--- rpl/lapack/lapack/dgehrd.f 2012/12/14 14:22:28 1.12
+++ rpl/lapack/lapack/dgehrd.f 2017/06/17 10:53:48 1.16
@@ -2,31 +2,31 @@
*
* =========== DOCUMENTATION ===========
*
-* Online html documentation available at
-* http://www.netlib.org/lapack/explore-html/
+* Online html documentation available at
+* http://www.netlib.org/lapack/explore-html/
*
*> \htmlonly
-*> Download DGEHRD + dependencies
-*>
-*> [TGZ]
-*>
-*> [ZIP]
-*>
+*> Download DGEHRD + dependencies
+*>
+*> [TGZ]
+*>
+*> [ZIP]
+*>
*> [TXT]
-*> \endhtmlonly
+*> \endhtmlonly
*
* Definition:
* ===========
*
* SUBROUTINE DGEHRD( N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO )
-*
+*
* .. Scalar Arguments ..
* INTEGER IHI, ILO, INFO, LDA, LWORK, N
* ..
* .. Array Arguments ..
* DOUBLE PRECISION A( LDA, * ), TAU( * ), WORK( * )
* ..
-*
+*
*
*> \par Purpose:
* =============
@@ -97,8 +97,7 @@
*> \verbatim
*> LWORK is INTEGER
*> The length of the array WORK. LWORK >= max(1,N).
-*> For optimum performance LWORK >= N*NB, where NB is the
-*> optimal blocksize.
+*> For good performance, LWORK should generally be larger.
*>
*> If LWORK = -1, then a workspace query is assumed; the routine
*> only calculates the optimal size of the WORK array, returns
@@ -116,12 +115,12 @@
* Authors:
* ========
*
-*> \author Univ. of Tennessee
-*> \author Univ. of California Berkeley
-*> \author Univ. of Colorado Denver
-*> \author NAG Ltd.
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
*
-*> \date November 2011
+*> \date December 2016
*
*> \ingroup doubleGEcomputational
*
@@ -168,10 +167,10 @@
* =====================================================================
SUBROUTINE DGEHRD( N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO )
*
-* -- LAPACK computational routine (version 3.4.0) --
+* -- LAPACK computational routine (version 3.7.0) --
* -- LAPACK is a software package provided by Univ. of Tennessee, --
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
-* November 2011
+* December 2016
*
* .. Scalar Arguments ..
INTEGER IHI, ILO, INFO, LDA, LWORK, N
@@ -183,21 +182,19 @@
* =====================================================================
*
* .. Parameters ..
- INTEGER NBMAX, LDT
- PARAMETER ( NBMAX = 64, LDT = NBMAX+1 )
+ INTEGER NBMAX, LDT, TSIZE
+ PARAMETER ( NBMAX = 64, LDT = NBMAX+1,
+ $ TSIZE = LDT*NBMAX )
DOUBLE PRECISION ZERO, ONE
- PARAMETER ( ZERO = 0.0D+0,
+ PARAMETER ( ZERO = 0.0D+0,
$ ONE = 1.0D+0 )
* ..
* .. Local Scalars ..
LOGICAL LQUERY
- INTEGER I, IB, IINFO, IWS, J, LDWORK, LWKOPT, NB,
+ INTEGER I, IB, IINFO, IWT, J, LDWORK, LWKOPT, NB,
$ NBMIN, NH, NX
DOUBLE PRECISION EI
* ..
-* .. Local Arrays ..
- DOUBLE PRECISION T( LDT, NBMAX )
-* ..
* .. External Subroutines ..
EXTERNAL DAXPY, DGEHD2, DGEMM, DLAHR2, DLARFB, DTRMM,
$ XERBLA
@@ -214,9 +211,6 @@
* Test the input parameters
*
INFO = 0
- NB = MIN( NBMAX, ILAENV( 1, 'DGEHRD', ' ', N, ILO, IHI, -1 ) )
- LWKOPT = N*NB
- WORK( 1 ) = LWKOPT
LQUERY = ( LWORK.EQ.-1 )
IF( N.LT.0 ) THEN
INFO = -1
@@ -229,6 +223,16 @@
ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
INFO = -8
END IF
+*
+ IF( INFO.EQ.0 ) THEN
+*
+* Compute the workspace requirements
+*
+ NB = MIN( NBMAX, ILAENV( 1, 'DGEHRD', ' ', N, ILO, IHI, -1 ) )
+ LWKOPT = N*NB + TSIZE
+ WORK( 1 ) = LWKOPT
+ END IF
+*
IF( INFO.NE.0 ) THEN
CALL XERBLA( 'DGEHRD', -INFO )
RETURN
@@ -257,7 +261,6 @@
*
NB = MIN( NBMAX, ILAENV( 1, 'DGEHRD', ' ', N, ILO, IHI, -1 ) )
NBMIN = 2
- IWS = 1
IF( NB.GT.1 .AND. NB.LT.NH ) THEN
*
* Determine when to cross over from blocked to unblocked code
@@ -268,8 +271,7 @@
*
* Determine if workspace is large enough for blocked code
*
- IWS = N*NB
- IF( LWORK.LT.IWS ) THEN
+ IF( LWORK.LT.N*NB+TSIZE ) THEN
*
* Not enough workspace to use optimal NB: determine the
* minimum value of NB, and reduce NB or force use of
@@ -277,8 +279,8 @@
*
NBMIN = MAX( 2, ILAENV( 2, 'DGEHRD', ' ', N, ILO, IHI,
$ -1 ) )
- IF( LWORK.GE.N*NBMIN ) THEN
- NB = LWORK / N
+ IF( LWORK.GE.(N*NBMIN + TSIZE) ) THEN
+ NB = (LWORK-TSIZE) / N
ELSE
NB = 1
END IF
@@ -297,6 +299,7 @@
*
* Use blocked code
*
+ IWT = 1 + N*NB
DO 40 I = ILO, IHI - 1 - NX, NB
IB = MIN( NB, IHI-I )
*
@@ -304,8 +307,8 @@
* matrices V and T of the block reflector H = I - V*T*V**T
* which performs the reduction, and also the matrix Y = A*V*T
*
- CALL DLAHR2( IHI, I, IB, A( 1, I ), LDA, TAU( I ), T, LDT,
- $ WORK, LDWORK )
+ CALL DLAHR2( IHI, I, IB, A( 1, I ), LDA, TAU( I ),
+ $ WORK( IWT ), LDT, WORK, LDWORK )
*
* Apply the block reflector H to A(1:ihi,i+ib:ihi) from the
* right, computing A := A - Y * V**T. V(i+ib,ib-1) must be set
@@ -313,7 +316,7 @@
*
EI = A( I+IB, I+IB-1 )
A( I+IB, I+IB-1 ) = ONE
- CALL DGEMM( 'No transpose', 'Transpose',
+ CALL DGEMM( 'No transpose', 'Transpose',
$ IHI, IHI-I-IB+1,
$ IB, -ONE, WORK, LDWORK, A( I+IB, I ), LDA, ONE,
$ A( 1, I+IB ), LDA )
@@ -335,15 +338,16 @@
*
CALL DLARFB( 'Left', 'Transpose', 'Forward',
$ 'Columnwise',
- $ IHI-I, N-I-IB+1, IB, A( I+1, I ), LDA, T, LDT,
- $ A( I+1, I+IB ), LDA, WORK, LDWORK )
+ $ IHI-I, N-I-IB+1, IB, A( I+1, I ), LDA,
+ $ WORK( IWT ), LDT, A( I+1, I+IB ), LDA,
+ $ WORK, LDWORK )
40 CONTINUE
END IF
*
* Use unblocked code to reduce the rest of the matrix
*
CALL DGEHD2( N, I, IHI, A, LDA, TAU, WORK, IINFO )
- WORK( 1 ) = IWS
+ WORK( 1 ) = LWKOPT
*
RETURN
*