SUBROUTINE PDLARZ( SIDE, M, N, L, V, IV, JV, DESCV, INCV, TAU, C, $ IC, JC, DESCC, WORK ) * * -- ScaLAPACK auxiliary routine (version 1.5) -- * University of Tennessee, Knoxville, Oak Ridge National Laboratory, * and University of California, Berkeley. * May 1, 1997 * * .. Scalar Arguments .. CHARACTER SIDE INTEGER IC, INCV, IV, JC, JV, L, M, N * .. * .. Array Arguments .. INTEGER DESCC( * ), DESCV( * ) DOUBLE PRECISION C( * ), TAU( * ), V( * ), WORK( * ) * .. * * Purpose * ======= * * PDLARZ applies a real elementary reflector Q (or Q**T) to a real * M-by-N distributed matrix sub( C ) = C(IC:IC+M-1,JC:JC+N-1), from * either the left or the right. Q is represented in the form * * Q = I - tau * v * v' * * where tau is a real scalar and v is a real vector. * * If tau = 0, then Q is taken to be the unit matrix. * * Q is a product of k elementary reflectors as returned by PDTZRZF. * * 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 * * Because vectors may be viewed as a subclass of matrices, a * distributed vector is considered to be a distributed matrix. * * Restrictions * ============ * * If SIDE = 'Left' and INCV = 1, then the row process having the first * entry V(IV,JV) must also own C(IC+M-L,JC:JC+N-1). Moreover, * MOD(IV-1,MB_V) must be equal to MOD(IC+N-L-1,MB_C), if INCV=M_V, only * the last equality must be satisfied. * * If SIDE = 'Right' and INCV = M_V then the column process having the * first entry V(IV,JV) must also own C(IC:IC+M-1,JC+N-L) and * MOD(JV-1,NB_V) must be equal to MOD(JC+N-L-1,NB_C), if INCV = 1 only * the last equality must be satisfied. * * Arguments * ========= * * SIDE (global input) CHARACTER * = 'L': form Q * sub( C ), * = 'R': form sub( C ) * Q, Q = Q**T. * * 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. * * L (global input) INTEGER * The columns of the distributed submatrix sub( A ) containing * the meaningful part of the Householder reflectors. * If SIDE = 'L', M >= L >= 0, if SIDE = 'R', N >= L >= 0. * * V (local input) DOUBLE PRECISION pointer into the local memory * to an array of dimension (LLD_V,*) containing the local * pieces of the distributed vectors V representing the * Householder transformation Q, * V(IV:IV+L-1,JV) if SIDE = 'L' and INCV = 1, * V(IV,JV:JV+L-1) if SIDE = 'L' and INCV = M_V, * V(IV:IV+L-1,JV) if SIDE = 'R' and INCV = 1, * V(IV,JV:JV+L-1) if SIDE = 'R' and INCV = M_V, * * The vector v in the representation of Q. V is not used if * TAU = 0. * * IV (global input) INTEGER * The row index in the global array V indicating the first * row of sub( V ). * * JV (global input) INTEGER * The column index in the global array V indicating the * first column of sub( V ). * * DESCV (global and local input) INTEGER array of dimension DLEN_. * The array descriptor for the distributed matrix V. * * INCV (global input) INTEGER * The global increment for the elements of V. Only two values * of INCV are supported in this version, namely 1 and M_V. * INCV must not be zero. * * TAU (local input) DOUBLE PRECISION, array, dimension LOCc(JV) if * INCV = 1, and LOCr(IV) otherwise. This array contains the * Householder scalars related to the Householder vectors. * TAU is tied to the distributed matrix V. * * C (local input/local output) DOUBLE PRECISION pointer into the * local memory to an array of dimension (LLD_C, LOCc(JC+N-1) ), * containing the local pieces of sub( C ). On exit, sub( C ) * is overwritten by the Q * sub( C ) if SIDE = 'L', or * sub( C ) * Q if SIDE = 'R'. * * 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) DOUBLE PRECISION array, dimension (LWORK) * If INCV = 1, * if SIDE = 'L', * if IVCOL = ICCOL, * LWORK >= NqC0 * else * LWORK >= MpC0 + MAX( 1, NqC0 ) * end if * else if SIDE = 'R', * LWORK >= NqC0 + MAX( MAX( 1, MpC0 ), NUMROC( NUMROC( * N+ICOFFC,NB_V,0,0,NPCOL ),NB_V,0,0,LCMQ ) ) * end if * else if INCV = M_V, * if SIDE = 'L', * LWORK >= MpC0 + MAX( MAX( 1, NqC0 ), NUMROC( NUMROC( * M+IROFFC,MB_V,0,0,NPROW ),MB_V,0,0,LCMP ) ) * else if SIDE = 'R', * if IVROW = ICROW, * LWORK >= MpC0 * else * LWORK >= NqC0 + MAX( 1, MpC0 ) * end if * end if * end if * * where LCM is the least common multiple of NPROW and NPCOL and * LCM = ILCM( NPROW, NPCOL ), LCMP = LCM / NPROW, * LCMQ = LCM / 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. * * Alignment requirements * ====================== * * The distributed submatrices V(IV:*, JV:*) and C(IC:IC+M-1,JC:JC+N-1) * must verify some alignment properties, namely the following * expressions should be true: * * MB_V = NB_V, * * If INCV = 1, * If SIDE = 'Left', * ( MB_V.EQ.MB_C .AND. IROFFV.EQ.IROFFC .AND. IVROW.EQ.ICROW ) * If SIDE = 'Right', * ( MB_V.EQ.NB_A .AND. MB_V.EQ.NB_C .AND. IROFFV.EQ.ICOFFC ) * else if INCV = M_V, * If SIDE = 'Left', * ( MB_V.EQ.NB_V .AND. MB_V.EQ.MB_C .AND. ICOFFV.EQ.IROFFC ) * If SIDE = 'Right', * ( NB_V.EQ.NB_C .AND. ICOFFV.EQ.ICOFFC .AND. IVCOL.EQ.ICCOL ) * end if * * ===================================================================== * * .. 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 ) DOUBLE PRECISION ONE, ZERO PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 ) * .. * .. Local Scalars .. LOGICAL CCBLCK, CRBLCK, LEFT CHARACTER COLBTOP, ROWBTOP INTEGER ICCOL1, ICCOL2, ICOFFC1, ICOFFC2, ICOFFV, $ ICROW1, ICROW2, ICTXT, IIC1, IIC2, IIV, IOFFC1, $ IOFFC2, IOFFV, IPW, IROFFC1, IROFFC2, IROFFV, $ IVCOL, IVROW, JJC1, JJC2, JJV, LDC, LDV, MPC2, $ MPV, MYCOL, MYROW, NCC, NCV, NPCOL, NPROW, $ NQC2, NQV, RDEST DOUBLE PRECISION TAULOC * .. * .. External Subroutines .. EXTERNAL BLACS_GRIDINFO, DAXPY, DCOPY, DGEBR2D, $ DGEBS2D, DGEMV, DGER, DGERV2D, $ DGESD2D, DGSUM2D, DLASET, INFOG2L, $ PTOPGET, PBDTRNV * .. * .. External Functions .. LOGICAL LSAME INTEGER NUMROC EXTERNAL LSAME, NUMROC * .. * .. Intrinsic Functions .. INTRINSIC MIN, MOD * .. * .. Executable Statements .. * * Quick return if possible * IF( M.LE.0 .OR. N.LE.0 ) $ RETURN * * Get grid parameters. * ICTXT = DESCC( CTXT_ ) CALL BLACS_GRIDINFO( ICTXT, NPROW, NPCOL, MYROW, MYCOL ) * * Figure local indexes * LEFT = LSAME( SIDE, 'L' ) CALL INFOG2L( IV, JV, DESCV, NPROW, NPCOL, MYROW, MYCOL, IIV, JJV, $ IVROW, IVCOL ) IROFFV = MOD( IV-1, DESCV( NB_ ) ) MPV = NUMROC( L+IROFFV, DESCV( MB_ ), MYROW, IVROW, NPROW ) IF( MYROW.EQ.IVROW ) $ MPV = MPV - IROFFV ICOFFV = MOD( JV-1, DESCV( NB_ ) ) NQV = NUMROC( L+ICOFFV, DESCV( NB_ ), MYCOL, IVCOL, NPCOL ) IF( MYCOL.EQ.IVCOL ) $ NQV = NQV - ICOFFV LDV = DESCV( LLD_ ) NCV = NUMROC( DESCV( N_ ), DESCV( NB_ ), MYCOL, DESCV( CSRC_ ), $ NPCOL ) LDV = DESCV( LLD_ ) IIV = MIN( IIV, LDV ) JJV = MIN( JJV, NCV ) IOFFV = IIV+(JJV-1)*LDV NCC = NUMROC( DESCC( N_ ), DESCC( NB_ ), MYCOL, DESCC( CSRC_ ), $ NPCOL ) CALL INFOG2L( IC, JC, DESCC, NPROW, NPCOL, MYROW, MYCOL, $ IIC1, JJC1, ICROW1, ICCOL1 ) IROFFC1 = MOD( IC-1, DESCC( MB_ ) ) ICOFFC1 = MOD( JC-1, DESCC( NB_ ) ) LDC = DESCC( LLD_ ) IIC1 = MIN( IIC1, LDC ) JJC1 = MIN( JJC1, MAX( 1, NCC ) ) IOFFC1 = IIC1 + ( JJC1-1 ) * LDC * IF( LEFT ) THEN CALL INFOG2L( IC+M-L, JC, DESCC, NPROW, NPCOL, MYROW, MYCOL, $ IIC2, JJC2, ICROW2, ICCOL2 ) IROFFC2 = MOD( IC+M-L-1, DESCC( MB_ ) ) ICOFFC2 = MOD( JC-1, DESCC( NB_ ) ) NQC2 = NUMROC( N+ICOFFC2, DESCC( NB_ ), MYCOL, ICCOL2, NPCOL ) IF( MYCOL.EQ.ICCOL2 ) $ NQC2 = NQC2 - ICOFFC2 ELSE CALL INFOG2L( IC, JC+N-L, DESCC, NPROW, NPCOL, MYROW, MYCOL, $ IIC2, JJC2, ICROW2, ICCOL2 ) IROFFC2 = MOD( IC-1, DESCC( MB_ ) ) MPC2 = NUMROC( M+IROFFC2, DESCC( MB_ ), MYROW, ICROW2, NPROW ) IF( MYROW.EQ.ICROW2 ) $ MPC2 = MPC2 - IROFFC2 ICOFFC2 = MOD( JC+N-L-1, DESCC( NB_ ) ) END IF IIC2 = MIN( IIC2, LDC ) JJC2 = MIN( JJC2, NCC ) IOFFC2 = IIC2 + ( JJC2-1 ) * LDC * * Is sub( C ) only distributed over a process row ? * CRBLCK = ( M.LE.(DESCC( MB_ )-IROFFC1) ) * * Is sub( C ) only distributed over a process column ? * CCBLCK = ( N.LE.(DESCC( NB_ )-ICOFFC1) ) * IF( LEFT ) THEN * IF( CRBLCK ) THEN RDEST = ICROW2 ELSE RDEST = -1 END IF * IF( CCBLCK ) THEN * * sub( C ) is distributed over a process column * IF( DESCV( M_ ).EQ.INCV ) THEN * * Transpose row vector V (ICOFFV = IROFFC2) * IPW = MPV+1 CALL PBDTRNV( ICTXT, 'Rowwise', 'Transpose', M, $ DESCV( NB_ ), IROFFC2, V( IOFFV ), LDV, $ ZERO, $ WORK, 1, IVROW, IVCOL, ICROW2, ICCOL2, $ WORK( IPW ) ) * * Perform the local computation within a process column * IF( MYCOL.EQ.ICCOL2 ) THEN * IF( MYROW.EQ.IVROW ) THEN * CALL DGEBS2D( ICTXT, 'Columnwise', ' ', 1, 1, $ TAU( IIV ), 1 ) TAULOC = TAU( IIV ) * ELSE * CALL DGEBR2D( ICTXT, 'Columnwise', ' ', 1, 1, $ TAULOC, 1, IVROW, MYCOL ) * END IF * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C )' * v * IF( MPV.GT.0 ) THEN CALL DGEMV( 'Transpose', MPV, NQC2, ONE, $ C( IOFFC2 ), LDC, WORK, 1, ZERO, $ WORK( IPW ), 1 ) ELSE CALL DLASET( 'All', NQC2, 1, ZERO, ZERO, $ WORK( IPW ), MAX( 1, NQC2 ) ) END IF IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, ONE, C( IOFFC1 ), LDC, $ WORK( IPW ), MAX( 1, NQC2 ) ) * CALL DGSUM2D( ICTXT, 'Columnwise', ' ', NQC2, 1, $ WORK( IPW ), MAX( 1, NQC2 ), RDEST, $ MYCOL ) * * sub( C ) := sub( C ) - v * w' * IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, -TAULOC, WORK( IPW ), $ MAX( 1, NQC2 ), C( IOFFC1 ), LDC ) CALL DGER( MPV, NQC2, -TAULOC, WORK, 1, $ WORK( IPW ), 1, C( IOFFC2 ), LDC ) END IF * END IF * ELSE * * V is a column vector * IF( IVCOL.EQ.ICCOL2 ) THEN * * Perform the local computation within a process column * IF( MYCOL.EQ.ICCOL2 ) THEN * TAULOC = TAU( JJV ) * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C )' * v * IF( MPV.GT.0 ) THEN CALL DGEMV( 'Transpose', MPV, NQC2, ONE, $ C( IOFFC2 ), LDC, V( IOFFV ), 1, $ ZERO, WORK, 1 ) ELSE CALL DLASET( 'All', NQC2, 1, ZERO, ZERO, $ WORK, MAX( 1, NQC2 ) ) END IF IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, ONE, C( IOFFC1 ), LDC, $ WORK, MAX( 1, NQC2 ) ) * CALL DGSUM2D( ICTXT, 'Columnwise', ' ', NQC2, 1, $ WORK, MAX( 1, NQC2 ), RDEST, $ MYCOL ) * * sub( C ) := sub( C ) - v * w' * IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, -TAULOC, WORK, $ MAX( 1, NQC2 ), C( IOFFC1 ), $ LDC ) CALL DGER( MPV, NQC2, -TAULOC, V( IOFFV ), 1, $ WORK, 1, C( IOFFC2 ), LDC ) END IF * END IF * ELSE * * Send V and TAU to the process column ICCOL2 * IF( MYCOL.EQ.IVCOL ) THEN * IPW = MPV+1 CALL DCOPY( MPV, V( IOFFV ), 1, WORK, 1 ) WORK( IPW ) = TAU( JJV ) CALL DGESD2D( ICTXT, IPW, 1, WORK, IPW, MYROW, $ ICCOL2 ) * ELSE IF( MYCOL.EQ.ICCOL2 ) THEN * IPW = MPV+1 CALL DGERV2D( ICTXT, IPW, 1, WORK, IPW, MYROW, $ IVCOL ) TAULOC = WORK( IPW ) * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C )' * v * IF( MPV.GT.0 ) THEN CALL DGEMV( 'Transpose', MPV, NQC2, ONE, $ C( IOFFC2 ), LDC, WORK, 1, ZERO, $ WORK( IPW ), 1 ) ELSE CALL DLASET( 'All', NQC2, 1, ZERO, ZERO, $ WORK( IPW ), MAX( 1, NQC2 ) ) END IF IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, ONE, C( IOFFC1 ), LDC, $ WORK( IPW ), MAX( 1, NQC2 ) ) * CALL DGSUM2D( ICTXT, 'Columnwise', ' ', NQC2, 1, $ WORK( IPW ), MAX( 1, NQC2 ), $ RDEST, MYCOL ) * * sub( C ) := sub( C ) - v * w' * IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, -TAULOC, WORK( IPW ), $ MAX( 1, NQC2 ), C( IOFFC1 ), $ LDC ) CALL DGER( MPV, NQC2, -TAULOC, WORK, 1, $ WORK( IPW ), 1, C( IOFFC2 ), LDC ) END IF * END IF * END IF * END IF * ELSE * * sub( C ) is a proper distributed matrix * IF( DESCV( M_ ).EQ.INCV ) THEN * * Transpose and broadcast row vector V (ICOFFV=IROFFC2) * IPW = MPV+1 CALL PBDTRNV( ICTXT, 'Rowwise', 'Transpose', M, $ DESCV( NB_ ), IROFFC2, V( IOFFV ), LDV, $ ZERO, $ WORK, 1, IVROW, IVCOL, ICROW2, -1, $ WORK( IPW ) ) * * Perform the local computation within a process column * IF( MYROW.EQ.IVROW ) THEN * CALL DGEBS2D( ICTXT, 'Columnwise', ' ', 1, 1, $ TAU( IIV ), 1 ) TAULOC = TAU( IIV ) * ELSE * CALL DGEBR2D( ICTXT, 'Columnwise', ' ', 1, 1, TAULOC, $ 1, IVROW, MYCOL ) * END IF * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C )' * v * IF( MPV.GT.0 ) THEN CALL DGEMV( 'Transpose', MPV, NQC2, ONE, $ C( IOFFC2 ), LDC, WORK, 1, ZERO, $ WORK( IPW ), 1 ) ELSE CALL DLASET( 'All', NQC2, 1, ZERO, ZERO, $ WORK( IPW ), MAX( 1, NQC2 ) ) END IF IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, ONE, C( IOFFC1 ), LDC, $ WORK( IPW ), MAX( 1, NQC2 ) ) * CALL DGSUM2D( ICTXT, 'Columnwise', ' ', NQC2, 1, $ WORK( IPW ), MAX( 1, NQC2 ), RDEST, $ MYCOL ) * * sub( C ) := sub( C ) - v * w' * IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, -TAULOC, WORK( IPW ), $ MAX( 1, NQC2 ), C( IOFFC1 ), LDC ) CALL DGER( MPV, NQC2, -TAULOC, WORK, 1, WORK( IPW ), $ 1, C( IOFFC2 ), LDC ) END IF * ELSE * * Broadcast column vector V * CALL PTOPGET( ICTXT, 'Broadcast', 'Rowwise', ROWBTOP ) IF( MYCOL.EQ.IVCOL ) THEN * IPW = MPV+1 CALL DCOPY( MPV, V( IOFFV ), 1, WORK, 1 ) WORK( IPW ) = TAU( JJV ) CALL DGEBS2D( ICTXT, 'Rowwise', ROWBTOP, IPW, 1, $ WORK, IPW ) TAULOC = TAU( JJV ) * ELSE * IPW = MPV+1 CALL DGEBR2D( ICTXT, 'Rowwise', ROWBTOP, IPW, 1, WORK, $ IPW, MYROW, IVCOL ) TAULOC = WORK( IPW ) * END IF * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C )' * v * IF( MPV.GT.0 ) THEN CALL DGEMV( 'Transpose', MPV, NQC2, ONE, $ C( IOFFC2 ), LDC, WORK, 1, ZERO, $ WORK( IPW ), 1 ) ELSE CALL DLASET( 'All', NQC2, 1, ZERO, ZERO, $ WORK( IPW ), MAX( 1, NQC2 ) ) END IF IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, ONE, C( IOFFC1 ), LDC, $ WORK( IPW ), MAX( 1, NQC2 ) ) * CALL DGSUM2D( ICTXT, 'Columnwise', ' ', NQC2, 1, $ WORK( IPW ), MAX( 1, NQC2 ), RDEST, $ MYCOL ) * * sub( C ) := sub( C ) - v * w' * IF( MYROW.EQ.ICROW1 ) $ CALL DAXPY( NQC2, -TAULOC, WORK( IPW ), $ MAX( 1, NQC2 ), C( IOFFC1 ), LDC ) CALL DGER( MPV, NQC2, -TAULOC, WORK, 1, WORK( IPW ), $ 1, C( IOFFC2 ), LDC ) END IF * END IF * END IF * ELSE * IF( CCBLCK ) THEN RDEST = MYROW ELSE RDEST = -1 END IF * IF( CRBLCK ) THEN * * sub( C ) is distributed over a process row * IF( DESCV( M_ ).EQ.INCV ) THEN * * V is a row vector * IF( IVROW.EQ.ICROW2 ) THEN * * Perform the local computation within a process row * IF( MYROW.EQ.ICROW2 ) THEN * TAULOC = TAU( IIV ) * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C ) * v * IF( NQV.GT.0 ) THEN CALL DGEMV( 'No transpose', MPC2, NQV, ONE, $ C( IOFFC2 ), LDC, V( IOFFV ), $ LDV, ZERO, WORK, 1 ) ELSE CALL DLASET( 'All', MPC2, 1, ZERO, ZERO, $ WORK, MAX( 1, MPC2 ) ) END IF IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, ONE, C( IOFFC1 ), 1, $ WORK, 1 ) * CALL DGSUM2D( ICTXT, 'Rowwise', ' ', MPC2, 1, $ WORK, MAX( 1, MPC2 ), RDEST, $ ICCOL2 ) * IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, -TAULOC, WORK, 1, $ C( IOFFC1 ), 1 ) * * sub( C ) := sub( C ) - w * v' * CALL DGER( MPC2, NQV, -TAULOC, WORK, 1, $ V( IOFFV ), LDV, C( IOFFC2 ), LDC ) END IF * END IF * ELSE * * Send V and TAU to the process row ICROW2 * IF( MYROW.EQ.IVROW ) THEN * IPW = NQV+1 CALL DCOPY( NQV, V( IOFFV ), LDV, WORK, 1 ) WORK( IPW ) = TAU( IIV ) CALL DGESD2D( ICTXT, IPW, 1, WORK, IPW, ICROW2, $ MYCOL ) * ELSE IF( MYROW.EQ.ICROW2 ) THEN * IPW = NQV+1 CALL DGERV2D( ICTXT, IPW, 1, WORK, IPW, IVROW, $ MYCOL ) TAULOC = WORK( IPW ) * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C ) * v * IF( NQV.GT.0 ) THEN CALL DGEMV( 'No transpose', MPC2, NQV, ONE, $ C( IOFFC2 ), LDC, WORK, 1, ZERO, $ WORK( IPW ), 1 ) ELSE CALL DLASET( 'All', MPC2, 1, ZERO, ZERO, $ WORK( IPW ), MAX( 1, MPC2 ) ) END IF IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, ONE, C( IOFFC1 ), 1, $ WORK( IPW ), 1 ) CALL DGSUM2D( ICTXT, 'Rowwise', ' ', MPC2, 1, $ WORK( IPW ), MAX( 1, MPC2 ), $ RDEST, ICCOL2 ) IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, -TAULOC, WORK( IPW ), 1, $ C( IOFFC1 ), 1 ) * * sub( C ) := sub( C ) - w * v' * CALL DGER( MPC2, NQV, -TAULOC, WORK( IPW ), 1, $ WORK, 1, C( IOFFC2 ), LDC ) END IF * END IF * END IF * ELSE * * Transpose column vector V (IROFFV = ICOFFC2) * IPW = NQV+1 CALL PBDTRNV( ICTXT, 'Columnwise', 'Transpose', N, $ DESCV( MB_ ), ICOFFC2, V( IOFFV ), 1, ZERO, $ WORK, 1, IVROW, IVCOL, ICROW2, ICCOL2, $ WORK( IPW ) ) * * Perform the local computation within a process column * IF( MYROW.EQ.ICROW2 ) THEN * IF( MYCOL.EQ.IVCOL ) THEN * CALL DGEBS2D( ICTXT, 'Rowwise', ' ', 1, 1, $ TAU( JJV ), 1 ) TAULOC = TAU( JJV ) * ELSE * CALL DGEBR2D( ICTXT, 'Rowwise', ' ', 1, 1, TAULOC, $ 1, MYROW, IVCOL ) * END IF * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C ) * v * IF( NQV.GT.0 ) THEN CALL DGEMV( 'No transpose', MPC2, NQV, ONE, $ C( IOFFC2 ), LDC, WORK, 1, ZERO, $ WORK( IPW ), 1 ) ELSE CALL DLASET( 'All', MPC2, 1, ZERO, ZERO, $ WORK( IPW ), MAX( 1, MPC2 ) ) END IF IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, ONE, C( IOFFC1 ), 1, $ WORK( IPW ), 1 ) CALL DGSUM2D( ICTXT, 'Rowwise', ' ', MPC2, 1, $ WORK( IPW ), MAX( 1, MPC2 ), RDEST, $ ICCOL2 ) IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, -TAULOC, WORK( IPW ), 1, $ C( IOFFC1 ), 1 ) * * sub( C ) := sub( C ) - w * v' * CALL DGER( MPC2, NQV, -TAULOC, WORK( IPW ), 1, $ WORK, 1, C( IOFFC2 ), LDC ) END IF * END IF * END IF * ELSE * * sub( C ) is a proper distributed matrix * IF( DESCV( M_ ).EQ.INCV ) THEN * * Broadcast row vector V * CALL PTOPGET( ICTXT, 'Broadcast', 'Columnwise', COLBTOP ) IF( MYROW.EQ.IVROW ) THEN * IPW = NQV+1 CALL DCOPY( NQV, V( IOFFV ), LDV, WORK, 1 ) WORK( IPW ) = TAU( IIV ) CALL DGEBS2D( ICTXT, 'Columnwise', COLBTOP, IPW, 1, $ WORK, IPW ) TAULOC = TAU( IIV ) * ELSE * IPW = NQV+1 CALL DGEBR2D( ICTXT, 'Columnwise', COLBTOP, IPW, 1, $ WORK, IPW, IVROW, MYCOL ) TAULOC = WORK( IPW ) * END IF * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C ) * v * IF( NQV.GT.0 ) THEN CALL DGEMV( 'No Transpose', MPC2, NQV, ONE, $ C( IOFFC2 ), LDC, WORK, 1, ZERO, $ WORK( IPW ), 1 ) ELSE CALL DLASET( 'All', MPC2, 1, ZERO, ZERO, $ WORK( IPW ), MAX( 1, MPC2 ) ) END IF IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, ONE, C( IOFFC1 ), 1, $ WORK( IPW ), 1 ) * CALL DGSUM2D( ICTXT, 'Rowwise', ' ', MPC2, 1, $ WORK( IPW ), MAX( 1, MPC2 ), RDEST, $ ICCOL2 ) IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, -TAULOC, WORK( IPW ), 1, $ C( IOFFC1 ), 1 ) * * sub( C ) := sub( C ) - w * v' * CALL DGER( MPC2, NQV, -TAULOC, WORK( IPW ), 1, WORK, $ 1, C( IOFFC2 ), LDC ) END IF * ELSE * * Transpose and broadcast column vector V (ICOFFC2=IROFFV) * IPW = NQV+1 CALL PBDTRNV( ICTXT, 'Columnwise', 'Transpose', N, $ DESCV( MB_ ), ICOFFC2, V( IOFFV ), 1, ZERO, $ WORK, 1, IVROW, IVCOL, -1, ICCOL2, $ WORK( IPW ) ) * * Perform the local computation within a process column * IF( MYCOL.EQ.IVCOL ) THEN * CALL DGEBS2D( ICTXT, 'Rowwise', ' ', 1, 1, TAU( JJV ), $ 1 ) TAULOC = TAU( JJV ) * ELSE * CALL DGEBR2D( ICTXT, 'Rowwise', ' ', 1, 1, TAULOC, 1, $ MYROW, IVCOL ) * END IF * IF( TAULOC.NE.ZERO ) THEN * * w := sub( C ) * v * IF( NQV.GT.0 ) THEN CALL DGEMV( 'No transpose', MPC2, NQV, ONE, $ C( IOFFC2 ), LDC, WORK, 1, ZERO, $ WORK( IPW ), 1 ) ELSE CALL DLASET( 'All', MPC2, 1, ZERO, ZERO, $ WORK( IPW ), MAX( 1, MPC2 ) ) END IF IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, ONE, C( IOFFC1 ), 1, $ WORK( IPW ), 1 ) CALL DGSUM2D( ICTXT, 'Rowwise', ' ', MPC2, 1, $ WORK( IPW ), MAX( 1, MPC2 ), RDEST, $ ICCOL2 ) IF( MYCOL.EQ.ICCOL1 ) $ CALL DAXPY( MPC2, -TAULOC, WORK( IPW ), 1, $ C( IOFFC1 ), 1 ) * * sub( C ) := sub( C ) - w * v' * CALL DGER( MPC2, NQV, -TAULOC, WORK( IPW ), 1, WORK, $ 1, C( IOFFC2 ), LDC ) END IF * END IF * END IF * END IF * RETURN * * End of PDLARZ * END