diff options
author | jason <jason@8a072113-8704-0410-8d35-dd094bca7971> | 2008-10-28 01:38:50 +0000 |
---|---|---|
committer | jason <jason@8a072113-8704-0410-8d35-dd094bca7971> | 2008-10-28 01:38:50 +0000 |
commit | baba851215b44ac3b60b9248eb02bcce7eb76247 (patch) | |
tree | 8c0f5c006875532a30d4409f5e94b0f310ff00a7 /SRC/clarfb.f | |
download | lapack-baba851215b44ac3b60b9248eb02bcce7eb76247.tar.gz lapack-baba851215b44ac3b60b9248eb02bcce7eb76247.tar.bz2 lapack-baba851215b44ac3b60b9248eb02bcce7eb76247.zip |
Move LAPACK trunk into position.
Diffstat (limited to 'SRC/clarfb.f')
-rw-r--r-- | SRC/clarfb.f | 649 |
1 files changed, 649 insertions, 0 deletions
diff --git a/SRC/clarfb.f b/SRC/clarfb.f new file mode 100644 index 00000000..3418b460 --- /dev/null +++ b/SRC/clarfb.f @@ -0,0 +1,649 @@ + SUBROUTINE CLARFB( SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV, + $ T, LDT, C, LDC, WORK, LDWORK ) + IMPLICIT NONE +* +* -- LAPACK auxiliary routine (version 3.1) -- +* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. +* November 2006 +* +* .. Scalar Arguments .. + CHARACTER DIRECT, SIDE, STOREV, TRANS + INTEGER K, LDC, LDT, LDV, LDWORK, M, N +* .. +* .. Array Arguments .. + COMPLEX C( LDC, * ), T( LDT, * ), V( LDV, * ), + $ WORK( LDWORK, * ) +* .. +* +* Purpose +* ======= +* +* CLARFB applies a complex block reflector H or its transpose H' to a +* complex M-by-N matrix C, from either the left or the right. +* +* Arguments +* ========= +* +* SIDE (input) CHARACTER*1 +* = 'L': apply H or H' from the Left +* = 'R': apply H or H' from the Right +* +* TRANS (input) CHARACTER*1 +* = 'N': apply H (No transpose) +* = 'C': apply H' (Conjugate transpose) +* +* DIRECT (input) CHARACTER*1 +* Indicates how H is formed from a product of elementary +* reflectors +* = 'F': H = H(1) H(2) . . . H(k) (Forward) +* = 'B': H = H(k) . . . H(2) H(1) (Backward) +* +* STOREV (input) CHARACTER*1 +* Indicates how the vectors which define the elementary +* reflectors are stored: +* = 'C': Columnwise +* = 'R': Rowwise +* +* M (input) INTEGER +* The number of rows of the matrix C. +* +* N (input) INTEGER +* The number of columns of the matrix C. +* +* K (input) INTEGER +* The order of the matrix T (= the number of elementary +* reflectors whose product defines the block reflector). +* +* V (input) COMPLEX array, dimension +* (LDV,K) if STOREV = 'C' +* (LDV,M) if STOREV = 'R' and SIDE = 'L' +* (LDV,N) if STOREV = 'R' and SIDE = 'R' +* The matrix V. See further details. +* +* LDV (input) INTEGER +* The leading dimension of the array V. +* If STOREV = 'C' and SIDE = 'L', LDV >= max(1,M); +* if STOREV = 'C' and SIDE = 'R', LDV >= max(1,N); +* if STOREV = 'R', LDV >= K. +* +* T (input) COMPLEX array, dimension (LDT,K) +* The triangular K-by-K matrix T in the representation of the +* block reflector. +* +* LDT (input) INTEGER +* The leading dimension of the array T. LDT >= K. +* +* C (input/output) COMPLEX array, dimension (LDC,N) +* On entry, the M-by-N matrix C. +* On exit, C is overwritten by H*C or H'*C or C*H or C*H'. +* +* LDC (input) INTEGER +* The leading dimension of the array C. LDC >= max(1,M). +* +* WORK (workspace) COMPLEX array, dimension (LDWORK,K) +* +* LDWORK (input) INTEGER +* The leading dimension of the array WORK. +* If SIDE = 'L', LDWORK >= max(1,N); +* if SIDE = 'R', LDWORK >= max(1,M). +* +* ===================================================================== +* +* .. Parameters .. + COMPLEX ONE + PARAMETER ( ONE = ( 1.0E+0, 0.0E+0 ) ) +* .. +* .. Local Scalars .. + CHARACTER TRANST + INTEGER I, J, LASTV, LASTC +* .. +* .. External Functions .. + LOGICAL LSAME + INTEGER ILACLR, ILACLC + EXTERNAL LSAME, ILACLR, ILACLC +* .. +* .. External Subroutines .. + EXTERNAL CCOPY, CGEMM, CLACGV, CTRMM +* .. +* .. Intrinsic Functions .. + INTRINSIC CONJG +* .. +* .. Executable Statements .. +* +* Quick return if possible +* + IF( M.LE.0 .OR. N.LE.0 ) + $ RETURN +* + IF( LSAME( TRANS, 'N' ) ) THEN + TRANST = 'C' + ELSE + TRANST = 'N' + END IF +* + IF( LSAME( STOREV, 'C' ) ) THEN +* + IF( LSAME( DIRECT, 'F' ) ) THEN +* +* Let V = ( V1 ) (first K rows) +* ( V2 ) +* where V1 is unit lower triangular. +* + IF( LSAME( SIDE, 'L' ) ) THEN +* +* Form H * C or H' * C where C = ( C1 ) +* ( C2 ) +* + LASTV = MAX( K, ILACLR( M, K, V, LDV ) ) + LASTC = ILACLC( LASTV, N, C, LDC ) +* +* W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) +* +* W := C1' +* + DO 10 J = 1, K + CALL CCOPY( LASTC, C( J, 1 ), LDC, WORK( 1, J ), 1 ) + CALL CLACGV( LASTC, WORK( 1, J ), 1 ) + 10 CONTINUE +* +* W := W * V1 +* + CALL CTRMM( 'Right', 'Lower', 'No transpose', 'Unit', + $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) + IF( LASTV.GT.K ) THEN +* +* W := W + C2'*V2 +* + CALL CGEMM( 'Conjugate transpose', 'No transpose', + $ LASTC, K, LASTV-K, ONE, C( K+1, 1 ), LDC, + $ V( K+1, 1 ), LDV, ONE, WORK, LDWORK ) + END IF +* +* W := W * T' or W * T +* + CALL CTRMM( 'Right', 'Upper', TRANST, 'Non-unit', + $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) +* +* C := C - V * W' +* + IF( M.GT.K ) THEN +* +* C2 := C2 - V2 * W' +* + CALL CGEMM( 'No transpose', 'Conjugate transpose', + $ LASTV-K, LASTC, K, -ONE, V( K+1, 1 ), LDV, + $ WORK, LDWORK, ONE, C( K+1, 1 ), LDC ) + END IF +* +* W := W * V1' +* + CALL CTRMM( 'Right', 'Lower', 'Conjugate transpose', + $ 'Unit', LASTC, K, ONE, V, LDV, WORK, LDWORK ) +* +* C1 := C1 - W' +* + DO 30 J = 1, K + DO 20 I = 1, LASTC + C( J, I ) = C( J, I ) - CONJG( WORK( I, J ) ) + 20 CONTINUE + 30 CONTINUE +* + ELSE IF( LSAME( SIDE, 'R' ) ) THEN +* +* Form C * H or C * H' where C = ( C1 C2 ) +* + LASTV = MAX( K, ILACLR( N, K, V, LDV ) ) + LASTC = ILACLR( M, LASTV, C, LDC ) +* +* W := C * V = (C1*V1 + C2*V2) (stored in WORK) +* +* W := C1 +* + DO 40 J = 1, K + CALL CCOPY( LASTC, C( 1, J ), 1, WORK( 1, J ), 1 ) + 40 CONTINUE +* +* W := W * V1 +* + CALL CTRMM( 'Right', 'Lower', 'No transpose', 'Unit', + $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) + IF( LASTV.GT.K ) THEN +* +* W := W + C2 * V2 +* + CALL CGEMM( 'No transpose', 'No transpose', + $ LASTC, K, LASTV-K, + $ ONE, C( 1, K+1 ), LDC, V( K+1, 1 ), LDV, + $ ONE, WORK, LDWORK ) + END IF +* +* W := W * T or W * T' +* + CALL CTRMM( 'Right', 'Upper', TRANS, 'Non-unit', + $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) +* +* C := C - W * V' +* + IF( LASTV.GT.K ) THEN +* +* C2 := C2 - W * V2' +* + CALL CGEMM( 'No transpose', 'Conjugate transpose', + $ LASTC, LASTV-K, K, + $ -ONE, WORK, LDWORK, V( K+1, 1 ), LDV, + $ ONE, C( 1, K+1 ), LDC ) + END IF +* +* W := W * V1' +* + CALL CTRMM( 'Right', 'Lower', 'Conjugate transpose', + $ 'Unit', LASTC, K, ONE, V, LDV, WORK, LDWORK ) +* +* C1 := C1 - W +* + DO 60 J = 1, K + DO 50 I = 1, LASTC + C( I, J ) = C( I, J ) - WORK( I, J ) + 50 CONTINUE + 60 CONTINUE + END IF +* + ELSE +* +* Let V = ( V1 ) +* ( V2 ) (last K rows) +* where V2 is unit upper triangular. +* + IF( LSAME( SIDE, 'L' ) ) THEN +* +* Form H * C or H' * C where C = ( C1 ) +* ( C2 ) +* + LASTV = MAX( K, ILACLR( M, K, V, LDV ) ) + LASTC = ILACLC( LASTV, N, C, LDC ) +* +* W := C' * V = (C1'*V1 + C2'*V2) (stored in WORK) +* +* W := C2' +* + DO 70 J = 1, K + CALL CCOPY( LASTC, C( LASTV-K+J, 1 ), LDC, + $ WORK( 1, J ), 1 ) + CALL CLACGV( LASTC, WORK( 1, J ), 1 ) + 70 CONTINUE +* +* W := W * V2 +* + CALL CTRMM( 'Right', 'Upper', 'No transpose', 'Unit', + $ LASTC, K, ONE, V( LASTV-K+1, 1 ), LDV, + $ WORK, LDWORK ) + IF( LASTV.GT.K ) THEN +* +* W := W + C1'*V1 +* + CALL CGEMM( 'Conjugate transpose', 'No transpose', + $ LASTC, K, LASTV-K, ONE, C, LDC, V, LDV, + $ ONE, WORK, LDWORK ) + END IF +* +* W := W * T' or W * T +* + CALL CTRMM( 'Right', 'Lower', TRANST, 'Non-unit', + $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) +* +* C := C - V * W' +* + IF( LASTV.GT.K ) THEN +* +* C1 := C1 - V1 * W' +* + CALL CGEMM( 'No transpose', 'Conjugate transpose', + $ LASTV-K, LASTC, K, -ONE, V, LDV, WORK, LDWORK, + $ ONE, C, LDC ) + END IF +* +* W := W * V2' +* + CALL CTRMM( 'Right', 'Upper', 'Conjugate transpose', + $ 'Unit', LASTC, K, ONE, V( LASTV-K+1, 1 ), LDV, + $ WORK, LDWORK ) +* +* C2 := C2 - W' +* + DO 90 J = 1, K + DO 80 I = 1, LASTC + C( LASTV-K+J, I ) = C( LASTV-K+J, I ) - + $ CONJG( WORK( I, J ) ) + 80 CONTINUE + 90 CONTINUE +* + ELSE IF( LSAME( SIDE, 'R' ) ) THEN +* +* Form C * H or C * H' where C = ( C1 C2 ) +* + LASTV = MAX( K, ILACLR( N, K, V, LDV ) ) + LASTC = ILACLR( M, LASTV, C, LDC ) +* +* W := C * V = (C1*V1 + C2*V2) (stored in WORK) +* +* W := C2 +* + DO 100 J = 1, K + CALL CCOPY( LASTC, C( 1, LASTV-K+J ), 1, + $ WORK( 1, J ), 1 ) + 100 CONTINUE +* +* W := W * V2 +* + CALL CTRMM( 'Right', 'Upper', 'No transpose', 'Unit', + $ LASTC, K, ONE, V( LASTV-K+1, 1 ), LDV, + $ WORK, LDWORK ) + IF( LASTV.GT.K ) THEN +* +* W := W + C1 * V1 +* + CALL CGEMM( 'No transpose', 'No transpose', + $ LASTC, K, LASTV-K, + $ ONE, C, LDC, V, LDV, ONE, WORK, LDWORK ) + END IF +* +* W := W * T or W * T' +* + CALL CTRMM( 'Right', 'Lower', TRANS, 'Non-unit', + $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) +* +* C := C - W * V' +* + IF( LASTV.GT.K ) THEN +* +* C1 := C1 - W * V1' +* + CALL CGEMM( 'No transpose', 'Conjugate transpose', + $ LASTC, LASTV-K, K, -ONE, WORK, LDWORK, V, LDV, + $ ONE, C, LDC ) + END IF +* +* W := W * V2' +* + CALL CTRMM( 'Right', 'Upper', 'Conjugate transpose', + $ 'Unit', LASTC, K, ONE, V( LASTV-K+1, 1 ), LDV, + $ WORK, LDWORK ) +* +* C2 := C2 - W +* + DO 120 J = 1, K + DO 110 I = 1, LASTC + C( I, LASTV-K+J ) = C( I, LASTV-K+J ) + $ - WORK( I, J ) + 110 CONTINUE + 120 CONTINUE + END IF + END IF +* + ELSE IF( LSAME( STOREV, 'R' ) ) THEN +* + IF( LSAME( DIRECT, 'F' ) ) THEN +* +* Let V = ( V1 V2 ) (V1: first K columns) +* where V1 is unit upper triangular. +* + IF( LSAME( SIDE, 'L' ) ) THEN +* +* Form H * C or H' * C where C = ( C1 ) +* ( C2 ) +* + LASTV = MAX( K, ILACLC( K, M, V, LDV ) ) + LASTC = ILACLC( LASTV, N, C, LDC ) +* +* W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) +* +* W := C1' +* + DO 130 J = 1, K + CALL CCOPY( LASTC, C( J, 1 ), LDC, WORK( 1, J ), 1 ) + CALL CLACGV( LASTC, WORK( 1, J ), 1 ) + 130 CONTINUE +* +* W := W * V1' +* + CALL CTRMM( 'Right', 'Upper', 'Conjugate transpose', + $ 'Unit', LASTC, K, ONE, V, LDV, WORK, LDWORK ) + IF( LASTV.GT.K ) THEN +* +* W := W + C2'*V2' +* + CALL CGEMM( 'Conjugate transpose', + $ 'Conjugate transpose', LASTC, K, LASTV-K, + $ ONE, C( K+1, 1 ), LDC, V( 1, K+1 ), LDV, + $ ONE, WORK, LDWORK ) + END IF +* +* W := W * T' or W * T +* + CALL CTRMM( 'Right', 'Upper', TRANST, 'Non-unit', + $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) +* +* C := C - V' * W' +* + IF( LASTV.GT.K ) THEN +* +* C2 := C2 - V2' * W' +* + CALL CGEMM( 'Conjugate transpose', + $ 'Conjugate transpose', LASTV-K, LASTC, K, + $ -ONE, V( 1, K+1 ), LDV, WORK, LDWORK, + $ ONE, C( K+1, 1 ), LDC ) + END IF +* +* W := W * V1 +* + CALL CTRMM( 'Right', 'Upper', 'No transpose', 'Unit', + $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) +* +* C1 := C1 - W' +* + DO 150 J = 1, K + DO 140 I = 1, LASTC + C( J, I ) = C( J, I ) - CONJG( WORK( I, J ) ) + 140 CONTINUE + 150 CONTINUE +* + ELSE IF( LSAME( SIDE, 'R' ) ) THEN +* +* Form C * H or C * H' where C = ( C1 C2 ) +* + LASTV = MAX( K, ILACLC( K, N, V, LDV ) ) + LASTC = ILACLR( M, LASTV, C, LDC ) +* +* W := C * V' = (C1*V1' + C2*V2') (stored in WORK) +* +* W := C1 +* + DO 160 J = 1, K + CALL CCOPY( LASTC, C( 1, J ), 1, WORK( 1, J ), 1 ) + 160 CONTINUE +* +* W := W * V1' +* + CALL CTRMM( 'Right', 'Upper', 'Conjugate transpose', + $ 'Unit', LASTC, K, ONE, V, LDV, WORK, LDWORK ) + IF( LASTV.GT.K ) THEN +* +* W := W + C2 * V2' +* + CALL CGEMM( 'No transpose', 'Conjugate transpose', + $ LASTC, K, LASTV-K, ONE, C( 1, K+1 ), LDC, + $ V( 1, K+1 ), LDV, ONE, WORK, LDWORK ) + END IF +* +* W := W * T or W * T' +* + CALL CTRMM( 'Right', 'Upper', TRANS, 'Non-unit', + $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) +* +* C := C - W * V +* + IF( LASTV.GT.K ) THEN +* +* C2 := C2 - W * V2 +* + CALL CGEMM( 'No transpose', 'No transpose', + $ LASTC, LASTV-K, K, + $ -ONE, WORK, LDWORK, V( 1, K+1 ), LDV, + $ ONE, C( 1, K+1 ), LDC ) + END IF +* +* W := W * V1 +* + CALL CTRMM( 'Right', 'Upper', 'No transpose', 'Unit', + $ LASTC, K, ONE, V, LDV, WORK, LDWORK ) +* +* C1 := C1 - W +* + DO 180 J = 1, K + DO 170 I = 1, LASTC + C( I, J ) = C( I, J ) - WORK( I, J ) + 170 CONTINUE + 180 CONTINUE +* + END IF +* + ELSE +* +* Let V = ( V1 V2 ) (V2: last K columns) +* where V2 is unit lower triangular. +* + IF( LSAME( SIDE, 'L' ) ) THEN +* +* Form H * C or H' * C where C = ( C1 ) +* ( C2 ) +* + LASTV = MAX( K, ILACLC( K, M, V, LDV ) ) + LASTC = ILACLC( LASTV, N, C, LDC ) +* +* W := C' * V' = (C1'*V1' + C2'*V2') (stored in WORK) +* +* W := C2' +* + DO 190 J = 1, K + CALL CCOPY( LASTC, C( LASTV-K+J, 1 ), LDC, + $ WORK( 1, J ), 1 ) + CALL CLACGV( LASTC, WORK( 1, J ), 1 ) + 190 CONTINUE +* +* W := W * V2' +* + CALL CTRMM( 'Right', 'Lower', 'Conjugate transpose', + $ 'Unit', LASTC, K, ONE, V( 1, LASTV-K+1 ), LDV, + $ WORK, LDWORK ) + IF( LASTV.GT.K ) THEN +* +* W := W + C1'*V1' +* + CALL CGEMM( 'Conjugate transpose', + $ 'Conjugate transpose', LASTC, K, LASTV-K, + $ ONE, C, LDC, V, LDV, ONE, WORK, LDWORK ) + END IF +* +* W := W * T' or W * T +* + CALL CTRMM( 'Right', 'Lower', TRANST, 'Non-unit', + $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) +* +* C := C - V' * W' +* + IF( LASTV.GT.K ) THEN +* +* C1 := C1 - V1' * W' +* + CALL CGEMM( 'Conjugate transpose', + $ 'Conjugate transpose', LASTV-K, LASTC, K, + $ -ONE, V, LDV, WORK, LDWORK, ONE, C, LDC ) + END IF +* +* W := W * V2 +* + CALL CTRMM( 'Right', 'Lower', 'No transpose', 'Unit', + $ LASTC, K, ONE, V( 1, LASTV-K+1 ), LDV, + $ WORK, LDWORK ) +* +* C2 := C2 - W' +* + DO 210 J = 1, K + DO 200 I = 1, LASTC + C( LASTV-K+J, I ) = C( LASTV-K+J, I ) - + $ CONJG( WORK( I, J ) ) + 200 CONTINUE + 210 CONTINUE +* + ELSE IF( LSAME( SIDE, 'R' ) ) THEN +* +* Form C * H or C * H' where C = ( C1 C2 ) +* + LASTV = MAX( K, ILACLC( K, N, V, LDV ) ) + LASTC = ILACLR( M, LASTV, C, LDC ) +* +* W := C * V' = (C1*V1' + C2*V2') (stored in WORK) +* +* W := C2 +* + DO 220 J = 1, K + CALL CCOPY( LASTC, C( 1, LASTV-K+J ), 1, + $ WORK( 1, J ), 1 ) + 220 CONTINUE +* +* W := W * V2' +* + CALL CTRMM( 'Right', 'Lower', 'Conjugate transpose', + $ 'Unit', LASTC, K, ONE, V( 1, LASTV-K+1 ), LDV, + $ WORK, LDWORK ) + IF( LASTV.GT.K ) THEN +* +* W := W + C1 * V1' +* + CALL CGEMM( 'No transpose', 'Conjugate transpose', + $ LASTC, K, LASTV-K, ONE, C, LDC, V, LDV, ONE, + $ WORK, LDWORK ) + END IF +* +* W := W * T or W * T' +* + CALL CTRMM( 'Right', 'Lower', TRANS, 'Non-unit', + $ LASTC, K, ONE, T, LDT, WORK, LDWORK ) +* +* C := C - W * V +* + IF( LASTV.GT.K ) THEN +* +* C1 := C1 - W * V1 +* + CALL CGEMM( 'No transpose', 'No transpose', + $ LASTC, LASTV-K, K, -ONE, WORK, LDWORK, V, LDV, + $ ONE, C, LDC ) + END IF +* +* W := W * V2 +* + CALL CTRMM( 'Right', 'Lower', 'No transpose', 'Unit', + $ LASTC, K, ONE, V( 1, LASTV-K+1 ), LDV, + $ WORK, LDWORK ) +* +* C1 := C1 - W +* + DO 240 J = 1, K + DO 230 I = 1, LASTC + C( I, LASTV-K+J ) = C( I, LASTV-K+J ) + $ - WORK( I, J ) + 230 CONTINUE + 240 CONTINUE +* + END IF +* + END IF + END IF +* + RETURN +* +* End of CLARFB +* + END |