Sun WorkShop Compiler C 5.0 User's Guide

Storage Allocation

Table A-1 shows the data types and how they are represented.

Table A-1 Storage Allocation for Data Types


Data Type	Internal Representation
`char` elements	A single 8-bit byte aligned on a byte boundary.
`short` integers	Halfword (two bytes or 16 bits), aligned on a two-byte boundary
`int` and `long`	32 bits on v8 (four bytes or one word), aligned on a four-byte boundary 64 bits on v9 (four bytes or one word) aligned on an eight-byte boundary)
`long long` [`long` `long` is not available in `-Xc` mode.]	(SPARC) 64 bits (eight bytes or two words), aligned on an eight-byte boundary (Intel) 64 bits (eight bytes or two words), aligned on a four-byte boundary
`float`	32 bits (four bytes or one word), aligned on a four-byte boundary. A `float` has a `sign` bit, 8-bit exponent, and 23-bit fraction.
`double`	64 bits (eight bytes or two words), aligned on an eight-byte boundary (SPARC) or aligned on a four-byte boundary (Intel). A `double` element has a `sign` bit, an 11-bit exponent and a 52-bit fraction.
`long double`	v8 (SPARC) 128 bits (16 bytes or four words), aligned on an eight-byte boundary. A `long double` element has a `sign` bit, a 15-bit exponent and a 112-bit fraction. v9 (SPARC) 128 bits (16 bytes or four words), aligned on a 16 byte boundary. A `long double` element has a `sign` bit, a 15-bit exponent and a 112-bit fraction. (Intel) 96 bits (12 bytes or three words) aligned on a four-byte boundary. A `long double` element has a `sign` bit, a 16-bit exponent, and a 64-bit fraction. 16 bits are unused.