Data Types

Data types are implemented in HP C/HP-UX as follows:

The char type is signed.
All types can have the register storage class, although it is only honored for scalar types. Ten register declarations per function are honored. More are honored when the +R option is used.
The signed integer types are represented internally using twos complement form.
Structures and unions start and end on an alignment boundary which is that of their most restrictive member.
The long long data type cannot be used to declare an array's size.
The long long data type is available only under -Ac, -Aa +e, and -Ae compilation modes.

Table 10-1 “HP C/HP-UX Data Types ” lists the sizes and ranges of different HP C/HP-UX data types.

Refer to the HP C Programmer's Guide for comparisons of data storage and alignment on the following computer systems:

HP 3000 Series 900
HP 3000/V
HP 9000 Series 700/800

Table 10-1 HP C/HP-UX Data Types

Type	Bits	Bytes	Low Bound	High Bound	Comments
`char`	8	1	-128	127	Character
`signed char`	8	1	-128	127	Signed integer
`unsigned char`	8	1	0	255	Unsigned integer
`short`	16	2	-32,768	32,767	Signed integer
`unsigned short`	16	2	0	65,535	Unsigned integer
`int`	32	4	-2,147,483,648	2,147,483,647	Signed integer
`unsigned int`	32	4	0	4,294,967,295	Unsigned integer
`long`	32	4	-2,147,483,648	2,147,483,647	Signed integer
`long long`	64	8	-2⁶³	2⁶³ -1	Signed integer
`unsigned long`	32	4	0	4,294,967,295	Unsigned integer
`unsigned long long`	64	8	0	2⁶⁴ -1	Unsigned integer
`float`	32	4	See (a) below.	See (b) below.	Floating-point
`double`	64	8	See (c) below.	See (d) below.	Floating-point
`long double`	128	16	See (e) below.	See (f) below.	Floating-point
`enum`	32	4	-2,147,483,648	2,147,483,647	Signed integer

Comments

In the following comments, the low bounds of float, double, and long double data types are given in their normalized and denormalized forms. Normalized and denormalized refer to the way data is stored. Normalized numbers are represented with a greater degree of accuracy than denormalized numbers. Denormalized numbers are very small numbers represented with fewer significant bits than normalized numbers.

a.  Least normalized:     1.17549435E-38F
    Least denormalized:  1.4012985E-45F
 
b.  3.40282347E+38F
 
c.  Least normalized:      2.2250738585072014E-308
    Least denormalized:  4.9406564584124654E-324
 
d.  1.7976931348623157E+308
 
e.  Least normalized:
    3.3621031431120935062626778173217526026E-4932L
 
    Least denormalized:
    6.4751751194380251109244389582276465525E-4966L
 
f.  1.1897314953572317650857593266280070162E+4932L

Data Types

Technical documentation

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