From fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 Mon Sep 17 00:00:00 2001 From: Joseph Hunkeler Date: Wed, 8 Jul 2015 20:46:52 -0400 Subject: Initial commit --- sys/osb/shift.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 sys/osb/shift.c (limited to 'sys/osb/shift.c') diff --git a/sys/osb/shift.c b/sys/osb/shift.c new file mode 100644 index 00000000..86eacfb3 --- /dev/null +++ b/sys/osb/shift.c @@ -0,0 +1,49 @@ +/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + */ + +#define import_spp +#define import_knames +#include + +/* + * 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)); +} -- cgit