Extract string->double and double->string conversions for use in the preparser.

src/cached-powers.cc

-// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// 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
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 #include <stdarg.h>
+#include <math.h>
 #include <limits.h>
 
-#include "v8.h"
-
+#include "../include/v8stdint.h"
+#include "globals.h"
+#include "checks.h"
 #include "cached-powers.h"
 
 namespace v8 {
 namespace internal {
 
 struct CachedPower {
   uint64_t significand;
   int16_t binary_exponent;
   int16_t decimal_exponent;
 };
@@ skipping 97 matching lines @@
     kCachedPowers[0].decimal_exponent;
 const int PowersOfTenCache::kMaxDecimalExponent =
     kCachedPowers[kCachedPowersLength - 1].decimal_exponent;
 
 void PowersOfTenCache::GetCachedPowerForBinaryExponentRange(
     int min_exponent,
     int max_exponent,
     DiyFp* power,
     int* decimal_exponent) {
   int kQ = DiyFp::kSignificandSize;
-  double k = ceiling((min_exponent + kQ - 1) * kD_1_LOG2_10);
+  // Some platforms return incorrect sign on 0 result. We can ignore that here,
+  // which means we can avoid depending on platform.h.
+  double k = ceil((min_exponent + kQ - 1) * kD_1_LOG2_10);
   int foo = kCachedPowersOffset;
   int index =
       (foo + static_cast<int>(k) - 1) / kDecimalExponentDistance + 1;
   ASSERT(0 <= index && index < kCachedPowersLength);
   CachedPower cached_power = kCachedPowers[index];
   ASSERT(min_exponent <= cached_power.binary_exponent);
   ASSERT(cached_power.binary_exponent <= max_exponent);
   *decimal_exponent = cached_power.decimal_exponent;
   *power = DiyFp(cached_power.significand, cached_power.binary_exponent);
 }
 
 
 void PowersOfTenCache::GetCachedPowerForDecimalExponent(int requested_exponent,
                                                         DiyFp* power,
                                                         int* found_exponent) {
   ASSERT(kMinDecimalExponent <= requested_exponent);
   ASSERT(requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance);
   int index =
       (requested_exponent + kCachedPowersOffset) / kDecimalExponentDistance;
   CachedPower cached_power = kCachedPowers[index];
   *power = DiyFp(cached_power.significand, cached_power.binary_exponent);
   *found_exponent = cached_power.decimal_exponent;
   ASSERT(*found_exponent <= requested_exponent);
   ASSERT(requested_exponent < *found_exponent + kDecimalExponentDistance);
 }
 
 } }  // namespace v8::internal