ESMF_IPARMQ Function

 This program sets problem and machine dependent parameters
 useful for xHSEQR and its subroutines. It is called whenever
 ESMF_ILAENV is called with 12 <= ISPEC <= 16

         ISPEC=12: (INMIN)  Matrices of order nmin or less
                   are sent directly to xLAHQR, the implicit
                   double shift QR algorithm.  NMIN must be
                   at least 11.

         ISPEC=13: (INWIN)  Size of the deflation window.
                   This is best set greater than or equal to
                   the number of simultaneous shifts NS.
                   Larger matrices benefit from larger deflation
                   windows.

         ISPEC=14: (INIBL) Determines when to stop nibbling and
                   invest in an (expensive) multi-shift QR sweep.
                   If the aggressive early deflation subroutine
                   finds LD converged eigenvalues from an order
                   NW deflation window and LD.GT.(NW*NIBBLE)/100,
                   then the next QR sweep is skipped and early
                   deflation is applied immediately to the
                   remaining active diagonal block.  Setting
                   ESMF_IPARMQ(ISPEC=14) = 0 causes TTQRE to skip a
                   multi-shift QR sweep whenever early deflation
                   finds a converged eigenvalue.  Setting
                   ESMF_IPARMQ(ISPEC=14) greater than or equal to 100
                   prevents TTQRE from skipping a multi-shift
                   QR sweep.

         ISPEC=15: (NSHFTS) The number of simultaneous shifts in
                   a multi-shift QR iteration.

         ISPEC=16: (IACC22) ESMF_IPARMQ is set to 0, 1 or 2 with the
                   following meanings.
                   0:  During the multi-shift QR sweep,
                       xLAQR5 does not accumulate reflections and
                       does not use matrix-matrix multiply to
                       update the far-from-diagonal matrix
                       entries.
                   1:  During the multi-shift QR sweep,
                       xLAQR5 and/or xLAQRaccumulates reflections and uses
                       matrix-matrix multiply to update the
                       far-from-diagonal matrix entries.
                   2:  During the multi-shift QR sweep.
                       xLAQR5 accumulates reflections and takes
                       advantage of 2-by-2 block structure during
                       matrix-matrix multiplies.
                   (If xTRMM is slower than xGEMM, then
                   ESMF_IPARMQ(ISPEC=16)=1 may be more efficient than
                   ESMF_IPARMQ(ISPEC=16)=2 despite the greater level of
                   arithmetic work implied by the latter choice.)

  Little is known about how best to choose these parameters.
  It is possible to use different values of the parameters
  for each of CHSEQR, ESMF_DHSEQR, SHSEQR and ZHSEQR.

  It is probably best to choose different parameters for
  different matrices and different parameters at different
  times during the iteration, but this has not been
  implemented --- yet.


  The best choices of most of the parameters depend
  in an ill-understood way on the relative execution
  rate of xLAQR3 and xLAQR5 and on the nature of each
  particular eigenvalue problem.  Experiment may be the
  only practical way to determine which choices are most
  effective.

  Following is a list of default values supplied by ESMF_IPARMQ.
  These defaults may be adjusted in order to attain better
  performance in any particular computational environment.

  ESMF_IPARMQ(ISPEC=12) The xLAHQR vs xLAQR0 crossover point.
                   Default: 75. (Must be at least 11.)

  ESMF_IPARMQ(ISPEC=13) Recommended deflation window size.
                   This depends on ILO, IHI and NS, the
                   number of simultaneous shifts returned
                   by ESMF_IPARMQ(ISPEC=15).  The default for
                   (IHI-ILO+1).LE.500 is NS.  The default
                   for (IHI-ILO+1).GT.500 is 3*NS/2.

  ESMF_IPARMQ(ISPEC=14) Nibble crossover point.  Default: 14.

  ESMF_IPARMQ(ISPEC=15) Number of simultaneous shifts, NS.
                   a multi-shift QR iteration.

                   If IHI-ILO+1 is ...

                   greater than      ...but less    ... the
                   or equal to ...      than        default is

                           0               30       NS =   2+
                          30               60       NS =   4+
                          60              150       NS =  10
                         150              590       NS =  **
                         590             3000       NS =  64
                        3000             6000       NS = 128
                        6000             infinity   NS = 256

               (+)  By default matrices of this order are
                    passed to the implicit double shift routine
                    xLAHQR.  See ESMF_IPARMQ(ISPEC=12) above.   These
                    values of NS are used only in case of a rare
                    xLAHQR failure.

               (**) The asterisks (**) indicate an ad-hoc
                    function increasing from 10 to 64.

  ESMF_IPARMQ(ISPEC=16) Select structured matrix multiply.
                   (See ISPEC=16 above for details.)
                   Default: 3.