#include "blaswrap.h"
#include "f2c.h"
/* Subroutine */ int cspr_(char *uplo, integer *n, complex *alpha, complex *x,
integer *incx, complex *ap)
{
/* -- LAPACK auxiliary routine (version 3.1) --
Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
November 2006
Purpose
=======
CSPR performs the symmetric rank 1 operation
A := alpha*x*conjg( x' ) + A,
where alpha is a complex scalar, x is an n element vector and A is an
n by n symmetric matrix, supplied in packed form.
Arguments
==========
UPLO (input) CHARACTER*1
On entry, UPLO specifies whether the upper or lower
triangular part of the matrix A is supplied in the packed
array AP as follows:
UPLO = 'U' or 'u' The upper triangular part of A is
supplied in AP.
UPLO = 'L' or 'l' The lower triangular part of A is
supplied in AP.
Unchanged on exit.
N (input) INTEGER
On entry, N specifies the order of the matrix A.
N must be at least zero.
Unchanged on exit.
ALPHA (input) COMPLEX
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
X (input) COMPLEX array, dimension at least
( 1 + ( N - 1 )*abs( INCX ) ).
Before entry, the incremented array X must contain the N-
element vector x.
Unchanged on exit.
INCX (input) INTEGER
On entry, INCX specifies the increment for the elements of
X. INCX must not be zero.
Unchanged on exit.
AP (input/output) COMPLEX array, dimension at least
( ( N*( N + 1 ) )/2 ).
Before entry, with UPLO = 'U' or 'u', the array AP must
contain the upper triangular part of the symmetric matrix
packed sequentially, column by column, so that AP( 1 )
contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 )
and a( 2, 2 ) respectively, and so on. On exit, the array
AP is overwritten by the upper triangular part of the
updated matrix.
Before entry, with UPLO = 'L' or 'l', the array AP must
contain the lower triangular part of the symmetric matrix
packed sequentially, column by column, so that AP( 1 )
contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 )
and a( 3, 1 ) respectively, and so on. On exit, the array
AP is overwritten by the lower triangular part of the
updated matrix.
Note that the imaginary parts of the diagonal elements need
not be set, they are assumed to be zero, and on exit they
are set to zero.
=====================================================================
Test the input parameters.
Parameter adjustments */
/* System generated locals */
integer i__1, i__2, i__3, i__4, i__5;
complex q__1, q__2;
/* Local variables */
static integer i__, j, k, kk, ix, jx, kx, info;
static complex temp;
extern logical lsame_(char *, char *);
extern /* Subroutine */ int xerbla_(char *, integer *);
--ap;
--x;
/* Function Body */
info = 0;
if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
info = 1;
} else if (*n < 0) {
info = 2;
} else if (*incx == 0) {
info = 5;
}
if (info != 0) {
xerbla_("CSPR ", &info);
return 0;
}
/* Quick return if possible. */
if (*n == 0 || alpha->r == 0.f && alpha->i == 0.f) {
return 0;
}
/* Set the start point in X if the increment is not unity. */
if (*incx <= 0) {
kx = 1 - (*n - 1) * *incx;
} else if (*incx != 1) {
kx = 1;
}
/* Start the operations. In this version the elements of the array AP
are accessed sequentially with one pass through AP. */
kk = 1;
if (lsame_(uplo, "U")) {
/* Form A when upper triangle is stored in AP. */
if (*incx == 1) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = j;
if (x[i__2].r != 0.f || x[i__2].i != 0.f) {
i__2 = j;
q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i,
q__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
.r;
temp.r = q__1.r, temp.i = q__1.i;
k = kk;
i__2 = j - 1;
for (i__ = 1; i__ <= i__2; ++i__) {
i__3 = k;
i__4 = k;
i__5 = i__;
q__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i,
q__2.i = x[i__5].r * temp.i + x[i__5].i *
temp.r;
q__1.r = ap[i__4].r + q__2.r, q__1.i = ap[i__4].i +
q__2.i;
ap[i__3].r = q__1.r, ap[i__3].i = q__1.i;
++k;
/* L10: */
}
i__2 = kk + j - 1;
i__3 = kk + j - 1;
i__4 = j;
q__2.r = x[i__4].r * temp.r - x[i__4].i * temp.i, q__2.i =
x[i__4].r * temp.i + x[i__4].i * temp.r;
q__1.r = ap[i__3].r + q__2.r, q__1.i = ap[i__3].i +
q__2.i;
ap[i__2].r = q__1.r, ap[i__2].i = q__1.i;
} else {
i__2 = kk + j - 1;
i__3 = kk + j - 1;
ap[i__2].r = ap[i__3].r, ap[i__2].i = ap[i__3].i;
}
kk += j;
/* L20: */
}
} else {
jx = kx;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = jx;
if (x[i__2].r != 0.f || x[i__2].i != 0.f) {
i__2 = jx;
q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i,
q__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
.r;
temp.r = q__1.r, temp.i = q__1.i;
ix = kx;
i__2 = kk + j - 2;
for (k = kk; k <= i__2; ++k) {
i__3 = k;
i__4 = k;
i__5 = ix;
q__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i,
q__2.i = x[i__5].r * temp.i + x[i__5].i *
temp.r;
q__1.r = ap[i__4].r + q__2.r, q__1.i = ap[i__4].i +
q__2.i;
ap[i__3].r = q__1.r, ap[i__3].i = q__1.i;
ix += *incx;
/* L30: */
}
i__2 = kk + j - 1;
i__3 = kk + j - 1;
i__4 = jx;
q__2.r = x[i__4].r * temp.r - x[i__4].i * temp.i, q__2.i =
x[i__4].r * temp.i + x[i__4].i * temp.r;
q__1.r = ap[i__3].r + q__2.r, q__1.i = ap[i__3].i +
q__2.i;
ap[i__2].r = q__1.r, ap[i__2].i = q__1.i;
} else {
i__2 = kk + j - 1;
i__3 = kk + j - 1;
ap[i__2].r = ap[i__3].r, ap[i__2].i = ap[i__3].i;
}
jx += *incx;
kk += j;
/* L40: */
}
}
} else {
/* Form A when lower triangle is stored in AP. */
if (*incx == 1) {
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = j;
if (x[i__2].r != 0.f || x[i__2].i != 0.f) {
i__2 = j;
q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i,
q__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
.r;
temp.r = q__1.r, temp.i = q__1.i;
i__2 = kk;
i__3 = kk;
i__4 = j;
q__2.r = temp.r * x[i__4].r - temp.i * x[i__4].i, q__2.i =
temp.r * x[i__4].i + temp.i * x[i__4].r;
q__1.r = ap[i__3].r + q__2.r, q__1.i = ap[i__3].i +
q__2.i;
ap[i__2].r = q__1.r, ap[i__2].i = q__1.i;
k = kk + 1;
i__2 = *n;
for (i__ = j + 1; i__ <= i__2; ++i__) {
i__3 = k;
i__4 = k;
i__5 = i__;
q__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i,
q__2.i = x[i__5].r * temp.i + x[i__5].i *
temp.r;
q__1.r = ap[i__4].r + q__2.r, q__1.i = ap[i__4].i +
q__2.i;
ap[i__3].r = q__1.r, ap[i__3].i = q__1.i;
++k;
/* L50: */
}
} else {
i__2 = kk;
i__3 = kk;
ap[i__2].r = ap[i__3].r, ap[i__2].i = ap[i__3].i;
}
kk = kk + *n - j + 1;
/* L60: */
}
} else {
jx = kx;
i__1 = *n;
for (j = 1; j <= i__1; ++j) {
i__2 = jx;
if (x[i__2].r != 0.f || x[i__2].i != 0.f) {
i__2 = jx;
q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i,
q__1.i = alpha->r * x[i__2].i + alpha->i * x[i__2]
.r;
temp.r = q__1.r, temp.i = q__1.i;
i__2 = kk;
i__3 = kk;
i__4 = jx;
q__2.r = temp.r * x[i__4].r - temp.i * x[i__4].i, q__2.i =
temp.r * x[i__4].i + temp.i * x[i__4].r;
q__1.r = ap[i__3].r + q__2.r, q__1.i = ap[i__3].i +
q__2.i;
ap[i__2].r = q__1.r, ap[i__2].i = q__1.i;
ix = jx;
i__2 = kk + *n - j;
for (k = kk + 1; k <= i__2; ++k) {
ix += *incx;
i__3 = k;
i__4 = k;
i__5 = ix;
q__2.r = x[i__5].r * temp.r - x[i__5].i * temp.i,
q__2.i = x[i__5].r * temp.i + x[i__5].i *
temp.r;
q__1.r = ap[i__4].r + q__2.r, q__1.i = ap[i__4].i +
q__2.i;
ap[i__3].r = q__1.r, ap[i__3].i = q__1.i;
/* L70: */
}
} else {
i__2 = kk;
i__3 = kk;
ap[i__2].r = ap[i__3].r, ap[i__2].i = ap[i__3].i;
}
jx += *incx;
kk = kk + *n - j + 1;
/* L80: */
}
}
}
return 0;
/* End of CSPR */
} /* cspr_ */