Fixed type feedback in presence of negative lookups.

To fix the issue at hand regarding constant function calls and perhaps
other hidden issues regarding negative lookups, we basically add a
"marker instruction", just for harvesting purposes. Our type feedback
oracle is really, really fragile, we should better switch to some more
explicit and robust scheme soon.

BUG=chromium:252797
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/19588002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15741 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
parent ced115b6
......@@ -1185,6 +1185,10 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
int save_at_depth,
Label* miss,
PrototypeCheckType check) {
// Make sure that the type feedback oracle harvests the receiver map.
// TODO(svenpanne) Remove this hack when all ICs are reworked.
__ mov(scratch1, Operand(Handle<Map>(object->map())));
Handle<JSObject> first = object;
// Make sure there's no overlap between holder and object registers.
ASSERT(!scratch1.is(object_reg) && !scratch1.is(holder_reg));
......
......@@ -1132,6 +1132,10 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
int save_at_depth,
Label* miss,
PrototypeCheckType check) {
// Make sure that the type feedback oracle harvests the receiver map.
// TODO(svenpanne) Remove this hack when all ICs are reworked.
__ mov(scratch1, Handle<Map>(object->map()));
Handle<JSObject> first = object;
// Make sure there's no overlap between holder and object registers.
ASSERT(!scratch1.is(object_reg) && !scratch1.is(holder_reg));
......
......@@ -1192,6 +1192,10 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
int save_at_depth,
Label* miss,
PrototypeCheckType check) {
// Make sure that the type feedback oracle harvests the receiver map.
// TODO(svenpanne) Remove this hack when all ICs are reworked.
__ li(scratch1, Operand(Handle<Map>(object->map())));
Handle<JSObject> first = object;
// Make sure there's no overlap between holder and object registers.
ASSERT(!scratch1.is(object_reg) && !scratch1.is(holder_reg));
......
......@@ -1059,6 +1059,10 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
int save_at_depth,
Label* miss,
PrototypeCheckType check) {
// Make sure that the type feedback oracle harvests the receiver map.
// TODO(svenpanne) Remove this hack when all ICs are reworked.
__ Move(scratch1, Handle<Map>(object->map()));
Handle<JSObject> first = object;
// Make sure there's no overlap between holder and object registers.
ASSERT(!scratch1.is(object_reg) && !scratch1.is(holder_reg));
......
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// Flags: --allow-natives-syntax
// The type feedback oracle had a bug when retrieving the map from an IC
// starting with a negative lookup.
// Create a holder in fast mode.
var holder = Object.create(null, {
holderMethod: {value: function() {}}
});
assertTrue(%HasFastProperties(holder));
// Create a receiver into dictionary mode.
var receiver = Object.create(holder, {
killMe: {value: 0, configurable: true},
});
delete receiver.killMe;
assertFalse(%HasFastProperties(receiver));
// The actual function to test, triggering the retrieval of the wrong map.
function callConstantFunctionOnPrototype(obj) {
obj.holderMethod();
}
callConstantFunctionOnPrototype(receiver);
callConstantFunctionOnPrototype(receiver);
%OptimizeFunctionOnNextCall(callConstantFunctionOnPrototype);
callConstantFunctionOnPrototype(receiver);
// Make sure that the function is still optimized.
assertTrue(2 != %GetOptimizationStatus(callConstantFunctionOnPrototype));
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