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LAPACK 3.3.0
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LAPACK 3.3.0
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00001 INTEGER FUNCTION ILAENV( ISPEC, NAME, OPTS, N1, N2, N3, N4 ) 00002 * 00003 * -- LAPACK auxiliary routine (version 3.2.1) -- 00004 * 00005 * -- April 2009 -- 00006 * 00007 * -- LAPACK is a software package provided by Univ. of Tennessee, -- 00008 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- 00009 * 00010 * .. Scalar Arguments .. 00011 CHARACTER*( * ) NAME, OPTS 00012 INTEGER ISPEC, N1, N2, N3, N4 00013 * .. 00014 * 00015 * Purpose 00016 * ======= 00017 * 00018 * ILAENV is called from the LAPACK routines to choose problem-dependent 00019 * parameters for the local environment. See ISPEC for a description of 00020 * the parameters. 00021 * 00022 * ILAENV returns an INTEGER 00023 * if ILAENV >= 0: ILAENV returns the value of the parameter specified by ISPEC 00024 * if ILAENV < 0: if ILAENV = -k, the k-th argument had an illegal value. 00025 * 00026 * This version provides a set of parameters which should give good, 00027 * but not optimal, performance on many of the currently available 00028 * computers. Users are encouraged to modify this subroutine to set 00029 * the tuning parameters for their particular machine using the option 00030 * and problem size information in the arguments. 00031 * 00032 * This routine will not function correctly if it is converted to all 00033 * lower case. Converting it to all upper case is allowed. 00034 * 00035 * Arguments 00036 * ========= 00037 * 00038 * ISPEC (input) INTEGER 00039 * Specifies the parameter to be returned as the value of 00040 * ILAENV. 00041 * = 1: the optimal blocksize; if this value is 1, an unblocked 00042 * algorithm will give the best performance. 00043 * = 2: the minimum block size for which the block routine 00044 * should be used; if the usable block size is less than 00045 * this value, an unblocked routine should be used. 00046 * = 3: the crossover point (in a block routine, for N less 00047 * than this value, an unblocked routine should be used) 00048 * = 4: the number of shifts, used in the nonsymmetric 00049 * eigenvalue routines (DEPRECATED) 00050 * = 5: the minimum column dimension for blocking to be used; 00051 * rectangular blocks must have dimension at least k by m, 00052 * where k is given by ILAENV(2,...) and m by ILAENV(5,...) 00053 * = 6: the crossover point for the SVD (when reducing an m by n 00054 * matrix to bidiagonal form, if max(m,n)/min(m,n) exceeds 00055 * this value, a QR factorization is used first to reduce 00056 * the matrix to a triangular form.) 00057 * = 7: the number of processors 00058 * = 8: the crossover point for the multishift QR method 00059 * for nonsymmetric eigenvalue problems (DEPRECATED) 00060 * = 9: maximum size of the subproblems at the bottom of the 00061 * computation tree in the divide-and-conquer algorithm 00062 * (used by xGELSD and xGESDD) 00063 * =10: ieee NaN arithmetic can be trusted not to trap 00064 * =11: infinity arithmetic can be trusted not to trap 00065 * 12 <= ISPEC <= 16: 00066 * xHSEQR or one of its subroutines, 00067 * see IPARMQ for detailed explanation 00068 * 00069 * NAME (input) CHARACTER*(*) 00070 * The name of the calling subroutine, in either upper case or 00071 * lower case. 00072 * 00073 * OPTS (input) CHARACTER*(*) 00074 * The character options to the subroutine NAME, concatenated 00075 * into a single character string. For example, UPLO = 'U', 00076 * TRANS = 'T', and DIAG = 'N' for a triangular routine would 00077 * be specified as OPTS = 'UTN'. 00078 * 00079 * N1 (input) INTEGER 00080 * N2 (input) INTEGER 00081 * N3 (input) INTEGER 00082 * N4 (input) INTEGER 00083 * Problem dimensions for the subroutine NAME; these may not all 00084 * be required. 00085 * 00086 * Further Details 00087 * =============== 00088 * 00089 * The following conventions have been used when calling ILAENV from the 00090 * LAPACK routines: 00091 * 1) OPTS is a concatenation of all of the character options to 00092 * subroutine NAME, in the same order that they appear in the 00093 * argument list for NAME, even if they are not used in determining 00094 * the value of the parameter specified by ISPEC. 00095 * 2) The problem dimensions N1, N2, N3, N4 are specified in the order 00096 * that they appear in the argument list for NAME. N1 is used 00097 * first, N2 second, and so on, and unused problem dimensions are 00098 * passed a value of -1. 00099 * 3) The parameter value returned by ILAENV is checked for validity in 00100 * the calling subroutine. For example, ILAENV is used to retrieve 00101 * the optimal blocksize for STRTRI as follows: 00102 * 00103 * NB = ILAENV( 1, 'STRTRI', UPLO // DIAG, N, -1, -1, -1 ) 00104 * IF( NB.LE.1 ) NB = MAX( 1, N ) 00105 * 00106 * ===================================================================== 00107 * 00108 * .. Local Scalars .. 00109 INTEGER I, IC, IZ, NB, NBMIN, NX 00110 LOGICAL CNAME, SNAME 00111 CHARACTER C1*1, C2*2, C4*2, C3*3, SUBNAM*6 00112 * .. 00113 * .. Intrinsic Functions .. 00114 INTRINSIC CHAR, ICHAR, INT, MIN, REAL 00115 * .. 00116 * .. External Functions .. 00117 INTEGER IEEECK, IPARMQ 00118 EXTERNAL IEEECK, IPARMQ 00119 * .. 00120 * .. Executable Statements .. 00121 * 00122 GO TO ( 10, 10, 10, 80, 90, 100, 110, 120, 00123 $ 130, 140, 150, 160, 160, 160, 160, 160 )ISPEC 00124 * 00125 * Invalid value for ISPEC 00126 * 00127 ILAENV = -1 00128 RETURN 00129 * 00130 10 CONTINUE 00131 * 00132 * Convert NAME to upper case if the first character is lower case. 00133 * 00134 ILAENV = 1 00135 SUBNAM = NAME 00136 IC = ICHAR( SUBNAM( 1: 1 ) ) 00137 IZ = ICHAR( 'Z' ) 00138 IF( IZ.EQ.90 .OR. IZ.EQ.122 ) THEN 00139 * 00140 * ASCII character set 00141 * 00142 IF( IC.GE.97 .AND. IC.LE.122 ) THEN 00143 SUBNAM( 1: 1 ) = CHAR( IC-32 ) 00144 DO 20 I = 2, 6 00145 IC = ICHAR( SUBNAM( I: I ) ) 00146 IF( IC.GE.97 .AND. IC.LE.122 ) 00147 $ SUBNAM( I: I ) = CHAR( IC-32 ) 00148 20 CONTINUE 00149 END IF 00150 * 00151 ELSE IF( IZ.EQ.233 .OR. IZ.EQ.169 ) THEN 00152 * 00153 * EBCDIC character set 00154 * 00155 IF( ( IC.GE.129 .AND. IC.LE.137 ) .OR. 00156 $ ( IC.GE.145 .AND. IC.LE.153 ) .OR. 00157 $ ( IC.GE.162 .AND. IC.LE.169 ) ) THEN 00158 SUBNAM( 1: 1 ) = CHAR( IC+64 ) 00159 DO 30 I = 2, 6 00160 IC = ICHAR( SUBNAM( I: I ) ) 00161 IF( ( IC.GE.129 .AND. IC.LE.137 ) .OR. 00162 $ ( IC.GE.145 .AND. IC.LE.153 ) .OR. 00163 $ ( IC.GE.162 .AND. IC.LE.169 ) )SUBNAM( I: 00164 $ I ) = CHAR( IC+64 ) 00165 30 CONTINUE 00166 END IF 00167 * 00168 ELSE IF( IZ.EQ.218 .OR. IZ.EQ.250 ) THEN 00169 * 00170 * Prime machines: ASCII+128 00171 * 00172 IF( IC.GE.225 .AND. IC.LE.250 ) THEN 00173 SUBNAM( 1: 1 ) = CHAR( IC-32 ) 00174 DO 40 I = 2, 6 00175 IC = ICHAR( SUBNAM( I: I ) ) 00176 IF( IC.GE.225 .AND. IC.LE.250 ) 00177 $ SUBNAM( I: I ) = CHAR( IC-32 ) 00178 40 CONTINUE 00179 END IF 00180 END IF 00181 * 00182 C1 = SUBNAM( 1: 1 ) 00183 SNAME = C1.EQ.'S' .OR. C1.EQ.'D' 00184 CNAME = C1.EQ.'C' .OR. C1.EQ.'Z' 00185 IF( .NOT.( CNAME .OR. SNAME ) ) 00186 $ RETURN 00187 C2 = SUBNAM( 2: 3 ) 00188 C3 = SUBNAM( 4: 6 ) 00189 C4 = C3( 2: 3 ) 00190 * 00191 GO TO ( 50, 60, 70 )ISPEC 00192 * 00193 50 CONTINUE 00194 * 00195 * ISPEC = 1: block size 00196 * 00197 * In these examples, separate code is provided for setting NB for 00198 * real and complex. We assume that NB will take the same value in 00199 * single or double precision. 00200 * 00201 NB = 1 00202 * 00203 IF( C2.EQ.'GE' ) THEN 00204 IF( C3.EQ.'TRF' ) THEN 00205 IF( SNAME ) THEN 00206 NB = 64 00207 ELSE 00208 NB = 64 00209 END IF 00210 ELSE IF( C3.EQ.'QRF' .OR. C3.EQ.'RQF' .OR. C3.EQ.'LQF' .OR. 00211 $ C3.EQ.'QLF' ) THEN 00212 IF( SNAME ) THEN 00213 NB = 32 00214 ELSE 00215 NB = 32 00216 END IF 00217 ELSE IF( C3.EQ.'HRD' ) THEN 00218 IF( SNAME ) THEN 00219 NB = 32 00220 ELSE 00221 NB = 32 00222 END IF 00223 ELSE IF( C3.EQ.'BRD' ) THEN 00224 IF( SNAME ) THEN 00225 NB = 32 00226 ELSE 00227 NB = 32 00228 END IF 00229 ELSE IF( C3.EQ.'TRI' ) THEN 00230 IF( SNAME ) THEN 00231 NB = 64 00232 ELSE 00233 NB = 64 00234 END IF 00235 END IF 00236 ELSE IF( C2.EQ.'PO' ) THEN 00237 IF( C3.EQ.'TRF' ) THEN 00238 IF( SNAME ) THEN 00239 NB = 64 00240 ELSE 00241 NB = 64 00242 END IF 00243 END IF 00244 ELSE IF( C2.EQ.'SY' ) THEN 00245 IF( C3.EQ.'TRF' ) THEN 00246 IF( SNAME ) THEN 00247 NB = 64 00248 ELSE 00249 NB = 64 00250 END IF 00251 ELSE IF( SNAME .AND. C3.EQ.'TRD' ) THEN 00252 NB = 32 00253 ELSE IF( SNAME .AND. C3.EQ.'GST' ) THEN 00254 NB = 64 00255 END IF 00256 ELSE IF( CNAME .AND. C2.EQ.'HE' ) THEN 00257 IF( C3.EQ.'TRF' ) THEN 00258 NB = 64 00259 ELSE IF( C3.EQ.'TRD' ) THEN 00260 NB = 32 00261 ELSE IF( C3.EQ.'GST' ) THEN 00262 NB = 64 00263 END IF 00264 ELSE IF( SNAME .AND. C2.EQ.'OR' ) THEN 00265 IF( C3( 1: 1 ).EQ.'G' ) THEN 00266 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00267 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00268 $ THEN 00269 NB = 32 00270 END IF 00271 ELSE IF( C3( 1: 1 ).EQ.'M' ) THEN 00272 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00273 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00274 $ THEN 00275 NB = 32 00276 END IF 00277 END IF 00278 ELSE IF( CNAME .AND. C2.EQ.'UN' ) THEN 00279 IF( C3( 1: 1 ).EQ.'G' ) THEN 00280 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00281 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00282 $ THEN 00283 NB = 32 00284 END IF 00285 ELSE IF( C3( 1: 1 ).EQ.'M' ) THEN 00286 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00287 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00288 $ THEN 00289 NB = 32 00290 END IF 00291 END IF 00292 ELSE IF( C2.EQ.'GB' ) THEN 00293 IF( C3.EQ.'TRF' ) THEN 00294 IF( SNAME ) THEN 00295 IF( N4.LE.64 ) THEN 00296 NB = 1 00297 ELSE 00298 NB = 32 00299 END IF 00300 ELSE 00301 IF( N4.LE.64 ) THEN 00302 NB = 1 00303 ELSE 00304 NB = 32 00305 END IF 00306 END IF 00307 END IF 00308 ELSE IF( C2.EQ.'PB' ) THEN 00309 IF( C3.EQ.'TRF' ) THEN 00310 IF( SNAME ) THEN 00311 IF( N2.LE.64 ) THEN 00312 NB = 1 00313 ELSE 00314 NB = 32 00315 END IF 00316 ELSE 00317 IF( N2.LE.64 ) THEN 00318 NB = 1 00319 ELSE 00320 NB = 32 00321 END IF 00322 END IF 00323 END IF 00324 ELSE IF( C2.EQ.'TR' ) THEN 00325 IF( C3.EQ.'TRI' ) THEN 00326 IF( SNAME ) THEN 00327 NB = 64 00328 ELSE 00329 NB = 64 00330 END IF 00331 END IF 00332 ELSE IF( C2.EQ.'LA' ) THEN 00333 IF( C3.EQ.'UUM' ) THEN 00334 IF( SNAME ) THEN 00335 NB = 64 00336 ELSE 00337 NB = 64 00338 END IF 00339 END IF 00340 ELSE IF( SNAME .AND. C2.EQ.'ST' ) THEN 00341 IF( C3.EQ.'EBZ' ) THEN 00342 NB = 1 00343 END IF 00344 END IF 00345 ILAENV = NB 00346 RETURN 00347 * 00348 60 CONTINUE 00349 * 00350 * ISPEC = 2: minimum block size 00351 * 00352 NBMIN = 2 00353 IF( C2.EQ.'GE' ) THEN 00354 IF( C3.EQ.'QRF' .OR. C3.EQ.'RQF' .OR. C3.EQ.'LQF' .OR. C3.EQ. 00355 $ 'QLF' ) THEN 00356 IF( SNAME ) THEN 00357 NBMIN = 2 00358 ELSE 00359 NBMIN = 2 00360 END IF 00361 ELSE IF( C3.EQ.'HRD' ) THEN 00362 IF( SNAME ) THEN 00363 NBMIN = 2 00364 ELSE 00365 NBMIN = 2 00366 END IF 00367 ELSE IF( C3.EQ.'BRD' ) THEN 00368 IF( SNAME ) THEN 00369 NBMIN = 2 00370 ELSE 00371 NBMIN = 2 00372 END IF 00373 ELSE IF( C3.EQ.'TRI' ) THEN 00374 IF( SNAME ) THEN 00375 NBMIN = 2 00376 ELSE 00377 NBMIN = 2 00378 END IF 00379 END IF 00380 ELSE IF( C2.EQ.'SY' ) THEN 00381 IF( C3.EQ.'TRF' ) THEN 00382 IF( SNAME ) THEN 00383 NBMIN = 8 00384 ELSE 00385 NBMIN = 8 00386 END IF 00387 ELSE IF( SNAME .AND. C3.EQ.'TRD' ) THEN 00388 NBMIN = 2 00389 END IF 00390 ELSE IF( CNAME .AND. C2.EQ.'HE' ) THEN 00391 IF( C3.EQ.'TRD' ) THEN 00392 NBMIN = 2 00393 END IF 00394 ELSE IF( SNAME .AND. C2.EQ.'OR' ) THEN 00395 IF( C3( 1: 1 ).EQ.'G' ) THEN 00396 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00397 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00398 $ THEN 00399 NBMIN = 2 00400 END IF 00401 ELSE IF( C3( 1: 1 ).EQ.'M' ) THEN 00402 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00403 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00404 $ THEN 00405 NBMIN = 2 00406 END IF 00407 END IF 00408 ELSE IF( CNAME .AND. C2.EQ.'UN' ) THEN 00409 IF( C3( 1: 1 ).EQ.'G' ) THEN 00410 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00411 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00412 $ THEN 00413 NBMIN = 2 00414 END IF 00415 ELSE IF( C3( 1: 1 ).EQ.'M' ) THEN 00416 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00417 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00418 $ THEN 00419 NBMIN = 2 00420 END IF 00421 END IF 00422 END IF 00423 ILAENV = NBMIN 00424 RETURN 00425 * 00426 70 CONTINUE 00427 * 00428 * ISPEC = 3: crossover point 00429 * 00430 NX = 0 00431 IF( C2.EQ.'GE' ) THEN 00432 IF( C3.EQ.'QRF' .OR. C3.EQ.'RQF' .OR. C3.EQ.'LQF' .OR. C3.EQ. 00433 $ 'QLF' ) THEN 00434 IF( SNAME ) THEN 00435 NX = 128 00436 ELSE 00437 NX = 128 00438 END IF 00439 ELSE IF( C3.EQ.'HRD' ) THEN 00440 IF( SNAME ) THEN 00441 NX = 128 00442 ELSE 00443 NX = 128 00444 END IF 00445 ELSE IF( C3.EQ.'BRD' ) THEN 00446 IF( SNAME ) THEN 00447 NX = 128 00448 ELSE 00449 NX = 128 00450 END IF 00451 END IF 00452 ELSE IF( C2.EQ.'SY' ) THEN 00453 IF( SNAME .AND. C3.EQ.'TRD' ) THEN 00454 NX = 32 00455 END IF 00456 ELSE IF( CNAME .AND. C2.EQ.'HE' ) THEN 00457 IF( C3.EQ.'TRD' ) THEN 00458 NX = 32 00459 END IF 00460 ELSE IF( SNAME .AND. C2.EQ.'OR' ) THEN 00461 IF( C3( 1: 1 ).EQ.'G' ) THEN 00462 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00463 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00464 $ THEN 00465 NX = 128 00466 END IF 00467 END IF 00468 ELSE IF( CNAME .AND. C2.EQ.'UN' ) THEN 00469 IF( C3( 1: 1 ).EQ.'G' ) THEN 00470 IF( C4.EQ.'QR' .OR. C4.EQ.'RQ' .OR. C4.EQ.'LQ' .OR. C4.EQ. 00471 $ 'QL' .OR. C4.EQ.'HR' .OR. C4.EQ.'TR' .OR. C4.EQ.'BR' ) 00472 $ THEN 00473 NX = 128 00474 END IF 00475 END IF 00476 END IF 00477 ILAENV = NX 00478 RETURN 00479 * 00480 80 CONTINUE 00481 * 00482 * ISPEC = 4: number of shifts (used by xHSEQR) 00483 * 00484 ILAENV = 6 00485 RETURN 00486 * 00487 90 CONTINUE 00488 * 00489 * ISPEC = 5: minimum column dimension (not used) 00490 * 00491 ILAENV = 2 00492 RETURN 00493 * 00494 100 CONTINUE 00495 * 00496 * ISPEC = 6: crossover point for SVD (used by xGELSS and xGESVD) 00497 * 00498 ILAENV = INT( REAL( MIN( N1, N2 ) )*1.6E0 ) 00499 RETURN 00500 * 00501 110 CONTINUE 00502 * 00503 * ISPEC = 7: number of processors (not used) 00504 * 00505 ILAENV = 1 00506 RETURN 00507 * 00508 120 CONTINUE 00509 * 00510 * ISPEC = 8: crossover point for multishift (used by xHSEQR) 00511 * 00512 ILAENV = 50 00513 RETURN 00514 * 00515 130 CONTINUE 00516 * 00517 * ISPEC = 9: maximum size of the subproblems at the bottom of the 00518 * computation tree in the divide-and-conquer algorithm 00519 * (used by xGELSD and xGESDD) 00520 * 00521 ILAENV = 25 00522 RETURN 00523 * 00524 140 CONTINUE 00525 * 00526 * ISPEC = 10: ieee NaN arithmetic can be trusted not to trap 00527 * 00528 * ILAENV = 0 00529 ILAENV = 1 00530 IF( ILAENV.EQ.1 ) THEN 00531 ILAENV = IEEECK( 1, 0.0, 1.0 ) 00532 END IF 00533 RETURN 00534 * 00535 150 CONTINUE 00536 * 00537 * ISPEC = 11: infinity arithmetic can be trusted not to trap 00538 * 00539 * ILAENV = 0 00540 ILAENV = 1 00541 IF( ILAENV.EQ.1 ) THEN 00542 ILAENV = IEEECK( 0, 0.0, 1.0 ) 00543 END IF 00544 RETURN 00545 * 00546 160 CONTINUE 00547 * 00548 * 12 <= ISPEC <= 16: xHSEQR or one of its subroutines. 00549 * 00550 ILAENV = IPARMQ( ISPEC, NAME, OPTS, N1, N2, N3, N4 ) 00551 RETURN 00552 * 00553 * End of ILAENV 00554 * 00555 END
1.7.3 
