Create and use shared stub for for DictionaryValue-based elements.

src/ia32/macro-assembler-ia32.cc

 // Copyright 2011 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 716 matching lines @@
                      Context::SECURITY_TOKEN_INDEX * kPointerSize;
   mov(scratch, FieldOperand(scratch, token_offset));
   cmp(scratch, FieldOperand(holder_reg, token_offset));
   pop(holder_reg);
   j(not_equal, miss);
 
   bind(&same_contexts);
 }
 
 
+void MacroAssembler::LoadFromNumberDictionary(Label* miss,
+                                              Register elements,
+                                              Register key,
+                                              Register r0,
+                                              Register r1,
+                                              Register r2,
+                                              Register result) {
+  // Register use:
+  //
+  // elements - holds the slow-case elements of the receiver and is unchanged.
+  //
+  // key      - holds the smi key on entry and is unchanged.
+  //
+  // Scratch registers:
+  //
+  // r0 - holds the untagged key on entry and holds the hash once computed.
+  //
+  // r1 - used to hold the capacity mask of the dictionary
+  //
+  // r2 - used for the index into the dictionary.
+  //
+  // result - holds the result on exit if the load succeeds and we fall through.
+
+  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);
+  mov(r1, r0);
+  not_(r0);
+  shl(r1, 15);
+  add(r0, Operand(r1));
+  // hash = hash ^ (hash >> 12);
+  mov(r1, r0);
+  shr(r1, 12);
+  xor_(r0, Operand(r1));
+  // hash = hash + (hash << 2);
+  lea(r0, Operand(r0, r0, times_4, 0));
+  // hash = hash ^ (hash >> 4);
+  mov(r1, r0);
+  shr(r1, 4);
+  xor_(r0, Operand(r1));
+  // hash = hash * 2057;
+  imul(r0, r0, 2057);
+  // hash = hash ^ (hash >> 16);
+  mov(r1, r0);
+  shr(r1, 16);
+  xor_(r0, Operand(r1));
+
+  // Compute capacity mask.
+  mov(r1, FieldOperand(elements, NumberDictionary::kCapacityOffset));
+  shr(r1, kSmiTagSize);  // convert smi to int
+  dec(r1);
+
+  // 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.
+    mov(r2, r0);
+    // Compute the masked index: (hash + i + i * i) & mask.
+    if (i > 0) {
+      add(Operand(r2), Immediate(NumberDictionary::GetProbeOffset(i)));
+    }
+    and_(r2, Operand(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.
+    cmp(key, FieldOperand(elements,
+                          r2,
+                          times_pointer_size,
+                          NumberDictionary::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 =
+      NumberDictionary::kElementsStartOffset + 2 * kPointerSize;
+  ASSERT_EQ(NORMAL, 0);
+  test(FieldOperand(elements, r2, times_pointer_size, kDetailsOffset),
+       Immediate(PropertyDetails::TypeField::mask() << kSmiTagSize));
+  j(not_zero, miss);
+
+  // Get the value at the masked, scaled index.
+  const int kValueOffset =
+      NumberDictionary::kElementsStartOffset + kPointerSize;
+  mov(result, FieldOperand(elements, r2, times_pointer_size, kValueOffset));
+}
+
+
 void MacroAssembler::LoadAllocationTopHelper(Register result,
                                              Register scratch,
                                              AllocationFlags flags) {
   ExternalReference new_space_allocation_top =
       ExternalReference::new_space_allocation_top_address(isolate());
 
   // Just return if allocation top is already known.
   if ((flags & RESULT_CONTAINS_TOP) != 0) {
     // No use of scratch if allocation top is provided.
     ASSERT(scratch.is(no_reg));
@@ skipping 1382 matching lines @@
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32