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authorshmel1k <shmel1k@ydb.tech>2022-09-02 12:44:59 +0300
committershmel1k <shmel1k@ydb.tech>2022-09-02 12:44:59 +0300
commit90d450f74722da7859d6f510a869f6c6908fd12f (patch)
tree538c718dedc76cdfe37ad6d01ff250dd930d9278 /contrib/libs/clapack/zlatrs.c
parent01f64c1ecd0d4ffa9e3a74478335f1745f26cc75 (diff)
downloadydb-90d450f74722da7859d6f510a869f6c6908fd12f.tar.gz
[] add metering mode to CLI
Diffstat (limited to 'contrib/libs/clapack/zlatrs.c')
-rw-r--r--contrib/libs/clapack/zlatrs.c1150
1 files changed, 1150 insertions, 0 deletions
diff --git a/contrib/libs/clapack/zlatrs.c b/contrib/libs/clapack/zlatrs.c
new file mode 100644
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+++ b/contrib/libs/clapack/zlatrs.c
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+/* zlatrs.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 integer c__1 = 1;
+static doublereal c_b36 = .5;
+
+/* Subroutine */ int zlatrs_(char *uplo, char *trans, char *diag, char *
+ normin, integer *n, doublecomplex *a, integer *lda, doublecomplex *x,
+ doublereal *scale, doublereal *cnorm, integer *info)
+{
+ /* System generated locals */
+ integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5;
+ doublereal d__1, d__2, d__3, d__4;
+ doublecomplex z__1, z__2, z__3, z__4;
+
+ /* Builtin functions */
+ double d_imag(doublecomplex *);
+ void d_cnjg(doublecomplex *, doublecomplex *);
+
+ /* Local variables */
+ integer i__, j;
+ doublereal xj, rec, tjj;
+ integer jinc;
+ doublereal xbnd;
+ integer imax;
+ doublereal tmax;
+ doublecomplex tjjs;
+ doublereal xmax, grow;
+ extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *,
+ integer *);
+ extern logical lsame_(char *, char *);
+ doublereal tscal;
+ doublecomplex uscal;
+ integer jlast;
+ doublecomplex csumj;
+ extern /* Double Complex */ VOID zdotc_(doublecomplex *, integer *,
+ doublecomplex *, integer *, doublecomplex *, integer *);
+ logical upper;
+ extern /* Double Complex */ VOID zdotu_(doublecomplex *, integer *,
+ doublecomplex *, integer *, doublecomplex *, integer *);
+ extern /* Subroutine */ int zaxpy_(integer *, doublecomplex *,
+ doublecomplex *, integer *, doublecomplex *, integer *), ztrsv_(
+ char *, char *, char *, integer *, doublecomplex *, integer *,
+ doublecomplex *, integer *), dlabad_(
+ doublereal *, doublereal *);
+ extern doublereal dlamch_(char *);
+ extern integer idamax_(integer *, doublereal *, integer *);
+ extern /* Subroutine */ int xerbla_(char *, integer *), zdscal_(
+ integer *, doublereal *, doublecomplex *, integer *);
+ doublereal bignum;
+ extern integer izamax_(integer *, doublecomplex *, integer *);
+ extern /* Double Complex */ VOID zladiv_(doublecomplex *, doublecomplex *,
+ doublecomplex *);
+ logical notran;
+ integer jfirst;
+ extern doublereal dzasum_(integer *, doublecomplex *, integer *);
+ doublereal smlnum;
+ logical nounit;
+
+
+/* -- LAPACK auxiliary routine (version 3.2) -- */
+/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
+/* November 2006 */
+
+/* .. Scalar Arguments .. */
+/* .. */
+/* .. Array Arguments .. */
+/* .. */
+
+/* Purpose */
+/* ======= */
+
+/* ZLATRS solves one of the triangular systems */
+
+/* A * x = s*b, A**T * x = s*b, or A**H * x = s*b, */
+
+/* with scaling to prevent overflow. Here A is an upper or lower */
+/* triangular matrix, A**T denotes the transpose of A, A**H denotes the */
+/* conjugate transpose of A, x and b are n-element vectors, and s is a */
+/* scaling factor, usually less than or equal to 1, chosen so that the */
+/* components of x will be less than the overflow threshold. If the */
+/* unscaled problem will not cause overflow, the Level 2 BLAS routine */
+/* ZTRSV is called. If the matrix A is singular (A(j,j) = 0 for some j), */
+/* then s is set to 0 and a non-trivial solution to A*x = 0 is returned. */
+
+/* Arguments */
+/* ========= */
+
+/* UPLO (input) CHARACTER*1 */
+/* Specifies whether the matrix A is upper or lower triangular. */
+/* = 'U': Upper triangular */
+/* = 'L': Lower triangular */
+
+/* TRANS (input) CHARACTER*1 */
+/* Specifies the operation applied to A. */
+/* = 'N': Solve A * x = s*b (No transpose) */
+/* = 'T': Solve A**T * x = s*b (Transpose) */
+/* = 'C': Solve A**H * x = s*b (Conjugate transpose) */
+
+/* DIAG (input) CHARACTER*1 */
+/* Specifies whether or not the matrix A is unit triangular. */
+/* = 'N': Non-unit triangular */
+/* = 'U': Unit triangular */
+
+/* NORMIN (input) CHARACTER*1 */
+/* Specifies whether CNORM has been set or not. */
+/* = 'Y': CNORM contains the column norms on entry */
+/* = 'N': CNORM is not set on entry. On exit, the norms will */
+/* be computed and stored in CNORM. */
+
+/* N (input) INTEGER */
+/* The order of the matrix A. N >= 0. */
+
+/* A (input) COMPLEX*16 array, dimension (LDA,N) */
+/* The triangular matrix A. If UPLO = 'U', the leading n by n */
+/* upper triangular part of the array A contains the upper */
+/* triangular matrix, and the strictly lower triangular part of */
+/* A is not referenced. If UPLO = 'L', the leading n by n lower */
+/* triangular part of the array A contains the lower triangular */
+/* matrix, and the strictly upper triangular part of A is not */
+/* referenced. If DIAG = 'U', the diagonal elements of A are */
+/* also not referenced and are assumed to be 1. */
+
+/* LDA (input) INTEGER */
+/* The leading dimension of the array A. LDA >= max (1,N). */
+
+/* X (input/output) COMPLEX*16 array, dimension (N) */
+/* On entry, the right hand side b of the triangular system. */
+/* On exit, X is overwritten by the solution vector x. */
+
+/* SCALE (output) DOUBLE PRECISION */
+/* The scaling factor s for the triangular system */
+/* A * x = s*b, A**T * x = s*b, or A**H * x = s*b. */
+/* If SCALE = 0, the matrix A is singular or badly scaled, and */
+/* the vector x is an exact or approximate solution to A*x = 0. */
+
+/* CNORM (input or output) DOUBLE PRECISION array, dimension (N) */
+
+/* If NORMIN = 'Y', CNORM is an input argument and CNORM(j) */
+/* contains the norm of the off-diagonal part of the j-th column */
+/* of A. If TRANS = 'N', CNORM(j) must be greater than or equal */
+/* to the infinity-norm, and if TRANS = 'T' or 'C', CNORM(j) */
+/* must be greater than or equal to the 1-norm. */
+
+/* If NORMIN = 'N', CNORM is an output argument and CNORM(j) */
+/* returns the 1-norm of the offdiagonal part of the j-th column */
+/* of A. */
+
+/* INFO (output) INTEGER */
+/* = 0: successful exit */
+/* < 0: if INFO = -k, the k-th argument had an illegal value */
+
+/* Further Details */
+/* ======= ======= */
+
+/* A rough bound on x is computed; if that is less than overflow, ZTRSV */
+/* is called, otherwise, specific code is used which checks for possible */
+/* overflow or divide-by-zero at every operation. */
+
+/* A columnwise scheme is used for solving A*x = b. The basic algorithm */
+/* if A is lower triangular is */
+
+/* x[1:n] := b[1:n] */
+/* for j = 1, ..., n */
+/* x(j) := x(j) / A(j,j) */
+/* x[j+1:n] := x[j+1:n] - x(j) * A[j+1:n,j] */
+/* end */
+
+/* Define bounds on the components of x after j iterations of the loop: */
+/* M(j) = bound on x[1:j] */
+/* G(j) = bound on x[j+1:n] */
+/* Initially, let M(0) = 0 and G(0) = max{x(i), i=1,...,n}. */
+
+/* Then for iteration j+1 we have */
+/* M(j+1) <= G(j) / | A(j+1,j+1) | */
+/* G(j+1) <= G(j) + M(j+1) * | A[j+2:n,j+1] | */
+/* <= G(j) ( 1 + CNORM(j+1) / | A(j+1,j+1) | ) */
+
+/* where CNORM(j+1) is greater than or equal to the infinity-norm of */
+/* column j+1 of A, not counting the diagonal. Hence */
+
+/* G(j) <= G(0) product ( 1 + CNORM(i) / | A(i,i) | ) */
+/* 1<=i<=j */
+/* and */
+
+/* |x(j)| <= ( G(0) / |A(j,j)| ) product ( 1 + CNORM(i) / |A(i,i)| ) */
+/* 1<=i< j */
+
+/* Since |x(j)| <= M(j), we use the Level 2 BLAS routine ZTRSV if the */
+/* reciprocal of the largest M(j), j=1,..,n, is larger than */
+/* max(underflow, 1/overflow). */
+
+/* The bound on x(j) is also used to determine when a step in the */
+/* columnwise method can be performed without fear of overflow. If */
+/* the computed bound is greater than a large constant, x is scaled to */
+/* prevent overflow, but if the bound overflows, x is set to 0, x(j) to */
+/* 1, and scale to 0, and a non-trivial solution to A*x = 0 is found. */
+
+/* Similarly, a row-wise scheme is used to solve A**T *x = b or */
+/* A**H *x = b. The basic algorithm for A upper triangular is */
+
+/* for j = 1, ..., n */
+/* x(j) := ( b(j) - A[1:j-1,j]' * x[1:j-1] ) / A(j,j) */
+/* end */
+
+/* We simultaneously compute two bounds */
+/* G(j) = bound on ( b(i) - A[1:i-1,i]' * x[1:i-1] ), 1<=i<=j */
+/* M(j) = bound on x(i), 1<=i<=j */
+
+/* The initial values are G(0) = 0, M(0) = max{b(i), i=1,..,n}, and we */
+/* add the constraint G(j) >= G(j-1) and M(j) >= M(j-1) for j >= 1. */
+/* Then the bound on x(j) is */
+
+/* M(j) <= M(j-1) * ( 1 + CNORM(j) ) / | A(j,j) | */
+
+/* <= M(0) * product ( ( 1 + CNORM(i) ) / |A(i,i)| ) */
+/* 1<=i<=j */
+
+/* and we can safely call ZTRSV if 1/M(n) and 1/G(n) are both greater */
+/* than max(underflow, 1/overflow). */
+
+/* ===================================================================== */
+
+/* .. Parameters .. */
+/* .. */
+/* .. Local Scalars .. */
+/* .. */
+/* .. External Functions .. */
+/* .. */
+/* .. External Subroutines .. */
+/* .. */
+/* .. Intrinsic Functions .. */
+/* .. */
+/* .. Statement Functions .. */
+/* .. */
+/* .. Statement Function definitions .. */
+/* .. */
+/* .. Executable Statements .. */
+
+ /* Parameter adjustments */
+ a_dim1 = *lda;
+ a_offset = 1 + a_dim1;
+ a -= a_offset;
+ --x;
+ --cnorm;
+
+ /* Function Body */
+ *info = 0;
+ upper = lsame_(uplo, "U");
+ notran = lsame_(trans, "N");
+ nounit = lsame_(diag, "N");
+
+/* Test the input parameters. */
+
+ if (! upper && ! lsame_(uplo, "L")) {
+ *info = -1;
+ } else if (! notran && ! lsame_(trans, "T") && !
+ lsame_(trans, "C")) {
+ *info = -2;
+ } else if (! nounit && ! lsame_(diag, "U")) {
+ *info = -3;
+ } else if (! lsame_(normin, "Y") && ! lsame_(normin,
+ "N")) {
+ *info = -4;
+ } else if (*n < 0) {
+ *info = -5;
+ } else if (*lda < max(1,*n)) {
+ *info = -7;
+ }
+ if (*info != 0) {
+ i__1 = -(*info);
+ xerbla_("ZLATRS", &i__1);
+ return 0;
+ }
+
+/* Quick return if possible */
+
+ if (*n == 0) {
+ return 0;
+ }
+
+/* Determine machine dependent parameters to control overflow. */
+
+ smlnum = dlamch_("Safe minimum");
+ bignum = 1. / smlnum;
+ dlabad_(&smlnum, &bignum);
+ smlnum /= dlamch_("Precision");
+ bignum = 1. / smlnum;
+ *scale = 1.;
+
+ if (lsame_(normin, "N")) {
+
+/* Compute the 1-norm of each column, not including the diagonal. */
+
+ if (upper) {
+
+/* A is upper triangular. */
+
+ i__1 = *n;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = j - 1;
+ cnorm[j] = dzasum_(&i__2, &a[j * a_dim1 + 1], &c__1);
+/* L10: */
+ }
+ } else {
+
+/* A is lower triangular. */
+
+ i__1 = *n - 1;
+ for (j = 1; j <= i__1; ++j) {
+ i__2 = *n - j;
+ cnorm[j] = dzasum_(&i__2, &a[j + 1 + j * a_dim1], &c__1);
+/* L20: */
+ }
+ cnorm[*n] = 0.;
+ }
+ }
+
+/* Scale the column norms by TSCAL if the maximum element in CNORM is */
+/* greater than BIGNUM/2. */
+
+ imax = idamax_(n, &cnorm[1], &c__1);
+ tmax = cnorm[imax];
+ if (tmax <= bignum * .5) {
+ tscal = 1.;
+ } else {
+ tscal = .5 / (smlnum * tmax);
+ dscal_(n, &tscal, &cnorm[1], &c__1);
+ }
+
+/* Compute a bound on the computed solution vector to see if the */
+/* Level 2 BLAS routine ZTRSV can be used. */
+
+ xmax = 0.;
+ i__1 = *n;
+ for (j = 1; j <= i__1; ++j) {
+/* Computing MAX */
+ i__2 = j;
+ d__3 = xmax, d__4 = (d__1 = x[i__2].r / 2., abs(d__1)) + (d__2 =
+ d_imag(&x[j]) / 2., abs(d__2));
+ xmax = max(d__3,d__4);
+/* L30: */
+ }
+ xbnd = xmax;
+
+ if (notran) {
+
+/* Compute the growth in A * x = b. */
+
+ if (upper) {
+ jfirst = *n;
+ jlast = 1;
+ jinc = -1;
+ } else {
+ jfirst = 1;
+ jlast = *n;
+ jinc = 1;
+ }
+
+ if (tscal != 1.) {
+ grow = 0.;
+ goto L60;
+ }
+
+ if (nounit) {
+
+/* A is non-unit triangular. */
+
+/* Compute GROW = 1/G(j) and XBND = 1/M(j). */
+/* Initially, G(0) = max{x(i), i=1,...,n}. */
+
+ grow = .5 / max(xbnd,smlnum);
+ xbnd = grow;
+ i__1 = jlast;
+ i__2 = jinc;
+ for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
+
+/* Exit the loop if the growth factor is too small. */
+
+ if (grow <= smlnum) {
+ goto L60;
+ }
+
+ i__3 = j + j * a_dim1;
+ tjjs.r = a[i__3].r, tjjs.i = a[i__3].i;
+ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(
+ d__2));
+
+ if (tjj >= smlnum) {
+
+/* M(j) = G(j-1) / abs(A(j,j)) */
+
+/* Computing MIN */
+ d__1 = xbnd, d__2 = min(1.,tjj) * grow;
+ xbnd = min(d__1,d__2);
+ } else {
+
+/* M(j) could overflow, set XBND to 0. */
+
+ xbnd = 0.;
+ }
+
+ if (tjj + cnorm[j] >= smlnum) {
+
+/* G(j) = G(j-1)*( 1 + CNORM(j) / abs(A(j,j)) ) */
+
+ grow *= tjj / (tjj + cnorm[j]);
+ } else {
+
+/* G(j) could overflow, set GROW to 0. */
+
+ grow = 0.;
+ }
+/* L40: */
+ }
+ grow = xbnd;
+ } else {
+
+/* A is unit triangular. */
+
+/* Compute GROW = 1/G(j), where G(0) = max{x(i), i=1,...,n}. */
+
+/* Computing MIN */
+ d__1 = 1., d__2 = .5 / max(xbnd,smlnum);
+ grow = min(d__1,d__2);
+ i__2 = jlast;
+ i__1 = jinc;
+ for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
+
+/* Exit the loop if the growth factor is too small. */
+
+ if (grow <= smlnum) {
+ goto L60;
+ }
+
+/* G(j) = G(j-1)*( 1 + CNORM(j) ) */
+
+ grow *= 1. / (cnorm[j] + 1.);
+/* L50: */
+ }
+ }
+L60:
+
+ ;
+ } else {
+
+/* Compute the growth in A**T * x = b or A**H * x = b. */
+
+ if (upper) {
+ jfirst = 1;
+ jlast = *n;
+ jinc = 1;
+ } else {
+ jfirst = *n;
+ jlast = 1;
+ jinc = -1;
+ }
+
+ if (tscal != 1.) {
+ grow = 0.;
+ goto L90;
+ }
+
+ if (nounit) {
+
+/* A is non-unit triangular. */
+
+/* Compute GROW = 1/G(j) and XBND = 1/M(j). */
+/* Initially, M(0) = max{x(i), i=1,...,n}. */
+
+ grow = .5 / max(xbnd,smlnum);
+ xbnd = grow;
+ i__1 = jlast;
+ i__2 = jinc;
+ for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
+
+/* Exit the loop if the growth factor is too small. */
+
+ if (grow <= smlnum) {
+ goto L90;
+ }
+
+/* G(j) = max( G(j-1), M(j-1)*( 1 + CNORM(j) ) ) */
+
+ xj = cnorm[j] + 1.;
+/* Computing MIN */
+ d__1 = grow, d__2 = xbnd / xj;
+ grow = min(d__1,d__2);
+
+ i__3 = j + j * a_dim1;
+ tjjs.r = a[i__3].r, tjjs.i = a[i__3].i;
+ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(
+ d__2));
+
+ if (tjj >= smlnum) {
+
+/* M(j) = M(j-1)*( 1 + CNORM(j) ) / abs(A(j,j)) */
+
+ if (xj > tjj) {
+ xbnd *= tjj / xj;
+ }
+ } else {
+
+/* M(j) could overflow, set XBND to 0. */
+
+ xbnd = 0.;
+ }
+/* L70: */
+ }
+ grow = min(grow,xbnd);
+ } else {
+
+/* A is unit triangular. */
+
+/* Compute GROW = 1/G(j), where G(0) = max{x(i), i=1,...,n}. */
+
+/* Computing MIN */
+ d__1 = 1., d__2 = .5 / max(xbnd,smlnum);
+ grow = min(d__1,d__2);
+ i__2 = jlast;
+ i__1 = jinc;
+ for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
+
+/* Exit the loop if the growth factor is too small. */
+
+ if (grow <= smlnum) {
+ goto L90;
+ }
+
+/* G(j) = ( 1 + CNORM(j) )*G(j-1) */
+
+ xj = cnorm[j] + 1.;
+ grow /= xj;
+/* L80: */
+ }
+ }
+L90:
+ ;
+ }
+
+ if (grow * tscal > smlnum) {
+
+/* Use the Level 2 BLAS solve if the reciprocal of the bound on */
+/* elements of X is not too small. */
+
+ ztrsv_(uplo, trans, diag, n, &a[a_offset], lda, &x[1], &c__1);
+ } else {
+
+/* Use a Level 1 BLAS solve, scaling intermediate results. */
+
+ if (xmax > bignum * .5) {
+
+/* Scale X so that its components are less than or equal to */
+/* BIGNUM in absolute value. */
+
+ *scale = bignum * .5 / xmax;
+ zdscal_(n, scale, &x[1], &c__1);
+ xmax = bignum;
+ } else {
+ xmax *= 2.;
+ }
+
+ if (notran) {
+
+/* Solve A * x = b */
+
+ i__1 = jlast;
+ i__2 = jinc;
+ for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
+
+/* Compute x(j) = b(j) / A(j,j), scaling x if necessary. */
+
+ i__3 = j;
+ xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]),
+ abs(d__2));
+ if (nounit) {
+ i__3 = j + j * a_dim1;
+ z__1.r = tscal * a[i__3].r, z__1.i = tscal * a[i__3].i;
+ tjjs.r = z__1.r, tjjs.i = z__1.i;
+ } else {
+ tjjs.r = tscal, tjjs.i = 0.;
+ if (tscal == 1.) {
+ goto L110;
+ }
+ }
+ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs), abs(
+ d__2));
+ if (tjj > smlnum) {
+
+/* abs(A(j,j)) > SMLNUM: */
+
+ if (tjj < 1.) {
+ if (xj > tjj * bignum) {
+
+/* Scale x by 1/b(j). */
+
+ rec = 1. / xj;
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ xmax *= rec;
+ }
+ }
+ i__3 = j;
+ zladiv_(&z__1, &x[j], &tjjs);
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ i__3 = j;
+ xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j])
+ , abs(d__2));
+ } else if (tjj > 0.) {
+
+/* 0 < abs(A(j,j)) <= SMLNUM: */
+
+ if (xj > tjj * bignum) {
+
+/* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM */
+/* to avoid overflow when dividing by A(j,j). */
+
+ rec = tjj * bignum / xj;
+ if (cnorm[j] > 1.) {
+
+/* Scale by 1/CNORM(j) to avoid overflow when */
+/* multiplying x(j) times column j. */
+
+ rec /= cnorm[j];
+ }
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ xmax *= rec;
+ }
+ i__3 = j;
+ zladiv_(&z__1, &x[j], &tjjs);
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ i__3 = j;
+ xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j])
+ , abs(d__2));
+ } else {
+
+/* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
+/* scale = 0, and compute a solution to A*x = 0. */
+
+ i__3 = *n;
+ for (i__ = 1; i__ <= i__3; ++i__) {
+ i__4 = i__;
+ x[i__4].r = 0., x[i__4].i = 0.;
+/* L100: */
+ }
+ i__3 = j;
+ x[i__3].r = 1., x[i__3].i = 0.;
+ xj = 1.;
+ *scale = 0.;
+ xmax = 0.;
+ }
+L110:
+
+/* Scale x if necessary to avoid overflow when adding a */
+/* multiple of column j of A. */
+
+ if (xj > 1.) {
+ rec = 1. / xj;
+ if (cnorm[j] > (bignum - xmax) * rec) {
+
+/* Scale x by 1/(2*abs(x(j))). */
+
+ rec *= .5;
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ }
+ } else if (xj * cnorm[j] > bignum - xmax) {
+
+/* Scale x by 1/2. */
+
+ zdscal_(n, &c_b36, &x[1], &c__1);
+ *scale *= .5;
+ }
+
+ if (upper) {
+ if (j > 1) {
+
+/* Compute the update */
+/* x(1:j-1) := x(1:j-1) - x(j) * A(1:j-1,j) */
+
+ i__3 = j - 1;
+ i__4 = j;
+ z__2.r = -x[i__4].r, z__2.i = -x[i__4].i;
+ z__1.r = tscal * z__2.r, z__1.i = tscal * z__2.i;
+ zaxpy_(&i__3, &z__1, &a[j * a_dim1 + 1], &c__1, &x[1],
+ &c__1);
+ i__3 = j - 1;
+ i__ = izamax_(&i__3, &x[1], &c__1);
+ i__3 = i__;
+ xmax = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(
+ &x[i__]), abs(d__2));
+ }
+ } else {
+ if (j < *n) {
+
+/* Compute the update */
+/* x(j+1:n) := x(j+1:n) - x(j) * A(j+1:n,j) */
+
+ i__3 = *n - j;
+ i__4 = j;
+ z__2.r = -x[i__4].r, z__2.i = -x[i__4].i;
+ z__1.r = tscal * z__2.r, z__1.i = tscal * z__2.i;
+ zaxpy_(&i__3, &z__1, &a[j + 1 + j * a_dim1], &c__1, &
+ x[j + 1], &c__1);
+ i__3 = *n - j;
+ i__ = j + izamax_(&i__3, &x[j + 1], &c__1);
+ i__3 = i__;
+ xmax = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(
+ &x[i__]), abs(d__2));
+ }
+ }
+/* L120: */
+ }
+
+ } else if (lsame_(trans, "T")) {
+
+/* Solve A**T * x = b */
+
+ i__2 = jlast;
+ i__1 = jinc;
+ for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
+
+/* Compute x(j) = b(j) - sum A(k,j)*x(k). */
+/* k<>j */
+
+ i__3 = j;
+ xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]),
+ abs(d__2));
+ uscal.r = tscal, uscal.i = 0.;
+ rec = 1. / max(xmax,1.);
+ if (cnorm[j] > (bignum - xj) * rec) {
+
+/* If x(j) could overflow, scale x by 1/(2*XMAX). */
+
+ rec *= .5;
+ if (nounit) {
+ i__3 = j + j * a_dim1;
+ z__1.r = tscal * a[i__3].r, z__1.i = tscal * a[i__3]
+ .i;
+ tjjs.r = z__1.r, tjjs.i = z__1.i;
+ } else {
+ tjjs.r = tscal, tjjs.i = 0.;
+ }
+ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs),
+ abs(d__2));
+ if (tjj > 1.) {
+
+/* Divide by A(j,j) when scaling x if A(j,j) > 1. */
+
+/* Computing MIN */
+ d__1 = 1., d__2 = rec * tjj;
+ rec = min(d__1,d__2);
+ zladiv_(&z__1, &uscal, &tjjs);
+ uscal.r = z__1.r, uscal.i = z__1.i;
+ }
+ if (rec < 1.) {
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ xmax *= rec;
+ }
+ }
+
+ csumj.r = 0., csumj.i = 0.;
+ if (uscal.r == 1. && uscal.i == 0.) {
+
+/* If the scaling needed for A in the dot product is 1, */
+/* call ZDOTU to perform the dot product. */
+
+ if (upper) {
+ i__3 = j - 1;
+ zdotu_(&z__1, &i__3, &a[j * a_dim1 + 1], &c__1, &x[1],
+ &c__1);
+ csumj.r = z__1.r, csumj.i = z__1.i;
+ } else if (j < *n) {
+ i__3 = *n - j;
+ zdotu_(&z__1, &i__3, &a[j + 1 + j * a_dim1], &c__1, &
+ x[j + 1], &c__1);
+ csumj.r = z__1.r, csumj.i = z__1.i;
+ }
+ } else {
+
+/* Otherwise, use in-line code for the dot product. */
+
+ if (upper) {
+ i__3 = j - 1;
+ for (i__ = 1; i__ <= i__3; ++i__) {
+ i__4 = i__ + j * a_dim1;
+ z__3.r = a[i__4].r * uscal.r - a[i__4].i *
+ uscal.i, z__3.i = a[i__4].r * uscal.i + a[
+ i__4].i * uscal.r;
+ i__5 = i__;
+ z__2.r = z__3.r * x[i__5].r - z__3.i * x[i__5].i,
+ z__2.i = z__3.r * x[i__5].i + z__3.i * x[
+ i__5].r;
+ z__1.r = csumj.r + z__2.r, z__1.i = csumj.i +
+ z__2.i;
+ csumj.r = z__1.r, csumj.i = z__1.i;
+/* L130: */
+ }
+ } else if (j < *n) {
+ i__3 = *n;
+ for (i__ = j + 1; i__ <= i__3; ++i__) {
+ i__4 = i__ + j * a_dim1;
+ z__3.r = a[i__4].r * uscal.r - a[i__4].i *
+ uscal.i, z__3.i = a[i__4].r * uscal.i + a[
+ i__4].i * uscal.r;
+ i__5 = i__;
+ z__2.r = z__3.r * x[i__5].r - z__3.i * x[i__5].i,
+ z__2.i = z__3.r * x[i__5].i + z__3.i * x[
+ i__5].r;
+ z__1.r = csumj.r + z__2.r, z__1.i = csumj.i +
+ z__2.i;
+ csumj.r = z__1.r, csumj.i = z__1.i;
+/* L140: */
+ }
+ }
+ }
+
+ z__1.r = tscal, z__1.i = 0.;
+ if (uscal.r == z__1.r && uscal.i == z__1.i) {
+
+/* Compute x(j) := ( x(j) - CSUMJ ) / A(j,j) if 1/A(j,j) */
+/* was not used to scale the dotproduct. */
+
+ i__3 = j;
+ i__4 = j;
+ z__1.r = x[i__4].r - csumj.r, z__1.i = x[i__4].i -
+ csumj.i;
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ i__3 = j;
+ xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j])
+ , abs(d__2));
+ if (nounit) {
+ i__3 = j + j * a_dim1;
+ z__1.r = tscal * a[i__3].r, z__1.i = tscal * a[i__3]
+ .i;
+ tjjs.r = z__1.r, tjjs.i = z__1.i;
+ } else {
+ tjjs.r = tscal, tjjs.i = 0.;
+ if (tscal == 1.) {
+ goto L160;
+ }
+ }
+
+/* Compute x(j) = x(j) / A(j,j), scaling if necessary. */
+
+ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs),
+ abs(d__2));
+ if (tjj > smlnum) {
+
+/* abs(A(j,j)) > SMLNUM: */
+
+ if (tjj < 1.) {
+ if (xj > tjj * bignum) {
+
+/* Scale X by 1/abs(x(j)). */
+
+ rec = 1. / xj;
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ xmax *= rec;
+ }
+ }
+ i__3 = j;
+ zladiv_(&z__1, &x[j], &tjjs);
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ } else if (tjj > 0.) {
+
+/* 0 < abs(A(j,j)) <= SMLNUM: */
+
+ if (xj > tjj * bignum) {
+
+/* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */
+
+ rec = tjj * bignum / xj;
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ xmax *= rec;
+ }
+ i__3 = j;
+ zladiv_(&z__1, &x[j], &tjjs);
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ } else {
+
+/* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
+/* scale = 0 and compute a solution to A**T *x = 0. */
+
+ i__3 = *n;
+ for (i__ = 1; i__ <= i__3; ++i__) {
+ i__4 = i__;
+ x[i__4].r = 0., x[i__4].i = 0.;
+/* L150: */
+ }
+ i__3 = j;
+ x[i__3].r = 1., x[i__3].i = 0.;
+ *scale = 0.;
+ xmax = 0.;
+ }
+L160:
+ ;
+ } else {
+
+/* Compute x(j) := x(j) / A(j,j) - CSUMJ if the dot */
+/* product has already been divided by 1/A(j,j). */
+
+ i__3 = j;
+ zladiv_(&z__2, &x[j], &tjjs);
+ z__1.r = z__2.r - csumj.r, z__1.i = z__2.i - csumj.i;
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ }
+/* Computing MAX */
+ i__3 = j;
+ d__3 = xmax, d__4 = (d__1 = x[i__3].r, abs(d__1)) + (d__2 =
+ d_imag(&x[j]), abs(d__2));
+ xmax = max(d__3,d__4);
+/* L170: */
+ }
+
+ } else {
+
+/* Solve A**H * x = b */
+
+ i__1 = jlast;
+ i__2 = jinc;
+ for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
+
+/* Compute x(j) = b(j) - sum A(k,j)*x(k). */
+/* k<>j */
+
+ i__3 = j;
+ xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j]),
+ abs(d__2));
+ uscal.r = tscal, uscal.i = 0.;
+ rec = 1. / max(xmax,1.);
+ if (cnorm[j] > (bignum - xj) * rec) {
+
+/* If x(j) could overflow, scale x by 1/(2*XMAX). */
+
+ rec *= .5;
+ if (nounit) {
+ d_cnjg(&z__2, &a[j + j * a_dim1]);
+ z__1.r = tscal * z__2.r, z__1.i = tscal * z__2.i;
+ tjjs.r = z__1.r, tjjs.i = z__1.i;
+ } else {
+ tjjs.r = tscal, tjjs.i = 0.;
+ }
+ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs),
+ abs(d__2));
+ if (tjj > 1.) {
+
+/* Divide by A(j,j) when scaling x if A(j,j) > 1. */
+
+/* Computing MIN */
+ d__1 = 1., d__2 = rec * tjj;
+ rec = min(d__1,d__2);
+ zladiv_(&z__1, &uscal, &tjjs);
+ uscal.r = z__1.r, uscal.i = z__1.i;
+ }
+ if (rec < 1.) {
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ xmax *= rec;
+ }
+ }
+
+ csumj.r = 0., csumj.i = 0.;
+ if (uscal.r == 1. && uscal.i == 0.) {
+
+/* If the scaling needed for A in the dot product is 1, */
+/* call ZDOTC to perform the dot product. */
+
+ if (upper) {
+ i__3 = j - 1;
+ zdotc_(&z__1, &i__3, &a[j * a_dim1 + 1], &c__1, &x[1],
+ &c__1);
+ csumj.r = z__1.r, csumj.i = z__1.i;
+ } else if (j < *n) {
+ i__3 = *n - j;
+ zdotc_(&z__1, &i__3, &a[j + 1 + j * a_dim1], &c__1, &
+ x[j + 1], &c__1);
+ csumj.r = z__1.r, csumj.i = z__1.i;
+ }
+ } else {
+
+/* Otherwise, use in-line code for the dot product. */
+
+ if (upper) {
+ i__3 = j - 1;
+ for (i__ = 1; i__ <= i__3; ++i__) {
+ d_cnjg(&z__4, &a[i__ + j * a_dim1]);
+ z__3.r = z__4.r * uscal.r - z__4.i * uscal.i,
+ z__3.i = z__4.r * uscal.i + z__4.i *
+ uscal.r;
+ i__4 = i__;
+ z__2.r = z__3.r * x[i__4].r - z__3.i * x[i__4].i,
+ z__2.i = z__3.r * x[i__4].i + z__3.i * x[
+ i__4].r;
+ z__1.r = csumj.r + z__2.r, z__1.i = csumj.i +
+ z__2.i;
+ csumj.r = z__1.r, csumj.i = z__1.i;
+/* L180: */
+ }
+ } else if (j < *n) {
+ i__3 = *n;
+ for (i__ = j + 1; i__ <= i__3; ++i__) {
+ d_cnjg(&z__4, &a[i__ + j * a_dim1]);
+ z__3.r = z__4.r * uscal.r - z__4.i * uscal.i,
+ z__3.i = z__4.r * uscal.i + z__4.i *
+ uscal.r;
+ i__4 = i__;
+ z__2.r = z__3.r * x[i__4].r - z__3.i * x[i__4].i,
+ z__2.i = z__3.r * x[i__4].i + z__3.i * x[
+ i__4].r;
+ z__1.r = csumj.r + z__2.r, z__1.i = csumj.i +
+ z__2.i;
+ csumj.r = z__1.r, csumj.i = z__1.i;
+/* L190: */
+ }
+ }
+ }
+
+ z__1.r = tscal, z__1.i = 0.;
+ if (uscal.r == z__1.r && uscal.i == z__1.i) {
+
+/* Compute x(j) := ( x(j) - CSUMJ ) / A(j,j) if 1/A(j,j) */
+/* was not used to scale the dotproduct. */
+
+ i__3 = j;
+ i__4 = j;
+ z__1.r = x[i__4].r - csumj.r, z__1.i = x[i__4].i -
+ csumj.i;
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ i__3 = j;
+ xj = (d__1 = x[i__3].r, abs(d__1)) + (d__2 = d_imag(&x[j])
+ , abs(d__2));
+ if (nounit) {
+ d_cnjg(&z__2, &a[j + j * a_dim1]);
+ z__1.r = tscal * z__2.r, z__1.i = tscal * z__2.i;
+ tjjs.r = z__1.r, tjjs.i = z__1.i;
+ } else {
+ tjjs.r = tscal, tjjs.i = 0.;
+ if (tscal == 1.) {
+ goto L210;
+ }
+ }
+
+/* Compute x(j) = x(j) / A(j,j), scaling if necessary. */
+
+ tjj = (d__1 = tjjs.r, abs(d__1)) + (d__2 = d_imag(&tjjs),
+ abs(d__2));
+ if (tjj > smlnum) {
+
+/* abs(A(j,j)) > SMLNUM: */
+
+ if (tjj < 1.) {
+ if (xj > tjj * bignum) {
+
+/* Scale X by 1/abs(x(j)). */
+
+ rec = 1. / xj;
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ xmax *= rec;
+ }
+ }
+ i__3 = j;
+ zladiv_(&z__1, &x[j], &tjjs);
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ } else if (tjj > 0.) {
+
+/* 0 < abs(A(j,j)) <= SMLNUM: */
+
+ if (xj > tjj * bignum) {
+
+/* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */
+
+ rec = tjj * bignum / xj;
+ zdscal_(n, &rec, &x[1], &c__1);
+ *scale *= rec;
+ xmax *= rec;
+ }
+ i__3 = j;
+ zladiv_(&z__1, &x[j], &tjjs);
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ } else {
+
+/* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
+/* scale = 0 and compute a solution to A**H *x = 0. */
+
+ i__3 = *n;
+ for (i__ = 1; i__ <= i__3; ++i__) {
+ i__4 = i__;
+ x[i__4].r = 0., x[i__4].i = 0.;
+/* L200: */
+ }
+ i__3 = j;
+ x[i__3].r = 1., x[i__3].i = 0.;
+ *scale = 0.;
+ xmax = 0.;
+ }
+L210:
+ ;
+ } else {
+
+/* Compute x(j) := x(j) / A(j,j) - CSUMJ if the dot */
+/* product has already been divided by 1/A(j,j). */
+
+ i__3 = j;
+ zladiv_(&z__2, &x[j], &tjjs);
+ z__1.r = z__2.r - csumj.r, z__1.i = z__2.i - csumj.i;
+ x[i__3].r = z__1.r, x[i__3].i = z__1.i;
+ }
+/* Computing MAX */
+ i__3 = j;
+ d__3 = xmax, d__4 = (d__1 = x[i__3].r, abs(d__1)) + (d__2 =
+ d_imag(&x[j]), abs(d__2));
+ xmax = max(d__3,d__4);
+/* L220: */
+ }
+ }
+ *scale /= tscal;
+ }
+
+/* Scale the column norms by 1/TSCAL for return. */
+
+ if (tscal != 1.) {
+ d__1 = 1. / tscal;
+ dscal_(n, &d__1, &cnorm[1], &c__1);
+ }
+
+ return 0;
+
+/* End of ZLATRS */
+
+} /* zlatrs_ */