14 typedef long long BLASLONG;
15 typedef unsigned long long BLASULONG;
17 typedef long BLASLONG;
18 typedef unsigned long BLASULONG;
22 typedef BLASLONG blasint;
24 #define blasabs(x) llabs(x)
26 #define blasabs(x) labs(x)
30 #define blasabs(x) abs(x)
33 typedef blasint integer;
35 typedef unsigned int uinteger;
36 typedef char *address;
37 typedef short int shortint;
39 typedef double doublereal;
40 typedef struct { real r, i; } complex;
41 typedef struct { doublereal r, i; } doublecomplex;
43 static inline _Fcomplex Cf(complex *z) {_Fcomplex zz={z->r , z->i}; return zz;}
44 static inline _Dcomplex Cd(doublecomplex *z) {_Dcomplex zz={z->r , z->i};return zz;}
45 static inline _Fcomplex * _pCf(complex *z) {return (_Fcomplex*)z;}
46 static inline _Dcomplex * _pCd(doublecomplex *z) {return (_Dcomplex*)z;}
48 static inline _Complex float Cf(complex *z) {return z->r + z->i*_Complex_I;}
49 static inline _Complex double Cd(doublecomplex *z) {return z->r + z->i*_Complex_I;}
50 static inline _Complex float * _pCf(complex *z) {return (_Complex float*)z;}
51 static inline _Complex double * _pCd(doublecomplex *z) {return (_Complex double*)z;}
53 #define pCf(z) (*_pCf(z))
54 #define pCd(z) (*_pCd(z))
56 typedef short int shortlogical;
57 typedef char logical1;
58 typedef char integer1;
63 /* Extern is for use with -E */
74 /*external read, write*/
83 /*internal read, write*/
113 /*rewind, backspace, endfile*/
125 ftnint *inex; /*parameters in standard's order*/
151 union Multitype { /* for multiple entry points */
162 typedef union Multitype Multitype;
164 struct Vardesc { /* for Namelist */
170 typedef struct Vardesc Vardesc;
177 typedef struct Namelist Namelist;
179 #define abs(x) ((x) >= 0 ? (x) : -(x))
180 #define dabs(x) (fabs(x))
181 #define f2cmin(a,b) ((a) <= (b) ? (a) : (b))
182 #define f2cmax(a,b) ((a) >= (b) ? (a) : (b))
183 #define dmin(a,b) (f2cmin(a,b))
184 #define dmax(a,b) (f2cmax(a,b))
185 #define bit_test(a,b) ((a) >> (b) & 1)
186 #define bit_clear(a,b) ((a) & ~((uinteger)1 << (b)))
187 #define bit_set(a,b) ((a) | ((uinteger)1 << (b)))
189 #define abort_() { sig_die("Fortran abort routine called", 1); }
190 #define c_abs(z) (cabsf(Cf(z)))
191 #define c_cos(R,Z) { pCf(R)=ccos(Cf(Z)); }
193 #define c_div(c, a, b) {Cf(c)._Val[0] = (Cf(a)._Val[0]/Cf(b)._Val[0]); Cf(c)._Val[1]=(Cf(a)._Val[1]/Cf(b)._Val[1]);}
194 #define z_div(c, a, b) {Cd(c)._Val[0] = (Cd(a)._Val[0]/Cd(b)._Val[0]); Cd(c)._Val[1]=(Cd(a)._Val[1]/df(b)._Val[1]);}
196 #define c_div(c, a, b) {pCf(c) = Cf(a)/Cf(b);}
197 #define z_div(c, a, b) {pCd(c) = Cd(a)/Cd(b);}
199 #define c_exp(R, Z) {pCf(R) = cexpf(Cf(Z));}
200 #define c_log(R, Z) {pCf(R) = clogf(Cf(Z));}
201 #define c_sin(R, Z) {pCf(R) = csinf(Cf(Z));}
202 //#define c_sqrt(R, Z) {*(R) = csqrtf(Cf(Z));}
203 #define c_sqrt(R, Z) {pCf(R) = csqrtf(Cf(Z));}
204 #define d_abs(x) (fabs(*(x)))
205 #define d_acos(x) (acos(*(x)))
206 #define d_asin(x) (asin(*(x)))
207 #define d_atan(x) (atan(*(x)))
208 #define d_atn2(x, y) (atan2(*(x),*(y)))
209 #define d_cnjg(R, Z) { pCd(R) = conj(Cd(Z)); }
210 #define r_cnjg(R, Z) { pCf(R) = conjf(Cf(Z)); }
211 #define d_cos(x) (cos(*(x)))
212 #define d_cosh(x) (cosh(*(x)))
213 #define d_dim(__a, __b) ( *(__a) > *(__b) ? *(__a) - *(__b) : 0.0 )
214 #define d_exp(x) (exp(*(x)))
215 #define d_imag(z) (cimag(Cd(z)))
216 #define r_imag(z) (cimagf(Cf(z)))
217 #define d_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
218 #define r_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
219 #define d_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
220 #define r_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
221 #define d_log(x) (log(*(x)))
222 #define d_mod(x, y) (fmod(*(x), *(y)))
223 #define u_nint(__x) ((__x)>=0 ? floor((__x) + .5) : -floor(.5 - (__x)))
224 #define d_nint(x) u_nint(*(x))
225 #define u_sign(__a,__b) ((__b) >= 0 ? ((__a) >= 0 ? (__a) : -(__a)) : -((__a) >= 0 ? (__a) : -(__a)))
226 #define d_sign(a,b) u_sign(*(a),*(b))
227 #define r_sign(a,b) u_sign(*(a),*(b))
228 #define d_sin(x) (sin(*(x)))
229 #define d_sinh(x) (sinh(*(x)))
230 #define d_sqrt(x) (sqrt(*(x)))
231 #define d_tan(x) (tan(*(x)))
232 #define d_tanh(x) (tanh(*(x)))
233 #define i_abs(x) abs(*(x))
234 #define i_dnnt(x) ((integer)u_nint(*(x)))
235 #define i_len(s, n) (n)
236 #define i_nint(x) ((integer)u_nint(*(x)))
237 #define i_sign(a,b) ((integer)u_sign((integer)*(a),(integer)*(b)))
238 #define pow_dd(ap, bp) ( pow(*(ap), *(bp)))
239 #define pow_si(B,E) spow_ui(*(B),*(E))
240 #define pow_ri(B,E) spow_ui(*(B),*(E))
241 #define pow_di(B,E) dpow_ui(*(B),*(E))
242 #define pow_zi(p, a, b) {pCd(p) = zpow_ui(Cd(a), *(b));}
243 #define pow_ci(p, a, b) {pCf(p) = cpow_ui(Cf(a), *(b));}
244 #define pow_zz(R,A,B) {pCd(R) = cpow(Cd(A),*(B));}
245 #define s_cat(lpp, rpp, rnp, np, llp) { ftnlen i, nc, ll; char *f__rp, *lp; ll = (llp); lp = (lpp); for(i=0; i < (int)*(np); ++i) { nc = ll; if((rnp)[i] < nc) nc = (rnp)[i]; ll -= nc; f__rp = (rpp)[i]; while(--nc >= 0) *lp++ = *(f__rp)++; } while(--ll >= 0) *lp++ = ' '; }
246 #define s_cmp(a,b,c,d) ((integer)strncmp((a),(b),f2cmin((c),(d))))
247 #define s_copy(A,B,C,D) { int __i,__m; for (__i=0, __m=f2cmin((C),(D)); __i<__m && (B)[__i] != 0; ++__i) (A)[__i] = (B)[__i]; }
248 #define sig_die(s, kill) { exit(1); }
249 #define s_stop(s, n) {exit(0);}
250 static char junk[] = "\n@(#)LIBF77 VERSION 19990503\n";
251 #define z_abs(z) (cabs(Cd(z)))
252 #define z_exp(R, Z) {pCd(R) = cexp(Cd(Z));}
253 #define z_sqrt(R, Z) {pCd(R) = csqrt(Cd(Z));}
254 #define myexit_() break;
255 #define mycycle() continue;
256 #define myceiling(w) {ceil(w)}
257 #define myhuge(w) {HUGE_VAL}
258 //#define mymaxloc_(w,s,e,n) {if (sizeof(*(w)) == sizeof(double)) dmaxloc_((w),*(s),*(e),n); else dmaxloc_((w),*(s),*(e),n);}
259 #define mymaxloc(w,s,e,n) {dmaxloc_(w,*(s),*(e),n)}
261 /* procedure parameter types for -A and -C++ */
263 #define F2C_proc_par_types 1
265 typedef logical (*L_fp)(...);
267 typedef logical (*L_fp)();
270 static float spow_ui(float x, integer n) {
271 float pow=1.0; unsigned long int u;
273 if(n < 0) n = -n, x = 1/x;
282 static double dpow_ui(double x, integer n) {
283 double pow=1.0; unsigned long int u;
285 if(n < 0) n = -n, x = 1/x;
295 static _Fcomplex cpow_ui(complex x, integer n) {
296 complex pow={1.0,0.0}; unsigned long int u;
298 if(n < 0) n = -n, x.r = 1/x.r, x.i=1/x.i;
300 if(u & 01) pow.r *= x.r, pow.i *= x.i;
301 if(u >>= 1) x.r *= x.r, x.i *= x.i;
305 _Fcomplex p={pow.r, pow.i};
309 static _Complex float cpow_ui(_Complex float x, integer n) {
310 _Complex float pow=1.0; unsigned long int u;
312 if(n < 0) n = -n, x = 1/x;
323 static _Dcomplex zpow_ui(_Dcomplex x, integer n) {
324 _Dcomplex pow={1.0,0.0}; unsigned long int u;
326 if(n < 0) n = -n, x._Val[0] = 1/x._Val[0], x._Val[1] =1/x._Val[1];
328 if(u & 01) pow._Val[0] *= x._Val[0], pow._Val[1] *= x._Val[1];
329 if(u >>= 1) x._Val[0] *= x._Val[0], x._Val[1] *= x._Val[1];
333 _Dcomplex p = {pow._Val[0], pow._Val[1]};
337 static _Complex double zpow_ui(_Complex double x, integer n) {
338 _Complex double pow=1.0; unsigned long int u;
340 if(n < 0) n = -n, x = 1/x;
350 static integer pow_ii(integer x, integer n) {
351 integer pow; unsigned long int u;
353 if (n == 0 || x == 1) pow = 1;
354 else if (x != -1) pow = x == 0 ? 1/x : 0;
357 if ((n > 0) || !(n == 0 || x == 1 || x != -1)) {
367 static integer dmaxloc_(double *w, integer s, integer e, integer *n)
369 double m; integer i, mi;
370 for(m=w[s-1], mi=s, i=s+1; i<=e; i++)
371 if (w[i-1]>m) mi=i ,m=w[i-1];
374 static integer smaxloc_(float *w, integer s, integer e, integer *n)
376 float m; integer i, mi;
377 for(m=w[s-1], mi=s, i=s+1; i<=e; i++)
378 if (w[i-1]>m) mi=i ,m=w[i-1];
381 static inline void cdotc_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) {
382 integer n = *n_, incx = *incx_, incy = *incy_, i;
384 _Fcomplex zdotc = {0.0, 0.0};
385 if (incx == 1 && incy == 1) {
386 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
387 zdotc._Val[0] += conjf(Cf(&x[i]))._Val[0] * Cf(&y[i])._Val[0];
388 zdotc._Val[1] += conjf(Cf(&x[i]))._Val[1] * Cf(&y[i])._Val[1];
391 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
392 zdotc._Val[0] += conjf(Cf(&x[i*incx]))._Val[0] * Cf(&y[i*incy])._Val[0];
393 zdotc._Val[1] += conjf(Cf(&x[i*incx]))._Val[1] * Cf(&y[i*incy])._Val[1];
399 _Complex float zdotc = 0.0;
400 if (incx == 1 && incy == 1) {
401 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
402 zdotc += conjf(Cf(&x[i])) * Cf(&y[i]);
405 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
406 zdotc += conjf(Cf(&x[i*incx])) * Cf(&y[i*incy]);
412 static inline void zdotc_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {
413 integer n = *n_, incx = *incx_, incy = *incy_, i;
415 _Dcomplex zdotc = {0.0, 0.0};
416 if (incx == 1 && incy == 1) {
417 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
418 zdotc._Val[0] += conj(Cd(&x[i]))._Val[0] * Cd(&y[i])._Val[0];
419 zdotc._Val[1] += conj(Cd(&x[i]))._Val[1] * Cd(&y[i])._Val[1];
422 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
423 zdotc._Val[0] += conj(Cd(&x[i*incx]))._Val[0] * Cd(&y[i*incy])._Val[0];
424 zdotc._Val[1] += conj(Cd(&x[i*incx]))._Val[1] * Cd(&y[i*incy])._Val[1];
430 _Complex double zdotc = 0.0;
431 if (incx == 1 && incy == 1) {
432 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
433 zdotc += conj(Cd(&x[i])) * Cd(&y[i]);
436 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
437 zdotc += conj(Cd(&x[i*incx])) * Cd(&y[i*incy]);
443 static inline void cdotu_(complex *z, integer *n_, complex *x, integer *incx_, complex *y, integer *incy_) {
444 integer n = *n_, incx = *incx_, incy = *incy_, i;
446 _Fcomplex zdotc = {0.0, 0.0};
447 if (incx == 1 && incy == 1) {
448 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
449 zdotc._Val[0] += Cf(&x[i])._Val[0] * Cf(&y[i])._Val[0];
450 zdotc._Val[1] += Cf(&x[i])._Val[1] * Cf(&y[i])._Val[1];
453 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
454 zdotc._Val[0] += Cf(&x[i*incx])._Val[0] * Cf(&y[i*incy])._Val[0];
455 zdotc._Val[1] += Cf(&x[i*incx])._Val[1] * Cf(&y[i*incy])._Val[1];
461 _Complex float zdotc = 0.0;
462 if (incx == 1 && incy == 1) {
463 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
464 zdotc += Cf(&x[i]) * Cf(&y[i]);
467 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
468 zdotc += Cf(&x[i*incx]) * Cf(&y[i*incy]);
474 static inline void zdotu_(doublecomplex *z, integer *n_, doublecomplex *x, integer *incx_, doublecomplex *y, integer *incy_) {
475 integer n = *n_, incx = *incx_, incy = *incy_, i;
477 _Dcomplex zdotc = {0.0, 0.0};
478 if (incx == 1 && incy == 1) {
479 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
480 zdotc._Val[0] += Cd(&x[i])._Val[0] * Cd(&y[i])._Val[0];
481 zdotc._Val[1] += Cd(&x[i])._Val[1] * Cd(&y[i])._Val[1];
484 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
485 zdotc._Val[0] += Cd(&x[i*incx])._Val[0] * Cd(&y[i*incy])._Val[0];
486 zdotc._Val[1] += Cd(&x[i*incx])._Val[1] * Cd(&y[i*incy])._Val[1];
492 _Complex double zdotc = 0.0;
493 if (incx == 1 && incy == 1) {
494 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
495 zdotc += Cd(&x[i]) * Cd(&y[i]);
498 for (i=0;i<n;i++) { /* zdotc = zdotc + dconjg(x(i))* y(i) */
499 zdotc += Cd(&x[i*incx]) * Cd(&y[i*incy]);
505 /* -- translated by f2c (version 20000121).
506 You must link the resulting object file with the libraries:
507 -lf2c -lm (in that order)
513 /* Table of constant values */
515 static integer c__1 = 1;
516 static real c_b36 = .5f;
518 /* > \brief \b CLATRS solves a triangular system of equations with the scale factor set to prevent overflow.
521 /* =========== DOCUMENTATION =========== */
523 /* Online html documentation available at */
524 /* http://www.netlib.org/lapack/explore-html/ */
527 /* > Download CLATRS + dependencies */
528 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/clatrs.
531 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/clatrs.
534 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/clatrs.
542 /* SUBROUTINE CLATRS( UPLO, TRANS, DIAG, NORMIN, N, A, LDA, X, SCALE, */
545 /* CHARACTER DIAG, NORMIN, TRANS, UPLO */
546 /* INTEGER INFO, LDA, N */
548 /* REAL CNORM( * ) */
549 /* COMPLEX A( LDA, * ), X( * ) */
552 /* > \par Purpose: */
557 /* > CLATRS solves one of the triangular systems */
559 /* > A * x = s*b, A**T * x = s*b, or A**H * x = s*b, */
561 /* > with scaling to prevent overflow. Here A is an upper or lower */
562 /* > triangular matrix, A**T denotes the transpose of A, A**H denotes the */
563 /* > conjugate transpose of A, x and b are n-element vectors, and s is a */
564 /* > scaling factor, usually less than or equal to 1, chosen so that the */
565 /* > components of x will be less than the overflow threshold. If the */
566 /* > unscaled problem will not cause overflow, the Level 2 BLAS routine */
567 /* > CTRSV is called. If the matrix A is singular (A(j,j) = 0 for some j), */
568 /* > then s is set to 0 and a non-trivial solution to A*x = 0 is returned. */
574 /* > \param[in] UPLO */
576 /* > UPLO is CHARACTER*1 */
577 /* > Specifies whether the matrix A is upper or lower triangular. */
578 /* > = 'U': Upper triangular */
579 /* > = 'L': Lower triangular */
582 /* > \param[in] TRANS */
584 /* > TRANS is CHARACTER*1 */
585 /* > Specifies the operation applied to A. */
586 /* > = 'N': Solve A * x = s*b (No transpose) */
587 /* > = 'T': Solve A**T * x = s*b (Transpose) */
588 /* > = 'C': Solve A**H * x = s*b (Conjugate transpose) */
591 /* > \param[in] DIAG */
593 /* > DIAG is CHARACTER*1 */
594 /* > Specifies whether or not the matrix A is unit triangular. */
595 /* > = 'N': Non-unit triangular */
596 /* > = 'U': Unit triangular */
599 /* > \param[in] NORMIN */
601 /* > NORMIN is CHARACTER*1 */
602 /* > Specifies whether CNORM has been set or not. */
603 /* > = 'Y': CNORM contains the column norms on entry */
604 /* > = 'N': CNORM is not set on entry. On exit, the norms will */
605 /* > be computed and stored in CNORM. */
611 /* > The order of the matrix A. N >= 0. */
616 /* > A is COMPLEX array, dimension (LDA,N) */
617 /* > The triangular matrix A. If UPLO = 'U', the leading n by n */
618 /* > upper triangular part of the array A contains the upper */
619 /* > triangular matrix, and the strictly lower triangular part of */
620 /* > A is not referenced. If UPLO = 'L', the leading n by n lower */
621 /* > triangular part of the array A contains the lower triangular */
622 /* > matrix, and the strictly upper triangular part of A is not */
623 /* > referenced. If DIAG = 'U', the diagonal elements of A are */
624 /* > also not referenced and are assumed to be 1. */
627 /* > \param[in] LDA */
629 /* > LDA is INTEGER */
630 /* > The leading dimension of the array A. LDA >= f2cmax (1,N). */
633 /* > \param[in,out] X */
635 /* > X is COMPLEX array, dimension (N) */
636 /* > On entry, the right hand side b of the triangular system. */
637 /* > On exit, X is overwritten by the solution vector x. */
640 /* > \param[out] SCALE */
642 /* > SCALE is REAL */
643 /* > The scaling factor s for the triangular system */
644 /* > A * x = s*b, A**T * x = s*b, or A**H * x = s*b. */
645 /* > If SCALE = 0, the matrix A is singular or badly scaled, and */
646 /* > the vector x is an exact or approximate solution to A*x = 0. */
649 /* > \param[in,out] CNORM */
651 /* > CNORM is REAL array, dimension (N) */
653 /* > If NORMIN = 'Y', CNORM is an input argument and CNORM(j) */
654 /* > contains the norm of the off-diagonal part of the j-th column */
655 /* > of A. If TRANS = 'N', CNORM(j) must be greater than or equal */
656 /* > to the infinity-norm, and if TRANS = 'T' or 'C', CNORM(j) */
657 /* > must be greater than or equal to the 1-norm. */
659 /* > If NORMIN = 'N', CNORM is an output argument and CNORM(j) */
660 /* > returns the 1-norm of the offdiagonal part of the j-th column */
664 /* > \param[out] INFO */
666 /* > INFO is INTEGER */
667 /* > = 0: successful exit */
668 /* > < 0: if INFO = -k, the k-th argument had an illegal value */
674 /* > \author Univ. of Tennessee */
675 /* > \author Univ. of California Berkeley */
676 /* > \author Univ. of Colorado Denver */
677 /* > \author NAG Ltd. */
679 /* > \date December 2016 */
681 /* > \ingroup complexOTHERauxiliary */
683 /* > \par Further Details: */
684 /* ===================== */
688 /* > A rough bound on x is computed; if that is less than overflow, CTRSV */
689 /* > is called, otherwise, specific code is used which checks for possible */
690 /* > overflow or divide-by-zero at every operation. */
692 /* > A columnwise scheme is used for solving A*x = b. The basic algorithm */
693 /* > if A is lower triangular is */
695 /* > x[1:n] := b[1:n] */
696 /* > for j = 1, ..., n */
697 /* > x(j) := x(j) / A(j,j) */
698 /* > x[j+1:n] := x[j+1:n] - x(j) * A[j+1:n,j] */
701 /* > Define bounds on the components of x after j iterations of the loop: */
702 /* > M(j) = bound on x[1:j] */
703 /* > G(j) = bound on x[j+1:n] */
704 /* > Initially, let M(0) = 0 and G(0) = f2cmax{x(i), i=1,...,n}. */
706 /* > Then for iteration j+1 we have */
707 /* > M(j+1) <= G(j) / | A(j+1,j+1) | */
708 /* > G(j+1) <= G(j) + M(j+1) * | A[j+2:n,j+1] | */
709 /* > <= G(j) ( 1 + CNORM(j+1) / | A(j+1,j+1) | ) */
711 /* > where CNORM(j+1) is greater than or equal to the infinity-norm of */
712 /* > column j+1 of A, not counting the diagonal. Hence */
714 /* > G(j) <= G(0) product ( 1 + CNORM(i) / | A(i,i) | ) */
718 /* > |x(j)| <= ( G(0) / |A(j,j)| ) product ( 1 + CNORM(i) / |A(i,i)| ) */
721 /* > Since |x(j)| <= M(j), we use the Level 2 BLAS routine CTRSV if the */
722 /* > reciprocal of the largest M(j), j=1,..,n, is larger than */
723 /* > f2cmax(underflow, 1/overflow). */
725 /* > The bound on x(j) is also used to determine when a step in the */
726 /* > columnwise method can be performed without fear of overflow. If */
727 /* > the computed bound is greater than a large constant, x is scaled to */
728 /* > prevent overflow, but if the bound overflows, x is set to 0, x(j) to */
729 /* > 1, and scale to 0, and a non-trivial solution to A*x = 0 is found. */
731 /* > Similarly, a row-wise scheme is used to solve A**T *x = b or */
732 /* > A**H *x = b. The basic algorithm for A upper triangular is */
734 /* > for j = 1, ..., n */
735 /* > x(j) := ( b(j) - A[1:j-1,j]' * x[1:j-1] ) / A(j,j) */
738 /* > We simultaneously compute two bounds */
739 /* > G(j) = bound on ( b(i) - A[1:i-1,i]' * x[1:i-1] ), 1<=i<=j */
740 /* > M(j) = bound on x(i), 1<=i<=j */
742 /* > The initial values are G(0) = 0, M(0) = f2cmax{b(i), i=1,..,n}, and we */
743 /* > add the constraint G(j) >= G(j-1) and M(j) >= M(j-1) for j >= 1. */
744 /* > Then the bound on x(j) is */
746 /* > M(j) <= M(j-1) * ( 1 + CNORM(j) ) / | A(j,j) | */
748 /* > <= M(0) * product ( ( 1 + CNORM(i) ) / |A(i,i)| ) */
751 /* > and we can safely call CTRSV if 1/M(n) and 1/G(n) are both greater */
752 /* > than f2cmax(underflow, 1/overflow). */
755 /* ===================================================================== */
756 /* Subroutine */ int clatrs_(char *uplo, char *trans, char *diag, char *
757 normin, integer *n, complex *a, integer *lda, complex *x, real *scale,
758 real *cnorm, integer *info)
760 /* System generated locals */
761 integer a_dim1, a_offset, i__1, i__2, i__3, i__4, i__5;
762 real r__1, r__2, r__3, r__4;
763 complex q__1, q__2, q__3, q__4;
765 /* Local variables */
773 extern /* Complex */ VOID cdotc_(complex *, integer *, complex *, integer
774 *, complex *, integer *);
775 extern logical lsame_(char *, char *);
776 extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *);
780 extern /* Complex */ VOID cdotu_(complex *, integer *, complex *, integer
781 *, complex *, integer *);
783 extern /* Subroutine */ int caxpy_(integer *, complex *, complex *,
784 integer *, complex *, integer *);
786 extern /* Subroutine */ int ctrsv_(char *, char *, char *, integer *,
787 complex *, integer *, complex *, integer *), slabad_(real *, real *);
789 extern integer icamax_(integer *, complex *, integer *);
790 extern /* Complex */ VOID cladiv_(complex *, complex *, complex *);
791 extern real slamch_(char *);
792 extern /* Subroutine */ int csscal_(integer *, real *, complex *, integer
793 *), xerbla_(char *, integer *, ftnlen);
795 extern integer isamax_(integer *, real *, integer *);
796 extern real scasum_(integer *, complex *, integer *);
804 /* -- LAPACK auxiliary routine (version 3.7.0) -- */
805 /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
806 /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
810 /* ===================================================================== */
813 /* Parameter adjustments */
815 a_offset = 1 + a_dim1 * 1;
822 upper = lsame_(uplo, "U");
823 notran = lsame_(trans, "N");
824 nounit = lsame_(diag, "N");
826 /* Test the input parameters. */
828 if (! upper && ! lsame_(uplo, "L")) {
830 } else if (! notran && ! lsame_(trans, "T") && !
831 lsame_(trans, "C")) {
833 } else if (! nounit && ! lsame_(diag, "U")) {
835 } else if (! lsame_(normin, "Y") && ! lsame_(normin,
840 } else if (*lda < f2cmax(1,*n)) {
845 xerbla_("CLATRS", &i__1, (ftnlen)6);
849 /* Quick return if possible */
855 /* Determine machine dependent parameters to control overflow. */
857 smlnum = slamch_("Safe minimum");
858 bignum = 1.f / smlnum;
859 slabad_(&smlnum, &bignum);
860 smlnum /= slamch_("Precision");
861 bignum = 1.f / smlnum;
864 if (lsame_(normin, "N")) {
866 /* Compute the 1-norm of each column, not including the diagonal. */
870 /* A is upper triangular. */
873 for (j = 1; j <= i__1; ++j) {
875 cnorm[j] = scasum_(&i__2, &a[j * a_dim1 + 1], &c__1);
880 /* A is lower triangular. */
883 for (j = 1; j <= i__1; ++j) {
885 cnorm[j] = scasum_(&i__2, &a[j + 1 + j * a_dim1], &c__1);
892 /* Scale the column norms by TSCAL if the maximum element in CNORM is */
893 /* greater than BIGNUM/2. */
895 imax = isamax_(n, &cnorm[1], &c__1);
897 if (tmax <= bignum * .5f) {
900 tscal = .5f / (smlnum * tmax);
901 sscal_(n, &tscal, &cnorm[1], &c__1);
904 /* Compute a bound on the computed solution vector to see if the */
905 /* Level 2 BLAS routine CTRSV can be used. */
909 for (j = 1; j <= i__1; ++j) {
912 r__3 = xmax, r__4 = (r__1 = x[i__2].r / 2.f, abs(r__1)) + (r__2 =
913 r_imag(&x[j]) / 2.f, abs(r__2));
914 xmax = f2cmax(r__3,r__4);
921 /* Compute the growth in A * x = b. */
940 /* A is non-unit triangular. */
942 /* Compute GROW = 1/G(j) and XBND = 1/M(j). */
943 /* Initially, G(0) = f2cmax{x(i), i=1,...,n}. */
945 grow = .5f / f2cmax(xbnd,smlnum);
949 for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
951 /* Exit the loop if the growth factor is too small. */
953 if (grow <= smlnum) {
957 i__3 = j + j * a_dim1;
958 tjjs.r = a[i__3].r, tjjs.i = a[i__3].i;
959 tjj = (r__1 = tjjs.r, abs(r__1)) + (r__2 = r_imag(&tjjs), abs(
964 /* M(j) = G(j-1) / abs(A(j,j)) */
967 r__1 = xbnd, r__2 = f2cmin(1.f,tjj) * grow;
968 xbnd = f2cmin(r__1,r__2);
971 /* M(j) could overflow, set XBND to 0. */
976 if (tjj + cnorm[j] >= smlnum) {
978 /* G(j) = G(j-1)*( 1 + CNORM(j) / abs(A(j,j)) ) */
980 grow *= tjj / (tjj + cnorm[j]);
983 /* G(j) could overflow, set GROW to 0. */
992 /* A is unit triangular. */
994 /* Compute GROW = 1/G(j), where G(0) = f2cmax{x(i), i=1,...,n}. */
997 r__1 = 1.f, r__2 = .5f / f2cmax(xbnd,smlnum);
998 grow = f2cmin(r__1,r__2);
1001 for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
1003 /* Exit the loop if the growth factor is too small. */
1005 if (grow <= smlnum) {
1009 /* G(j) = G(j-1)*( 1 + CNORM(j) ) */
1011 grow *= 1.f / (cnorm[j] + 1.f);
1020 /* Compute the growth in A**T * x = b or A**H * x = b. */
1039 /* A is non-unit triangular. */
1041 /* Compute GROW = 1/G(j) and XBND = 1/M(j). */
1042 /* Initially, M(0) = f2cmax{x(i), i=1,...,n}. */
1044 grow = .5f / f2cmax(xbnd,smlnum);
1048 for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
1050 /* Exit the loop if the growth factor is too small. */
1052 if (grow <= smlnum) {
1056 /* G(j) = f2cmax( G(j-1), M(j-1)*( 1 + CNORM(j) ) ) */
1058 xj = cnorm[j] + 1.f;
1060 r__1 = grow, r__2 = xbnd / xj;
1061 grow = f2cmin(r__1,r__2);
1063 i__3 = j + j * a_dim1;
1064 tjjs.r = a[i__3].r, tjjs.i = a[i__3].i;
1065 tjj = (r__1 = tjjs.r, abs(r__1)) + (r__2 = r_imag(&tjjs), abs(
1068 if (tjj >= smlnum) {
1070 /* M(j) = M(j-1)*( 1 + CNORM(j) ) / abs(A(j,j)) */
1077 /* M(j) could overflow, set XBND to 0. */
1083 grow = f2cmin(grow,xbnd);
1086 /* A is unit triangular. */
1088 /* Compute GROW = 1/G(j), where G(0) = f2cmax{x(i), i=1,...,n}. */
1091 r__1 = 1.f, r__2 = .5f / f2cmax(xbnd,smlnum);
1092 grow = f2cmin(r__1,r__2);
1095 for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
1097 /* Exit the loop if the growth factor is too small. */
1099 if (grow <= smlnum) {
1103 /* G(j) = ( 1 + CNORM(j) )*G(j-1) */
1105 xj = cnorm[j] + 1.f;
1114 if (grow * tscal > smlnum) {
1116 /* Use the Level 2 BLAS solve if the reciprocal of the bound on */
1117 /* elements of X is not too small. */
1119 ctrsv_(uplo, trans, diag, n, &a[a_offset], lda, &x[1], &c__1);
1122 /* Use a Level 1 BLAS solve, scaling intermediate results. */
1124 if (xmax > bignum * .5f) {
1126 /* Scale X so that its components are less than or equal to */
1127 /* BIGNUM in absolute value. */
1129 *scale = bignum * .5f / xmax;
1130 csscal_(n, scale, &x[1], &c__1);
1138 /* Solve A * x = b */
1142 for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
1144 /* Compute x(j) = b(j) / A(j,j), scaling x if necessary. */
1147 xj = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(&x[j]),
1150 i__3 = j + j * a_dim1;
1151 q__1.r = tscal * a[i__3].r, q__1.i = tscal * a[i__3].i;
1152 tjjs.r = q__1.r, tjjs.i = q__1.i;
1154 tjjs.r = tscal, tjjs.i = 0.f;
1159 tjj = (r__1 = tjjs.r, abs(r__1)) + (r__2 = r_imag(&tjjs), abs(
1163 /* abs(A(j,j)) > SMLNUM: */
1166 if (xj > tjj * bignum) {
1168 /* Scale x by 1/b(j). */
1171 csscal_(n, &rec, &x[1], &c__1);
1177 cladiv_(&q__1, &x[j], &tjjs);
1178 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1180 xj = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(&x[j])
1182 } else if (tjj > 0.f) {
1184 /* 0 < abs(A(j,j)) <= SMLNUM: */
1186 if (xj > tjj * bignum) {
1188 /* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM */
1189 /* to avoid overflow when dividing by A(j,j). */
1191 rec = tjj * bignum / xj;
1192 if (cnorm[j] > 1.f) {
1194 /* Scale by 1/CNORM(j) to avoid overflow when */
1195 /* multiplying x(j) times column j. */
1199 csscal_(n, &rec, &x[1], &c__1);
1204 cladiv_(&q__1, &x[j], &tjjs);
1205 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1207 xj = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(&x[j])
1211 /* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
1212 /* scale = 0, and compute a solution to A*x = 0. */
1215 for (i__ = 1; i__ <= i__3; ++i__) {
1217 x[i__4].r = 0.f, x[i__4].i = 0.f;
1221 x[i__3].r = 1.f, x[i__3].i = 0.f;
1228 /* Scale x if necessary to avoid overflow when adding a */
1229 /* multiple of column j of A. */
1233 if (cnorm[j] > (bignum - xmax) * rec) {
1235 /* Scale x by 1/(2*abs(x(j))). */
1238 csscal_(n, &rec, &x[1], &c__1);
1241 } else if (xj * cnorm[j] > bignum - xmax) {
1243 /* Scale x by 1/2. */
1245 csscal_(n, &c_b36, &x[1], &c__1);
1252 /* Compute the update */
1253 /* x(1:j-1) := x(1:j-1) - x(j) * A(1:j-1,j) */
1257 q__2.r = -x[i__4].r, q__2.i = -x[i__4].i;
1258 q__1.r = tscal * q__2.r, q__1.i = tscal * q__2.i;
1259 caxpy_(&i__3, &q__1, &a[j * a_dim1 + 1], &c__1, &x[1],
1262 i__ = icamax_(&i__3, &x[1], &c__1);
1264 xmax = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(
1265 &x[i__]), abs(r__2));
1270 /* Compute the update */
1271 /* x(j+1:n) := x(j+1:n) - x(j) * A(j+1:n,j) */
1275 q__2.r = -x[i__4].r, q__2.i = -x[i__4].i;
1276 q__1.r = tscal * q__2.r, q__1.i = tscal * q__2.i;
1277 caxpy_(&i__3, &q__1, &a[j + 1 + j * a_dim1], &c__1, &
1280 i__ = j + icamax_(&i__3, &x[j + 1], &c__1);
1282 xmax = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(
1283 &x[i__]), abs(r__2));
1289 } else if (lsame_(trans, "T")) {
1291 /* Solve A**T * x = b */
1295 for (j = jfirst; i__1 < 0 ? j >= i__2 : j <= i__2; j += i__1) {
1297 /* Compute x(j) = b(j) - sum A(k,j)*x(k). */
1301 xj = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(&x[j]),
1303 uscal.r = tscal, uscal.i = 0.f;
1304 rec = 1.f / f2cmax(xmax,1.f);
1305 if (cnorm[j] > (bignum - xj) * rec) {
1307 /* If x(j) could overflow, scale x by 1/(2*XMAX). */
1311 i__3 = j + j * a_dim1;
1312 q__1.r = tscal * a[i__3].r, q__1.i = tscal * a[i__3]
1314 tjjs.r = q__1.r, tjjs.i = q__1.i;
1316 tjjs.r = tscal, tjjs.i = 0.f;
1318 tjj = (r__1 = tjjs.r, abs(r__1)) + (r__2 = r_imag(&tjjs),
1322 /* Divide by A(j,j) when scaling x if A(j,j) > 1. */
1325 r__1 = 1.f, r__2 = rec * tjj;
1326 rec = f2cmin(r__1,r__2);
1327 cladiv_(&q__1, &uscal, &tjjs);
1328 uscal.r = q__1.r, uscal.i = q__1.i;
1331 csscal_(n, &rec, &x[1], &c__1);
1337 csumj.r = 0.f, csumj.i = 0.f;
1338 if (uscal.r == 1.f && uscal.i == 0.f) {
1340 /* If the scaling needed for A in the dot product is 1, */
1341 /* call CDOTU to perform the dot product. */
1345 cdotu_(&q__1, &i__3, &a[j * a_dim1 + 1], &c__1, &x[1],
1347 csumj.r = q__1.r, csumj.i = q__1.i;
1348 } else if (j < *n) {
1350 cdotu_(&q__1, &i__3, &a[j + 1 + j * a_dim1], &c__1, &
1352 csumj.r = q__1.r, csumj.i = q__1.i;
1356 /* Otherwise, use in-line code for the dot product. */
1360 for (i__ = 1; i__ <= i__3; ++i__) {
1361 i__4 = i__ + j * a_dim1;
1362 q__3.r = a[i__4].r * uscal.r - a[i__4].i *
1363 uscal.i, q__3.i = a[i__4].r * uscal.i + a[
1366 q__2.r = q__3.r * x[i__5].r - q__3.i * x[i__5].i,
1367 q__2.i = q__3.r * x[i__5].i + q__3.i * x[
1369 q__1.r = csumj.r + q__2.r, q__1.i = csumj.i +
1371 csumj.r = q__1.r, csumj.i = q__1.i;
1374 } else if (j < *n) {
1376 for (i__ = j + 1; i__ <= i__3; ++i__) {
1377 i__4 = i__ + j * a_dim1;
1378 q__3.r = a[i__4].r * uscal.r - a[i__4].i *
1379 uscal.i, q__3.i = a[i__4].r * uscal.i + a[
1382 q__2.r = q__3.r * x[i__5].r - q__3.i * x[i__5].i,
1383 q__2.i = q__3.r * x[i__5].i + q__3.i * x[
1385 q__1.r = csumj.r + q__2.r, q__1.i = csumj.i +
1387 csumj.r = q__1.r, csumj.i = q__1.i;
1393 q__1.r = tscal, q__1.i = 0.f;
1394 if (uscal.r == q__1.r && uscal.i == q__1.i) {
1396 /* Compute x(j) := ( x(j) - CSUMJ ) / A(j,j) if 1/A(j,j) */
1397 /* was not used to scale the dotproduct. */
1401 q__1.r = x[i__4].r - csumj.r, q__1.i = x[i__4].i -
1403 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1405 xj = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(&x[j])
1408 i__3 = j + j * a_dim1;
1409 q__1.r = tscal * a[i__3].r, q__1.i = tscal * a[i__3]
1411 tjjs.r = q__1.r, tjjs.i = q__1.i;
1413 tjjs.r = tscal, tjjs.i = 0.f;
1419 /* Compute x(j) = x(j) / A(j,j), scaling if necessary. */
1421 tjj = (r__1 = tjjs.r, abs(r__1)) + (r__2 = r_imag(&tjjs),
1425 /* abs(A(j,j)) > SMLNUM: */
1428 if (xj > tjj * bignum) {
1430 /* Scale X by 1/abs(x(j)). */
1433 csscal_(n, &rec, &x[1], &c__1);
1439 cladiv_(&q__1, &x[j], &tjjs);
1440 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1441 } else if (tjj > 0.f) {
1443 /* 0 < abs(A(j,j)) <= SMLNUM: */
1445 if (xj > tjj * bignum) {
1447 /* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */
1449 rec = tjj * bignum / xj;
1450 csscal_(n, &rec, &x[1], &c__1);
1455 cladiv_(&q__1, &x[j], &tjjs);
1456 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1459 /* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
1460 /* scale = 0 and compute a solution to A**T *x = 0. */
1463 for (i__ = 1; i__ <= i__3; ++i__) {
1465 x[i__4].r = 0.f, x[i__4].i = 0.f;
1469 x[i__3].r = 1.f, x[i__3].i = 0.f;
1477 /* Compute x(j) := x(j) / A(j,j) - CSUMJ if the dot */
1478 /* product has already been divided by 1/A(j,j). */
1481 cladiv_(&q__2, &x[j], &tjjs);
1482 q__1.r = q__2.r - csumj.r, q__1.i = q__2.i - csumj.i;
1483 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1487 r__3 = xmax, r__4 = (r__1 = x[i__3].r, abs(r__1)) + (r__2 =
1488 r_imag(&x[j]), abs(r__2));
1489 xmax = f2cmax(r__3,r__4);
1495 /* Solve A**H * x = b */
1499 for (j = jfirst; i__2 < 0 ? j >= i__1 : j <= i__1; j += i__2) {
1501 /* Compute x(j) = b(j) - sum A(k,j)*x(k). */
1505 xj = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(&x[j]),
1507 uscal.r = tscal, uscal.i = 0.f;
1508 rec = 1.f / f2cmax(xmax,1.f);
1509 if (cnorm[j] > (bignum - xj) * rec) {
1511 /* If x(j) could overflow, scale x by 1/(2*XMAX). */
1515 r_cnjg(&q__2, &a[j + j * a_dim1]);
1516 q__1.r = tscal * q__2.r, q__1.i = tscal * q__2.i;
1517 tjjs.r = q__1.r, tjjs.i = q__1.i;
1519 tjjs.r = tscal, tjjs.i = 0.f;
1521 tjj = (r__1 = tjjs.r, abs(r__1)) + (r__2 = r_imag(&tjjs),
1525 /* Divide by A(j,j) when scaling x if A(j,j) > 1. */
1528 r__1 = 1.f, r__2 = rec * tjj;
1529 rec = f2cmin(r__1,r__2);
1530 cladiv_(&q__1, &uscal, &tjjs);
1531 uscal.r = q__1.r, uscal.i = q__1.i;
1534 csscal_(n, &rec, &x[1], &c__1);
1540 csumj.r = 0.f, csumj.i = 0.f;
1541 if (uscal.r == 1.f && uscal.i == 0.f) {
1543 /* If the scaling needed for A in the dot product is 1, */
1544 /* call CDOTC to perform the dot product. */
1548 cdotc_(&q__1, &i__3, &a[j * a_dim1 + 1], &c__1, &x[1],
1550 csumj.r = q__1.r, csumj.i = q__1.i;
1551 } else if (j < *n) {
1553 cdotc_(&q__1, &i__3, &a[j + 1 + j * a_dim1], &c__1, &
1555 csumj.r = q__1.r, csumj.i = q__1.i;
1559 /* Otherwise, use in-line code for the dot product. */
1563 for (i__ = 1; i__ <= i__3; ++i__) {
1564 r_cnjg(&q__4, &a[i__ + j * a_dim1]);
1565 q__3.r = q__4.r * uscal.r - q__4.i * uscal.i,
1566 q__3.i = q__4.r * uscal.i + q__4.i *
1569 q__2.r = q__3.r * x[i__4].r - q__3.i * x[i__4].i,
1570 q__2.i = q__3.r * x[i__4].i + q__3.i * x[
1572 q__1.r = csumj.r + q__2.r, q__1.i = csumj.i +
1574 csumj.r = q__1.r, csumj.i = q__1.i;
1577 } else if (j < *n) {
1579 for (i__ = j + 1; i__ <= i__3; ++i__) {
1580 r_cnjg(&q__4, &a[i__ + j * a_dim1]);
1581 q__3.r = q__4.r * uscal.r - q__4.i * uscal.i,
1582 q__3.i = q__4.r * uscal.i + q__4.i *
1585 q__2.r = q__3.r * x[i__4].r - q__3.i * x[i__4].i,
1586 q__2.i = q__3.r * x[i__4].i + q__3.i * x[
1588 q__1.r = csumj.r + q__2.r, q__1.i = csumj.i +
1590 csumj.r = q__1.r, csumj.i = q__1.i;
1596 q__1.r = tscal, q__1.i = 0.f;
1597 if (uscal.r == q__1.r && uscal.i == q__1.i) {
1599 /* Compute x(j) := ( x(j) - CSUMJ ) / A(j,j) if 1/A(j,j) */
1600 /* was not used to scale the dotproduct. */
1604 q__1.r = x[i__4].r - csumj.r, q__1.i = x[i__4].i -
1606 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1608 xj = (r__1 = x[i__3].r, abs(r__1)) + (r__2 = r_imag(&x[j])
1611 r_cnjg(&q__2, &a[j + j * a_dim1]);
1612 q__1.r = tscal * q__2.r, q__1.i = tscal * q__2.i;
1613 tjjs.r = q__1.r, tjjs.i = q__1.i;
1615 tjjs.r = tscal, tjjs.i = 0.f;
1621 /* Compute x(j) = x(j) / A(j,j), scaling if necessary. */
1623 tjj = (r__1 = tjjs.r, abs(r__1)) + (r__2 = r_imag(&tjjs),
1627 /* abs(A(j,j)) > SMLNUM: */
1630 if (xj > tjj * bignum) {
1632 /* Scale X by 1/abs(x(j)). */
1635 csscal_(n, &rec, &x[1], &c__1);
1641 cladiv_(&q__1, &x[j], &tjjs);
1642 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1643 } else if (tjj > 0.f) {
1645 /* 0 < abs(A(j,j)) <= SMLNUM: */
1647 if (xj > tjj * bignum) {
1649 /* Scale x by (1/abs(x(j)))*abs(A(j,j))*BIGNUM. */
1651 rec = tjj * bignum / xj;
1652 csscal_(n, &rec, &x[1], &c__1);
1657 cladiv_(&q__1, &x[j], &tjjs);
1658 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1661 /* A(j,j) = 0: Set x(1:n) = 0, x(j) = 1, and */
1662 /* scale = 0 and compute a solution to A**H *x = 0. */
1665 for (i__ = 1; i__ <= i__3; ++i__) {
1667 x[i__4].r = 0.f, x[i__4].i = 0.f;
1671 x[i__3].r = 1.f, x[i__3].i = 0.f;
1679 /* Compute x(j) := x(j) / A(j,j) - CSUMJ if the dot */
1680 /* product has already been divided by 1/A(j,j). */
1683 cladiv_(&q__2, &x[j], &tjjs);
1684 q__1.r = q__2.r - csumj.r, q__1.i = q__2.i - csumj.i;
1685 x[i__3].r = q__1.r, x[i__3].i = q__1.i;
1689 r__3 = xmax, r__4 = (r__1 = x[i__3].r, abs(r__1)) + (r__2 =
1690 r_imag(&x[j]), abs(r__2));
1691 xmax = f2cmax(r__3,r__4);
1698 /* Scale the column norms by 1/TSCAL for return. */
1702 sscal_(n, &r__1, &cnorm[1], &c__1);