Next: Named Address Spaces, Previous: Hex Floats, Up: C Extensions [Contents][Index]
As an extension, GNU C supports fixed-point types as defined in the N1169 draft of ISO/IEC DTR 18037. Support for fixed-point types in GCC will evolve as the draft technical report changes. Calling conventions for any target might also change. Not all targets support fixed-point types.
The fixed-point types are
short _Fract,
_Fract,
long _Fract,
long long _Fract,
unsigned short _Fract,
unsigned _Fract,
unsigned long _Fract,
unsigned long long _Fract,
_Sat short _Fract,
_Sat _Fract,
_Sat long _Fract,
_Sat long long _Fract,
_Sat unsigned short _Fract,
_Sat unsigned _Fract,
_Sat unsigned long _Fract,
_Sat unsigned long long _Fract,
short _Accum,
_Accum,
long _Accum,
long long _Accum,
unsigned short _Accum,
unsigned _Accum,
unsigned long _Accum,
unsigned long long _Accum,
_Sat short _Accum,
_Sat _Accum,
_Sat long _Accum,
_Sat long long _Accum,
_Sat unsigned short _Accum,
_Sat unsigned _Accum,
_Sat unsigned long _Accum,
_Sat unsigned long long _Accum.
Fixed-point data values contain fractional and optional integral parts. The format of fixed-point data varies and depends on the target machine.
Support for fixed-point types includes:
++, --)
+, -, !)
+, -, *, /)
<<, >>)
<, <=, >=, >)
==, !=)
+=, -=, *=, /=,
<<=, >>=)
Use a suffix in a fixed-point literal constant:
short _Fract and
_Sat short _Fract
_Fract and _Sat _Fract
long _Fract and
_Sat long _Fract
long long _Fract and
_Sat long long _Fract
unsigned short _Fract and
_Sat unsigned short _Fract
unsigned _Fract and
_Sat unsigned _Fract
unsigned long _Fract and
_Sat unsigned long _Fract
unsigned long long _Fract
and _Sat unsigned long long _Fract
short _Accum and
_Sat short _Accum
_Accum and _Sat _Accum
long _Accum and
_Sat long _Accum
long long _Accum and
_Sat long long _Accum
unsigned short _Accum and
_Sat unsigned short _Accum
unsigned _Accum and
_Sat unsigned _Accum
unsigned long _Accum and
_Sat unsigned long _Accum
unsigned long long _Accum
and _Sat unsigned long long _Accum
GCC support of fixed-point types as specified by the draft technical report is incomplete:
Fixed-point types are supported by the DWARF debug information format.
Next: Named Address Spaces, Previous: Hex Floats, Up: C Extensions [Contents][Index]