is not used"), isNull("object tested is null"), exception("type test failed with a ClassCastException"); @@ -267,7 +266,7 @@ Object hintHub = hintHubs[i]; if (hintHub == objectHub) { if (hintsAreExact) { - exact.inc(); + exactType.inc(); } else { hintsHit.inc(); } @@ -381,19 +380,21 @@ public static class Templates { private final ConcurrentHashMap templates; - private final RiResolvedMethod counters; + private final RiResolvedMethod exact; private final RiResolvedMethod primary; private final RiResolvedMethod secondary; private final RiResolvedMethod unknown; + private final RiResolvedMethod counters; private final RiRuntime runtime; public Templates(RiRuntime runtime) { this.runtime = runtime; this.templates = new ConcurrentHashMap<>(); try { - primary = runtime.getRiMethod(CheckCastSnippets.class.getDeclaredMethod("checkcastPrimary", Object.class, Object.class, Object[].class, boolean.class, boolean.class, int.class)); - secondary = runtime.getRiMethod(CheckCastSnippets.class.getDeclaredMethod("checkcastSecondary", Object.class, Object.class, Object[].class, boolean.class, boolean.class)); - unknown = runtime.getRiMethod(CheckCastSnippets.class.getDeclaredMethod("checkcastUnknown", Object.class, Object.class, Object[].class, boolean.class, boolean.class)); + exact = runtime.getRiMethod(CheckCastSnippets.class.getDeclaredMethod("checkcastExact", Object.class, Object.class, boolean.class)); + primary = runtime.getRiMethod(CheckCastSnippets.class.getDeclaredMethod("checkcastPrimary", Object.class, Object.class, boolean.class, int.class)); + secondary = runtime.getRiMethod(CheckCastSnippets.class.getDeclaredMethod("checkcastSecondary", Object.class, Object.class, Object[].class, boolean.class)); + unknown = runtime.getRiMethod(CheckCastSnippets.class.getDeclaredMethod("checkcastUnknown", Object.class, Object.class, Object[].class, boolean.class)); counters = runtime.getRiMethod(CheckCastSnippets.class.getDeclaredMethod("checkcastCounters", Object.class, Object.class, Object[].class, boolean.class)); } catch (NoSuchMethodException e) { throw new GraalInternalError(e); @@ -428,6 +429,14 @@ return result; } + private static HotSpotKlassOop[] createHintHubs(TypeCheckHints hints) { + HotSpotKlassOop[] hintHubs = new HotSpotKlassOop[hints.types.length]; + for (int i = 0; i < hintHubs.length; i++) { + hintHubs[i] = ((HotSpotType) hints.types[i]).klassOop(); + } + return hintHubs; + } + /** * Lowers a checkcast node. */ @@ -436,16 +445,13 @@ ValueNode hub = checkcast.targetClassInstruction(); ValueNode object = checkcast.object(); TypeCheckHints hints = new TypeCheckHints(checkcast.targetClass(), checkcast.profile(), tool.assumptions(), GraalOptions.CheckcastMinHintHitProbability, GraalOptions.CheckcastMaxHints); - HotSpotKlassOop[] hintHubs = new HotSpotKlassOop[hints.types.length]; - for (int i = 0; i < hintHubs.length; i++) { - hintHubs[i] = ((HotSpotType) hints.types[i]).klassOop(); - } Debug.log("Lowering checkcast in %s: node=%s, hintsHubs=%s, exact=%b", graph, checkcast, Arrays.toString(hints.types), hints.exact); final HotSpotTypeResolvedImpl target = (HotSpotTypeResolvedImpl) checkcast.targetClass(); - int flags = EXACT_HINTS.bit(hints.exact) | CHECK_NULL.bit(!object.stamp().nonNull()); + int flags = CHECK_NULL.bit(!object.stamp().nonNull()); if (GraalOptions.CheckcastCounters) { - SnippetTemplate template = getTemplate(hintHubs.length, flags | COUNTERS.bit(), 0, new Factory() { + HotSpotKlassOop[] hintHubs = createHintHubs(hints); + SnippetTemplate template = getTemplate(hintHubs.length, flags | EXACT_HINTS.bit(hints.exact) | COUNTERS.bit(), 0, new Factory() { @SuppressWarnings("hiding") @Override SnippetTemplate create(HotSpotKlassOop[] hints, int flags) { @@ -455,32 +461,46 @@ }); template.instantiate(runtime, checkcast, checkcast, hub, object, hintHubs, hints.exact); } else if (target == null) { + HotSpotKlassOop[] hintHubs = createHintHubs(hints); SnippetTemplate template = getTemplate(hintHubs.length, flags | UNKNOWN_SUPER.bit(), 0, new Factory() { @SuppressWarnings("hiding") @Override SnippetTemplate create(HotSpotKlassOop[] hints, int flags) { - // checkcastUnknown(Object hub, Object object, Object[] hintHubs, boolean hintsAreExact, boolean checkNull) - return SnippetTemplate.create(runtime, unknown, _, _, hints, EXACT_HINTS.bool(flags), CHECK_NULL.bool(flags)); + // checkcastUnknown(Object hub, Object object, Object[] hintHubs, boolean checkNull) + return SnippetTemplate.create(runtime, unknown, _, _, hints, CHECK_NULL.bool(flags)); } }); template.instantiate(runtime, checkcast, checkcast, hub, object, hintHubs); - } else if (target.isPrimaryType()) { - SnippetTemplate template = getTemplate(hintHubs.length, flags | PRIMARY_SUPER.bit(), target.superCheckOffset(), new Factory() { + } else if (hints.exact) { + HotSpotKlassOop[] hintHubs = createHintHubs(hints); + assert hintHubs.length == 1; + SnippetTemplate template = getTemplate(hintHubs.length, flags | EXACT_HINTS.bit(), 0, new Factory() { @SuppressWarnings("hiding") @Override SnippetTemplate create(HotSpotKlassOop[] hints, int flags) { - // checkcastPrimary(Object hub, Object object, Object[] hintHubs, boolean hintsAreExact, boolean checkNull, int superCheckOffset) - return SnippetTemplate.create(runtime, primary, _, _, hints, EXACT_HINTS.bool(flags), CHECK_NULL.bool(flags), target.superCheckOffset()); + // checkcastExact(Object object, Object exactHub, boolean checkNull) + return SnippetTemplate.create(runtime, exact, _, hints[0], CHECK_NULL.bool(flags)); } }); - template.instantiate(runtime, checkcast, checkcast, hub, object, hintHubs); + template.instantiate(runtime, checkcast, checkcast, object, hintHubs[0]); + } else if (target.isPrimaryType()) { + SnippetTemplate template = getTemplate(0, flags | PRIMARY_SUPER.bit(), target.superCheckOffset(), new Factory() { + @SuppressWarnings("hiding") + @Override + SnippetTemplate create(HotSpotKlassOop[] hints, int flags) { + // checkcastPrimary(Object hub, Object object, boolean checkNull, int superCheckOffset) + return SnippetTemplate.create(runtime, primary, _, _, CHECK_NULL.bool(flags), target.superCheckOffset()); + } + }); + template.instantiate(runtime, checkcast, checkcast, hub, object); } else { + HotSpotKlassOop[] hintHubs = createHintHubs(hints); SnippetTemplate template = getTemplate(hintHubs.length, flags | SECONDARY_SUPER.bit(), 0, new Factory() { @SuppressWarnings("hiding") @Override SnippetTemplate create(HotSpotKlassOop[] hints, int flags) { - // checkcastSecondary(Object hub, Object object, Object[] hintHubs, boolean hintsAreExact, boolean checkNull) - return SnippetTemplate.create(runtime, secondary, _, _, hints, EXACT_HINTS.bool(flags), CHECK_NULL.bool(flags)); + // checkcastSecondary(Object hub, Object object, Object[] hintHubs, boolean checkNull) + return SnippetTemplate.create(runtime, secondary, _, _, hints, CHECK_NULL.bool(flags)); } }); template.instantiate(runtime, checkcast, checkcast, hub, object, hintHubs);