aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/clapack/zlauum.c
blob: 21c37890c1ee2bd06b5a7ff925334b25f5c5de16 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
/* zlauum.f -- translated by f2c (version 20061008).
   You must link the resulting object file with libf2c:
	on Microsoft Windows system, link with libf2c.lib;
	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
	or, if you install libf2c.a in a standard place, with -lf2c -lm
	-- in that order, at the end of the command line, as in
		cc *.o -lf2c -lm
	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,

		http://www.netlib.org/f2c/libf2c.zip
*/

#include "f2c.h"
#include "blaswrap.h"

/* Table of constant values */

static doublecomplex c_b1 = {1.,0.};
static integer c__1 = 1;
static integer c_n1 = -1;
static doublereal c_b21 = 1.;

/* Subroutine */ int zlauum_(char *uplo, integer *n, doublecomplex *a, 
	integer *lda, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, i__1, i__2, i__3, i__4;

    /* Local variables */
    integer i__, ib, nb;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int zgemm_(char *, char *, integer *, integer *, 
	    integer *, doublecomplex *, doublecomplex *, integer *, 
	    doublecomplex *, integer *, doublecomplex *, doublecomplex *, 
	    integer *), zherk_(char *, char *, integer *, 
	    integer *, doublereal *, doublecomplex *, integer *, doublereal *, 
	     doublecomplex *, integer *);
    logical upper;
    extern /* Subroutine */ int ztrmm_(char *, char *, char *, char *, 
	    integer *, integer *, doublecomplex *, doublecomplex *, integer *, 
	     doublecomplex *, integer *), 
	    zlauu2_(char *, integer *, doublecomplex *, integer *, integer *), xerbla_(char *, integer *);
    extern integer ilaenv_(integer *, char *, char *, integer *, integer *, 
	    integer *, integer *);


/*  -- LAPACK auxiliary routine (version 3.2) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  ZLAUUM computes the product U * U' or L' * L, where the triangular */
/*  factor U or L is stored in the upper or lower triangular part of */
/*  the array A. */

/*  If UPLO = 'U' or 'u' then the upper triangle of the result is stored, */
/*  overwriting the factor U in A. */
/*  If UPLO = 'L' or 'l' then the lower triangle of the result is stored, */
/*  overwriting the factor L in A. */

/*  This is the blocked form of the algorithm, calling Level 3 BLAS. */

/*  Arguments */
/*  ========= */

/*  UPLO    (input) CHARACTER*1 */
/*          Specifies whether the triangular factor stored in the array A */
/*          is upper or lower triangular: */
/*          = 'U':  Upper triangular */
/*          = 'L':  Lower triangular */

/*  N       (input) INTEGER */
/*          The order of the triangular factor U or L.  N >= 0. */

/*  A       (input/output) COMPLEX*16 array, dimension (LDA,N) */
/*          On entry, the triangular factor U or L. */
/*          On exit, if UPLO = 'U', the upper triangle of A is */
/*          overwritten with the upper triangle of the product U * U'; */
/*          if UPLO = 'L', the lower triangle of A is overwritten with */
/*          the lower triangle of the product L' * L. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A.  LDA >= max(1,N). */

/*  INFO    (output) INTEGER */
/*          = 0: successful exit */
/*          < 0: if INFO = -k, the k-th argument had an illegal value */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

/*     Test the input parameters. */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;

    /* Function Body */
    *info = 0;
    upper = lsame_(uplo, "U");
    if (! upper && ! lsame_(uplo, "L")) {
	*info = -1;
    } else if (*n < 0) {
	*info = -2;
    } else if (*lda < max(1,*n)) {
	*info = -4;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("ZLAUUM", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*n == 0) {
	return 0;
    }

/*     Determine the block size for this environment. */

    nb = ilaenv_(&c__1, "ZLAUUM", uplo, n, &c_n1, &c_n1, &c_n1);

    if (nb <= 1 || nb >= *n) {

/*        Use unblocked code */

	zlauu2_(uplo, n, &a[a_offset], lda, info);
    } else {

/*        Use blocked code */

	if (upper) {

/*           Compute the product U * U'. */

	    i__1 = *n;
	    i__2 = nb;
	    for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
/* Computing MIN */
		i__3 = nb, i__4 = *n - i__ + 1;
		ib = min(i__3,i__4);
		i__3 = i__ - 1;
		ztrmm_("Right", "Upper", "Conjugate transpose", "Non-unit", &
			i__3, &ib, &c_b1, &a[i__ + i__ * a_dim1], lda, &a[i__ 
			* a_dim1 + 1], lda);
		zlauu2_("Upper", &ib, &a[i__ + i__ * a_dim1], lda, info);
		if (i__ + ib <= *n) {
		    i__3 = i__ - 1;
		    i__4 = *n - i__ - ib + 1;
		    zgemm_("No transpose", "Conjugate transpose", &i__3, &ib, 
			    &i__4, &c_b1, &a[(i__ + ib) * a_dim1 + 1], lda, &
			    a[i__ + (i__ + ib) * a_dim1], lda, &c_b1, &a[i__ *
			     a_dim1 + 1], lda);
		    i__3 = *n - i__ - ib + 1;
		    zherk_("Upper", "No transpose", &ib, &i__3, &c_b21, &a[
			    i__ + (i__ + ib) * a_dim1], lda, &c_b21, &a[i__ + 
			    i__ * a_dim1], lda);
		}
/* L10: */
	    }
	} else {

/*           Compute the product L' * L. */

	    i__2 = *n;
	    i__1 = nb;
	    for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) {
/* Computing MIN */
		i__3 = nb, i__4 = *n - i__ + 1;
		ib = min(i__3,i__4);
		i__3 = i__ - 1;
		ztrmm_("Left", "Lower", "Conjugate transpose", "Non-unit", &
			ib, &i__3, &c_b1, &a[i__ + i__ * a_dim1], lda, &a[i__ 
			+ a_dim1], lda);
		zlauu2_("Lower", &ib, &a[i__ + i__ * a_dim1], lda, info);
		if (i__ + ib <= *n) {
		    i__3 = i__ - 1;
		    i__4 = *n - i__ - ib + 1;
		    zgemm_("Conjugate transpose", "No transpose", &ib, &i__3, 
			    &i__4, &c_b1, &a[i__ + ib + i__ * a_dim1], lda, &
			    a[i__ + ib + a_dim1], lda, &c_b1, &a[i__ + a_dim1]
, lda);
		    i__3 = *n - i__ - ib + 1;
		    zherk_("Lower", "Conjugate transpose", &ib, &i__3, &c_b21, 
			     &a[i__ + ib + i__ * a_dim1], lda, &c_b21, &a[i__ 
			    + i__ * a_dim1], lda);
		}
/* L20: */
	    }
	}
    }

    return 0;

/*     End of ZLAUUM */

} /* zlauum_ */