SCALAPACK 2.2.2
LAPACK: Linear Algebra PACKage
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pjlaenv.f
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1 INTEGER FUNCTION pjlaenv( ICTXT, ISPEC, NAME, OPTS, N1,
2 $ N2, N3, N4 )
3*
4* -- ScaLAPACK test routine (version 1.7) --
5* University of Tennessee, Knoxville, Oak Ridge National Laboratory,
6* and University of California, Berkeley.
7* October 15, 1999
8*
9* .. Scalar Arguments ..
10 CHARACTER*( * ) name, opts
11 INTEGER ictxt, ispec, n1, n2, n3, n4
12* ..
13*
14* Purpose
15*
16* =======
17*
18* PJLAENV is called from the ScaLAPACK symmetric and Hermitian
19* tailored eigen-routines to choose
20* problem-dependent parameters for the local environment. See ISPEC
21* for a description of the parameters.
22*
23* This version provides a set of parameters which should give good,
24* but not optimal, performance on many of the currently available
25* computers. Users are encouraged to modify this subroutine to set
26* the tuning parameters for their particular machine using the option
27* and problem size information in the arguments.
28*
29* This routine will not function correctly if it is converted to all
30* lower case. Converting it to all upper case is allowed.
31*
32* Arguments
33* =========
34*
35* ISPEC (global input) INTEGER
36* Specifies the parameter to be returned as the value of
37* PJLAENV.
38* = 1: the data layout blocksize;
39* = 2: the panel blocking factor;
40* = 3: the algorithmic blocking factor;
41* = 4: execution path control;
42* = 5: maximum size for direct call to the LAPACK routine
43*
44* NAME (global input) CHARACTER*(*)
45* The name of the calling subroutine, in either upper case or
46* lower case.
47*
48* OPTS (global input) CHARACTER*(*)
49* The character options to the subroutine NAME, concatenated
50* into a single character string. For example, UPLO = 'U',
51* TRANS = 'T', and DIAG = 'N' for a triangular routine would
52* be specified as OPTS = 'UTN'.
53*
54* N1 (global input) INTEGER
55* N2 (global input) INTEGER
56* N3 (global input) INTEGER
57* N4 (global input) INTEGER
58* Problem dimensions for the subroutine NAME; these may not all
59* be required.
60*
61* At present, only N1 is used, and it (N1) is used only for
62* 'TTRD'
63*
64* (PJLAENV) (global or local output) INTEGER
65* >= 0: the value of the parameter specified by ISPEC
66* < 0: if PJLAENV = -k, the k-th argument had an illegal
67* value.
68*
69* Most parameters set via a call to PJLAENV must be identical
70* on all processors and hence PJLAENV will return the same
71* value to all procesors (i.e. global output). However some,
72* in particular, the panel blocking factor can be different
73* on each processor and hence PJLAENV can return different
74* values on different processors (i.e. local output).
75*
76* Further Details
77* ===============
78*
79* The following conventions have been used when calling PJLAENV from
80* the ScaLAPACK routines:
81* 1) OPTS is a concatenation of all of the character options to
82* subroutine NAME, in the same order that they appear in the
83* argument list for NAME, even if they are not used in determining
84* the value of the parameter specified by ISPEC.
85* 2) The problem dimensions N1, N2, N3, N4 are specified in the order
86* that they appear in the argument list for NAME. N1 is used
87* first, N2 second, and so on, and unused problem dimensions are
88* passed a value of -1.
89* 3) The parameter value returned by PJLAENV is checked for validity
90* in the calling subroutine. For example, PJLAENV is used to
91* retrieve the optimal blocksize for STRTRI as follows:
92*
93* NB = PJLAENV( 1, 'STRTRI', UPLO // DIAG, N, -1, -1, -1 )
94* IF( NB.LE.1 ) NB = MAX( 1, N )
95*
96* PJLAENV is patterned after ILAENV and keeps the same interface in
97* anticipation of future needs, even though PJLAENV is only sparsely
98* used at present in ScaLAPACK. Most ScaLAPACK codes use the input
99* data layout blocking factor as the algorithmic blocking factor -
100* hence there is no need or opportunity to set the algorithmic or
101* data decomposition blocking factor.
102*
103* pXYYtevx.f and pXYYtgvx.f and pXYYttrd.f are the only codes which
104* call PJLAENV in this release. pXYYtevx.f and pXYYtgvx.f redistribute
105* the data to the best data layout for each transformation. pXYYttrd.f
106* uses a data layout blocking factor of 1 and a
107*
108* =====================================================================
109*
110* .. Parameters ..
111 INTEGER block_cyclic_2d, csrc_, ctxt_, dlen_, dtype_,
112 $ lld_, mb_, m_, nb_, n_, rsrc_
113 parameter( block_cyclic_2d = 1, dlen_ = 9, dtype_ = 1,
114 $ ctxt_ = 2, m_ = 3, n_ = 4, mb_ = 5, nb_ = 6,
115 $ rsrc_ = 7, csrc_ = 8, lld_ = 9 )
116* ..
117* .. Local Scalars ..
118 LOGICAL cname, global, sname
119 CHARACTER c1
120 CHARACTER*2 c2, c4
121 CHARACTER*3 c3
122 CHARACTER*8 subnam
123 INTEGER i, ic, idumm, iz, msz, nb
124* ..
125* .. Intrinsic Functions ..
126 INTRINSIC char, ichar
127* ..
128*
129*
130* .. External Subroutines ..
131 EXTERNAL igamx2d
132* ..
133* .. Executable Statements ..
134* This is just to keep ftnchek and toolpack/1 happy
135 IF( block_cyclic_2d*csrc_*ctxt_*dlen_*dtype_*lld_*mb_*m_*nb_*n_*
136 $ rsrc_.LT.0 )RETURN
137*
138*
139*
140 GO TO ( 10, 10, 10, 10, 10 )ispec
141*
142* Invalid value for ISPEC
143*
144 pjlaenv = -1
145 RETURN
146*
147 10 CONTINUE
148*
149* Convert NAME to upper case if the first character is lower case.
150*
151 pjlaenv = 1
152 subnam = name
153 ic = ichar( subnam( 1: 1 ) )
154 iz = ichar( 'Z' )
155 IF( iz.EQ.100 .OR. iz.EQ.122 ) THEN
156*
157* ASCII character set
158*
159 IF( ic.GE.97 .AND. ic.LE.122 ) THEN
160 subnam( 1: 1 ) = char( ic-32 )
161 DO 20 i = 2, 6
162 ic = ichar( subnam( i: i ) )
163 IF( ic.GE.97 .AND. ic.LE.122 )
164 $ subnam( i: i ) = char( ic-32 )
165 20 CONTINUE
166 END IF
167*
168 ELSE IF( iz.EQ.233 .OR. iz.EQ.169 ) THEN
169*
170* EBCDIC character set
171*
172 IF( ( ic.GE.129 .AND. ic.LE.137 ) .OR.
173 $ ( ic.GE.145 .AND. ic.LE.153 ) .OR.
174 $ ( ic.GE.162 .AND. ic.LE.169 ) ) THEN
175 subnam( 1: 1 ) = char( ic+64 )
176 DO 30 i = 2, 6
177 ic = ichar( subnam( i: i ) )
178 IF( ( ic.GE.129 .AND. ic.LE.137 ) .OR.
179 $ ( ic.GE.145 .AND. ic.LE.153 ) .OR.
180 $ ( ic.GE.162 .AND. ic.LE.169 ) )subnam( i:
181 $ i ) = char( ic+64 )
182 30 CONTINUE
183 END IF
184*
185 ELSE IF( iz.EQ.218 .OR. iz.EQ.250 ) THEN
186*
187* Prime machines: ASCII+128
188*
189 IF( ic.GE.225 .AND. ic.LE.250 ) THEN
190 subnam( 1: 1 ) = char( ic-32 )
191 DO 40 i = 2, 6
192 ic = ichar( subnam( i: i ) )
193 IF( ic.GE.225 .AND. ic.LE.250 )
194 $ subnam( i: i ) = char( ic-32 )
195 40 CONTINUE
196 END IF
197 END IF
198*
199 c1 = subnam( 2: 2 )
200 sname = c1.EQ.'S' .OR. c1.EQ.'D'
201 cname = c1.EQ.'C' .OR. c1.EQ.'Z'
202 IF( .NOT.( cname .OR. sname ) )
203 $ RETURN
204 c2 = subnam( 3: 4 )
205 c3 = subnam( 5: 7 )
206 c4 = c3( 2: 3 )
207*
208* This is to keep ftnchek happy
209*
210 IF( ( n2+n3+n4 )*0.NE.0 ) THEN
211 c4 = opts
212 c3 = c4
213 END IF
214*
215 GO TO ( 50, 60, 70, 80, 90 )ispec
216*
217 50 CONTINUE
218*
219* ISPEC = 1: data layout block size
220* (global - all processes must use the same value)
221*
222* In these examples, separate code is provided for setting NB for
223* real and complex. We assume that NB will take the same value in
224* single or double precision.
225*
226 nb = 1
227*
228 IF( c2.EQ.'SY' .OR. c2.EQ.'HE' ) THEN
229 IF( c3.EQ.'LLT' ) THEN
230 IF( sname ) THEN
231 nb = 64
232 ELSE
233 nb = 64
234 END IF
235 ELSE IF( c3.EQ.'TTR' ) THEN
236 IF( sname ) THEN
237 nb = 1
238 ELSE
239 nb = 1
240 END IF
241 ELSE IF( c3.EQ.'GST' ) THEN
242 IF( sname ) THEN
243 nb = 32
244 ELSE
245 nb = 32
246 END IF
247 ELSE IF( c3.EQ.'BCK' ) THEN
248 IF( sname ) THEN
249 nb = 32
250 ELSE
251 nb = 32
252 END IF
253 ELSE IF( c3.EQ.'TRS' ) THEN
254 IF( sname ) THEN
255 nb = 64
256 ELSE
257 nb = 64
258 END IF
259 END IF
260 END IF
261*
262*
263 pjlaenv = nb
264 global = .true.
265 GO TO 100
266*
267 60 CONTINUE
268*
269* ISPEC = 2: panel blocking factor (Used only in PxyyTTRD)
270* (local - different processes may use different values)
271*
272 nb = 16
273 IF( c2.EQ.'SY' .OR. c2.EQ.'HE' ) THEN
274 IF( c3.EQ.'TTR' ) THEN
275 IF( sname ) THEN
276 nb = 32
277 ELSE
278 nb = 32
279 END IF
280 END IF
281 END IF
282 pjlaenv = nb
283 global = .false.
284 GO TO 100
285*
286*
287 70 CONTINUE
288*
289* ISPEC = 3: algorithmic blocking factor (Used only in PxyyTTRD)
290* (global - all processes must use the same value)
291*
292 nb = 1
293 IF( c2.EQ.'SY' .OR. c2.EQ.'HE' ) THEN
294 IF( c3.EQ.'TTR' ) THEN
295 IF( sname ) THEN
296 nb = 16
297 ELSE
298 nb = 16
299 END IF
300 END IF
301 END IF
302 pjlaenv = nb
303 global = .true.
304 GO TO 100
305*
306 80 CONTINUE
307*
308* ISPEC = 4: Execution path options (Used only in PxyyTTRD)
309* (global - all processes must use the same value)
310*
311 pjlaenv = -4
312 IF( c2.EQ.'SY' .OR. c2.EQ.'HE' ) THEN
313 IF( c3.EQ.'TTR' ) THEN
314* V and H interleaved (default is not interleaved)
315 IF( n1.EQ.1 ) THEN
316 pjlaenv = 1
317 END IF
318*
319* Two ZGEMMs (default is one ZGEMM)
320 IF( n1.EQ.2 ) THEN
321 pjlaenv = 0
322 END IF
323* Balanced Update (default is minimum communication update)
324 IF( n1.EQ.3 ) THEN
325 pjlaenv = 0
326 END IF
327 END IF
328 END IF
329 global = .true.
330 GO TO 100
331*
332 90 CONTINUE
333*
334* ISPEC = 5: Minimum size to justify call to parallel code
335* (global - all processes must use the same value)
336*
337 msz = 0
338 IF( c2.EQ.'SY' .OR. c2.EQ.'HE' ) THEN
339 IF( c3.EQ.'TTR' ) THEN
340 IF( sname ) THEN
341 msz = 100
342 ELSE
343 msz = 100
344 END IF
345 END IF
346 END IF
347 pjlaenv = msz
348 global = .true.
349 GO TO 100
350*
351 100 CONTINUE
352*
353 IF( global ) THEN
354 idumm = 0
355 CALL igamx2d( ictxt, 'All', ' ', 1, 1, pjlaenv, 1, idumm,
356 $ idumm, -1, -1, idumm )
357 END IF
358*
359*
360*
361 RETURN
362*
363* End of PJLAENV
364*
365 END
pjlaenv
integer function pjlaenv(ictxt, ispec, name, opts, n1, n2, n3, n4)
Definition pjlaenv.f:3