#include "blaswrap.h" #include "f2c.h" /* Subroutine */ int slauum_(char *uplo, integer *n, real *a, integer *lda, integer *info) { /* -- LAPACK auxiliary routine (version 3.1) -- Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. November 2006 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__, ib, nb; 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 * ), slauu2_(char *, integer *, real *, integer *, integer *), xerbla_(char *, integer *); extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *, ftnlen, ftnlen); 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, (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[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_ */