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.TH LIBJ2_J2I_RSH 3 LIBJ2
.SH NAME
libj2_j2i_rsh \- Right-shift bits
.SH SYNOPSIS
.nf
#include <libj2.h>
void \fBlibj2_j2i_rsh\fP(struct libj2_j2i *\fIa\fP, unsigned \fIb\fP);
void \fBlibj2_j2i_rsh_to_j2i\fP(const struct libj2_j2i *\fIa\fP, unsigned \fIb\fP, struct libj2_j2i *\fIr\fP);
void \fBlibj2_ji_rsh_to_j2i\fP(intmax_t \fIa\fP, unsigned \fIb\fP, struct libj2_j2i *\fIr\fP);
void \fBlibj2_j2u_rsh\fP(struct libj2_j2u *\fIa\fP, unsigned \fIb\fP);
void \fBlibj2_j2u_rsh_to_j2u\fP(const struct libj2_j2u *\fIa\fP, unsigned \fIb\fP, struct libj2_j2u *\fIr\fP);
void \fBlibj2_ju_rsh_to_j2u\fP(uintmax_t \fIa\fP, unsigned \fIb\fP, struct libj2_j2u *\fIr\fP);
int \fBlibj2_j2i_rsh_underflow\fP(struct libj2_j2i *\fIa\fP, unsigned \fIb\fP);
int \fBlibj2_j2i_rsh_to_j2i_underflow\fP(const struct libj2_j2i *\fIa\fP, unsigned \fIb\fP, struct libj2_j2i *\fIr\fP);
int \fBlibj2_ji_rsh_to_j2i_underflow\fP(intmax_t \fIa\fP, unsigned \fIb\fP, struct libj2_j2i *\fIr\fP);
int \fBlibj2_j2u_rsh_underflow\fP(struct libj2_j2u *\fIa\fP, unsigned \fIb\fP);
int \fBlibj2_j2u_rsh_to_j2u_underflow\fP(const struct libj2_j2u *\fIa\fP, unsigned \fIb\fP, struct libj2_j2u *\fIr\fP);
int \fBlibj2_ju_rsh_to_j2u_underflow\fP(uintmax_t \fIa\fP, unsigned \fIb\fP, struct libj2_j2u *\fIr\fP);
int \fBlibj2_j2i_rsh_underflow_p\fP(const struct libj2_j2i *\fIa\fP, unsigned \fIb\fP);
int \fBlibj2_ji_rsh_underflow_p\fP(intmax_t \fIa\fP, unsigned \fIb\fP);
int \fBlibj2_j2u_rsh_underflow_p\fP(const struct libj2_j2u *\fIa\fP, unsigned \fIb\fP);
int \fBlibj2_ju_rsh_underflow_p\fP(uintmax_t \fIa\fP, unsigned \fIb\fP);
.fi
.PP
Link with
.IR -lj2 .
.SH DESCRIPTION
The above listed functions discard the
.I b
least significant bits in
.IR a ,
shift all bits to
.I b
less significant positions, and clears the
.I b
most significant bits if
.I a
was non-negative, but sets the
.I b
most significant bits if
.I a
was negative, effectively dividing
.I a
by 2 to the power of
.IR b ,
rounding towards negative infinity.
The functions with the parameter
.I r
store the result in
.IR r ,
the other functions store the result in
.IR a ,
except the functions
.BR libj2_j2i_rsh_underflow_p (),
.BR libj2_ji_rsh_underflow_p (),
.BR libj2_j2u_rsh_underflow_p (),
and
.BR libj2_ju_rsh_underflow_p (),
only predict underflow, and do not perform
any bit-shifting, and therefore does store
it anywhere.
.PP
For the functions where
.I a
is a
.B uintmax_t
it is convert to a
.BR "struct libj2_j2u *" ,
and for the functions where
.I a
is a
.B intmax_t
it is convert to a
.BR "struct libj2_j2i *" ,
before described operations.
.PP
The value-returning functions (that is, those
with word
.B underflow
in their name), detect underflow, that is,
if any discarded bit (any of the
.I b
most significant bits) was set.
.PP
The arguments are assumed to be
.RI non- NULL .
.SH RETURN VALUE
For functions with a return value, the functions
return +1 if any discarded bit was set and
.I a
was positive, -1 if any discarded bit was cleared and
.I a
was negative,
and 0 otherwise.
.SH ERRORS
The above listed functions cannot fail.
.SH HISTORY
The
.BR libj2_j2u_rsh (),
.BR libj2_j2u_rsh_to_j2u (),
.BR libj2_ju_rsh_to_j2u (),
.BR libj2_j2u_rsh_underflow (),
.BR libj2_j2u_rsh_to_j2u_underflow (),
.BR libj2_ju_rsh_to_j2u_underflow (),
.BR libj2_j2u_rsh_underflow_p (),
and
.BR libj2_ju_rsh_underflow_p ()
functions were added in version 1.0 of
.BR libj2 .
.PP
The
.BR libj2_j2i_rsh (),
.BR libj2_j2i_rsh_to_j2i (),
.BR libj2_ji_rsh_to_j2i (),
.BR libj2_j2i_rsh_underflow (),
.BR libj2_j2i_rsh_to_j2i_underflow (),
.BR libj2_ji_rsh_to_j2i_underflow (),
.BR libj2_j2i_rsh_underflow_p (),
and
.BR libj2_ji_rsh_underflow_p ()
functions were added in version 1.1 of
.BR libj2 .
.SH SEE ALSO
.BR libj2 (7),
.BR libj2_j2i_lsh (3),
.BR libj2_j2u_lrot (3),
.BR libj2_j2u_rrot (3)
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