Fix the negative lookup stub to handle deleted entries in a

dictionary.  This fixes http://code.google.com/p/v8/issues/detail?id=1964
"Closure-uri benchmark is sensitive to hash seed".
Review URL: https://chromiumcodereview.appspot.com/9463012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10848 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/arm/code-stubs-arm.cc b/src/arm/code-stubs-arm.cc
index 62e6c80..25563ed 100644 (file)
--- a/src/arm/code-stubs-arm.cc
+++ b/src/arm/code-stubs-arm.cc
@@ -6812,7 +6812,7 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
   // 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
   // property. It's true even if some slots represent deleted properties
-  // (their names are the null value).
+  // (their names are the hole value).
   for (int i = 0; i < kInlinedProbes; i++) {
     // scratch0 points to properties hash.
     // Compute the masked index: (hash + i + i * i) & mask.
@@ -6840,10 +6840,17 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
     __ b(eq, done);
 
     if (i != kInlinedProbes - 1) {
+      // Load the hole ready for use below:
+      __ LoadRoot(tmp, Heap::kTheHoleValueRootIndex);
+
       // Stop if found the property.
       __ cmp(entity_name, Operand(Handle<String>(name)));
       __ b(eq, miss);
 
+      Label the_hole;
+      __ cmp(entity_name, tmp);
+      __ b(eq, &the_hole);
+
       // Check if the entry name is not a symbol.
       __ ldr(entity_name, FieldMemOperand(entity_name, HeapObject::kMapOffset));
       __ ldrb(entity_name,
@@ -6851,6 +6858,8 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
       __ tst(entity_name, Operand(kIsSymbolMask));
       __ b(eq, miss);
 
+      __ bind(&the_hole);
+
       // Restore the properties.
       __ ldr(properties,
              FieldMemOperand(receiver, JSObject::kPropertiesOffset));

diff --git a/src/ia32/code-stubs-ia32.cc b/src/ia32/code-stubs-ia32.cc
index 2d078cd..864e76c 100644 (file)
--- a/src/ia32/code-stubs-ia32.cc
+++ b/src/ia32/code-stubs-ia32.cc
@@ -6823,7 +6823,7 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
   // 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
   // property. It's true even if some slots represent deleted properties
-  // (their names are the null value).
+  // (their names are the hole value).
   for (int i = 0; i < kInlinedProbes; i++) {
     // Compute the masked index: (hash + i + i * i) & mask.
     Register index = r0;
@@ -6849,11 +6849,17 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
     __ cmp(entity_name, Handle<String>(name));
     __ j(equal, miss);
 
+    Label the_hole;
+    // Check for the hole and skip.
+    __ cmp(entity_name, masm->isolate()->factory()->the_hole_value());
+    __ j(equal, &the_hole, Label::kNear);
+
     // Check if the entry name is not a symbol.
     __ mov(entity_name, FieldOperand(entity_name, HeapObject::kMapOffset));
     __ test_b(FieldOperand(entity_name, Map::kInstanceTypeOffset),
               kIsSymbolMask);
     __ j(zero, miss);
+    __ bind(&the_hole);
   }
 
   StringDictionaryLookupStub stub(properties,

diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index de6fb95..6f79225 100644 (file)
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -7070,7 +7070,7 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
   // 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
   // property. It's true even if some slots represent deleted properties
-  // (their names are the null value).
+  // (their names are the hole value).
   for (int i = 0; i < kInlinedProbes; i++) {
     // scratch0 points to properties hash.
     // Compute the masked index: (hash + i + i * i) & mask.
@@ -7099,9 +7099,15 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
     __ Branch(done, eq, entity_name, Operand(tmp));
 
     if (i != kInlinedProbes - 1) {
+      // Load the hole ready for use below:
+      __ LoadRoot(tmp, Heap::kTheHoleValueRootIndex);
+
       // Stop if found the property.
       __ Branch(miss, eq, entity_name, Operand(Handle<String>(name)));
 
+      Label the_hole;
+      __ Branch(&the_hole, eq, entity_name, Operand(tmp));
+
       // Check if the entry name is not a symbol.
       __ lw(entity_name, FieldMemOperand(entity_name, HeapObject::kMapOffset));
       __ lbu(entity_name,
@@ -7109,6 +7115,8 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
       __ And(scratch0, entity_name, Operand(kIsSymbolMask));
       __ Branch(miss, eq, scratch0, Operand(zero_reg));
 
+      __ bind(&the_hole);
+
       // Restore the properties.
       __ lw(properties,
             FieldMemOperand(receiver, JSObject::kPropertiesOffset));

diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 61404fa..5587609 100644 (file)
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -5753,7 +5753,7 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
   // 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
   // property. It's true even if some slots represent deleted properties
-  // (their names are the null value).
+  // (their names are the hole value).
   for (int i = 0; i < kInlinedProbes; i++) {
     // r0 points to properties hash.
     // Compute the masked index: (hash + i + i * i) & mask.
@@ -5782,11 +5782,18 @@ void StringDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
     __ Cmp(entity_name, Handle<String>(name));
     __ j(equal, miss);
 
+    Label the_hole;
+    // Check for the hole and skip.
+    __ CompareRoot(entity_name, Heap::kTheHoleValueRootIndex);
+    __ j(equal, &the_hole, Label::kNear);
+
     // Check if the entry name is not a symbol.
     __ movq(entity_name, FieldOperand(entity_name, HeapObject::kMapOffset));
     __ testb(FieldOperand(entity_name, Map::kInstanceTypeOffset),
              Immediate(kIsSymbolMask));
     __ j(zero, miss);
+
+    __ bind(&the_hole);
   }
 
   StringDictionaryLookupStub stub(properties,