Remove the different length string types...

src/x64/ic-x64.cc

 // Copyright 2009 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 13 matching lines @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "v8.h"
 
 #include "codegen-inl.h"
 #include "ic-inl.h"
 #include "runtime.h"
 #include "stub-cache.h"
+#include "utils.h"
 
 namespace v8 {
 namespace internal {
 
 // ----------------------------------------------------------------------------
 // Static IC stub generators.
 //
 
 #define __ ACCESS_MASM(masm)
 
@@ skipping 56 matching lines @@
 
   // Generate an unrolled loop that performs a few probes before
   // giving up. Measurements done on Gmail indicate that 2 probes
   // cover ~93% of loads from dictionaries.
   static const int kProbes = 4;
   const int kElementsStartOffset =
       StringDictionary::kHeaderSize +
       StringDictionary::kElementsStartIndex * kPointerSize;
   for (int i = 0; i < kProbes; i++) {
     // Compute the masked index: (hash + i + i * i) & mask.
-    __ movl(r1, FieldOperand(name, String::kLengthOffset));
+    __ movl(r1, FieldOperand(name, String::kHashFieldOffset));
     __ shrl(r1, Immediate(String::kHashShift));
     if (i > 0) {
       __ addl(r1, Immediate(StringDictionary::GetProbeOffset(i)));
     }
     __ and_(r1, r2);
 
     // Scale the index by multiplying by the entry size.
     ASSERT(StringDictionary::kEntrySize == 3);
     __ lea(r1, Operand(r1, r1, times_2, 0));  // r1 = r1 * 3
 
@@ skipping 111 matching lines @@
   __ pop(rbx);
   __ push(rcx);  // receiver
   __ push(rax);  // name
   __ push(rbx);  // return address
 
   // Perform tail call to the entry.
   __ TailCallRuntime(f, 2, 1);
 }
 
 
-#ifdef DEBUG
-// For use in assert below.
-static int TenToThe(int exponent) {
-  ASSERT(exponent <= 9);
-  ASSERT(exponent >= 1);
-  int answer = 10;
-  for (int i = 1; i < exponent; i++) answer *= 10;
-  return answer;
-}
-#endif
-
-
 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, check_pixel_array;
 
   // Load name and receiver.
   __ movq(rax, Operand(rsp, kPointerSize));
@@ skipping 56 matching lines @@
   // Slow case: Load name and receiver from stack and jump to runtime.
   __ bind(&slow);
   __ IncrementCounter(&Counters::keyed_load_generic_slow, 1);
   Generate(masm, ExternalReference(Runtime::kKeyedGetProperty));
   __ 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?
-  __ movl(rbx, FieldOperand(rax, String::kLengthOffset));
+  __ 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.
   __ 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);
   GenerateCheckNonObjectOrLoaded(masm, &slow, rcx);
   __ movq(rax, rcx);
   __ IncrementCounter(&Counters::keyed_load_generic_symbol, 1);
   __ ret(0);
-  // Array index string: If short enough use cache in length/hash field (rbx).
-  // We assert that there are enough bits in an int32_t after the hash shift
-  // bits have been subtracted to allow space for the length and the cached
-  // array index.
+  // 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::kShortLengthShift - String::kHashShift)));
+         (1 << String::kArrayIndexValueBits));
   __ bind(&index_string);
-  const int kLengthFieldLimit =
-      (String::kMaxCachedArrayIndexLength + 1) << String::kShortLengthShift;
-  __ cmpl(rbx, Immediate(kLengthFieldLimit));
-  __ j(above_equal, &slow);
   __ movl(rax, rbx);
-  __ and_(rax, Immediate((1 << String::kShortLengthShift) - 1));
-  __ shrl(rax, Immediate(String::kLongLengthShift));
+  __ and_(rax, Immediate(String::kArrayIndexHashMask));
+  __ shrl(rax, Immediate(String::kHashShift));
   __ jmp(&index_int);
 }
 
 
 void KeyedLoadIC::GenerateExternalArray(MacroAssembler* masm,
                                         ExternalArrayType array_type) {
   // ----------- S t a t e -------------
   //  -- rsp[0] : return address
   //  -- rsp[8] : name
   //  -- rsp[16] : receiver
@@ skipping 958 matching lines @@
 
   // Cache miss: Jump to runtime.
   Generate(masm, ExternalReference(IC_Utility(kStoreIC_Miss)));
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal