Reviewers: danno,
Description:
Fix polymorphic load on named fields.
This fixes polymorphic loads to correctly compare in-object offsets
instead of indices, because indices might coincide even though the
actual slot is different because of different instance sizes.
[email protected]
BUG=v8:2030
TEST=mjsunit/regress/regress-2030,mjsunit/mirror-array
Please review this at https://chromiumcodereview.appspot.com/9864028/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/hydrogen.cc
A test/mjsunit/regress/regress-2030.js
Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index
4da1609842b3d2efb454d36c1576822fffec8ac7..8c55a32af42642a356df79f4685d8ca609f7dc2c
100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -4029,7 +4029,8 @@ void
HGraphBuilder::HandlePolymorphicLoadNamedField(Property* expr,
SmallMapList* types,
Handle<String> name) {
int count = 0;
- int previous_field_index = 0;
+ int previous_field_offset = 0;
+ bool previous_field_is_in_object = false;
bool is_monomorphic_field = true;
Handle<Map> map;
LookupResult lookup(isolate());
@@ -4037,10 +4038,21 @@ void
HGraphBuilder::HandlePolymorphicLoadNamedField(Property* expr,
map = types->at(i);
if (ComputeLoadStoreField(map, name, &lookup, false)) {
int index = ComputeLoadStoreFieldIndex(map, name, &lookup);
+ bool is_in_object = index < 0;
+ int offset = index * kPointerSize;
+ if (index < 0) {
+ // Negative property indices are in-object properties, indexed
+ // from the end of the fixed part of the object.
+ offset += map->instance_size();
+ } else {
+ offset += FixedArray::kHeaderSize;
+ }
if (count == 0) {
- previous_field_index = index;
+ previous_field_offset = offset;
+ previous_field_is_in_object = is_in_object;
} else if (is_monomorphic_field) {
- is_monomorphic_field = (index == previous_field_index);
+ is_monomorphic_field = (offset == previous_field_offset) &&
+ (is_in_object ==
previous_field_is_in_object);
}
++count;
}
Index: test/mjsunit/regress/regress-2030.js
diff --git a/test/mjsunit/regress/regress-2030.js
b/test/mjsunit/regress/regress-2030.js
new file mode 100644
index
0000000000000000000000000000000000000000..fb5a3d0c4633e2350f6ff0185f13416248296c29
--- /dev/null
+++ b/test/mjsunit/regress/regress-2030.js
@@ -0,0 +1,53 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following
+// disclaimer in the documentation and/or other materials provided
+// with the distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+function a() {
+ this.x = 1;
+}
+var aa = new a();
+%DebugPrint(aa);
+
+function b() {
+ this.z = 23;
+ this.x = 2;
+}
+var bb = new b();
+%DebugPrint(bb);
+
+function f(o) {
+ return o.x;
+}
+
+assertSame(1, f(aa));
+assertSame(1, f(aa));
+assertSame(2, f(bb));
+assertSame(2, f(bb));
+%OptimizeFunctionOnNextCall(f);
+assertSame(1, f(aa));
+assertSame(2, f(bb));
--
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