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Functions
dormqr.c File Reference

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Functions

int dormqr_fla (char *side, char *trans, integer *m, integer *n, integer *k, doublereal *a, integer *lda, doublereal *tau, doublereal *c__, integer *ldc, doublereal *work, integer *lwork, integer *info)
 

Function Documentation

◆ dormqr_fla()

int dormqr_fla ( char *  side,
char *  trans,
integer m,
integer n,
integer k,
doublereal a,
integer lda,
doublereal tau,
doublereal c__,
integer ldc,
doublereal work,
integer lwork,
integer info 
)

References dorm2r_fla().

Referenced by dormhr_(), and dormtr_fla().

169 {
170  /* System generated locals */
171  integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__4, i__5;
172  char ch__1[2];
173  /* Builtin functions */
174  /* Subroutine */
175 
176  /* Local variables */
177  integer i__;
178  doublereal t[4160] /* was [65][64] */
179  ;
180  integer i1, i2, i3, ib, ic, jc, nb, mi, ni, nq, nw, iws;
181  logical left;
182  extern logical lsame_(char *, char *);
183  integer nbmin, iinfo;
184  extern /* Subroutine */
185  int dorm2r_fla(char *, char *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *), dlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *), dlarft_(char *, char *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *), xerbla_(char *, integer *);
186  extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *);
187  logical notran;
188  integer ldwork, lwkopt;
189  logical lquery;
190  /* -- LAPACK computational routine (version 3.4.0) -- */
191  /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
192  /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
193  /* November 2011 */
194  /* .. Scalar Arguments .. */
195  /* .. */
196  /* .. Array Arguments .. */
197  /* .. */
198  /* ===================================================================== */
199  /* .. Parameters .. */
200  /* .. */
201  /* .. Local Scalars .. */
202  /* .. */
203  /* .. Local Arrays .. */
204  /* .. */
205  /* .. External Functions .. */
206  /* .. */
207  /* .. External Subroutines .. */
208  /* .. */
209  /* .. Intrinsic Functions .. */
210  /* .. */
211  /* .. Executable Statements .. */
212  /* Test the input arguments */
213  /* Parameter adjustments */
214  a_dim1 = *lda;
215  a_offset = 1 + a_dim1;
216  a -= a_offset;
217  --tau;
218  c_dim1 = *ldc;
219  c_offset = 1 + c_dim1;
220  c__ -= c_offset;
221  --work;
222  /* Function Body */
223  *info = 0;
224  left = lsame_(side, "L");
225  notran = lsame_(trans, "N");
226  lquery = *lwork == -1;
227  /* NQ is the order of Q and NW is the minimum dimension of WORK */
228  if (left)
229  {
230  nq = *m;
231  nw = *n;
232  }
233  else
234  {
235  nq = *n;
236  nw = *m;
237  }
238  if (! left && ! lsame_(side, "R"))
239  {
240  *info = -1;
241  }
242  else if (! notran && ! lsame_(trans, "T"))
243  {
244  *info = -2;
245  }
246  else if (*m < 0)
247  {
248  *info = -3;
249  }
250  else if (*n < 0)
251  {
252  *info = -4;
253  }
254  else if (*k < 0 || *k > nq)
255  {
256  *info = -5;
257  }
258  else if (*lda < max(1,nq))
259  {
260  *info = -7;
261  }
262  else if (*ldc < max(1,*m))
263  {
264  *info = -10;
265  }
266  else if (*lwork < max(1,nw) && ! lquery)
267  {
268  *info = -12;
269  }
270  if (*info == 0)
271  {
272  /* Determine the block size. NB may be at most NBMAX, where NBMAX */
273  /* is used to define the local array T. */
274  /* Computing MIN */
275  i__1 = 64;
276  i__2 = ilaenv_(&c__1, "DORMQR", ch__1, m, n, k, &c_n1); // , expr subst
277  nb = min(i__1,i__2);
278  lwkopt = max(1,nw) * nb;
279  work[1] = (doublereal) lwkopt;
280  }
281  if (*info != 0)
282  {
283  i__1 = -(*info);
284  xerbla_("DORMQR", &i__1);
285  return 0;
286  }
287  else if (lquery)
288  {
289  return 0;
290  }
291  /* Quick return if possible */
292  if (*m == 0 || *n == 0 || *k == 0)
293  {
294  work[1] = 1.;
295  return 0;
296  }
297  nbmin = 2;
298  ldwork = nw;
299  if (nb > 1 && nb < *k)
300  {
301  iws = nw * nb;
302  if (*lwork < iws)
303  {
304  nb = *lwork / ldwork;
305  /* Computing MAX */
306  i__1 = 2;
307  i__2 = ilaenv_(&c__2, "DORMQR", ch__1, m, n, k, &c_n1); // , expr subst
308  nbmin = max(i__1,i__2);
309  }
310  }
311  else
312  {
313  iws = nw;
314  }
315  if (nb < nbmin || nb >= *k)
316  {
317  /* Use unblocked code */
318  dorm2r_fla(side, trans, m, n, k, &a[a_offset], lda, &tau[1], &c__[ c_offset], ldc, &work[1], &iinfo);
319  }
320  else
321  {
322  /* Use blocked code */
323  if (left && ! notran || ! left && notran)
324  {
325  i1 = 1;
326  i2 = *k;
327  i3 = nb;
328  }
329  else
330  {
331  i1 = (*k - 1) / nb * nb + 1;
332  i2 = 1;
333  i3 = -nb;
334  }
335  if (left)
336  {
337  ni = *n;
338  jc = 1;
339  }
340  else
341  {
342  mi = *m;
343  ic = 1;
344  }
345  i__1 = i2;
346  i__2 = i3;
347  for (i__ = i1;
348  i__2 < 0 ? i__ >= i__1 : i__ <= i__1;
349  i__ += i__2)
350  {
351  /* Computing MIN */
352  i__4 = nb;
353  i__5 = *k - i__ + 1; // , expr subst
354  ib = min(i__4,i__5);
355  /* Form the triangular factor of the block reflector */
356  /* H = H(i) H(i+1) . . . H(i+ib-1) */
357  i__4 = nq - i__ + 1;
358  dlarft_("Forward", "Columnwise", &i__4, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], t, &c__65) ;
359  if (left)
360  {
361  /* H or H**T is applied to C(i:m,1:n) */
362  mi = *m - i__ + 1;
363  ic = i__;
364  }
365  else
366  {
367  /* H or H**T is applied to C(1:m,i:n) */
368  ni = *n - i__ + 1;
369  jc = i__;
370  }
371  /* Apply H or H**T */
372  dlarfb_(side, trans, "Forward", "Columnwise", &mi, &ni, &ib, &a[ i__ + i__ * a_dim1], lda, t, &c__65, &c__[ic + jc * c_dim1], ldc, &work[1], &ldwork);
373  /* L10: */
374  }
375  }
376  work[1] = (doublereal) lwkopt;
377  return 0;
378  /* End of DORMQR */
379 }
double doublereal
Definition: FLA_f2c.h:31
int logical
Definition: FLA_f2c.h:36
int integer
Definition: FLA_f2c.h:25
int dorm2r_fla(char *side, char *trans, integer *m, integer *n, integer *k, doublereal *a, integer *lda, doublereal *tau, doublereal *c__, integer *ldc, doublereal *work, integer *info)
Definition: dorm2r.c:151