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Diff for /rpl/lapack/lapack/dlahqr.f between versions 1.19 and 1.20

version 1.19, 2020/05/21 21:45:59 version 1.20, 2023/08/07 08:38:54
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 *> \author Univ. of Colorado Denver  *> \author Univ. of Colorado Denver
 *> \author NAG Ltd.  *> \author NAG Ltd.
 *  *
 *> \date December 2016  
 *  
 *> \ingroup doubleOTHERauxiliary  *> \ingroup doubleOTHERauxiliary
 *  *
 *> \par Further Details:  *> \par Further Details:
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 *  =====================================================================  *  =====================================================================
       SUBROUTINE DLAHQR( WANTT, WANTZ, N, ILO, IHI, H, LDH, WR, WI,        SUBROUTINE DLAHQR( WANTT, WANTZ, N, ILO, IHI, H, LDH, WR, WI,
      $                   ILOZ, IHIZ, Z, LDZ, INFO )       $                   ILOZ, IHIZ, Z, LDZ, INFO )
         IMPLICIT NONE
 *  *
 *  -- LAPACK auxiliary routine (version 3.7.0) --  *  -- LAPACK auxiliary routine --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --  *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--  *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
 *     December 2016  
 *  *
 *     .. Scalar Arguments ..  *     .. Scalar Arguments ..
       INTEGER            IHI, IHIZ, ILO, ILOZ, INFO, LDH, LDZ, N        INTEGER            IHI, IHIZ, ILO, ILOZ, INFO, LDH, LDZ, N
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       PARAMETER          ( ZERO = 0.0d0, ONE = 1.0d0, TWO = 2.0d0 )        PARAMETER          ( ZERO = 0.0d0, ONE = 1.0d0, TWO = 2.0d0 )
       DOUBLE PRECISION   DAT1, DAT2        DOUBLE PRECISION   DAT1, DAT2
       PARAMETER          ( DAT1 = 3.0d0 / 4.0d0, DAT2 = -0.4375d0 )        PARAMETER          ( DAT1 = 3.0d0 / 4.0d0, DAT2 = -0.4375d0 )
         INTEGER            KEXSH
         PARAMETER          ( KEXSH = 10 )
 *     ..  *     ..
 *     .. Local Scalars ..  *     .. Local Scalars ..
       DOUBLE PRECISION   AA, AB, BA, BB, CS, DET, H11, H12, H21, H21S,        DOUBLE PRECISION   AA, AB, BA, BB, CS, DET, H11, H12, H21, H21S,
      $                   H22, RT1I, RT1R, RT2I, RT2R, RTDISC, S, SAFMAX,       $                   H22, RT1I, RT1R, RT2I, RT2R, RTDISC, S, SAFMAX,
      $                   SAFMIN, SMLNUM, SN, SUM, T1, T2, T3, TR, TST,       $                   SAFMIN, SMLNUM, SN, SUM, T1, T2, T3, TR, TST,
      $                   ULP, V2, V3       $                   ULP, V2, V3
       INTEGER            I, I1, I2, ITS, ITMAX, J, K, L, M, NH, NR, NZ        INTEGER            I, I1, I2, ITS, ITMAX, J, K, L, M, NH, NR, NZ,
        $                   KDEFL 
 *     ..  *     ..
 *     .. Local Arrays ..  *     .. Local Arrays ..
       DOUBLE PRECISION   V( 3 )        DOUBLE PRECISION   V( 3 )
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 *  *
       ITMAX = 30 * MAX( 10, NH )        ITMAX = 30 * MAX( 10, NH )
 *  *
   *     KDEFL counts the number of iterations since a deflation
   *
         KDEFL = 0
   *
 *     The main loop begins here. I is the loop index and decreases from  *     The main loop begins here. I is the loop index and decreases from
 *     IHI to ILO in steps of 1 or 2. Each iteration of the loop works  *     IHI to ILO in steps of 1 or 2. Each iteration of the loop works
 *     with the active submatrix in rows and columns L to I.  *     with the active submatrix in rows and columns L to I.
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 *  *
          IF( L.GE.I-1 )           IF( L.GE.I-1 )
      $      GO TO 150       $      GO TO 150
            KDEFL = KDEFL + 1
 *  *
 *        Now the active submatrix is in rows and columns L to I. If  *        Now the active submatrix is in rows and columns L to I. If
 *        eigenvalues only are being computed, only the active submatrix  *        eigenvalues only are being computed, only the active submatrix
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             I2 = I              I2 = I
          END IF           END IF
 *  *
          IF( ITS.EQ.10 ) THEN           IF( MOD(KDEFL,2*KEXSH).EQ.0 ) THEN
 *  *
 *           Exceptional shift.  *           Exceptional shift.
 *  *
             S = ABS( H( L+1, L ) ) + ABS( H( L+2, L+1 ) )              S = ABS( H( I, I-1 ) ) + ABS( H( I-1, I-2 ) )
             H11 = DAT1*S + H( L, L )              H11 = DAT1*S + H( I, I )
             H12 = DAT2*S              H12 = DAT2*S
             H21 = S              H21 = S
             H22 = H11              H22 = H11
          ELSE IF( ITS.EQ.20 ) THEN           ELSE IF( MOD(KDEFL,KEXSH).EQ.0 ) THEN
 *  *
 *           Exceptional shift.  *           Exceptional shift.
 *  *
             S = ABS( H( I, I-1 ) ) + ABS( H( I-1, I-2 ) )              S = ABS( H( L+1, L ) ) + ABS( H( L+2, L+1 ) )
             H11 = DAT1*S + H( I, I )              H11 = DAT1*S + H( L, L )
             H12 = DAT2*S              H12 = DAT2*S
             H21 = S              H21 = S
             H22 = H11              H22 = H11
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             CALL DROT( NZ, Z( ILOZ, I-1 ), 1, Z( ILOZ, I ), 1, CS, SN )              CALL DROT( NZ, Z( ILOZ, I-1 ), 1, Z( ILOZ, I ), 1, CS, SN )
          END IF           END IF
       END IF        END IF
   *     reset deflation counter
         KDEFL = 0
 *  *
 *     return to start of the main loop with new value of I.  *     return to start of the main loop with new value of I.
 *  *
Removed from v.1.19  
changed lines
  Added in v.1.20

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