Using array index hash code for string-to-number conversion.

src/arm/ic-arm.cc

 // Copyright 2006-2008 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 509 matching lines @@
 
   // Is the string a symbol?
   // map: key map
   __ ldrb(hash, FieldMemOperand(map, Map::kInstanceTypeOffset));
   ASSERT(kSymbolTag != 0);
   __ tst(hash, Operand(kIsSymbolMask));
   __ b(eq, not_symbol);
 }
 
 
-// Picks out an array index from the hash field.
-static void GenerateIndexFromHash(MacroAssembler* masm,
-                                  Register key,
-                                  Register hash) {
-  // Register use:
-  //   key - holds the overwritten key on exit.
-  //   hash - holds the key's hash. Clobbered.
-
-  // If the hash field contains an array index pick it out. The assert checks
-  // that the constants for the maximum number of digits for an array index
-  // cached in the hash field and the number of bits reserved for it does not
-  // conflict.
-  ASSERT(TenToThe(String::kMaxCachedArrayIndexLength) <
-         (1 << String::kArrayIndexValueBits));
-  // We want the smi-tagged index in key.  kArrayIndexValueMask has zeros in
-  // the low kHashShift bits.
-  ASSERT(String::kHashShift >= kSmiTagSize);
-  // Here we actually clobber the key which will be used if calling into
-  // runtime later. However as the new key is the numeric value of a string key
-  // there is no difference in using either key.
-  ASSERT(String::kHashShift >= kSmiTagSize);
-  __ Ubfx(hash, hash, String::kHashShift, String::kArrayIndexValueBits);
-  __ mov(key, Operand(hash, LSL, kSmiTagSize));
-}
-
-
 // Defined in ic.cc.
 Object* CallIC_Miss(Arguments args);
 
 // The generated code does not accept smi keys.
 // The generated code falls through if both probes miss.
 static void GenerateMonomorphicCacheProbe(MacroAssembler* masm,
                                           int argc,
                                           Code::Kind kind) {
   // ----------- S t a t e -------------
   //  -- r1    : receiver
@@ skipping 279 matching lines @@
   // This branch is taken if:
   // - the receiver requires boxing or access check,
   // - the key is neither smi nor symbol,
   // - the value loaded is not a function,
   // - there is hope that the runtime will create a monomorphic call stub
   //   that will get fetched next time.
   __ IncrementCounter(&Counters::keyed_call_generic_slow, 1, r0, r3);
   GenerateMiss(masm, argc);
 
   __ bind(&index_string);
-  GenerateIndexFromHash(masm, r2, r3);
+  __ IndexFromHash(r3, r2);
   // Now jump to the place where smi keys are handled.
   __ jmp(&index_smi);
 }
 
 
 void KeyedCallIC::GenerateNormal(MacroAssembler* masm, int argc) {
   // ----------- S t a t e -------------
   //  -- r2    : name
   //  -- lr    : return address
   // -----------------------------------
@@ skipping 376 matching lines @@
   // r3: elements
   __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
   __ ldrb(r2, FieldMemOperand(r2, Map::kInstanceTypeOffset));
   GenerateGlobalInstanceTypeCheck(masm, r2, &slow);
   // Load the property to r0.
   GenerateDictionaryLoad(masm, &slow, r3, r0, r0, r2, r4);
   __ IncrementCounter(&Counters::keyed_load_generic_symbol, 1, r2, r3);
   __ Ret();
 
   __ bind(&index_string);
-  GenerateIndexFromHash(masm, key, r3);
+  __ IndexFromHash(r3, key);
   // Now jump to the place where smi keys are handled.
   __ jmp(&index_smi);
 }
 
 
 void KeyedLoadIC::GenerateString(MacroAssembler* masm) {
   // ---------- S t a t e --------------
   //  -- lr     : return address
   //  -- r0     : key (index)
   //  -- r1     : receiver
@@ skipping 1010 matching lines @@
   GenerateMiss(masm);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM