Merge revision 3813 to 3930 from bleeding_edge to partial snapshots branch.

src/utils.h

 // 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 139 matching lines @@
 template<class T, int shift, int size>
 class BitField {
  public:
   // Tells whether the provided value fits into the bit field.
   static bool is_valid(T value) {
     return (static_cast<uint32_t>(value) & ~((1U << (size)) - 1)) == 0;
   }
 
   // Returns a uint32_t mask of bit field.
   static uint32_t mask() {
-    return (1U << (size + shift)) - (1U << shift);
+    // To use all bits of a uint32 in a bitfield without compiler warnings we
+    // have to compute 2^32 without using a shift count of 32.
+    return ((1U << shift) << size) - (1U << shift);
   }
 
   // Returns a uint32_t with the bit field value encoded.
   static uint32_t encode(T value) {
     ASSERT(is_valid(value));
     return static_cast<uint32_t>(value) << shift;
   }
 
   // Extracts the bit field from the value.
   static T decode(uint32_t value) {
-    return static_cast<T>((value >> shift) & ((1U << (size)) - 1));
+    return static_cast<T>((value & mask()) >> shift);
   }
 };
 
 
 // ----------------------------------------------------------------------------
-// Support for compressed, machine-independent encoding
-// and decoding of integer values of arbitrary size.
-
-// Encoding and decoding from/to a buffer at position p;
-// the result is the position after the encoded integer.
-// Small signed integers in the range -64 <= x && x < 64
-// are encoded in 1 byte; larger values are encoded in 2
-// or more bytes. At most sizeof(int) + 1 bytes are used
-// in the worst case.
-byte* EncodeInt(byte* p, int x);
-byte* DecodeInt(byte* p, int* x);
-
-
-// Encoding and decoding from/to a buffer at position p - 1
-// moving backward; the result is the position of the last
-// byte written. These routines are useful to read/write
-// into a buffer starting at the end of the buffer.
-byte* EncodeUnsignedIntBackward(byte* p, unsigned int x);
-
-// The decoding function is inlined since its performance is
-// important to mark-sweep garbage collection.
-inline byte* DecodeUnsignedIntBackward(byte* p, unsigned int* x) {
-  byte b = *--p;
-  if (b >= 128) {
-    *x = static_cast<unsigned int>(b) - 128;
-    return p;
-  }
-  unsigned int r = static_cast<unsigned int>(b);
-  unsigned int s = 7;
-  b = *--p;
-  while (b < 128) {
-    r |= static_cast<unsigned int>(b) << s;
-    s += 7;
-    b = *--p;
-  }
-  // b >= 128
-  *x = r | ((static_cast<unsigned int>(b) - 128) << s);
-  return p;
-}
-
-
-// ----------------------------------------------------------------------------
 // Hash function.
 
 uint32_t ComputeIntegerHash(uint32_t key);
 
 
 // ----------------------------------------------------------------------------
 // I/O support.
 
 // Our version of printf(). Avoids compilation errors that we get
 // with standard printf when attempting to print pointers, etc.
@@ skipping 354 matching lines @@
   }
 }
 
 
 // Calculate 10^exponent.
 int TenToThe(int exponent);
 
 } }  // namespace v8::internal
 
 #endif  // V8_UTILS_H_