NAME
Q_SIGNSHFT,
Q_SSIGN, Q_CRAWMASK,
Q_SRAWMASK, Q_GCRAW,
Q_GCVAL, Q_SCVAL —
fixed-point math functions which
manipulate the control/sign data bits
SYNOPSIS
#include
<sys/qmath.h>
uint32_t
Q_SIGNSHFT(QTYPE
q);
QTYPE
Q_SSIGN(QTYPE
q, bool isneg);
ITYPE
Q_CRAWMASK(QTYPE
q);
ITYPE
Q_SRAWMASK(QTYPE
q);
ITYPE
Q_GCRAW(QTYPE
q);
ITYPE
Q_GCVAL(QTYPE
q);
QTYPE
Q_SCVAL(QTYPE
q, ITYPE cv);
DESCRIPTION
Q_SIGNSHFT()
gets the bit position of q's sign bit relative to bit
zero.
Q_SSIGN()
sets the sign bit of q based on the boolean
isneg.
Q_CRAWMASK()
and
Q_SRAWMASK()
return q-specific bit masks for
q's control bits and sign bit respectively.
Q_GCRAW()
and
Q_GCVAL()
get the raw masked control bits and value of q's
control bits respectively.
Q_SCVAL()
sets q's control bits to the value
cv.
All of those functions operate on the following data types: s8q_t, u8q_t, s16q_t, u16q_t, s32q_t, u32q_t, s64q_t, and u64q_t, which are referred to generically as QTYPE. The ITYPE refers to the stdint(7) integer types.
For more details, see qmath(3).
RETURN VALUES
Q_SIGNSHFT() returns the sign bit's
position as an integer.
Q_SSIGN() returns the value of
q post change.
Q_CRAWMASK(),
Q_SRAWMASK(), Q_GCRAW() and
Q_GCVAL() return their respective values as integers
of the same underlying ITYPE as q.
Q_SCVAL() returns the value of
q post change.
SEE ALSO
HISTORY
The qmath(3) functions first appeared in FreeBSD 13.0.
AUTHORS
The qmath(3) functions and this manual page were written by Lawrence Stewart <lstewart@FreeBSD.org> and sponsored by Netflix, Inc.