/* Subroutine */ int slauum_(char *uplo, integer *n, real *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 sgemm_(char *, char *, integer *, integer *,
integer *, real *, real *, integer *, real *, integer *, real *,
real *, integer *);
logical upper;
extern /* Subroutine */ int strmm_(char *, char *, char *, char *,
integer *, integer *, real *, real *, integer *, real *, integer *
), ssyrk_(char *, char *, integer
*, integer *, real *, real *, integer *, real *, real *, integer *
), slauu2_(char *, integer *, real *, 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 */
/* ======= */
/* SLAUUM 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) REAL 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_("SLAUUM", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Determine the block size for this environment. */
nb = ilaenv_(&c__1, "SLAUUM", uplo, n, &c_n1, &c_n1, &c_n1);
if (nb <= 1 || nb >= *n) {
/* Use unblocked code */
slauu2_(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;
strmm_("Right", "Upper", "Transpose", "Non-unit", &i__3, &ib,
&c_b15, &a[i__ + i__ * a_dim1], lda, &a[i__ * a_dim1
+ 1], lda)
;
slauu2_("Upper", &ib, &a[i__ + i__ * a_dim1], lda, info);
if (i__ + ib <= *n) {
i__3 = i__ - 1;
i__4 = *n - i__ - ib + 1;
sgemm_("No transpose", "Transpose", &i__3, &ib, &i__4, &
c_b15, &a[(i__ + ib) * a_dim1 + 1], lda, &a[i__ +
(i__ + ib) * a_dim1], lda, &c_b15, &a[i__ *
a_dim1 + 1], lda);
i__3 = *n - i__ - ib + 1;
ssyrk_("Upper", "No transpose", &ib, &i__3, &c_b15, &a[
i__ + (i__ + ib) * a_dim1], lda, &c_b15, &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;
strmm_("Left", "Lower", "Transpose", "Non-unit", &ib, &i__3, &
c_b15, &a[i__ + i__ * a_dim1], lda, &a[i__ + a_dim1],
lda);
slauu2_("Lower", &ib, &a[i__ + i__ * a_dim1], lda, info);
if (i__ + ib <= *n) {
i__3 = i__ - 1;
i__4 = *n - i__ - ib + 1;
sgemm_("Transpose", "No transpose", &ib, &i__3, &i__4, &
c_b15, &a[i__ + ib + i__ * a_dim1], lda, &a[i__ +
ib + a_dim1], lda, &c_b15, &a[i__ + a_dim1], lda);
i__3 = *n - i__ - ib + 1;
ssyrk_("Lower", "Transpose", &ib, &i__3, &c_b15, &a[i__ +
ib + i__ * a_dim1], lda, &c_b15, &a[i__ + i__ *
a_dim1], lda);
}
/* L20: */
}
}
}
return 0;
/* End of SLAUUM */
} /* slauum_ */
/* Subroutine */ int slauum_(char *uplo, integer *n, real *a, integer *lda,
integer *info)
{
/* -- LAPACK auxiliary routine (version 3.0) --
Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
Courant Institute, Argonne National Lab, and Rice University
February 29, 1992
Purpose
=======
SLAUUM 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) REAL 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
=====================================================================
Test the input parameters.
Parameter adjustments */
/* Table of constant values */
static integer c__1 = 1;
static integer c_n1 = -1;
static real c_b15 = 1.f;
/* System generated locals */
integer a_dim1, a_offset, i__1, i__2, i__3, i__4;
/* Local variables */
static integer i__;
extern logical lsame_(char *, char *);
extern /* Subroutine */ int sgemm_(char *, char *, integer *, integer *,
integer *, real *, real *, integer *, real *, integer *, real *,
real *, integer *);
static logical upper;
extern /* Subroutine */ int strmm_(char *, char *, char *, char *,
integer *, integer *, real *, real *, integer *, real *, integer *
), ssyrk_(char *, char *, integer
*, integer *, real *, real *, integer *, real *, real *, integer *
);
static integer ib;
extern /* Subroutine */ int slauu2_(char *, integer *, real *, integer *,
integer *);
static integer nb;
extern /* Subroutine */ int xerbla_(char *, integer *);
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
integer *, integer *, ftnlen, ftnlen);
#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1]
a_dim1 = *lda;
a_offset = 1 + a_dim1 * 1;
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_("SLAUUM", &i__1);
return 0;
}
/* Quick return if possible */
if (*n == 0) {
return 0;
}
/* Determine the block size for this environment. */
nb = ilaenv_(&c__1, "SLAUUM", uplo, n, &c_n1, &c_n1, &c_n1, (ftnlen)6, (
ftnlen)1);
if (nb <= 1 || nb >= *n) {
/* Use unblocked code */
slauu2_(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;
strmm_("Right", "Upper", "Transpose", "Non-unit", &i__3, &ib,
&c_b15, &a_ref(i__, i__), lda, &a_ref(1, i__), lda);
slauu2_("Upper", &ib, &a_ref(i__, i__), lda, info);
if (i__ + ib <= *n) {
i__3 = i__ - 1;
i__4 = *n - i__ - ib + 1;
sgemm_("No transpose", "Transpose", &i__3, &ib, &i__4, &
c_b15, &a_ref(1, i__ + ib), lda, &a_ref(i__, i__
+ ib), lda, &c_b15, &a_ref(1, i__), lda);
i__3 = *n - i__ - ib + 1;
ssyrk_("Upper", "No transpose", &ib, &i__3, &c_b15, &
a_ref(i__, i__ + ib), lda, &c_b15, &a_ref(i__,
i__), 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;
strmm_("Left", "Lower", "Transpose", "Non-unit", &ib, &i__3, &
c_b15, &a_ref(i__, i__), lda, &a_ref(i__, 1), lda);
slauu2_("Lower", &ib, &a_ref(i__, i__), lda, info);
if (i__ + ib <= *n) {
i__3 = i__ - 1;
i__4 = *n - i__ - ib + 1;
sgemm_("Transpose", "No transpose", &ib, &i__3, &i__4, &
c_b15, &a_ref(i__ + ib, i__), lda, &a_ref(i__ +
ib, 1), lda, &c_b15, &a_ref(i__, 1), lda);
i__3 = *n - i__ - ib + 1;
ssyrk_("Lower", "Transpose", &ib, &i__3, &c_b15, &a_ref(
i__ + ib, i__), lda, &c_b15, &a_ref(i__, i__),
lda);
}
/* L20: */
}
}
}
return 0;
/* End of SLAUUM */
} /* slauum_ */
