i.
VEC_$ISUB_MULT_CONSTANT16 Domain/OS VEC_$ISUB_MULT_CONSTANT16
NAME
vec_$isub_mult_constant16 - subtract two 16-bit integer vectors, multiply
by a scalar
SYNOPSIS (C)
#include <apollo/base.h>
#include <apollo/vec.h>
void vec_$isub_mult_constant16(
short int *start_vec,
short int *sub_vec,
long int &length,
short int &constant,
short int *result_vec)
SYNOPSIS (Pascal)
%include '/sys/ins/base.ins.pas';
%include '/sys/ins/vec.ins.pas';
procedure vec_$isub_mult_constant16(
in start_vec: univ vec_$integer16_vector;
in sub_vec: univ vec_$integer16_vector;
in length: integer32;
in constant: integer16;
out result_vec: univ vec_$integer16_vector);
SYNOPSIS (FORTRAN)
%include '/sys/ins/base.ins.ftn'
%include '/sys/ins/vec.ins.ftn'
parameter (nvec = 10)
integer*2 start_vec(nvec), sub_vec(nvec), result_vec(nvec), constant
integer*4 length
call vec_$isub_mult_constant16(start_vec, sub_vec,length, constant, result_vec)
DESCRIPTION
Vec_$isub_mult_constant16 subtracts the vector sub_vec from the vector
start_vec, multiplies the result by the scalar constant, and stores the
final result in result_vec. It differs from vec_$sub_mult_constant in
that the vectors being handled contain 16-bit integers.
The calculation performed is as follows:
For each integer I such that 1 <= I <= length,
result_vec(I) = (start_vec(I) - sub_vec(I)) x constant
start_vec
The vector to be subtracted from.
sub_vec
The vector to be subtracted.
length
The number of elements to be operated on; normally the same as the
number of elements in the vectors.
constant
The scalar constant by which the result of the subtraction is multi-
plied.
result_vec
The vector created by subtracting sub_vec from start_vec and multi-
plying the resulting vector by constant.
NOTES
When vec_$isub_mult_constant16 is used to operate on matrixes in C and
Pascal, start_vec, sub_vec, and result_vec are row vectors; in FORTRAN,
they are column vectors.
As in all the vec_$ calls, the result array must not overlap any of the
input arrays; the result array may be identical to an input, but must not
contain any subset of it. Because of pipelining, using overlapping
input and output arrays may cause incorrect results.
Vec_$isub_mult_constant16, like all 16-bit integer routines, performs
poorly when compared to the 32-bit integer routines. Its use should be
avoided wherever possible, especially on high-performance workstations.
SEE ALSO
vec_$sub_mult_constant, vec_$add_mult_constant, vec_$sub_mult_constant_i,
vec_$dsub_mult_constant, vec_$dsub_mult_constant_i,
vec_$isub_mult_constant, vec_$isub_mult_constant_i,
vec_$isub_mult_constant16_i.