You can not select more than 25 topics Topics must start with a chinese character,a letter or number, can include dashes ('-') and can be up to 35 characters long.

sgebrd.c 20 kB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655
  1. #include <math.h>
  2. #include <stdlib.h>
  3. #include <string.h>
  4. #include <stdio.h>
  5. #include <complex.h>
  6. #ifdef complex
  7. #undef complex
  8. #endif
  9. #ifdef I
  10. #undef I
  11. #endif
  12. #if defined(_WIN64)
  13. typedef long long BLASLONG;
  14. typedef unsigned long long BLASULONG;
  15. #else
  16. typedef long BLASLONG;
  17. typedef unsigned long BLASULONG;
  18. #endif
  19. #ifdef LAPACK_ILP64
  20. typedef BLASLONG blasint;
  21. #if defined(_WIN64)
  22. #define blasabs(x) llabs(x)
  23. #else
  24. #define blasabs(x) labs(x)
  25. #endif
  26. #else
  27. typedef int blasint;
  28. #define blasabs(x) abs(x)
  29. #endif
  30. typedef blasint integer;
  31. typedef unsigned int uinteger;
  32. typedef char *address;
  33. typedef short int shortint;
  34. typedef float real;
  35. typedef double doublereal;
  36. typedef struct { real r, i; } complex;
  37. typedef struct { doublereal r, i; } doublecomplex;
  38. #ifdef _MSC_VER
  39. static inline _Fcomplex Cf(complex *z) {_Fcomplex zz={z->r , z->i}; return zz;}
  40. static inline _Dcomplex Cd(doublecomplex *z) {_Dcomplex zz={z->r , z->i};return zz;}
  41. static inline _Fcomplex * _pCf(complex *z) {return (_Fcomplex*)z;}
  42. static inline _Dcomplex * _pCd(doublecomplex *z) {return (_Dcomplex*)z;}
  43. #else
  44. static inline _Complex float Cf(complex *z) {return z->r + z->i*_Complex_I;}
  45. static inline _Complex double Cd(doublecomplex *z) {return z->r + z->i*_Complex_I;}
  46. static inline _Complex float * _pCf(complex *z) {return (_Complex float*)z;}
  47. static inline _Complex double * _pCd(doublecomplex *z) {return (_Complex double*)z;}
  48. #endif
  49. #define pCf(z) (*_pCf(z))
  50. #define pCd(z) (*_pCd(z))
  51. typedef blasint logical;
  52. typedef char logical1;
  53. typedef char integer1;
  54. #define TRUE_ (1)
  55. #define FALSE_ (0)
  56. /* Extern is for use with -E */
  57. #ifndef Extern
  58. #define Extern extern
  59. #endif
  60. /* I/O stuff */
  61. typedef int flag;
  62. typedef int ftnlen;
  63. typedef int ftnint;
  64. /*external read, write*/
  65. typedef struct
  66. { flag cierr;
  67. ftnint ciunit;
  68. flag ciend;
  69. char *cifmt;
  70. ftnint cirec;
  71. } cilist;
  72. /*internal read, write*/
  73. typedef struct
  74. { flag icierr;
  75. char *iciunit;
  76. flag iciend;
  77. char *icifmt;
  78. ftnint icirlen;
  79. ftnint icirnum;
  80. } icilist;
  81. /*open*/
  82. typedef struct
  83. { flag oerr;
  84. ftnint ounit;
  85. char *ofnm;
  86. ftnlen ofnmlen;
  87. char *osta;
  88. char *oacc;
  89. char *ofm;
  90. ftnint orl;
  91. char *oblnk;
  92. } olist;
  93. /*close*/
  94. typedef struct
  95. { flag cerr;
  96. ftnint cunit;
  97. char *csta;
  98. } cllist;
  99. /*rewind, backspace, endfile*/
  100. typedef struct
  101. { flag aerr;
  102. ftnint aunit;
  103. } alist;
  104. /* inquire */
  105. typedef struct
  106. { flag inerr;
  107. ftnint inunit;
  108. char *infile;
  109. ftnlen infilen;
  110. ftnint *inex; /*parameters in standard's order*/
  111. ftnint *inopen;
  112. ftnint *innum;
  113. ftnint *innamed;
  114. char *inname;
  115. ftnlen innamlen;
  116. char *inacc;
  117. ftnlen inacclen;
  118. char *inseq;
  119. ftnlen inseqlen;
  120. char *indir;
  121. ftnlen indirlen;
  122. char *infmt;
  123. ftnlen infmtlen;
  124. char *inform;
  125. ftnint informlen;
  126. char *inunf;
  127. ftnlen inunflen;
  128. ftnint *inrecl;
  129. ftnint *innrec;
  130. char *inblank;
  131. ftnlen inblanklen;
  132. } inlist;
  133. #define VOID void
  134. union Multitype { /* for multiple entry points */
  135. integer1 g;
  136. shortint h;
  137. integer i;
  138. /* longint j; */
  139. real r;
  140. doublereal d;
  141. complex c;
  142. doublecomplex z;
  143. };
  144. typedef union Multitype Multitype;
  145. struct Vardesc { /* for Namelist */
  146. char *name;
  147. char *addr;
  148. ftnlen *dims;
  149. int type;
  150. };
  151. typedef struct Vardesc Vardesc;
  152. struct Namelist {
  153. char *name;
  154. Vardesc **vars;
  155. int nvars;
  156. };
  157. typedef struct Namelist Namelist;
  158. #define abs(x) ((x) >= 0 ? (x) : -(x))
  159. #define dabs(x) (fabs(x))
  160. #define f2cmin(a,b) ((a) <= (b) ? (a) : (b))
  161. #define f2cmax(a,b) ((a) >= (b) ? (a) : (b))
  162. #define dmin(a,b) (f2cmin(a,b))
  163. #define dmax(a,b) (f2cmax(a,b))
  164. #define bit_test(a,b) ((a) >> (b) & 1)
  165. #define bit_clear(a,b) ((a) & ~((uinteger)1 << (b)))
  166. #define bit_set(a,b) ((a) | ((uinteger)1 << (b)))
  167. #define abort_() { sig_die("Fortran abort routine called", 1); }
  168. #define c_abs(z) (cabsf(Cf(z)))
  169. #define c_cos(R,Z) { pCf(R)=ccos(Cf(Z)); }
  170. #ifdef _MSC_VER
  171. #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]);}
  172. #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]);}
  173. #else
  174. #define c_div(c, a, b) {pCf(c) = Cf(a)/Cf(b);}
  175. #define z_div(c, a, b) {pCd(c) = Cd(a)/Cd(b);}
  176. #endif
  177. #define c_exp(R, Z) {pCf(R) = cexpf(Cf(Z));}
  178. #define c_log(R, Z) {pCf(R) = clogf(Cf(Z));}
  179. #define c_sin(R, Z) {pCf(R) = csinf(Cf(Z));}
  180. //#define c_sqrt(R, Z) {*(R) = csqrtf(Cf(Z));}
  181. #define c_sqrt(R, Z) {pCf(R) = csqrtf(Cf(Z));}
  182. #define d_abs(x) (fabs(*(x)))
  183. #define d_acos(x) (acos(*(x)))
  184. #define d_asin(x) (asin(*(x)))
  185. #define d_atan(x) (atan(*(x)))
  186. #define d_atn2(x, y) (atan2(*(x),*(y)))
  187. #define d_cnjg(R, Z) { pCd(R) = conj(Cd(Z)); }
  188. #define r_cnjg(R, Z) { pCf(R) = conjf(Cf(Z)); }
  189. #define d_cos(x) (cos(*(x)))
  190. #define d_cosh(x) (cosh(*(x)))
  191. #define d_dim(__a, __b) ( *(__a) > *(__b) ? *(__a) - *(__b) : 0.0 )
  192. #define d_exp(x) (exp(*(x)))
  193. #define d_imag(z) (cimag(Cd(z)))
  194. #define r_imag(z) (cimagf(Cf(z)))
  195. #define d_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
  196. #define r_int(__x) (*(__x)>0 ? floor(*(__x)) : -floor(- *(__x)))
  197. #define d_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
  198. #define r_lg10(x) ( 0.43429448190325182765 * log(*(x)) )
  199. #define d_log(x) (log(*(x)))
  200. #define d_mod(x, y) (fmod(*(x), *(y)))
  201. #define u_nint(__x) ((__x)>=0 ? floor((__x) + .5) : -floor(.5 - (__x)))
  202. #define d_nint(x) u_nint(*(x))
  203. #define u_sign(__a,__b) ((__b) >= 0 ? ((__a) >= 0 ? (__a) : -(__a)) : -((__a) >= 0 ? (__a) : -(__a)))
  204. #define d_sign(a,b) u_sign(*(a),*(b))
  205. #define r_sign(a,b) u_sign(*(a),*(b))
  206. #define d_sin(x) (sin(*(x)))
  207. #define d_sinh(x) (sinh(*(x)))
  208. #define d_sqrt(x) (sqrt(*(x)))
  209. #define d_tan(x) (tan(*(x)))
  210. #define d_tanh(x) (tanh(*(x)))
  211. #define i_abs(x) abs(*(x))
  212. #define i_dnnt(x) ((integer)u_nint(*(x)))
  213. #define i_len(s, n) (n)
  214. #define i_nint(x) ((integer)u_nint(*(x)))
  215. #define i_sign(a,b) ((integer)u_sign((integer)*(a),(integer)*(b)))
  216. #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++ = ' '; }
  217. #define s_cmp(a,b,c,d) ((integer)strncmp((a),(b),f2cmin((c),(d))))
  218. #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]; }
  219. #define sig_die(s, kill) { exit(1); }
  220. #define s_stop(s, n) {exit(0);}
  221. #define z_abs(z) (cabs(Cd(z)))
  222. #define z_exp(R, Z) {pCd(R) = cexp(Cd(Z));}
  223. #define z_sqrt(R, Z) {pCd(R) = csqrt(Cd(Z));}
  224. #define myexit_() break;
  225. #define mycycle() continue;
  226. #define myceiling(w) {ceil(w)}
  227. #define myhuge(w) {HUGE_VAL}
  228. //#define mymaxloc_(w,s,e,n) {if (sizeof(*(w)) == sizeof(double)) dmaxloc_((w),*(s),*(e),n); else dmaxloc_((w),*(s),*(e),n);}
  229. #define mymaxloc(w,s,e,n) {dmaxloc_(w,*(s),*(e),n)}
  230. /* -- translated by f2c (version 20000121).
  231. You must link the resulting object file with the libraries:
  232. -lf2c -lm (in that order)
  233. */
  234. /* Table of constant values */
  235. static integer c__1 = 1;
  236. static integer c_n1 = -1;
  237. static integer c__3 = 3;
  238. static integer c__2 = 2;
  239. static real c_b21 = -1.f;
  240. static real c_b22 = 1.f;
  241. /* > \brief \b SGEBRD */
  242. /* =========== DOCUMENTATION =========== */
  243. /* Online html documentation available at */
  244. /* http://www.netlib.org/lapack/explore-html/ */
  245. /* > \htmlonly */
  246. /* > Download SGEBRD + dependencies */
  247. /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/sgebrd.
  248. f"> */
  249. /* > [TGZ]</a> */
  250. /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/sgebrd.
  251. f"> */
  252. /* > [ZIP]</a> */
  253. /* > <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/sgebrd.
  254. f"> */
  255. /* > [TXT]</a> */
  256. /* > \endhtmlonly */
  257. /* Definition: */
  258. /* =========== */
  259. /* SUBROUTINE SGEBRD( M, N, A, LDA, D, E, TAUQ, TAUP, WORK, LWORK, */
  260. /* INFO ) */
  261. /* INTEGER INFO, LDA, LWORK, M, N */
  262. /* REAL A( LDA, * ), D( * ), E( * ), TAUP( * ), */
  263. /* $ TAUQ( * ), WORK( * ) */
  264. /* > \par Purpose: */
  265. /* ============= */
  266. /* > */
  267. /* > \verbatim */
  268. /* > */
  269. /* > SGEBRD reduces a general real M-by-N matrix A to upper or lower */
  270. /* > bidiagonal form B by an orthogonal transformation: Q**T * A * P = B. */
  271. /* > */
  272. /* > If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal. */
  273. /* > \endverbatim */
  274. /* Arguments: */
  275. /* ========== */
  276. /* > \param[in] M */
  277. /* > \verbatim */
  278. /* > M is INTEGER */
  279. /* > The number of rows in the matrix A. M >= 0. */
  280. /* > \endverbatim */
  281. /* > */
  282. /* > \param[in] N */
  283. /* > \verbatim */
  284. /* > N is INTEGER */
  285. /* > The number of columns in the matrix A. N >= 0. */
  286. /* > \endverbatim */
  287. /* > */
  288. /* > \param[in,out] A */
  289. /* > \verbatim */
  290. /* > A is REAL array, dimension (LDA,N) */
  291. /* > On entry, the M-by-N general matrix to be reduced. */
  292. /* > On exit, */
  293. /* > if m >= n, the diagonal and the first superdiagonal are */
  294. /* > overwritten with the upper bidiagonal matrix B; the */
  295. /* > elements below the diagonal, with the array TAUQ, represent */
  296. /* > the orthogonal matrix Q as a product of elementary */
  297. /* > reflectors, and the elements above the first superdiagonal, */
  298. /* > with the array TAUP, represent the orthogonal matrix P as */
  299. /* > a product of elementary reflectors; */
  300. /* > if m < n, the diagonal and the first subdiagonal are */
  301. /* > overwritten with the lower bidiagonal matrix B; the */
  302. /* > elements below the first subdiagonal, with the array TAUQ, */
  303. /* > represent the orthogonal matrix Q as a product of */
  304. /* > elementary reflectors, and the elements above the diagonal, */
  305. /* > with the array TAUP, represent the orthogonal matrix P as */
  306. /* > a product of elementary reflectors. */
  307. /* > See Further Details. */
  308. /* > \endverbatim */
  309. /* > */
  310. /* > \param[in] LDA */
  311. /* > \verbatim */
  312. /* > LDA is INTEGER */
  313. /* > The leading dimension of the array A. LDA >= f2cmax(1,M). */
  314. /* > \endverbatim */
  315. /* > */
  316. /* > \param[out] D */
  317. /* > \verbatim */
  318. /* > D is REAL array, dimension (f2cmin(M,N)) */
  319. /* > The diagonal elements of the bidiagonal matrix B: */
  320. /* > D(i) = A(i,i). */
  321. /* > \endverbatim */
  322. /* > */
  323. /* > \param[out] E */
  324. /* > \verbatim */
  325. /* > E is REAL array, dimension (f2cmin(M,N)-1) */
  326. /* > The off-diagonal elements of the bidiagonal matrix B: */
  327. /* > if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1; */
  328. /* > if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1. */
  329. /* > \endverbatim */
  330. /* > */
  331. /* > \param[out] TAUQ */
  332. /* > \verbatim */
  333. /* > TAUQ is REAL array, dimension (f2cmin(M,N)) */
  334. /* > The scalar factors of the elementary reflectors which */
  335. /* > represent the orthogonal matrix Q. See Further Details. */
  336. /* > \endverbatim */
  337. /* > */
  338. /* > \param[out] TAUP */
  339. /* > \verbatim */
  340. /* > TAUP is REAL array, dimension (f2cmin(M,N)) */
  341. /* > The scalar factors of the elementary reflectors which */
  342. /* > represent the orthogonal matrix P. See Further Details. */
  343. /* > \endverbatim */
  344. /* > */
  345. /* > \param[out] WORK */
  346. /* > \verbatim */
  347. /* > WORK is REAL array, dimension (MAX(1,LWORK)) */
  348. /* > On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
  349. /* > \endverbatim */
  350. /* > */
  351. /* > \param[in] LWORK */
  352. /* > \verbatim */
  353. /* > LWORK is INTEGER */
  354. /* > The length of the array WORK. LWORK >= f2cmax(1,M,N). */
  355. /* > For optimum performance LWORK >= (M+N)*NB, where NB */
  356. /* > is the optimal blocksize. */
  357. /* > */
  358. /* > If LWORK = -1, then a workspace query is assumed; the routine */
  359. /* > only calculates the optimal size of the WORK array, returns */
  360. /* > this value as the first entry of the WORK array, and no error */
  361. /* > message related to LWORK is issued by XERBLA. */
  362. /* > \endverbatim */
  363. /* > */
  364. /* > \param[out] INFO */
  365. /* > \verbatim */
  366. /* > INFO is INTEGER */
  367. /* > = 0: successful exit */
  368. /* > < 0: if INFO = -i, the i-th argument had an illegal value. */
  369. /* > \endverbatim */
  370. /* Authors: */
  371. /* ======== */
  372. /* > \author Univ. of Tennessee */
  373. /* > \author Univ. of California Berkeley */
  374. /* > \author Univ. of Colorado Denver */
  375. /* > \author NAG Ltd. */
  376. /* > \date November 2017 */
  377. /* > \ingroup realGEcomputational */
  378. /* > \par Further Details: */
  379. /* ===================== */
  380. /* > */
  381. /* > \verbatim */
  382. /* > */
  383. /* > The matrices Q and P are represented as products of elementary */
  384. /* > reflectors: */
  385. /* > */
  386. /* > If m >= n, */
  387. /* > */
  388. /* > Q = H(1) H(2) . . . H(n) and P = G(1) G(2) . . . G(n-1) */
  389. /* > */
  390. /* > Each H(i) and G(i) has the form: */
  391. /* > */
  392. /* > H(i) = I - tauq * v * v**T and G(i) = I - taup * u * u**T */
  393. /* > */
  394. /* > where tauq and taup are real scalars, and v and u are real vectors; */
  395. /* > v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in A(i+1:m,i); */
  396. /* > u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in A(i,i+2:n); */
  397. /* > tauq is stored in TAUQ(i) and taup in TAUP(i). */
  398. /* > */
  399. /* > If m < n, */
  400. /* > */
  401. /* > Q = H(1) H(2) . . . H(m-1) and P = G(1) G(2) . . . G(m) */
  402. /* > */
  403. /* > Each H(i) and G(i) has the form: */
  404. /* > */
  405. /* > H(i) = I - tauq * v * v**T and G(i) = I - taup * u * u**T */
  406. /* > */
  407. /* > where tauq and taup are real scalars, and v and u are real vectors; */
  408. /* > v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in A(i+2:m,i); */
  409. /* > u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n); */
  410. /* > tauq is stored in TAUQ(i) and taup in TAUP(i). */
  411. /* > */
  412. /* > The contents of A on exit are illustrated by the following examples: */
  413. /* > */
  414. /* > m = 6 and n = 5 (m > n): m = 5 and n = 6 (m < n): */
  415. /* > */
  416. /* > ( d e u1 u1 u1 ) ( d u1 u1 u1 u1 u1 ) */
  417. /* > ( v1 d e u2 u2 ) ( e d u2 u2 u2 u2 ) */
  418. /* > ( v1 v2 d e u3 ) ( v1 e d u3 u3 u3 ) */
  419. /* > ( v1 v2 v3 d e ) ( v1 v2 e d u4 u4 ) */
  420. /* > ( v1 v2 v3 v4 d ) ( v1 v2 v3 e d u5 ) */
  421. /* > ( v1 v2 v3 v4 v5 ) */
  422. /* > */
  423. /* > where d and e denote diagonal and off-diagonal elements of B, vi */
  424. /* > denotes an element of the vector defining H(i), and ui an element of */
  425. /* > the vector defining G(i). */
  426. /* > \endverbatim */
  427. /* > */
  428. /* ===================================================================== */
  429. /* Subroutine */ void sgebrd_(integer *m, integer *n, real *a, integer *lda,
  430. real *d__, real *e, real *tauq, real *taup, real *work, integer *
  431. lwork, integer *info)
  432. {
  433. /* System generated locals */
  434. integer a_dim1, a_offset, i__1, i__2, i__3, i__4;
  435. /* Local variables */
  436. integer i__, j, nbmin, iinfo;
  437. extern /* Subroutine */ void sgemm_(char *, char *, integer *, integer *,
  438. integer *, real *, real *, integer *, real *, integer *, real *,
  439. real *, integer *);
  440. integer minmn;
  441. extern /* Subroutine */ void sgebd2_(integer *, integer *, real *, integer
  442. *, real *, real *, real *, real *, real *, integer *);
  443. integer nb, nx;
  444. extern /* Subroutine */ void slabrd_(integer *, integer *, integer *, real
  445. *, integer *, real *, real *, real *, real *, real *, integer *,
  446. real *, integer *);
  447. integer ws;
  448. extern /* Subroutine */ int xerbla_(char *, integer *, ftnlen);
  449. extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
  450. integer *, integer *, ftnlen, ftnlen);
  451. integer ldwrkx, ldwrky, lwkopt;
  452. logical lquery;
  453. /* -- LAPACK computational routine (version 3.8.0) -- */
  454. /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
  455. /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
  456. /* November 2017 */
  457. /* ===================================================================== */
  458. /* Test the input parameters */
  459. /* Parameter adjustments */
  460. a_dim1 = *lda;
  461. a_offset = 1 + a_dim1 * 1;
  462. a -= a_offset;
  463. --d__;
  464. --e;
  465. --tauq;
  466. --taup;
  467. --work;
  468. /* Function Body */
  469. *info = 0;
  470. /* Computing MAX */
  471. i__1 = 1, i__2 = ilaenv_(&c__1, "SGEBRD", " ", m, n, &c_n1, &c_n1, (
  472. ftnlen)6, (ftnlen)1);
  473. nb = f2cmax(i__1,i__2);
  474. lwkopt = (*m + *n) * nb;
  475. work[1] = (real) lwkopt;
  476. lquery = *lwork == -1;
  477. if (*m < 0) {
  478. *info = -1;
  479. } else if (*n < 0) {
  480. *info = -2;
  481. } else if (*lda < f2cmax(1,*m)) {
  482. *info = -4;
  483. } else /* if(complicated condition) */ {
  484. /* Computing MAX */
  485. i__1 = f2cmax(1,*m);
  486. if (*lwork < f2cmax(i__1,*n) && ! lquery) {
  487. *info = -10;
  488. }
  489. }
  490. if (*info < 0) {
  491. i__1 = -(*info);
  492. xerbla_("SGEBRD", &i__1, (ftnlen)6);
  493. return;
  494. } else if (lquery) {
  495. return;
  496. }
  497. /* Quick return if possible */
  498. minmn = f2cmin(*m,*n);
  499. if (minmn == 0) {
  500. work[1] = 1.f;
  501. return;
  502. }
  503. ws = f2cmax(*m,*n);
  504. ldwrkx = *m;
  505. ldwrky = *n;
  506. if (nb > 1 && nb < minmn) {
  507. /* Set the crossover point NX. */
  508. /* Computing MAX */
  509. i__1 = nb, i__2 = ilaenv_(&c__3, "SGEBRD", " ", m, n, &c_n1, &c_n1, (
  510. ftnlen)6, (ftnlen)1);
  511. nx = f2cmax(i__1,i__2);
  512. /* Determine when to switch from blocked to unblocked code. */
  513. if (nx < minmn) {
  514. ws = (*m + *n) * nb;
  515. if (*lwork < ws) {
  516. /* Not enough work space for the optimal NB, consider using */
  517. /* a smaller block size. */
  518. nbmin = ilaenv_(&c__2, "SGEBRD", " ", m, n, &c_n1, &c_n1, (
  519. ftnlen)6, (ftnlen)1);
  520. if (*lwork >= (*m + *n) * nbmin) {
  521. nb = *lwork / (*m + *n);
  522. } else {
  523. nb = 1;
  524. nx = minmn;
  525. }
  526. }
  527. }
  528. } else {
  529. nx = minmn;
  530. }
  531. i__1 = minmn - nx;
  532. i__2 = nb;
  533. for (i__ = 1; i__2 < 0 ? i__ >= i__1 : i__ <= i__1; i__ += i__2) {
  534. /* Reduce rows and columns i:i+nb-1 to bidiagonal form and return */
  535. /* the matrices X and Y which are needed to update the unreduced */
  536. /* part of the matrix */
  537. i__3 = *m - i__ + 1;
  538. i__4 = *n - i__ + 1;
  539. slabrd_(&i__3, &i__4, &nb, &a[i__ + i__ * a_dim1], lda, &d__[i__], &e[
  540. i__], &tauq[i__], &taup[i__], &work[1], &ldwrkx, &work[ldwrkx
  541. * nb + 1], &ldwrky);
  542. /* Update the trailing submatrix A(i+nb:m,i+nb:n), using an update */
  543. /* of the form A := A - V*Y**T - X*U**T */
  544. i__3 = *m - i__ - nb + 1;
  545. i__4 = *n - i__ - nb + 1;
  546. sgemm_("No transpose", "Transpose", &i__3, &i__4, &nb, &c_b21, &a[i__
  547. + nb + i__ * a_dim1], lda, &work[ldwrkx * nb + nb + 1], &
  548. ldwrky, &c_b22, &a[i__ + nb + (i__ + nb) * a_dim1], lda);
  549. i__3 = *m - i__ - nb + 1;
  550. i__4 = *n - i__ - nb + 1;
  551. sgemm_("No transpose", "No transpose", &i__3, &i__4, &nb, &c_b21, &
  552. work[nb + 1], &ldwrkx, &a[i__ + (i__ + nb) * a_dim1], lda, &
  553. c_b22, &a[i__ + nb + (i__ + nb) * a_dim1], lda);
  554. /* Copy diagonal and off-diagonal elements of B back into A */
  555. if (*m >= *n) {
  556. i__3 = i__ + nb - 1;
  557. for (j = i__; j <= i__3; ++j) {
  558. a[j + j * a_dim1] = d__[j];
  559. a[j + (j + 1) * a_dim1] = e[j];
  560. /* L10: */
  561. }
  562. } else {
  563. i__3 = i__ + nb - 1;
  564. for (j = i__; j <= i__3; ++j) {
  565. a[j + j * a_dim1] = d__[j];
  566. a[j + 1 + j * a_dim1] = e[j];
  567. /* L20: */
  568. }
  569. }
  570. /* L30: */
  571. }
  572. /* Use unblocked code to reduce the remainder of the matrix */
  573. i__2 = *m - i__ + 1;
  574. i__1 = *n - i__ + 1;
  575. sgebd2_(&i__2, &i__1, &a[i__ + i__ * a_dim1], lda, &d__[i__], &e[i__], &
  576. tauq[i__], &taup[i__], &work[1], &iinfo);
  577. work[1] = (real) ws;
  578. return;
  579. /* End of SGEBRD */
  580. } /* sgebrd_ */