SUBROUTINE PCUNMR2( SIDE, TRANS, M, N, K, A, IA, JA, DESCA, TAU, $ C, IC, JC, DESCC, WORK, LWORK, INFO ) * * -- ScaLAPACK routine (version 1.5) -- * University of Tennessee, Knoxville, Oak Ridge National Laboratory, * and University of California, Berkeley. * May 1, 1997 * * .. Scalar Arguments .. CHARACTER SIDE, TRANS INTEGER IA, IC, INFO, JA, JC, K, LWORK, M, N * .. * .. Array Arguments .. INTEGER DESCA( * ), DESCC( * ) COMPLEX A( * ), C( * ), TAU( * ), WORK( * ) * .. * * Purpose * ======= * * PCUNMR2 overwrites the general complex M-by-N distributed matrix * sub( C ) = C(IC:IC+M-1,JC:JC+N-1) with * * SIDE = 'L' SIDE = 'R' * TRANS = 'N': Q * sub( C ) sub( C ) * Q * TRANS = 'C': Q**H * sub( C ) sub( C ) * Q**H * * where Q is a complex unitary distributed matrix defined as the * product of K elementary reflectors * * Q = H(1)' H(2)' . . . H(k)' * * as returned by PCGERQF. Q is of order M if SIDE = 'L' and of order N * if SIDE = 'R'. * * Notes * ===== * * Each global data object is described by an associated description * vector. This vector stores the information required to establish * the mapping between an object element and its corresponding process * and memory location. * * Let A be a generic term for any 2D block cyclicly distributed array. * Such a global array has an associated description vector DESCA. * In the following comments, the character _ should be read as * "of the global array". * * NOTATION STORED IN EXPLANATION * --------------- -------------- -------------------------------------- * DTYPE_A(global) DESCA( DTYPE_ )The descriptor type. In this case, * DTYPE_A = 1. * CTXT_A (global) DESCA( CTXT_ ) The BLACS context handle, indicating * the BLACS process grid A is distribu- * ted over. The context itself is glo- * bal, but the handle (the integer * value) may vary. * M_A (global) DESCA( M_ ) The number of rows in the global * array A. * N_A (global) DESCA( N_ ) The number of columns in the global * array A. * MB_A (global) DESCA( MB_ ) The blocking factor used to distribute * the rows of the array. * NB_A (global) DESCA( NB_ ) The blocking factor used to distribute * the columns of the array. * RSRC_A (global) DESCA( RSRC_ ) The process row over which the first * row of the array A is distributed. * CSRC_A (global) DESCA( CSRC_ ) The process column over which the * first column of the array A is * distributed. * LLD_A (local) DESCA( LLD_ ) The leading dimension of the local * array. LLD_A >= MAX(1,LOCr(M_A)). * * Let K be the number of rows or columns of a distributed matrix, * and assume that its process grid has dimension p x q. * LOCr( K ) denotes the number of elements of K that a process * would receive if K were distributed over the p processes of its * process column. * Similarly, LOCc( K ) denotes the number of elements of K that a * process would receive if K were distributed over the q processes of * its process row. * The values of LOCr() and LOCc() may be determined via a call to the * ScaLAPACK tool function, NUMROC: * LOCr( M ) = NUMROC( M, MB_A, MYROW, RSRC_A, NPROW ), * LOCc( N ) = NUMROC( N, NB_A, MYCOL, CSRC_A, NPCOL ). * An upper bound for these quantities may be computed by: * LOCr( M ) <= ceil( ceil(M/MB_A)/NPROW )*MB_A * LOCc( N ) <= ceil( ceil(N/NB_A)/NPCOL )*NB_A * * Arguments * ========= * * SIDE (global input) CHARACTER * = 'L': apply Q or Q**H from the Left; * = 'R': apply Q or Q**H from the Right. * * TRANS (global input) CHARACTER * = 'N': No transpose, apply Q; * = 'C': Conjugate transpose, apply Q**H. * * M (global input) INTEGER * The number of rows to be operated on i.e the number of rows * of the distributed submatrix sub( C ). M >= 0. * * N (global input) INTEGER * The number of columns to be operated on i.e the number of * columns of the distributed submatrix sub( C ). N >= 0. * * K (global input) INTEGER * The number of elementary reflectors whose product defines the * matrix Q. If SIDE = 'L', M >= K >= 0, if SIDE = 'R', * N >= K >= 0. * * A (local input) COMPLEX pointer into the local memory * to an array of dimension (LLD_A,LOCc(JA+M-1)) if SIDE='L', * and (LLD_A,LOCc(JA+N-1)) if SIDE='R', where * LLD_A >= MAX(1,LOCr(IA+K-1)); On entry, the i-th row must * contain the vector which defines the elementary reflector * H(i), IA <= i <= IA+K-1, as returned by PCGERQF in the * K rows of its distributed matrix argument A(IA:IA+K-1,JA:*). * A(IA:IA+K-1,JA:*) is modified by the routine but restored on * exit. * * IA (global input) INTEGER * The row index in the global array A indicating the first * row of sub( A ). * * JA (global input) INTEGER * The column index in the global array A indicating the * first column of sub( A ). * * DESCA (global and local input) INTEGER array of dimension DLEN_. * The array descriptor for the distributed matrix A. * * TAU (local input) COMPLEX, array, dimension LOCc(IA+K-1). * This array contains the scalar factors TAU(i) of the * elementary reflectors H(i) as returned by PCGERQF. * TAU is tied to the distributed matrix A. * * C (local input/local output) COMPLEX pointer into the * local memory to an array of dimension (LLD_C,LOCc(JC+N-1)). * On entry, the local pieces of the distributed matrix sub(C). * On exit, sub( C ) is overwritten by Q*sub( C ) or Q'*sub( C ) * or sub( C )*Q' or sub( C )*Q. * * IC (global input) INTEGER * The row index in the global array C indicating the first * row of sub( C ). * * JC (global input) INTEGER * The column index in the global array C indicating the * first column of sub( C ). * * DESCC (global and local input) INTEGER array of dimension DLEN_. * The array descriptor for the distributed matrix C. * * WORK (local workspace/local output) COMPLEX array, * dimension (LWORK) * On exit, WORK(1) returns the minimal and optimal LWORK. * * LWORK (local or global input) INTEGER * The dimension of the array WORK. * LWORK is local input and must be at least * If SIDE = 'L', LWORK >= MpC0 + MAX( MAX( 1, NqC0 ), NUMROC( * NUMROC( M+IROFFC,MB_A,0,0,NPROW ),MB_A,0,0,LCMP ) ); * if SIDE = 'R', LWORK >= NqC0 + MAX( 1, MpC0 ); * * where LCMP = LCM / NPROW with LCM = ICLM( NPROW, NPCOL ), * * IROFFC = MOD( IC-1, MB_C ), ICOFFC = MOD( JC-1, NB_C ), * ICROW = INDXG2P( IC, MB_C, MYROW, RSRC_C, NPROW ), * ICCOL = INDXG2P( JC, NB_C, MYCOL, CSRC_C, NPCOL ), * MpC0 = NUMROC( M+IROFFC, MB_C, MYROW, ICROW, NPROW ), * NqC0 = NUMROC( N+ICOFFC, NB_C, MYCOL, ICCOL, NPCOL ), * * ILCM, INDXG2P and NUMROC are ScaLAPACK tool functions; * MYROW, MYCOL, NPROW and NPCOL can be determined by calling * the subroutine BLACS_GRIDINFO. * * If LWORK = -1, then LWORK is global input and a workspace * query is assumed; the routine only calculates the minimum * and optimal size for all work arrays. Each of these * values is returned in the first entry of the corresponding * work array, and no error message is issued by PXERBLA. * * * INFO (local output) INTEGER * = 0: successful exit * < 0: If the i-th argument is an array and the j-entry had * an illegal value, then INFO = -(i*100+j), if the i-th * argument is a scalar and had an illegal value, then * INFO = -i. * * Alignment requirements * ====================== * * The distributed submatrices A(IA:*, JA:*) and C(IC:IC+M-1,JC:JC+N-1) * must verify some alignment properties, namely the following * expressions should be true: * * If SIDE = 'L', * ( NB_A.EQ.MB_C .AND. ICOFFA.EQ.IROFFC ) * If SIDE = 'R', * ( NB_A.EQ.NB_C .AND. ICOFFA.EQ.ICOFFC .AND. IACOL.EQ.ICCOL ) * * ===================================================================== * * .. Parameters .. INTEGER BLOCK_CYCLIC_2D, CSRC_, CTXT_, DLEN_, DTYPE_, $ LLD_, MB_, M_, NB_, N_, RSRC_ PARAMETER ( BLOCK_CYCLIC_2D = 1, DLEN_ = 9, DTYPE_ = 1, $ CTXT_ = 2, M_ = 3, N_ = 4, MB_ = 5, NB_ = 6, $ RSRC_ = 7, CSRC_ = 8, LLD_ = 9 ) COMPLEX ONE PARAMETER ( ONE = ( 1.0E+0, 0.0E+0 ) ) * .. * .. Local Scalars .. LOGICAL LEFT, LQUERY, NOTRAN CHARACTER COLBTOP, ROWBTOP INTEGER I, I1, I2, I3, IACOL, ICCOL, ICOFFA, ICOFFC, $ ICROW, ICTXT, IROFFC, LCM, LCMP, LWMIN, MI, $ MPC0, MYCOL, MYROW, NI, NPCOL, NPROW, NQ, NQC0 COMPLEX AII * .. * .. External Subroutines .. EXTERNAL BLACS_ABORT, BLACS_GRIDINFO, CHK1MAT, PCELSET, $ PCELSET2, PCLACGV, PCLARF, PCLARFC, $ PTOPGET, PTOPSET, PXERBLA * .. * .. External Functions .. LOGICAL LSAME INTEGER ILCM, INDXG2P, NUMROC EXTERNAL ILCM, INDXG2P, LSAME, NUMROC * .. * .. Intrinsic Functions .. INTRINSIC CMPLX, MAX, MOD, REAL * .. * .. Executable Statements .. * * Get grid parameters * ICTXT = DESCA( CTXT_ ) CALL BLACS_GRIDINFO( ICTXT, NPROW, NPCOL, MYROW, MYCOL ) * * Test the input parameters * INFO = 0 IF( NPROW.EQ.-1 ) THEN INFO = -(900+CTXT_) ELSE LEFT = LSAME( SIDE, 'L' ) NOTRAN = LSAME( TRANS, 'N' ) * * NQ is the order of Q * IF( LEFT ) THEN NQ = M CALL CHK1MAT( K, 5, M, 3, IA, JA, DESCA, 9, INFO ) ELSE NQ = N CALL CHK1MAT( K, 5, N, 4, IA, JA, DESCA, 9, INFO ) END IF CALL CHK1MAT( M, 3, N, 4, IC, JC, DESCC, 14, INFO ) IF( INFO.EQ.0 ) THEN ICOFFA = MOD( JA-1, DESCA( NB_ ) ) IROFFC = MOD( IC-1, DESCC( MB_ ) ) ICOFFC = MOD( JC-1, DESCC( NB_ ) ) IACOL = INDXG2P( JA, DESCA( NB_ ), MYCOL, DESCA( CSRC_ ), $ NPCOL ) ICROW = INDXG2P( IC, DESCC( MB_ ), MYROW, DESCC( RSRC_ ), $ NPROW ) ICCOL = INDXG2P( JC, DESCC( NB_ ), MYCOL, DESCC( CSRC_ ), $ NPCOL ) MPC0 = NUMROC( M+IROFFC, DESCC( MB_ ), MYROW, ICROW, NPROW ) NQC0 = NUMROC( N+ICOFFC, DESCC( NB_ ), MYCOL, ICCOL, NPCOL ) * IF( LEFT ) THEN LCM = ILCM( NPROW, NPCOL ) LCMP = LCM / NPROW LWMIN = MPC0 + MAX( MAX( 1, NQC0 ), NUMROC( NUMROC( $ M+IROFFC, DESCA( MB_ ), 0, 0, NPROW ), $ DESCA( MB_ ), 0, 0, LCMP ) ) ELSE LWMIN = NQC0 + MAX( 1, MPC0 ) END IF * WORK( 1 ) = CMPLX( REAL( LWMIN ) ) LQUERY = ( LWORK.EQ.-1 ) IF( .NOT.LEFT .AND. .NOT.LSAME( SIDE, 'R' ) ) THEN INFO = -1 ELSE IF( .NOT.NOTRAN .AND. .NOT.LSAME( TRANS, 'C' ) ) THEN INFO = -2 ELSE IF( K.LT.0 .OR. K.GT.NQ ) THEN INFO = -5 ELSE IF( LEFT .AND. DESCA( NB_ ).NE.DESCC( MB_ ) ) THEN INFO = -(900+NB_) ELSE IF( LEFT .AND. ICOFFA.NE.IROFFC ) THEN INFO = -12 ELSE IF( .NOT.LEFT .AND. ICOFFA.NE.ICOFFC ) THEN INFO = -13 ELSE IF( .NOT.LEFT .AND. IACOL.NE.ICCOL ) THEN INFO = -13 ELSE IF( .NOT.LEFT .AND. DESCA( NB_ ).NE.DESCC( NB_ ) ) THEN INFO = -(1400+NB_) ELSE IF( ICTXT.NE.DESCC( CTXT_ ) ) THEN INFO = -(1400+CTXT_) ELSE IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN INFO = -16 END IF END IF END IF * IF( INFO.NE.0 ) THEN CALL PXERBLA( ICTXT, 'PCUNMR2', -INFO ) CALL BLACS_ABORT( ICTXT, 1 ) RETURN ELSE IF( LQUERY ) THEN RETURN END IF * * Quick return if possible * IF( M.EQ.0 .OR. N.EQ.0 .OR. K.EQ.0 ) $ RETURN * CALL PTOPGET( ICTXT, 'Broadcast', 'Rowwise', ROWBTOP ) CALL PTOPGET( ICTXT, 'Broadcast', 'Columnwise', COLBTOP ) * IF( ( LEFT .AND. .NOT.NOTRAN .OR. .NOT.LEFT .AND. NOTRAN ) ) THEN I1 = IA I2 = IA + K - 1 I3 = 1 ELSE I1 = IA + K - 1 I2 = IA I3 = -1 END IF * IF( LEFT ) THEN NI = N ELSE MI = M CALL PTOPSET( ICTXT, 'Broadcast', 'Rowwise', ' ' ) IF( NOTRAN ) THEN CALL PTOPSET( ICTXT, 'Broadcast', 'Columnwise', 'I-ring' ) ELSE CALL PTOPSET( ICTXT, 'Broadcast', 'Columnwise', 'D-ring' ) END IF END IF * DO 10 I = I1, I2, I3 IF( LEFT ) THEN * * H(i) or H(i)' is applied to C(ic:ic+m-k+i-ia,jc:jc+n-1) * MI = M - K + I - IA + 1 ELSE * * H(i) or H(i)' is applied to C(ic:ic+m-1,jc:jc+n-k+i-ia+1) * NI = N - K + I - IA + 1 END IF * * Apply H(i) or H(i)' * CALL PCLACGV( NQ-K+I-IA, A, I, JA, DESCA, DESCA( M_ ) ) CALL PCELSET2( AII, A, I, JA+NQ-K+I-IA, DESCA, ONE ) IF( NOTRAN ) THEN CALL PCLARFC( SIDE, MI, NI, A, I, JA, DESCA, DESCA( M_ ), $ TAU, C, IC, JC, DESCC, WORK ) ELSE CALL PCLARF( SIDE, MI, NI, A, I, JA, DESCA, DESCA( M_ ), $ TAU, C, IC, JC, DESCC, WORK ) END IF CALL PCELSET( A, I, JA+NQ-K+I-IA, DESCA, AII ) CALL PCLACGV( NQ-K+I-IA, A, I, JA, DESCA, DESCA( M_ ) ) * 10 CONTINUE * CALL PTOPSET( ICTXT, 'Broadcast', 'Rowwise', ROWBTOP ) CALL PTOPSET( ICTXT, 'Broadcast', 'Columnwise', COLBTOP ) * WORK( 1 ) = CMPLX( REAL( LWMIN ) ) * RETURN * * End of PCUNMR2 * END