Developer Reference for Intel® oneAPI Math Kernel Library for Fortran
?lasq5
Computes one dqds transform in ping-pong form. Used by ?bdsqr and ?stegr .
Syntax
call slasq5 ( i0 , n0 , z , pp , tau , sigma , dmin , dmin1 , dmin2 , dn , dnm1 , dnm2 , ieee , eps )
call dlasq5 ( i0 , n0 , z , pp , tau , sigma , dmin , dmin1 , dmin2 , dn , dnm1 , dnm2 , ieee , eps )
Include Files
mkl.fi
Description
slasq5 dlasq5
The routine computes one dqds transform in ping-pong form: one version for ieee machines, another for non-ieee machines.
Input Parameters
- i0
-
INTEGER. First index.
- n0
-
INTEGER . Last index.
- z
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . Array, DIMENSION (4 n ). z holds the qd array. emin is stored in z(4*n0) to avoid an extra argument.
- pp
-
INTEGER . pp=0 for ping, pp=1 for pong.
- tau
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . This is the shift.
- sigma
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . This is the accumulated shift up to the current point.
- ieee
-
LOGICAL . Flag for IEEE or non-IEEE arithmetic.
- eps
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . This is the value of epsilon used.
Output Parameters
- dmin
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . Minimum value of d .
- dmin1
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . Minimum value of d , excluding d ( n0 ).
- dmin2
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . Minimum value of d , excluding d ( n0 ) and d(n0-1) .
- dn
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . Contains d(n0) , the last value of d .
- dnm1
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . Contains d(n0-1) .
- dnm2
-
REAL for slasq5 DOUBLE PRECISION for dlasq5 . Contains d(n0-2) .