LAPACK 3.11.0
LAPACK: Linear Algebra PACKage
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◆ sroundup_lwork()

real function sroundup_lwork ( integer  LWORK)

SROUNDUP_LWORK

Purpose:
 SROUNDUP_LWORK deals with a subtle bug with returning LWORK as a Float.
 This routine guarantees it is rounded up instead of down by
 multiplying LWORK by 1+eps when it is necessary, where eps is the relative machine precision.
 E.g.,

        float( 16777217            ) == 16777216
        float( 16777217 ) * (1.+eps) == 16777218

 \return SROUNDUP_LWORK
 \verbatim
         SROUNDUP_LWORK >= LWORK.
         SROUNDUP_LWORK is guaranteed to have zero decimal part.
Parameters
[in]LWORKWorkspace size.
Author
Weslley Pereira, University of Colorado Denver, USA
Further Details:
  This routine was inspired in the method `magma_zmake_lwork` from MAGMA.
  \see https://bitbucket.org/icl/magma/src/master/control/magma_zauxiliary.cpp

Definition at line 58 of file sroundup_lwork.f.

59*
60* -- LAPACK auxiliary routine --
61* -- LAPACK is a software package provided by Univ. of Tennessee, --
62* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
63*
64* .. Scalar Arguments ..
65 INTEGER LWORK
66* ..
67*
68* =====================================================================
69* ..
70* .. Intrinsic Functions ..
71 INTRINSIC epsilon, real, int
72* ..
73* .. Executable Statements ..
74* ..
75 sroundup_lwork = real( lwork )
76*
77 IF( int( sroundup_lwork ) .LT. lwork ) THEN
78* Force round up of LWORK
79 sroundup_lwork = sroundup_lwork * ( 1.0e+0 + epsilon(0.0e+0) )
80 ENDIF
81*
82 RETURN
83*
84* End of SROUNDUP_LWORK
85*
real function sroundup_lwork(LWORK)
SROUNDUP_LWORK
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