RealView Compilation Tools Compiler Reference Guide - ARM ...

C and C++ Implementation Details
See Structures, unions, enumerations, and bitfields on page 5-7 for more information.
Integer
Integers are represented in two's complement form. The low word of a long long is at
the low address in little-endian mode, and at the high address in big-endian mode.
Float
Floating-point quantities are stored in IEEE format:
• float values are represented by IEEE single-precision values
• double and long double values are represented by IEEE double-precision values.
For double and long double quantities the word containing the sign, the exponent, and
the most significant part of the mantissa is stored with the lower machine address in
big-endian mode and at the higher address in little-endian mode. See Operations on
floating-point types on page 5-6 for more information.
Arrays and pointers
The following statements apply to all pointers to objects in C and C++, except pointers
to members:
• Adjacent bytes have addresses that differ by one.
• The macro NULL expands to the value 0.
• Casting between integers and pointers results in no change of representation.
• The compiler warns of casts between pointers to functions and pointers to data.
• The type size_t is defined as unsigned int.
• The type ptrdiff_t is defined as signed int.
5.1.3 Operations on basic data types
The ARM compiler performs the usual arithmetic conversions set out in relevant
sections of the ISO C99 and ISO C++ standards. The following subsections describe
additional points that relate to arithmetic operations.
See also Expression evaluation on page B-7.
Operations on integral types
The following statements apply to operations on the integral types:
• All signed integer arithmetic uses a two's complement representation.
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