MIPS: ES6 symbols: Allow symbols as property names

Port r13811 (0e64f280)

Original commit message:
Since symbols and strings share a common representation, most of this change is about consistently replacing 'String' with 'Name' in all places where property names are expected. In particular, no new logic at all is necessary for maps, property dictionaries, or transitions. :) The only places where an actual case distinction is needed have to do with generated type checks, and with conversions of names to strings (especially in logger and profiler).

Left in some TODOs wrt to the API: interceptors and native getters don't accept symbols as property names yet, because that would require extending the external v8.h.

(Baseline CL: https://codereview.chromium.org/12296026/)

BUG=

Review URL: https://codereview.chromium.org/12561003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13874 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/code-stubs-mips.cc

@@ -7519,13 +7519,14 @@ void DirectCEntryStub::GenerateCall(MacroAssembler* masm,
 }
 
 
-void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
+void NameDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
                                                       Label* miss,
                                                       Label* done,
                                                       Register receiver,
                                                       Register properties,
-                                                        Handle<String> name,
+                                                      Handle<Name> name,
                                                       Register scratch0) {
+  ASSERT(name->IsUniqueName());
   // If names of slots in range from 1 to kProbes - 1 for the hash value are
   // not equal to the name and kProbes-th slot is not used (its name is the
   // undefined value), it guarantees the hash table doesn't contain the
@@ -7539,10 +7540,10 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
     __ lw(index, FieldMemOperand(properties, kCapacityOffset));
     __ Subu(index, index, Operand(1));
     __ And(index, index, Operand(
-        Smi::FromInt(name->Hash() + StringDictionary::GetProbeOffset(i))));
+        Smi::FromInt(name->Hash() + NameDictionary::GetProbeOffset(i))));
 
     // Scale the index by multiplying by the entry size.
-    ASSERT(StringDictionary::kEntrySize == 3);
+    ASSERT(NameDictionary::kEntrySize == 3);
     __ sll(at, index, 1);
     __ Addu(index, index, at);
 
@@ -7563,19 +7564,20 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
       __ LoadRoot(tmp, Heap::kTheHoleValueRootIndex);
 
       // Stop if found the property.
-      __ Branch(miss, eq, entity_name, Operand(Handle<String>(name)));
+      __ Branch(miss, eq, entity_name, Operand(Handle<Name>(name)));
 
-      Label the_hole;
-      __ Branch(&the_hole, eq, entity_name, Operand(tmp));
+      Label good;
+      __ Branch(&good, eq, entity_name, Operand(tmp));
 
-      // Check if the entry name is not a internalized string.
+      // Check if the entry name is not a unique name.
       __ lw(entity_name, FieldMemOperand(entity_name, HeapObject::kMapOffset));
       __ lbu(entity_name,
              FieldMemOperand(entity_name, Map::kInstanceTypeOffset));
       __ And(scratch0, entity_name, Operand(kIsInternalizedMask));
-      __ Branch(miss, eq, scratch0, Operand(zero_reg));
+      __ Branch(&good, ne, scratch0, Operand(zero_reg));
+      __ Branch(miss, ne, entity_name, Operand(SYMBOL_TYPE));
 
-      __ bind(&the_hole);
+      __ bind(&good);
 
       // Restore the properties.
       __ lw(properties,
@@ -7589,8 +7591,8 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
 
   __ MultiPush(spill_mask);
   __ lw(a0, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
-  __ li(a1, Operand(Handle<String>(name)));
-  StringDictionaryLookupStub stub(NEGATIVE_LOOKUP);
+  __ li(a1, Operand(Handle<Name>(name)));
+  NameDictionaryLookupStub stub(NEGATIVE_LOOKUP);
   __ CallStub(&stub);
   __ mov(at, v0);
   __ MultiPop(spill_mask);
@@ -7600,11 +7602,11 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
 }
 
 
-// Probe the string dictionary in the |elements| register. Jump to the
+// Probe the name dictionary in the |elements| register. Jump to the
 // |done| label if a property with the given name is found. Jump to
 // the |miss| label otherwise.
 // If lookup was successful |scratch2| will be equal to elements + 4 * index.
-void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
+void NameDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
                                                       Label* miss,
                                                       Label* done,
                                                       Register elements,
@@ -7616,7 +7618,7 @@ void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
   ASSERT(!name.is(scratch1));
   ASSERT(!name.is(scratch2));
 
-  __ AssertString(name);
+  __ AssertName(name);
 
   // Compute the capacity mask.
   __ lw(scratch1, FieldMemOperand(elements, kCapacityOffset));
@@ -7628,21 +7630,21 @@ void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
   // cover ~93% of loads from dictionaries.
   for (int i = 0; i < kInlinedProbes; i++) {
     // Compute the masked index: (hash + i + i * i) & mask.
-    __ lw(scratch2, FieldMemOperand(name, String::kHashFieldOffset));
+    __ lw(scratch2, FieldMemOperand(name, Name::kHashFieldOffset));
     if (i > 0) {
       // Add the probe offset (i + i * i) left shifted to avoid right shifting
       // the hash in a separate instruction. The value hash + i + i * i is right
       // shifted in the following and instruction.
-      ASSERT(StringDictionary::GetProbeOffset(i) <
-             1 << (32 - String::kHashFieldOffset));
+      ASSERT(NameDictionary::GetProbeOffset(i) <
+             1 << (32 - Name::kHashFieldOffset));
       __ Addu(scratch2, scratch2, Operand(
-           StringDictionary::GetProbeOffset(i) << String::kHashShift));
+          NameDictionary::GetProbeOffset(i) << Name::kHashShift));
     }
-    __ srl(scratch2, scratch2, String::kHashShift);
+    __ srl(scratch2, scratch2, Name::kHashShift);
     __ And(scratch2, scratch1, scratch2);
 
     // Scale the index by multiplying by the element size.
-    ASSERT(StringDictionary::kEntrySize == 3);
+    ASSERT(NameDictionary::kEntrySize == 3);
     // scratch2 = scratch2 * 3.
 
     __ sll(at, scratch2, 1);
@@ -7669,7 +7671,7 @@ void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
     __ Move(a0, elements);
     __ Move(a1, name);
   }
-  StringDictionaryLookupStub stub(POSITIVE_LOOKUP);
+  NameDictionaryLookupStub stub(POSITIVE_LOOKUP);
   __ CallStub(&stub);
   __ mov(scratch2, a2);
   __ mov(at, v0);
@@ -7680,14 +7682,14 @@ void StringDictionaryLookupStub::GeneratePositiveLookup(MacroAssembler* masm,
 }
 
 
-void StringDictionaryLookupStub::Generate(MacroAssembler* masm) {
+void NameDictionaryLookupStub::Generate(MacroAssembler* masm) {
   // This stub overrides SometimesSetsUpAFrame() to return false.  That means
   // we cannot call anything that could cause a GC from this stub.
   // Registers:
-  //  result: StringDictionary to probe
+  //  result: NameDictionary to probe
   //  a1: key
-  //  : StringDictionary to probe.
-  //  index_: will hold an index of entry if lookup is successful.
+  //  dictionary: NameDictionary to probe.
+  //  index: will hold an index of entry if lookup is successful.
   //         might alias with result_.
   // Returns:
   //  result_ is zero if lookup failed, non zero otherwise.
@@ -7707,7 +7709,7 @@ void StringDictionaryLookupStub::Generate(MacroAssembler* masm) {
   __ sra(mask, mask, kSmiTagSize);
   __ Subu(mask, mask, Operand(1));
 
-  __ lw(hash, FieldMemOperand(key, String::kHashFieldOffset));
+  __ lw(hash, FieldMemOperand(key, Name::kHashFieldOffset));
 
   __ LoadRoot(undefined, Heap::kUndefinedValueRootIndex);
 
@@ -7718,18 +7720,18 @@ void StringDictionaryLookupStub::Generate(MacroAssembler* masm) {
       // Add the probe offset (i + i * i) left shifted to avoid right shifting
       // the hash in a separate instruction. The value hash + i + i * i is right
       // shifted in the following and instruction.
-      ASSERT(StringDictionary::GetProbeOffset(i) <
-             1 << (32 - String::kHashFieldOffset));
+      ASSERT(NameDictionary::GetProbeOffset(i) <
+             1 << (32 - Name::kHashFieldOffset));
       __ Addu(index, hash, Operand(
-           StringDictionary::GetProbeOffset(i) << String::kHashShift));
+          NameDictionary::GetProbeOffset(i) << Name::kHashShift));
     } else {
       __ mov(index, hash);
     }
-    __ srl(index, index, String::kHashShift);
+    __ srl(index, index, Name::kHashShift);
     __ And(index, mask, index);
 
     // Scale the index by multiplying by the entry size.
-    ASSERT(StringDictionary::kEntrySize == 3);
+    ASSERT(NameDictionary::kEntrySize == 3);
     // index *= 3.
     __ mov(at, index);
     __ sll(index, index, 1);
@@ -7748,12 +7750,15 @@ void StringDictionaryLookupStub::Generate(MacroAssembler* masm) {
     __ Branch(&in_dictionary, eq, entry_key, Operand(key));
 
     if (i != kTotalProbes - 1 && mode_ == NEGATIVE_LOOKUP) {
-      // Check if the entry name is not a internalized string.
+      // Check if the entry name is not a unique name.
+      Label cont;
       __ lw(entry_key, FieldMemOperand(entry_key, HeapObject::kMapOffset));
       __ lbu(entry_key,
              FieldMemOperand(entry_key, Map::kInstanceTypeOffset));
       __ And(result, entry_key, Operand(kIsInternalizedMask));
-      __ Branch(&maybe_in_dictionary, eq, result, Operand(zero_reg));
+      __ Branch(&cont, ne, result, Operand(zero_reg));
+      __ Branch(&maybe_in_dictionary, ne, entry_key, Operand(SYMBOL_TYPE));
+      __ bind(&cont);
     }
   }
 

src/mips/code-stubs-mips.h

@@ -739,11 +739,11 @@ class FloatingPointHelper : public AllStatic {
 };
 
 
-class StringDictionaryLookupStub: public PlatformCodeStub {
+class NameDictionaryLookupStub: public PlatformCodeStub {
  public:
   enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
 
-  explicit StringDictionaryLookupStub(LookupMode mode) : mode_(mode) { }
+  explicit NameDictionaryLookupStub(LookupMode mode) : mode_(mode) { }
 
   void Generate(MacroAssembler* masm);
 
@@ -752,7 +752,7 @@ class StringDictionaryLookupStub: public PlatformCodeStub {
                                      Label* done,
                                      Register receiver,
                                      Register properties,
-                                     Handle<String> name,
+                                     Handle<Name> name,
                                      Register scratch0);
 
   static void GeneratePositiveLookup(MacroAssembler* masm,
@@ -770,14 +770,14 @@ class StringDictionaryLookupStub: public PlatformCodeStub {
   static const int kTotalProbes = 20;
 
   static const int kCapacityOffset =
-      StringDictionary::kHeaderSize +
-      StringDictionary::kCapacityIndex * kPointerSize;
+      NameDictionary::kHeaderSize +
+      NameDictionary::kCapacityIndex * kPointerSize;
 
   static const int kElementsStartOffset =
-      StringDictionary::kHeaderSize +
-      StringDictionary::kElementsStartIndex * kPointerSize;
+      NameDictionary::kHeaderSize +
+      NameDictionary::kElementsStartIndex * kPointerSize;
 
-  Major MajorKey() { return StringDictionaryLookup; }
+  Major MajorKey() { return NameDictionaryLookup; }
 
   int MinorKey() {
     return LookupModeBits::encode(mode_);

src/mips/macro-assembler-mips.cc

@@ -3866,6 +3866,15 @@ void MacroAssembler::IsObjectJSStringType(Register object,
 }
 
 
+void MacroAssembler::IsObjectNameType(Register object,
+                                      Register scratch,
+                                      Label* fail) {
+  lw(scratch, FieldMemOperand(object, HeapObject::kMapOffset));
+  lbu(scratch, FieldMemOperand(scratch, Map::kInstanceTypeOffset));
+  Branch(fail, hi, scratch, Operand(LAST_NAME_TYPE));
+}
+
+
 // ---------------------------------------------------------------------------
 // Support functions.
 
@@ -4897,6 +4906,20 @@ void MacroAssembler::AssertString(Register object) {
 }
 
 
+void MacroAssembler::AssertName(Register object) {
+  if (emit_debug_code()) {
+    STATIC_ASSERT(kSmiTag == 0);
+    And(t0, object, Operand(kSmiTagMask));
+    Check(ne, "Operand is a smi and not a name", t0, Operand(zero_reg));
+    push(object);
+    lw(object, FieldMemOperand(object, HeapObject::kMapOffset));
+    lbu(object, FieldMemOperand(object, Map::kInstanceTypeOffset));
+    pop(object);
+    Check(le, "Operand is not a name", object, Operand(LAST_NAME_TYPE));
+  }
+}
+
+
 void MacroAssembler::AssertRootValue(Register src,
                                      Heap::RootListIndex root_value_index,
                                      const char* message) {

src/mips/macro-assembler-mips.h

@@ -900,6 +900,10 @@ class MacroAssembler: public Assembler {
                             Register scratch,
                             Label* fail);
 
+  void IsObjectNameType(Register object,
+                        Register scratch,
+                        Label* fail);
+
 #ifdef ENABLE_DEBUGGER_SUPPORT
   // -------------------------------------------------------------------------
   // Debugger Support.
@@ -1357,6 +1361,9 @@ class MacroAssembler: public Assembler {
   // Abort execution if argument is not a string, enabled via --debug-code.
   void AssertString(Register object);
 
+  // Abort execution if argument is not a name, enabled via --debug-code.
+  void AssertName(Register object);
+
   // Abort execution if argument is not the root value with the given index,
   // enabled via --debug-code.
   void AssertRootValue(Register src,