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 /* > \brief \b SLAGS2 computes 2-by-2 orthogonal matrices U, V, and Q, and applies them to matrices A and B su
514 ch that the rows of the transformed A and B are parallel. */
516 /* =========== DOCUMENTATION =========== */
518 /* Online html documentation available at */
519 /* http://www.netlib.org/lapack/explore-html/ */
522 /* > Download SLAGS2 + dependencies */
523 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/slags2.
526 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/slags2.
529 /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/slags2.
537 /* SUBROUTINE SLAGS2( UPPER, A1, A2, A3, B1, B2, B3, CSU, SNU, CSV, */
538 /* SNV, CSQ, SNQ ) */
541 /* REAL A1, A2, A3, B1, B2, B3, CSQ, CSU, CSV, SNQ, */
545 /* > \par Purpose: */
550 /* > SLAGS2 computes 2-by-2 orthogonal matrices U, V and Q, such */
551 /* > that if ( UPPER ) then */
553 /* > U**T *A*Q = U**T *( A1 A2 )*Q = ( x 0 ) */
554 /* > ( 0 A3 ) ( x x ) */
556 /* > V**T*B*Q = V**T *( B1 B2 )*Q = ( x 0 ) */
557 /* > ( 0 B3 ) ( x x ) */
559 /* > or if ( .NOT.UPPER ) then */
561 /* > U**T *A*Q = U**T *( A1 0 )*Q = ( x x ) */
562 /* > ( A2 A3 ) ( 0 x ) */
564 /* > V**T*B*Q = V**T*( B1 0 )*Q = ( x x ) */
565 /* > ( B2 B3 ) ( 0 x ) */
567 /* > The rows of the transformed A and B are parallel, where */
569 /* > U = ( CSU SNU ), V = ( CSV SNV ), Q = ( CSQ SNQ ) */
570 /* > ( -SNU CSU ) ( -SNV CSV ) ( -SNQ CSQ ) */
572 /* > Z**T denotes the transpose of Z. */
579 /* > \param[in] UPPER */
581 /* > UPPER is LOGICAL */
582 /* > = .TRUE.: the input matrices A and B are upper triangular. */
583 /* > = .FALSE.: the input matrices A and B are lower triangular. */
586 /* > \param[in] A1 */
591 /* > \param[in] A2 */
596 /* > \param[in] A3 */
599 /* > On entry, A1, A2 and A3 are elements of the input 2-by-2 */
600 /* > upper (lower) triangular matrix A. */
603 /* > \param[in] B1 */
608 /* > \param[in] B2 */
613 /* > \param[in] B3 */
616 /* > On entry, B1, B2 and B3 are elements of the input 2-by-2 */
617 /* > upper (lower) triangular matrix B. */
620 /* > \param[out] CSU */
625 /* > \param[out] SNU */
628 /* > The desired orthogonal matrix U. */
631 /* > \param[out] CSV */
636 /* > \param[out] SNV */
639 /* > The desired orthogonal matrix V. */
642 /* > \param[out] CSQ */
647 /* > \param[out] SNQ */
650 /* > The desired orthogonal matrix Q. */
656 /* > \author Univ. of Tennessee */
657 /* > \author Univ. of California Berkeley */
658 /* > \author Univ. of Colorado Denver */
659 /* > \author NAG Ltd. */
661 /* > \date December 2016 */
663 /* > \ingroup realOTHERauxiliary */
665 /* ===================================================================== */
666 /* Subroutine */ int slags2_(logical *upper, real *a1, real *a2, real *a3,
667 real *b1, real *b2, real *b3, real *csu, real *snu, real *csv, real *
668 snv, real *csq, real *snq)
670 /* System generated locals */
673 /* Local variables */
674 real aua11, aua12, aua21, aua22, avb11, avb12, avb21, avb22, ua11r, ua22r,
675 vb11r, vb22r, a, b, c__, d__, r__, s1, s2;
676 extern /* Subroutine */ int slasv2_(real *, real *, real *, real *, real *
677 , real *, real *, real *, real *), slartg_(real *, real *, real *,
679 real ua11, ua12, ua21, ua22, vb11, vb12, vb21, vb22, csl, csr, snl, snr;
682 /* -- LAPACK auxiliary routine (version 3.7.0) -- */
683 /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
684 /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
688 /* ===================================================================== */
693 /* Input matrices A and B are upper triangular matrices */
695 /* Form matrix C = A*adj(B) = ( a b ) */
700 b = *a2 * *b1 - *a1 * *b2;
702 /* The SVD of real 2-by-2 triangular C */
704 /* ( CSL -SNL )*( A B )*( CSR SNR ) = ( R 0 ) */
705 /* ( SNL CSL ) ( 0 D ) ( -SNR CSR ) ( 0 T ) */
707 slasv2_(&a, &b, &d__, &s1, &s2, &snr, &csr, &snl, &csl);
709 if (abs(csl) >= abs(snl) || abs(csr) >= abs(snr)) {
711 /* Compute the (1,1) and (1,2) elements of U**T *A and V**T *B, */
712 /* and (1,2) element of |U|**T *|A| and |V|**T *|B|. */
715 ua12 = csl * *a2 + snl * *a3;
718 vb12 = csr * *b2 + snr * *b3;
720 aua12 = abs(csl) * abs(*a2) + abs(snl) * abs(*a3);
721 avb12 = abs(csr) * abs(*b2) + abs(snr) * abs(*b3);
723 /* zero (1,2) elements of U**T *A and V**T *B */
725 if (abs(ua11r) + abs(ua12) != 0.f) {
726 if (aua12 / (abs(ua11r) + abs(ua12)) <= avb12 / (abs(vb11r) +
729 slartg_(&r__1, &ua12, csq, snq, &r__);
732 slartg_(&r__1, &vb12, csq, snq, &r__);
736 slartg_(&r__1, &vb12, csq, snq, &r__);
746 /* Compute the (2,1) and (2,2) elements of U**T *A and V**T *B, */
747 /* and (2,2) element of |U|**T *|A| and |V|**T *|B|. */
750 ua22 = -snl * *a2 + csl * *a3;
753 vb22 = -snr * *b2 + csr * *b3;
755 aua22 = abs(snl) * abs(*a2) + abs(csl) * abs(*a3);
756 avb22 = abs(snr) * abs(*b2) + abs(csr) * abs(*b3);
758 /* zero (2,2) elements of U**T*A and V**T*B, and then swap. */
760 if (abs(ua21) + abs(ua22) != 0.f) {
761 if (aua22 / (abs(ua21) + abs(ua22)) <= avb22 / (abs(vb21) +
764 slartg_(&r__1, &ua22, csq, snq, &r__);
767 slartg_(&r__1, &vb22, csq, snq, &r__);
771 slartg_(&r__1, &vb22, csq, snq, &r__);
783 /* Input matrices A and B are lower triangular matrices */
785 /* Form matrix C = A*adj(B) = ( a 0 ) */
790 c__ = *a2 * *b3 - *a3 * *b2;
792 /* The SVD of real 2-by-2 triangular C */
794 /* ( CSL -SNL )*( A 0 )*( CSR SNR ) = ( R 0 ) */
795 /* ( SNL CSL ) ( C D ) ( -SNR CSR ) ( 0 T ) */
797 slasv2_(&a, &c__, &d__, &s1, &s2, &snr, &csr, &snl, &csl);
799 if (abs(csr) >= abs(snr) || abs(csl) >= abs(snl)) {
801 /* Compute the (2,1) and (2,2) elements of U**T *A and V**T *B, */
802 /* and (2,1) element of |U|**T *|A| and |V|**T *|B|. */
804 ua21 = -snr * *a1 + csr * *a2;
807 vb21 = -snl * *b1 + csl * *b2;
810 aua21 = abs(snr) * abs(*a1) + abs(csr) * abs(*a2);
811 avb21 = abs(snl) * abs(*b1) + abs(csl) * abs(*b2);
813 /* zero (2,1) elements of U**T *A and V**T *B. */
815 if (abs(ua21) + abs(ua22r) != 0.f) {
816 if (aua21 / (abs(ua21) + abs(ua22r)) <= avb21 / (abs(vb21) +
818 slartg_(&ua22r, &ua21, csq, snq, &r__);
820 slartg_(&vb22r, &vb21, csq, snq, &r__);
823 slartg_(&vb22r, &vb21, csq, snq, &r__);
833 /* Compute the (1,1) and (1,2) elements of U**T *A and V**T *B, */
834 /* and (1,1) element of |U|**T *|A| and |V|**T *|B|. */
836 ua11 = csr * *a1 + snr * *a2;
839 vb11 = csl * *b1 + snl * *b2;
842 aua11 = abs(csr) * abs(*a1) + abs(snr) * abs(*a2);
843 avb11 = abs(csl) * abs(*b1) + abs(snl) * abs(*b2);
845 /* zero (1,1) elements of U**T*A and V**T*B, and then swap. */
847 if (abs(ua11) + abs(ua12) != 0.f) {
848 if (aua11 / (abs(ua11) + abs(ua12)) <= avb11 / (abs(vb11) +
850 slartg_(&ua12, &ua11, csq, snq, &r__);
852 slartg_(&vb12, &vb11, csq, snq, &r__);
855 slartg_(&vb12, &vb11, csq, snq, &r__);