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/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
*/
#define import_spp
#define import_knames
#include <iraf.h>
/*
* SHIFT.C -- Bitwise shift operators. A positive bitshift shifts to the left,
* zero-filling at the right, i.e., a left shift by 1 is equivalent to a
* multiplication by 2 (but does not cause integer overflow). A negative shift
* shifts to the right and is equivalent to a division.
*/
/* SHIFTI -- Bitwise boolean SHIFT of two integer variables.
*/
XINT
SHIFTI (
XINT *a_a, /* operand to be shifted */
XINT *a_bits /* number of bits to shift */
)
{
register XINT a = *a_a, bits = *a_bits;
return (bits > 0 ? (a << bits) : (a >> -bits));
}
/* SHIFTS -- Bitwise boolean SHIFT of two short-integer variables.
*/
XSHORT
SHIFTS (
XSHORT *a_a, /* operand to be shifted */
XSHORT *a_bits /* number of bits to shift */
)
{
register XSHORT a = *a_a, bits = *a_bits;
return (bits > 0 ? (a << bits) : (a >> -bits));
}
/* SHIFTL -- Bitwise boolean SHIFT of two long-integer variables.
*/
XLONG
SHIFTL (
XLONG *a_a, /* operand to be shifted */
XLONG *a_bits /* number of bits to shift */
)
{
register XLONG a = *a_a, bits = *a_bits;
return (bits > 0 ? (a << bits) : (a >> -bits));
}
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