Probe keyed load cache in generic keyed load stub....

src/x64/ic-x64.cc

Index: src/x64/ic-x64.cc
===================================================================
--- src/x64/ic-x64.cc	(revision 3428)
+++ src/x64/ic-x64.cc	(working copy)
@@ -50,7 +50,7 @@
 // or if name is not a symbol, and will jump to the miss_label in that case.
 static void GenerateDictionaryLoad(MacroAssembler* masm, Label* miss_label,
                                    Register r0, Register r1, Register r2,
-                                   Register name) {
+                                   Register name, bool check_dictionary) {

[Erik Corry, 2009/12/09 10:43:40]

Use enum.

   // Register use:
   //
   // r0   - used to hold the property dictionary.
@@ -86,11 +86,15 @@
   __ cmpb(r0, Immediate(JS_BUILTINS_OBJECT_TYPE));
   __ j(equal, miss_label);
 
-  // Check that the properties array is a dictionary.
+  // Load properties array.
   __ movq(r0, FieldOperand(r1, JSObject::kPropertiesOffset));
-  __ Cmp(FieldOperand(r0, HeapObject::kMapOffset), Factory::hash_table_map());
-  __ j(not_equal, miss_label);
 
+  if (check_dictionary) {
+    // Check that the properties array is a dictionary.
+    __ Cmp(FieldOperand(r0, HeapObject::kMapOffset), Factory::hash_table_map());
+    __ j(not_equal, miss_label);
+  }
+
   // Compute the capacity mask.
   const int kCapacityOffset =
       StringDictionary::kHeaderSize +
@@ -246,7 +250,8 @@
   //  -- rsp[8] : name
   //  -- rsp[16] : receiver
   // -----------------------------------
-  Label slow, check_string, index_int, index_string, check_pixel_array;
+  Label slow, check_string, index_int, index_string;
+  Label check_pixel_array, probe_dictionary;
 
   // Load name and receiver.
   __ movq(rax, Operand(rsp, kPointerSize));
@@ -319,14 +324,65 @@
   __ movl(rbx, FieldOperand(rax, String::kHashFieldOffset));
   __ testl(rbx, Immediate(String::kIsArrayIndexMask));
 
-  // If the string is a symbol, do a quick inline probe of the receiver's
-  // dictionary, if it exists.
+  // Is the string a symbol?
   __ j(not_zero, &index_string);  // The value in rbx is used at jump target.
   __ testb(FieldOperand(rdx, Map::kInstanceTypeOffset),
            Immediate(kIsSymbolMask));
   __ j(zero, &slow);
-  // Probe the dictionary leaving result in rcx.
-  GenerateDictionaryLoad(masm, &slow, rbx, rcx, rdx, rax);
+
+  // If the receiver is a fast-case object, check the keyed lookup
+  // cache. Otherwise probe the dictionary leaving result in rcx.
+  __ movq(rbx, FieldOperand(rcx, JSObject::kPropertiesOffset));
+  __ Cmp(FieldOperand(rbx, HeapObject::kMapOffset), Factory::hash_table_map());
+  __ j(equal, &probe_dictionary);
+
+  // Load the map of the receiver, compute the keyed lookup cache hash
+  // based on 32 bits of the map pointer and the string hash.
+  __ movq(rbx, FieldOperand(rcx, HeapObject::kMapOffset));
+  __ movl(rdx, rbx);
+  __ shr(rdx, Immediate(KeyedLookupCache::kMapHashShift));
+  __ movl(rax, FieldOperand(rax, String::kHashFieldOffset));
+  __ shr(rax, Immediate(String::kHashShift));
+  __ xor_(rdx, rax);
+  __ and_(rdx, Immediate(KeyedLookupCache::kCapacityMask));
+
+  // Load the key (consisting of map and symbol) from the cache and
+  // check for match.
+  ExternalReference cache_keys
+      = ExternalReference::keyed_lookup_cache_keys();
+  __ movq(rdi, rdx);
+  __ shl(rdi, Immediate(kPointerSizeLog2 + 1));
+  __ movq(kScratchRegister, cache_keys);
+  __ movq(rax, Operand(kScratchRegister, rdi, times_1, 0));
+  __ cmpq(rbx, rax);
+  __ j(not_equal, &slow);
+  __ movq(rax, Operand(rsp, kPointerSize));
+  __ addq(rdi, Immediate(kPointerSize));
+  __ movq(rdi, Operand(kScratchRegister, rdi, times_1, 0));
+  __ cmpq(rax, rdi);
+  __ j(not_equal, &slow);
+
+  // Get field offset which is a 32-bit integer and check that it is
+  // an in-object property.
+  ExternalReference cache_field_offsets
+      = ExternalReference::keyed_lookup_cache_field_offsets();
+  __ movq(kScratchRegister, cache_field_offsets);
+  __ movl(rax, Operand(kScratchRegister, rdx, times_4, 0));
+  __ movzxbq(rdx, FieldOperand(rbx, Map::kInObjectPropertiesOffset));
+  __ cmpq(rax, rdx);
+  __ j(above_equal, &slow);
+
+  // Load in-object property.
+  __ subq(rax, rdx);
+  __ movzxbq(rdx, FieldOperand(rbx, Map::kInstanceSizeOffset));
+  __ addq(rax, rdx);
+  __ movq(rax, FieldOperand(rcx, rax, times_pointer_size, 0));
+  __ ret(0);
+
+  // Do a quick inline probe of the receiver's dictionary, if it
+  // exists.
+  __ bind(&probe_dictionary);
+  GenerateDictionaryLoad(masm, &slow, rbx, rcx, rdx, rax, false);
   GenerateCheckNonObjectOrLoaded(masm, &slow, rcx);
   __ movq(rax, rcx);
   __ IncrementCounter(&Counters::keyed_load_generic_symbol, 1);
@@ -971,8 +1027,8 @@
                                  int argc,
                                  bool is_global_object,
                                  Label* miss) {
-  // Search dictionary - put result in register edx.
-  GenerateDictionaryLoad(masm, miss, rax, rdx, rbx, rcx);
+  // Search dictionary - put result in register rdx.
+  GenerateDictionaryLoad(masm, miss, rax, rdx, rbx, rcx, true);
 
   // Move the result to register rdi and check that it isn't a smi.
   __ movq(rdi, rdx);
@@ -1196,9 +1252,9 @@
           Immediate(1 << Map::kIsAccessCheckNeeded));
   __ j(not_zero, &miss);
 
-  // Search the dictionary placing the result in eax.
+  // Search the dictionary placing the result in rax.
   __ bind(&probe);
-  GenerateDictionaryLoad(masm, &miss, rdx, rax, rbx, rcx);
+  GenerateDictionaryLoad(masm, &miss, rdx, rax, rbx, rcx, true);
   GenerateCheckNonObjectOrLoaded(masm, &miss, rax);
   __ ret(0);