Port number-dictionary probing in generated code to x64.

src/x64/ic-x64.cc

 // Copyright 2010 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
@@ skipping 133 matching lines @@
           Smi::FromInt(PropertyDetails::TypeField::mask()));
   __ j(not_zero, miss_label);
 
   // Get the value at the masked, scaled index.
   const int kValueOffset = kElementsStartOffset + kPointerSize;
   __ movq(r1,
           Operand(r0, r1, times_pointer_size, kValueOffset - kHeapObjectTag));
 }
 
 
+static void GenerateNumberDictionaryLoad(MacroAssembler* masm,
+                                         Label* miss,
+                                         Register elements,
+                                         Register key,
+                                         Register r0,
+                                         Register r1,
+                                         Register r2) {
+  // Register use:
+  //
+  // elements - holds the slow-case elements of the receiver and is unchanged.
+  //
+  // key      - holds the smi key on entry and is unchanged if a branch is
+  //            performed to the miss label.
+  //
+  // Scratch registers:
+  //
+  // r0 - holds the untagged key on entry and holds the hash once computed.
+  //      Holds the result on exit if the load succeeded.
+  //
+  // r1 - used to hold the capacity mask of the dictionary
+  //
+  // r2 - used for the index into the dictionary.
+  Label done;
+
+  // Compute the hash code from the untagged key.  This must be kept in sync
+  // with ComputeIntegerHash in utils.h.
+  //
+  // hash = ~hash + (hash << 15);
+  __ movl(r1, r0);
+  __ notl(r0);
+  __ shll(r1, Immediate(15));
+  __ addl(r0, r1);
+  // hash = hash ^ (hash >> 12);
+  __ movl(r1, r0);
+  __ shrl(r1, Immediate(12));
+  __ xorl(r0, r1);
+  // hash = hash + (hash << 2);
+  __ leal(r0, Operand(r0, r0, times_4, 0));
+  // hash = hash ^ (hash >> 4);
+  __ movl(r1, r0);
+  __ shrl(r1, Immediate(4));
+  __ xorl(r0, r1);
+  // hash = hash * 2057;
+  __ imull(r0, r0, Immediate(2057));
+  // hash = hash ^ (hash >> 16);
+  __ movl(r1, r0);
+  __ shrl(r1, Immediate(16));
+  __ xorl(r0, r1);
+
+  // Compute capacity mask.
+  const int kCapacityOffset =
+      StringDictionary::kHeaderSize +
+      StringDictionary::kCapacityIndex * kPointerSize;
+  __ movq(r1, FieldOperand(elements, kCapacityOffset));
+  __ SmiToInteger32(r1, r1);
+  __ decl(r1);
+
+  const int kElementsStartOffset =
+      NumberDictionary::kHeaderSize +
+      NumberDictionary::kElementsStartIndex * kPointerSize;
+
+  // Generate an unrolled loop that performs a few probes before giving up.
+  const int kProbes = 4;
+  for (int i = 0; i < kProbes; i++) {
+    // Use r2 for index calculations and keep the hash intact in r0.
+    __ movq(r2, r0);
+    // Compute the masked index: (hash + i + i * i) & mask.
+    if (i > 0) {
+      __ addl(r2, Immediate(NumberDictionary::GetProbeOffset(i)));
+    }
+    __ and_(r2, r1);
+
+    // Scale the index by multiplying by the entry size.
+    ASSERT(NumberDictionary::kEntrySize == 3);
+    __ lea(r2, Operand(r2, r2, times_2, 0));  // r2 = r2 * 3
+
+    // Check if the key matches.
+    __ cmpq(key, FieldOperand(elements,
+                              r2,
+                              times_pointer_size,
+                              kElementsStartOffset));
+    if (i != (kProbes - 1)) {
+      __ j(equal, &done);
+    } else {
+      __ j(not_equal, miss);
+    }
+  }
+
+  __ bind(&done);
+  // Check that the value is a normal propety.
+  const int kDetailsOffset = kElementsStartOffset + 2 * kPointerSize;
+  ASSERT_EQ(NORMAL, 0);
+  __ Test(FieldOperand(elements, r2, times_pointer_size, kDetailsOffset),
+          Smi::FromInt(PropertyDetails::TypeField::mask()));
+  __ j(not_zero, miss);
+
+  // Get the value at the masked, scaled index.
+  const int kValueOffset = kElementsStartOffset + kPointerSize;
+  __ movq(r0, FieldOperand(elements, r2, times_pointer_size, kValueOffset));
+}
+
+
 // Helper function used to check that a value is either not an object
 // or is loaded if it is an object.
 static void GenerateCheckNonObjectOrLoaded(MacroAssembler* masm, Label* miss,
                                            Register value) {
   Label done;
   // Check if the value is a Smi.
   __ JumpIfSmi(value, &done);
   // Check if the object has been loaded.
   __ movq(kScratchRegister, FieldOperand(value, JSFunction::kMapOffset));
   __ testb(FieldOperand(kScratchRegister, Map::kBitField2Offset),
@@ skipping 100 matching lines @@
 
 
 void KeyedLoadIC::GenerateGeneric(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- rsp[0] : return address
   //  -- rsp[8] : name
   //  -- rsp[16] : receiver
   // -----------------------------------
   Label slow, check_string, index_int, index_string;
   Label check_pixel_array, probe_dictionary;
+  Label check_number_dictionary;
 
   // Load name and receiver.
   __ movq(rax, Operand(rsp, kPointerSize));
   __ movq(rcx, Operand(rsp, 2 * kPointerSize));
 
   // Check that the object isn't a smi.
   __ JumpIfSmi(rcx, &slow);
 
   // Check that the object is some kind of JS object EXCEPT JS Value type.
   // In the case that the object is a value-wrapper object,
   // we enter the runtime system to make sure that indexing
   // into string objects work as intended.
   ASSERT(JS_OBJECT_TYPE > JS_VALUE_TYPE);
   __ CmpObjectType(rcx, JS_OBJECT_TYPE, rdx);
   __ j(below, &slow);
 
   // Check bit field.
   __ testb(FieldOperand(rdx, Map::kBitFieldOffset),
            Immediate(kSlowCaseBitFieldMask));
   __ j(not_zero, &slow);
 
   // Check that the key is a smi.
   __ JumpIfNotSmi(rax, &check_string);
+  // Save key in rbx in case we want it for the number dictionary
+  // case.
+  __ movq(rbx, rax);
   __ SmiToInteger32(rax, rax);
   // Get the elements array of the object.
   __ bind(&index_int);
   __ movq(rcx, FieldOperand(rcx, JSObject::kElementsOffset));
   // Check that the object is in fast mode (not dictionary).
   __ CompareRoot(FieldOperand(rcx, HeapObject::kMapOffset),
                  Heap::kFixedArrayMapRootIndex);
   __ j(not_equal, &check_pixel_array);
   // Check that the key (index) is within bounds.
   __ cmpl(rax, FieldOperand(rcx, FixedArray::kLengthOffset));
   __ j(above_equal, &slow);  // Unsigned comparison rejects negative indices.
   // Fast case: Do the load.
   __ movq(rax, Operand(rcx, rax, times_pointer_size,
                       FixedArray::kHeaderSize - kHeapObjectTag));
   __ CompareRoot(rax, Heap::kTheHoleValueRootIndex);
   // In case the loaded value is the_hole we have to consult GetProperty
   // to ensure the prototype chain is searched.
   __ j(equal, &slow);
   __ IncrementCounter(&Counters::keyed_load_generic_smi, 1);
   __ ret(0);
 
   // Check whether the elements is a pixel array.
   // rax: untagged index
   // rcx: elements array
   __ bind(&check_pixel_array);
   __ CompareRoot(FieldOperand(rcx, HeapObject::kMapOffset),
                  Heap::kPixelArrayMapRootIndex);
-  __ j(not_equal, &slow);
+  __ j(not_equal, &check_number_dictionary);
   __ cmpl(rax, FieldOperand(rcx, PixelArray::kLengthOffset));
   __ j(above_equal, &slow);
   __ movq(rcx, FieldOperand(rcx, PixelArray::kExternalPointerOffset));
   __ movzxbq(rax, Operand(rcx, rax, times_1, 0));
   __ Integer32ToSmi(rax, rax);
   __ ret(0);
 
+  __ bind(&check_number_dictionary);
+  // Check whether the elements is a number dictionary.
+  // rax: untagged index
+  // rbx: key
+  // rcx: elements
+  __ CompareRoot(FieldOperand(rcx, HeapObject::kMapOffset),
+                 Heap::kHashTableMapRootIndex);
+  __ j(not_equal, &slow);
+  GenerateNumberDictionaryLoad(masm, &slow, rcx, rbx, rax, rdx, rdi);
+  __ ret(0);
+
   // Slow case: Load name and receiver from stack and jump to runtime.
   __ bind(&slow);
   __ IncrementCounter(&Counters::keyed_load_generic_slow, 1);
   GenerateRuntimeGetProperty(masm);
   __ bind(&check_string);
   // The key is not a smi.
   // Is it a string?
   __ CmpObjectType(rax, FIRST_NONSTRING_TYPE, rdx);
   __ j(above_equal, &slow);
   // Is the string an array index, with cached numeric value?
@@ skipping 1117 matching lines @@
   __ bind(&miss);
 
   GenerateMiss(masm);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal