Unix and Linux Discussions Tagged with compile |
|
Thread / Thread Starter |
Last Post |
Replies |
Views |
Forum |
|
|
|
0 |
25,027 |
Shell Programming and Scripting |
|
|
|
1 |
9,096 |
UNIX for Advanced & Expert Users |
|
|
|
1 |
5,898 |
Shell Programming and Scripting |
|
|
|
1 |
4,241 |
Programming |
|
|
|
1 |
8,562 |
UNIX for Advanced & Expert Users |
|
|
|
9 |
9,884 |
Solaris |
|
|
|
14 |
4,551 |
Programming |
|
|
|
1 |
5,301 |
UNIX for Beginners Questions & Answers |
|
|
|
11 |
5,253 |
UNIX for Beginners Questions & Answers |
|
|
|
2 |
1,363 |
Programming |
|
|
|
1 |
33,389 |
Shell Programming and Scripting |
|
|
|
0 |
6,472 |
AIX |
|
|
|
4 |
7,101 |
Slackware |
|
|
|
10 |
6,696 |
Solaris |
|
|
|
1 |
6,199 |
Red Hat |
|
|
|
1 |
4,951 |
OS X (Apple) |
|
|
|
0 |
12,001 |
Solaris |
|
|
|
17 |
29,739 |
Solaris |
|
|
|
0 |
4,901 |
UNIX for Dummies Questions & Answers |
|
|
|
2 |
4,829 |
Solaris |
|
|
|
1 |
4,974 |
Linux |
|
|
|
0 |
2,210 |
Ubuntu |
|
|
|
2 |
3,105 |
Programming |
|
|
|
2 |
4,547 |
UNIX for Advanced & Expert Users |
|
|
|
4 |
4,451 |
OS X (Apple) |
|
|
|
17 |
12,336 |
Solaris |
|
|
|
5 |
49,315 |
Shell Programming and Scripting |
|
|
|
4 |
4,707 |
Programming |
|
|
|
5 |
13,153 |
Ubuntu |
|
|
|
1 |
2,984 |
UNIX for Dummies Questions & Answers |
|
|
|
4 |
4,753 |
Solaris |
|
|
|
1 |
5,548 |
UNIX and Linux Applications |
|
|
|
1 |
9,226 |
Shell Programming and Scripting |
|
|
|
1 |
5,123 |
Linux |
|
|
|
0 |
6,228 |
Programming |
|
|
|
0 |
3,643 |
Programming |
|
|
|
5 |
7,954 |
Programming |
|
|
|
2 |
4,594 |
Shell Programming and Scripting |
|
|
|
2 |
6,725 |
AIX |
|
|
|
0 |
892 |
Software Releases - RSS News |
__BUILTIN_CONSTANT_P(3) BSD Library Functions Manual __BUILTIN_CONSTANT_P(3)
NAME
__builtin_constant_p -- GNU extension to determine compile time constants
SYNOPSIS
int
__builtin_constant_p(value);
DESCRIPTION
The __builtin_constant_p() is a GNU extension for determining whether a value is known to be constant at compile time. The function is
closely related to the concept of ``constant folding'' used by modern optimizing compilers.
If the value is known to be a compile-time constant, a value 1 is returned. If __builtin_constant_p() returns 0, the value is not a compile-
time constant in the sense that gcc(1) was unable to determine whether the value is constant or not.
EXAMPLES
A typical example of the use of __builtin_constant_p() involves a situation where it may be desirable to fold the computation if it involves
a constant, but a function call is needed otherwise. For instance, bswap16(3) is defined in NetBSD as:
#define bswap16(x)
(__builtin_constant_p((x)) ?
__byte_swap_u16_constant(x) : __BYTE_SWAP_U16_VARIABLE(x))
SEE ALSO
gcc(1), __builtin_object_size(3), __builtin_return_address(3)
CAVEATS
This is a non-standard, compiler-specific extension.
BSD
December 19, 2010 BSD