3 /* Table of constant values */
5 static integer c__1 = 1;
6 static integer c_n1 = -1;
7 static doublereal c_b15 = 1.;
9 /* Subroutine */ int dlauum_(char *uplo, integer *n, doublereal *a, integer *
12 /* System generated locals */
13 integer a_dim1, a_offset, i__1, i__2, i__3, i__4;
17 extern /* Subroutine */ int dgemm_(char *, char *, integer *, integer *,
18 integer *, doublereal *, doublereal *, integer *, doublereal *,
19 integer *, doublereal *, doublereal *, integer *);
20 extern logical lsame_(char *, char *);
21 extern /* Subroutine */ int dtrmm_(char *, char *, char *, char *,
22 integer *, integer *, doublereal *, doublereal *, integer *,
23 doublereal *, integer *);
25 extern /* Subroutine */ int dsyrk_(char *, char *, integer *, integer *,
26 doublereal *, doublereal *, integer *, doublereal *, doublereal *,
27 integer *), dlauu2_(char *, integer *,
28 doublereal *, integer *, integer *), xerbla_(char *,
30 extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
31 integer *, integer *);
34 /* -- LAPACK auxiliary routine (version 3.1) -- */
35 /* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
38 /* .. Scalar Arguments .. */
40 /* .. Array Arguments .. */
46 /* DLAUUM computes the product U * U' or L' * L, where the triangular */
47 /* factor U or L is stored in the upper or lower triangular part of */
50 /* If UPLO = 'U' or 'u' then the upper triangle of the result is stored, */
51 /* overwriting the factor U in A. */
52 /* If UPLO = 'L' or 'l' then the lower triangle of the result is stored, */
53 /* overwriting the factor L in A. */
55 /* This is the blocked form of the algorithm, calling Level 3 BLAS. */
60 /* UPLO (input) CHARACTER*1 */
61 /* Specifies whether the triangular factor stored in the array A */
62 /* is upper or lower triangular: */
63 /* = 'U': Upper triangular */
64 /* = 'L': Lower triangular */
66 /* N (input) INTEGER */
67 /* The order of the triangular factor U or L. N >= 0. */
69 /* A (input/output) DOUBLE PRECISION array, dimension (LDA,N) */
70 /* On entry, the triangular factor U or L. */
71 /* On exit, if UPLO = 'U', the upper triangle of A is */
72 /* overwritten with the upper triangle of the product U * U'; */
73 /* if UPLO = 'L', the lower triangle of A is overwritten with */
74 /* the lower triangle of the product L' * L. */
76 /* LDA (input) INTEGER */
77 /* The leading dimension of the array A. LDA >= max(1,N). */
79 /* INFO (output) INTEGER */
80 /* = 0: successful exit */
81 /* < 0: if INFO = -k, the k-th argument had an illegal value */
83 /* ===================================================================== */
85 /* .. Parameters .. */
87 /* .. Local Scalars .. */
89 /* .. External Functions .. */
91 /* .. External Subroutines .. */
93 /* .. Intrinsic Functions .. */
95 /* .. Executable Statements .. */
97 /* Test the input parameters. */
99 /* Parameter adjustments */
101 a_offset = 1 + a_dim1;
106 upper = lsame_(uplo, "U");
107 if (! upper && ! lsame_(uplo, "L")) {
111 } else if (*lda < max(1,*n)) {
116 xerbla_("DLAUUM", &i__1);
120 /* Quick return if possible */
126 /* Determine the block size for this environment. */
128 nb = ilaenv_(&c__1, "DLAUUM", uplo, n, &c_n1, &c_n1, &c_n1);
130 if (nb <= 1 || nb >= *n) {
132 /* Use unblocked code */
134 dlauu2_(uplo, n, &a[a_offset], lda, info);
137 /* Use blocked code */
141 /* Compute the product U * U'. */
145 for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
147 i__3 = nb, i__4 = *n - i__ + 1;
150 dtrmm_("Right", "Upper", "Transpose", "Non-unit", &i__3, &ib,
151 &c_b15, &a[i__ + i__ * a_dim1], lda, &a[i__ * a_dim1
154 dlauu2_("Upper", &ib, &a[i__ + i__ * a_dim1], lda, info);
155 if (i__ + ib <= *n) {
157 i__4 = *n - i__ - ib + 1;
158 dgemm_("No transpose", "Transpose", &i__3, &ib, &i__4, &
159 c_b15, &a[(i__ + ib) * a_dim1 + 1], lda, &a[i__ +
160 (i__ + ib) * a_dim1], lda, &c_b15, &a[i__ *
162 i__3 = *n - i__ - ib + 1;
163 dsyrk_("Upper", "No transpose", &ib, &i__3, &c_b15, &a[
164 i__ + (i__ + ib) * a_dim1], lda, &c_b15, &a[i__ +
171 /* Compute the product L' * L. */
175 for (i__ = 1; i__1 < 0 ? i__ >= i__2 : i__ <= i__2; i__ += i__1) {
177 i__3 = nb, i__4 = *n - i__ + 1;
180 dtrmm_("Left", "Lower", "Transpose", "Non-unit", &ib, &i__3, &
181 c_b15, &a[i__ + i__ * a_dim1], lda, &a[i__ + a_dim1],
183 dlauu2_("Lower", &ib, &a[i__ + i__ * a_dim1], lda, info);
184 if (i__ + ib <= *n) {
186 i__4 = *n - i__ - ib + 1;
187 dgemm_("Transpose", "No transpose", &ib, &i__3, &i__4, &
188 c_b15, &a[i__ + ib + i__ * a_dim1], lda, &a[i__ +
189 ib + a_dim1], lda, &c_b15, &a[i__ + a_dim1], lda);
190 i__3 = *n - i__ - ib + 1;
191 dsyrk_("Lower", "Transpose", &ib, &i__3, &c_b15, &a[i__ +
192 ib + i__ * a_dim1], lda, &c_b15, &a[i__ + i__ *