Parser: Delay internalizing strings and values.

src/utils.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdarg.h>
 #include <sys/stat.h>
 
 #include "src/v8.h"
 
 #include "src/checks.h"
@@ skipping 357 matching lines @@
 #elif V8_OS_POSIX && V8_HOST_ARCH_ARM
   memcopy_uint8_function = CreateMemCopyUint8Function(&MemCopyUint8Wrapper);
   memcopy_uint16_uint8_function =
       CreateMemCopyUint16Uint8Function(&MemCopyUint16Uint8Wrapper);
 #elif V8_OS_POSIX && V8_HOST_ARCH_MIPS
   memcopy_uint8_function = CreateMemCopyUint8Function(&MemCopyUint8Wrapper);
 #endif
 }
 
 
+bool DoubleToBoolean(double d) {
+  // NaN, +0, and -0 should return the false object
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+  union IeeeDoubleLittleEndianArchType u;
+#elif __BYTE_ORDER == __BIG_ENDIAN
+  union IeeeDoubleBigEndianArchType u;
+#endif
+  u.d = d;
+  if (u.bits.exp == 2047) {
+    // Detect NaN for IEEE double precision floating point.
+    if ((u.bits.man_low | u.bits.man_high) != 0) return false;
+  }
+  if (u.bits.exp == 0) {
+    // Detect +0, and -0 for IEEE double precision floating point.
+    if ((u.bits.man_low | u.bits.man_high) == 0) return false;
+  }
+  return true;
+}
+
+
 } }  // namespace v8::internal