diff --git a/src/conversions.h b/src/conversions.h
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+// 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
+//       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,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// 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.
+
+#ifndef V8_CONVERSIONS_H_
+#define V8_CONVERSIONS_H_
+
+namespace v8 {
+namespace internal {
+
+// The fast double-to-int conversion routine does not guarantee
+// rounding towards zero.
+// The result is unspecified if x is infinite or NaN, or if the rounded
+// integer value is outside the range of type int.
+static inline int FastD2I(double x);
+
+
+static inline double FastI2D(int x) {
+  // There is no rounding involved in converting an integer to a
+  // double, so this code should compile to a few instructions without
+  // any FPU pipeline stalls.
+  return static_cast<double>(x);
+}
+
+
+static inline double FastUI2D(unsigned x) {
+  // There is no rounding involved in converting an unsigned integer to a
+  // double, so this code should compile to a few instructions without
+  // any FPU pipeline stalls.
+  return static_cast<double>(x);
+}
+
+
+// This function should match the exact semantics of ECMA-262 9.4.
+static inline double DoubleToInteger(double x);
+
+
+// This function should match the exact semantics of ECMA-262 9.5.
+static inline int32_t DoubleToInt32(double x);
+
+
+// This function should match the exact semantics of ECMA-262 9.6.
+static inline uint32_t DoubleToUint32(double x) {
+  return static_cast<uint32_t>(DoubleToInt32(x));
+}
+
+
+// Returns the value (0 .. 15) of a hexadecimal character c.
+// If c is not a legal hexadecimal character, returns a value < 0.
+int HexValue(uc32 c);
+
+
+// Enumeration for allowing octals and ignoring junk when converting
+// strings to numbers.
+enum ConversionFlags {
+  NO_FLAGS = 0,
+  ALLOW_HEX = 1,
+  ALLOW_OCTALS = 2,
+  ALLOW_TRAILING_JUNK = 4
+};
+
+
+// Convert from Number object to C integer.
+static inline int32_t NumberToInt32(Object* number);
+static inline uint32_t NumberToUint32(Object* number);
+
+
+// Converts a string into a double value according to ECMA-262 9.3.1
+double StringToDouble(const char* str, int flags, double empty_string_val = 0);
+double StringToDouble(String* str, int flags, double empty_string_val = 0);
+
+// Converts a string into an integer.
+int StringToInt(String* str, int index, int radix, double* value);
+int StringToInt(const char* str, int index, int radix, double* value);
+
+// Converts a double to a string value according to ECMA-262 9.8.1.
+// The buffer should be large enough for any floating point number.
+// 100 characters is enough.
+const char* DoubleToCString(double value, Vector<char> buffer);
+
+// Convert an int to a null-terminated string. The returned string is
+// located inside the buffer, but not necessarily at the start.
+const char* IntToCString(int n, Vector<char> buffer);
+
+// Additional number to string conversions for the number type.
+// The caller is responsible for calling free on the returned pointer.
+char* DoubleToFixedCString(double value, int f);
+char* DoubleToExponentialCString(double value, int f);
+char* DoubleToPrecisionCString(double value, int f);
+char* DoubleToRadixCString(double value, int radix);
+
+} }  // namespace v8::internal
+
+#endif  // V8_CONVERSIONS_H_