1/* chpmv.f -- translated by f2c (version 20100827).
2   You must link the resulting object file with libf2c:
3	on Microsoft Windows system, link with libf2c.lib;
4	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
5	or, if you install libf2c.a in a standard place, with -lf2c -lm
6	-- in that order, at the end of the command line, as in
7		cc *.o -lf2c -lm
8	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
9
10		http://www.netlib.org/f2c/libf2c.zip
11*/
12
13#include "datatypes.h"
14
15/* Subroutine */ int chpmv_(char *uplo, integer *n, complex *alpha, complex *
16	ap, complex *x, integer *incx, complex *beta, complex *y, integer *
17	incy, ftnlen uplo_len)
18{
19    /* System generated locals */
20    integer i__1, i__2, i__3, i__4, i__5;
21    real r__1;
22    complex q__1, q__2, q__3, q__4;
23
24    /* Builtin functions */
25    void r_cnjg(complex *, complex *);
26
27    /* Local variables */
28    integer i__, j, k, kk, ix, iy, jx, jy, kx, ky, info;
29    complex temp1, temp2;
30    extern logical lsame_(char *, char *, ftnlen, ftnlen);
31    extern /* Subroutine */ int xerbla_(char *, integer *, ftnlen);
32
33/*     .. Scalar Arguments .. */
34/*     .. */
35/*     .. Array Arguments .. */
36/*     .. */
37
38/*  Purpose */
39/*  ======= */
40
41/*  CHPMV  performs the matrix-vector operation */
42
43/*     y := alpha*A*x + beta*y, */
44
45/*  where alpha and beta are scalars, x and y are n element vectors and */
46/*  A is an n by n hermitian matrix, supplied in packed form. */
47
48/*  Arguments */
49/*  ========== */
50
51/*  UPLO   - CHARACTER*1. */
52/*           On entry, UPLO specifies whether the upper or lower */
53/*           triangular part of the matrix A is supplied in the packed */
54/*           array AP as follows: */
55
56/*              UPLO = 'U' or 'u'   The upper triangular part of A is */
57/*                                  supplied in AP. */
58
59/*              UPLO = 'L' or 'l'   The lower triangular part of A is */
60/*                                  supplied in AP. */
61
62/*           Unchanged on exit. */
63
64/*  N      - INTEGER. */
65/*           On entry, N specifies the order of the matrix A. */
66/*           N must be at least zero. */
67/*           Unchanged on exit. */
68
69/*  ALPHA  - COMPLEX         . */
70/*           On entry, ALPHA specifies the scalar alpha. */
71/*           Unchanged on exit. */
72
73/*  AP     - COMPLEX          array of DIMENSION at least */
74/*           ( ( n*( n + 1 ) )/2 ). */
75/*           Before entry with UPLO = 'U' or 'u', the array AP must */
76/*           contain the upper triangular part of the hermitian matrix */
77/*           packed sequentially, column by column, so that AP( 1 ) */
78/*           contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 1, 2 ) */
79/*           and a( 2, 2 ) respectively, and so on. */
80/*           Before entry with UPLO = 'L' or 'l', the array AP must */
81/*           contain the lower triangular part of the hermitian matrix */
82/*           packed sequentially, column by column, so that AP( 1 ) */
83/*           contains a( 1, 1 ), AP( 2 ) and AP( 3 ) contain a( 2, 1 ) */
84/*           and a( 3, 1 ) respectively, and so on. */
85/*           Note that the imaginary parts of the diagonal elements need */
86/*           not be set and are assumed to be zero. */
87/*           Unchanged on exit. */
88
89/*  X      - COMPLEX          array of dimension at least */
90/*           ( 1 + ( n - 1 )*abs( INCX ) ). */
91/*           Before entry, the incremented array X must contain the n */
92/*           element vector x. */
93/*           Unchanged on exit. */
94
95/*  INCX   - INTEGER. */
96/*           On entry, INCX specifies the increment for the elements of */
97/*           X. INCX must not be zero. */
98/*           Unchanged on exit. */
99
100/*  BETA   - COMPLEX         . */
101/*           On entry, BETA specifies the scalar beta. When BETA is */
102/*           supplied as zero then Y need not be set on input. */
103/*           Unchanged on exit. */
104
105/*  Y      - COMPLEX          array of dimension at least */
106/*           ( 1 + ( n - 1 )*abs( INCY ) ). */
107/*           Before entry, the incremented array Y must contain the n */
108/*           element vector y. On exit, Y is overwritten by the updated */
109/*           vector y. */
110
111/*  INCY   - INTEGER. */
112/*           On entry, INCY specifies the increment for the elements of */
113/*           Y. INCY must not be zero. */
114/*           Unchanged on exit. */
115
116/*  Further Details */
117/*  =============== */
118
119/*  Level 2 Blas routine. */
120
121/*  -- Written on 22-October-1986. */
122/*     Jack Dongarra, Argonne National Lab. */
123/*     Jeremy Du Croz, Nag Central Office. */
124/*     Sven Hammarling, Nag Central Office. */
125/*     Richard Hanson, Sandia National Labs. */
126
127/*  ===================================================================== */
128
129/*     .. Parameters .. */
130/*     .. */
131/*     .. Local Scalars .. */
132/*     .. */
133/*     .. External Functions .. */
134/*     .. */
135/*     .. External Subroutines .. */
136/*     .. */
137/*     .. Intrinsic Functions .. */
138/*     .. */
139
140/*     Test the input parameters. */
141
142    /* Parameter adjustments */
143    --y;
144    --x;
145    --ap;
146
147    /* Function Body */
148    info = 0;
149    if (! lsame_(uplo, "U", (ftnlen)1, (ftnlen)1) && ! lsame_(uplo, "L", (
150	    ftnlen)1, (ftnlen)1)) {
151	info = 1;
152    } else if (*n < 0) {
153	info = 2;
154    } else if (*incx == 0) {
155	info = 6;
156    } else if (*incy == 0) {
157	info = 9;
158    }
159    if (info != 0) {
160	xerbla_("CHPMV ", &info, (ftnlen)6);
161	return 0;
162    }
163
164/*     Quick return if possible. */
165
166    if (*n == 0 || (alpha->r == 0.f && alpha->i == 0.f && (beta->r == 1.f &&
167                                                           beta->i == 0.f))) {
168	return 0;
169    }
170
171/*     Set up the start points in  X  and  Y. */
172
173    if (*incx > 0) {
174	kx = 1;
175    } else {
176	kx = 1 - (*n - 1) * *incx;
177    }
178    if (*incy > 0) {
179	ky = 1;
180    } else {
181	ky = 1 - (*n - 1) * *incy;
182    }
183
184/*     Start the operations. In this version the elements of the array AP */
185/*     are accessed sequentially with one pass through AP. */
186
187/*     First form  y := beta*y. */
188
189    if (beta->r != 1.f || beta->i != 0.f) {
190	if (*incy == 1) {
191	    if (beta->r == 0.f && beta->i == 0.f) {
192		i__1 = *n;
193		for (i__ = 1; i__ <= i__1; ++i__) {
194		    i__2 = i__;
195		    y[i__2].r = 0.f, y[i__2].i = 0.f;
196/* L10: */
197		}
198	    } else {
199		i__1 = *n;
200		for (i__ = 1; i__ <= i__1; ++i__) {
201		    i__2 = i__;
202		    i__3 = i__;
203		    q__1.r = beta->r * y[i__3].r - beta->i * y[i__3].i,
204			    q__1.i = beta->r * y[i__3].i + beta->i * y[i__3]
205			    .r;
206		    y[i__2].r = q__1.r, y[i__2].i = q__1.i;
207/* L20: */
208		}
209	    }
210	} else {
211	    iy = ky;
212	    if (beta->r == 0.f && beta->i == 0.f) {
213		i__1 = *n;
214		for (i__ = 1; i__ <= i__1; ++i__) {
215		    i__2 = iy;
216		    y[i__2].r = 0.f, y[i__2].i = 0.f;
217		    iy += *incy;
218/* L30: */
219		}
220	    } else {
221		i__1 = *n;
222		for (i__ = 1; i__ <= i__1; ++i__) {
223		    i__2 = iy;
224		    i__3 = iy;
225		    q__1.r = beta->r * y[i__3].r - beta->i * y[i__3].i,
226			    q__1.i = beta->r * y[i__3].i + beta->i * y[i__3]
227			    .r;
228		    y[i__2].r = q__1.r, y[i__2].i = q__1.i;
229		    iy += *incy;
230/* L40: */
231		}
232	    }
233	}
234    }
235    if (alpha->r == 0.f && alpha->i == 0.f) {
236	return 0;
237    }
238    kk = 1;
239    if (lsame_(uplo, "U", (ftnlen)1, (ftnlen)1)) {
240
241/*        Form  y  when AP contains the upper triangle. */
242
243	if (*incx == 1 && *incy == 1) {
244	    i__1 = *n;
245	    for (j = 1; j <= i__1; ++j) {
246		i__2 = j;
247		q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, q__1.i =
248			 alpha->r * x[i__2].i + alpha->i * x[i__2].r;
249		temp1.r = q__1.r, temp1.i = q__1.i;
250		temp2.r = 0.f, temp2.i = 0.f;
251		k = kk;
252		i__2 = j - 1;
253		for (i__ = 1; i__ <= i__2; ++i__) {
254		    i__3 = i__;
255		    i__4 = i__;
256		    i__5 = k;
257		    q__2.r = temp1.r * ap[i__5].r - temp1.i * ap[i__5].i,
258			    q__2.i = temp1.r * ap[i__5].i + temp1.i * ap[i__5]
259			    .r;
260		    q__1.r = y[i__4].r + q__2.r, q__1.i = y[i__4].i + q__2.i;
261		    y[i__3].r = q__1.r, y[i__3].i = q__1.i;
262		    r_cnjg(&q__3, &ap[k]);
263		    i__3 = i__;
264		    q__2.r = q__3.r * x[i__3].r - q__3.i * x[i__3].i, q__2.i =
265			     q__3.r * x[i__3].i + q__3.i * x[i__3].r;
266		    q__1.r = temp2.r + q__2.r, q__1.i = temp2.i + q__2.i;
267		    temp2.r = q__1.r, temp2.i = q__1.i;
268		    ++k;
269/* L50: */
270		}
271		i__2 = j;
272		i__3 = j;
273		i__4 = kk + j - 1;
274		r__1 = ap[i__4].r;
275		q__3.r = r__1 * temp1.r, q__3.i = r__1 * temp1.i;
276		q__2.r = y[i__3].r + q__3.r, q__2.i = y[i__3].i + q__3.i;
277		q__4.r = alpha->r * temp2.r - alpha->i * temp2.i, q__4.i =
278			alpha->r * temp2.i + alpha->i * temp2.r;
279		q__1.r = q__2.r + q__4.r, q__1.i = q__2.i + q__4.i;
280		y[i__2].r = q__1.r, y[i__2].i = q__1.i;
281		kk += j;
282/* L60: */
283	    }
284	} else {
285	    jx = kx;
286	    jy = ky;
287	    i__1 = *n;
288	    for (j = 1; j <= i__1; ++j) {
289		i__2 = jx;
290		q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, q__1.i =
291			 alpha->r * x[i__2].i + alpha->i * x[i__2].r;
292		temp1.r = q__1.r, temp1.i = q__1.i;
293		temp2.r = 0.f, temp2.i = 0.f;
294		ix = kx;
295		iy = ky;
296		i__2 = kk + j - 2;
297		for (k = kk; k <= i__2; ++k) {
298		    i__3 = iy;
299		    i__4 = iy;
300		    i__5 = k;
301		    q__2.r = temp1.r * ap[i__5].r - temp1.i * ap[i__5].i,
302			    q__2.i = temp1.r * ap[i__5].i + temp1.i * ap[i__5]
303			    .r;
304		    q__1.r = y[i__4].r + q__2.r, q__1.i = y[i__4].i + q__2.i;
305		    y[i__3].r = q__1.r, y[i__3].i = q__1.i;
306		    r_cnjg(&q__3, &ap[k]);
307		    i__3 = ix;
308		    q__2.r = q__3.r * x[i__3].r - q__3.i * x[i__3].i, q__2.i =
309			     q__3.r * x[i__3].i + q__3.i * x[i__3].r;
310		    q__1.r = temp2.r + q__2.r, q__1.i = temp2.i + q__2.i;
311		    temp2.r = q__1.r, temp2.i = q__1.i;
312		    ix += *incx;
313		    iy += *incy;
314/* L70: */
315		}
316		i__2 = jy;
317		i__3 = jy;
318		i__4 = kk + j - 1;
319		r__1 = ap[i__4].r;
320		q__3.r = r__1 * temp1.r, q__3.i = r__1 * temp1.i;
321		q__2.r = y[i__3].r + q__3.r, q__2.i = y[i__3].i + q__3.i;
322		q__4.r = alpha->r * temp2.r - alpha->i * temp2.i, q__4.i =
323			alpha->r * temp2.i + alpha->i * temp2.r;
324		q__1.r = q__2.r + q__4.r, q__1.i = q__2.i + q__4.i;
325		y[i__2].r = q__1.r, y[i__2].i = q__1.i;
326		jx += *incx;
327		jy += *incy;
328		kk += j;
329/* L80: */
330	    }
331	}
332    } else {
333
334/*        Form  y  when AP contains the lower triangle. */
335
336	if (*incx == 1 && *incy == 1) {
337	    i__1 = *n;
338	    for (j = 1; j <= i__1; ++j) {
339		i__2 = j;
340		q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, q__1.i =
341			 alpha->r * x[i__2].i + alpha->i * x[i__2].r;
342		temp1.r = q__1.r, temp1.i = q__1.i;
343		temp2.r = 0.f, temp2.i = 0.f;
344		i__2 = j;
345		i__3 = j;
346		i__4 = kk;
347		r__1 = ap[i__4].r;
348		q__2.r = r__1 * temp1.r, q__2.i = r__1 * temp1.i;
349		q__1.r = y[i__3].r + q__2.r, q__1.i = y[i__3].i + q__2.i;
350		y[i__2].r = q__1.r, y[i__2].i = q__1.i;
351		k = kk + 1;
352		i__2 = *n;
353		for (i__ = j + 1; i__ <= i__2; ++i__) {
354		    i__3 = i__;
355		    i__4 = i__;
356		    i__5 = k;
357		    q__2.r = temp1.r * ap[i__5].r - temp1.i * ap[i__5].i,
358			    q__2.i = temp1.r * ap[i__5].i + temp1.i * ap[i__5]
359			    .r;
360		    q__1.r = y[i__4].r + q__2.r, q__1.i = y[i__4].i + q__2.i;
361		    y[i__3].r = q__1.r, y[i__3].i = q__1.i;
362		    r_cnjg(&q__3, &ap[k]);
363		    i__3 = i__;
364		    q__2.r = q__3.r * x[i__3].r - q__3.i * x[i__3].i, q__2.i =
365			     q__3.r * x[i__3].i + q__3.i * x[i__3].r;
366		    q__1.r = temp2.r + q__2.r, q__1.i = temp2.i + q__2.i;
367		    temp2.r = q__1.r, temp2.i = q__1.i;
368		    ++k;
369/* L90: */
370		}
371		i__2 = j;
372		i__3 = j;
373		q__2.r = alpha->r * temp2.r - alpha->i * temp2.i, q__2.i =
374			alpha->r * temp2.i + alpha->i * temp2.r;
375		q__1.r = y[i__3].r + q__2.r, q__1.i = y[i__3].i + q__2.i;
376		y[i__2].r = q__1.r, y[i__2].i = q__1.i;
377		kk += *n - j + 1;
378/* L100: */
379	    }
380	} else {
381	    jx = kx;
382	    jy = ky;
383	    i__1 = *n;
384	    for (j = 1; j <= i__1; ++j) {
385		i__2 = jx;
386		q__1.r = alpha->r * x[i__2].r - alpha->i * x[i__2].i, q__1.i =
387			 alpha->r * x[i__2].i + alpha->i * x[i__2].r;
388		temp1.r = q__1.r, temp1.i = q__1.i;
389		temp2.r = 0.f, temp2.i = 0.f;
390		i__2 = jy;
391		i__3 = jy;
392		i__4 = kk;
393		r__1 = ap[i__4].r;
394		q__2.r = r__1 * temp1.r, q__2.i = r__1 * temp1.i;
395		q__1.r = y[i__3].r + q__2.r, q__1.i = y[i__3].i + q__2.i;
396		y[i__2].r = q__1.r, y[i__2].i = q__1.i;
397		ix = jx;
398		iy = jy;
399		i__2 = kk + *n - j;
400		for (k = kk + 1; k <= i__2; ++k) {
401		    ix += *incx;
402		    iy += *incy;
403		    i__3 = iy;
404		    i__4 = iy;
405		    i__5 = k;
406		    q__2.r = temp1.r * ap[i__5].r - temp1.i * ap[i__5].i,
407			    q__2.i = temp1.r * ap[i__5].i + temp1.i * ap[i__5]
408			    .r;
409		    q__1.r = y[i__4].r + q__2.r, q__1.i = y[i__4].i + q__2.i;
410		    y[i__3].r = q__1.r, y[i__3].i = q__1.i;
411		    r_cnjg(&q__3, &ap[k]);
412		    i__3 = ix;
413		    q__2.r = q__3.r * x[i__3].r - q__3.i * x[i__3].i, q__2.i =
414			     q__3.r * x[i__3].i + q__3.i * x[i__3].r;
415		    q__1.r = temp2.r + q__2.r, q__1.i = temp2.i + q__2.i;
416		    temp2.r = q__1.r, temp2.i = q__1.i;
417/* L110: */
418		}
419		i__2 = jy;
420		i__3 = jy;
421		q__2.r = alpha->r * temp2.r - alpha->i * temp2.i, q__2.i =
422			alpha->r * temp2.i + alpha->i * temp2.r;
423		q__1.r = y[i__3].r + q__2.r, q__1.i = y[i__3].i + q__2.i;
424		y[i__2].r = q__1.r, y[i__2].i = q__1.i;
425		jx += *incx;
426		jy += *incy;
427		kk += *n - j + 1;
428/* L120: */
429	    }
430	}
431    }
432
433    return 0;
434
435/*     End of CHPMV . */
436
437} /* chpmv_ */
438
439