SCALAPACK 2.2.2
LAPACK: Linear Algebra PACKage
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◆ pschekpad()

subroutine pschekpad ( integer  ictxt,
character, dimension(*)  mess,
integer  m,
integer  n,
real, dimension( * )  a,
integer  lda,
integer  ipre,
integer  ipost,
real  chkval 
)

Definition at line 1 of file pschekpad.f.

3*
4* -- ScaLAPACK tools routine (version 1.7) --
5* University of Tennessee, Knoxville, Oak Ridge National Laboratory,
6* and University of California, Berkeley.
7* May 1, 1997
8*
9* .. Scalar Arguments ..
10 INTEGER ICTXT, IPOST, IPRE, LDA, M, N
11 REAL CHKVAL
12* ..
13* .. Array Arguments ..
14 CHARACTER MESS*(*)
15 REAL A( * )
16* ..
17*
18* Purpose
19* =======
20*
21* PSCHEKPAD checks that the padding around a local array has not
22* been overwritten since the call to PSFILLPAD. 3 types of errors
23* are reported:
24*
25* 1) Overwrite in pre-guardzone. This indicates a memory overwrite has
26* occurred in the first IPRE elements which form a buffer before the
27* beginning of A. Therefore, the error message:
28* 'Overwrite in pre-guardzone: loc( 5) = 18.00000'
29* tells you that the 5th element of the IPRE long buffer has been
30* overwritten with the value 18, where it should still have the value
31* of CHKVAL.
32*
33* 2) Overwrite in post-guardzone. This indicates a memory overwrite has
34* occurred in the last IPOST elements which form a buffer after the end
35* of A. Error reports are refered from the end of A. Therefore,
36* 'Overwrite in post-guardzone: loc( 19) = 24.00000'
37* tells you that the 19th element after the end of A was overwritten
38* with the value 24, where it should still have the value of CHKVAL.
39*
40* 3) Overwrite in lda-m gap. Tells you elements between M and LDA were
41* overwritten. So,
42* 'Overwrite in lda-m gap: A( 12, 3) = 22.00000'
43* tells you that the element at the 12th row and 3rd column of A was
44* overwritten with the value of 22, where it should still have the
45* value of CHKVAL.
46*
47* Arguments
48* =========
49*
50* ICTXT (global input) INTEGER
51* The BLACS context handle, indicating the global context of
52* the operation. The context itself is global.
53*
54* MESS (local input) CHARACTER*(*)
55* String containing a user-defined message.
56*
57* M (local input) INTEGER
58* The number of rows in the local array A.
59*
60* N (input) INTEGER
61* The number of columns in the local array A.
62*
63* A (local input) REAL array of dimension (LDA,N).
64* A location IPRE elements in front of the array to be checked.
65*
66* LDA (local input) INTEGER
67* The leading Dimension of the local array to be checked.
68*
69* IPRE (local input) INTEGER
70* The size of the guard zone before the start of padded array.
71*
72* IPOST (local input) INTEGER
73* The size of guard zone after the padded array.
74*
75* CHKVAL (local input) REAL
76* The value the local array was padded with.
77*
78* =====================================================================
79*
80* .. Local Scalars ..
81 INTEGER I, IAM, IDUMM, INFO, J, K, MYCOL, MYROW,
82 $ NPCOL, NPROW
83* ..
84* .. External Subroutines ..
85 EXTERNAL blacs_gridinfo, igamx2d
86* ..
87* .. Executable Statements ..
88*
89* Get grid parameters
90*
91 CALL blacs_gridinfo( ictxt, nprow, npcol, myrow, mycol )
92 iam = myrow*npcol + mycol
93 info = -1
94*
95* Check buffer in front of A
96*
97 IF( ipre.GT.0 ) THEN
98 DO 10 i = 1, ipre
99 IF( a( i ).NE.chkval ) THEN
100 WRITE( *, fmt = 9998 ) myrow, mycol, mess, ' pre', i,
101 $ a( i )
102 info = iam
103 END IF
104 10 CONTINUE
105 ELSE
106 WRITE( *, fmt = * ) 'WARNING no pre-guardzone in PSCHEKPAD'
107 END IF
108*
109* Check buffer after A
110*
111 IF( ipost.GT.0 ) THEN
112 j = ipre+lda*n+1
113 DO 20 i = j, j+ipost-1
114 IF( a( i ).NE.chkval ) THEN
115 WRITE( *, fmt = 9998 ) myrow, mycol, mess, 'post',
116 $ i-j+1, a( i )
117 info = iam
118 END IF
119 20 CONTINUE
120 ELSE
121 WRITE( *, fmt = * )
122 $ 'WARNING no post-guardzone buffer in PSCHEKPAD'
123 END IF
124*
125* Check all (LDA-M) gaps
126*
127 IF( lda.GT.m ) THEN
128 k = ipre + m + 1
129 DO 40 j = 1, n
130 DO 30 i = k, k + (lda-m) - 1
131 IF( a( i ).NE.chkval ) THEN
132 WRITE( *, fmt = 9997 ) myrow, mycol, mess,
133 $ i-ipre-lda*(j-1), j, a( i )
134 info = iam
135 END IF
136 30 CONTINUE
137 k = k + lda
138 40 CONTINUE
139 END IF
140*
141 CALL igamx2d( ictxt, 'All', ' ', 1, 1, info, 1, idumm, idumm, -1,
142 $ 0, 0 )
143 IF( iam.EQ.0 .AND. info.GE.0 ) THEN
144 WRITE( *, fmt = 9999 ) info / npcol, mod( info, npcol ), mess
145 END IF
146*
147 9999 FORMAT( '{', i5, ',', i5, '}: Memory overwrite in ', a )
148 9998 FORMAT( '{', i5, ',', i5, '}: ', a, ' memory overwrite in ',
149 $ a4, '-guardzone: loc(', i3, ') = ', g11.4 )
150 9997 FORMAT( '{', i5, ',', i5, '}: ', a, ' memory overwrite in ',
151 $ 'lda-m gap: loc(', i3, ',', i3, ') = ', g11.4 )
152*
153 RETURN
154*
155* End of PSCHEKPAD
156*
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