Fix r11780 to avoid bugs where near branches are used to labels that are out of range.

Review URL: http://codereview.chromium.org/10542137

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11792 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index d3e9932..7fd64ca 100644 (file)
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -2357,6 +2357,18 @@ void LCodeGen::EmitPushTaggedOperand(LOperand* operand) {
 }
 
 
+// Check for cases where EmitLoadFieldOrConstantFunction needs to walk the
+// prototype chain, which causes unbounded code generation.
+static bool CompactEmit(
+    SmallMapList* list, Handle<String> name, int i, Isolate* isolate) {
+  LookupResult lookup(isolate);
+  Handle<Map> map = list->at(i);
+  map->LookupInDescriptors(NULL, *name, &lookup);
+  return lookup.IsFound() &&
+      (lookup.type() == FIELD || lookup.type() == CONSTANT_FUNCTION);
+}
+
+
 void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
   Register object = ToRegister(instr->object());
   Register result = ToRegister(instr->result());
@@ -2370,16 +2382,10 @@ void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
   }
   Handle<String> name = instr->hydrogen()->name();
   Label done;
-  bool compact_code = true;
+  bool all_are_compact = true;
   for (int i = 0; i < map_count; ++i) {
-    LookupResult lookup(isolate());
-    Handle<Map> map = instr->hydrogen()->types()->at(i);
-    map->LookupInDescriptors(NULL, *name, &lookup);
-    if (!lookup.IsFound() ||
-        (lookup.type() != FIELD && lookup.type() != CONSTANT_FUNCTION)) {
-      // The two cases above cause a bounded amount of code to be emitted.  This
-      // is not necessarily the case for other lookup results.
-      compact_code = false;
+    if (!CompactEmit(instr->hydrogen()->types(), name, i, isolate())) {
+      all_are_compact = false;
       break;
     }
   }
@@ -2395,11 +2401,13 @@ void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
           result, object, map, name, instr->environment());
     } else {
       Label next;
-      __ j(not_equal, &next, Label::kNear);
+      bool compact = all_are_compact ? true :
+          CompactEmit(instr->hydrogen()->types(), name, i, isolate());
+      __ j(not_equal, &next, compact ? Label::kNear : Label::kFar);
       __ bind(&check_passed);
       EmitLoadFieldOrConstantFunction(
           result, object, map, name, instr->environment());
-      __ jmp(&done, compact_code ? Label::kNear : Label::kFar);
+      __ jmp(&done, all_are_compact ? Label::kNear : Label::kFar);
       __ bind(&next);
     }
   }

diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index 4ac2fec..bc8f848 100644 (file)
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2233,6 +2233,18 @@ void LCodeGen::EmitLoadFieldOrConstantFunction(Register result,
 }
 
 
+// Check for cases where EmitLoadFieldOrConstantFunction needs to walk the
+// prototype chain, which causes unbounded code generation.
+static bool CompactEmit(
+    SmallMapList* list, Handle<String> name, int i, Isolate* isolate) {
+  LookupResult lookup(isolate);
+  Handle<Map> map = list->at(i);
+  map->LookupInDescriptors(NULL, *name, &lookup);
+  return lookup.IsFound() &&
+      (lookup.type() == FIELD || lookup.type() == CONSTANT_FUNCTION);
+}
+
+
 void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
   Register object = ToRegister(instr->object());
   Register result = ToRegister(instr->result());
@@ -2246,16 +2258,10 @@ void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
   }
   Handle<String> name = instr->hydrogen()->name();
   Label done;
-  bool compact_code = true;
+  bool all_are_compact = true;
   for (int i = 0; i < map_count; ++i) {
-    LookupResult lookup(isolate());
-    Handle<Map> map = instr->hydrogen()->types()->at(i);
-    map->LookupInDescriptors(NULL, *name, &lookup);
-    if (!lookup.IsFound() ||
-        (lookup.type() != FIELD && lookup.type() != CONSTANT_FUNCTION)) {
-      // The two cases above cause a bounded amount of code to be emitted.  This
-      // is not necessarily the case for other lookup results.
-      compact_code = false;
+    if (!CompactEmit(instr->hydrogen()->types(), name, i, isolate())) {
+      all_are_compact = false;
       break;
     }
   }
@@ -2271,11 +2277,13 @@ void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
           result, object, map, name, instr->environment());
     } else {
       Label next;
-      __ j(not_equal, &next, Label::kNear);
+      bool compact = all_are_compact ? true :
+          CompactEmit(instr->hydrogen()->types(), name, i, isolate());
+      __ j(not_equal, &next, compact ? Label::kNear : Label::kFar);
       __ bind(&check_passed);
       EmitLoadFieldOrConstantFunction(
           result, object, map, name, instr->environment());
-      __ jmp(&done, compact_code ? Label::kNear: Label::kFar);
+      __ jmp(&done, all_are_compact ? Label::kNear : Label::kFar);
       __ bind(&next);
     }
   }

diff --git a/test/mjsunit/regress/regress-deep-proto.js b/test/mjsunit/regress/regress-deep-proto.js
new file mode 100644 (file)
index 0000000..5d2758c
--- /dev/null
+++ b/test/mjsunit/regress/regress-deep-proto.js
@@ -0,0 +1,45 @@
+// 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.
+
+function poly(x) {
+  return x.foo;
+}
+
+var one = {foo: 0};
+var two = {foo: 0, bar: 1};
+var three = {bar: 0};
+three.__proto__ = {};
+three.__proto__.__proto__ = {};
+three.__proto__.__proto__.__proto__ = {};
+three.__proto__.__proto__.__proto__.__proto__ = {};
+three.__proto__.__proto__.__proto__.__proto__.__proto__ = {};
+
+for (var i = 0; i < 1e6; i++) {
+  poly(one);
+  poly(two);
+  poly(three);
+}