Annotation of rpl/lapack/lapack/zla_wwaddw.f, revision 1.1
1.1 ! bertrand 1: SUBROUTINE ZLA_WWADDW( N, X, Y, W )
! 2: *
! 3: * -- LAPACK routine (version 3.2.2) --
! 4: * -- Contributed by James Demmel, Deaglan Halligan, Yozo Hida and --
! 5: * -- Jason Riedy of Univ. of California Berkeley. --
! 6: * -- June 2010 --
! 7: *
! 8: * -- LAPACK is a software package provided by Univ. of Tennessee, --
! 9: * -- Univ. of California Berkeley and NAG Ltd. --
! 10: *
! 11: IMPLICIT NONE
! 12: * ..
! 13: * .. Scalar Arguments ..
! 14: INTEGER N
! 15: * ..
! 16: * .. Array Arguments ..
! 17: COMPLEX*16 X( * ), Y( * ), W( * )
! 18: * ..
! 19: *
! 20: * Purpose
! 21: * =======
! 22: *
! 23: * ZLA_WWADDW adds a vector W into a doubled-single vector (X, Y).
! 24: *
! 25: * This works for all extant IBM's hex and binary floating point
! 26: * arithmetics, but not for decimal.
! 27: *
! 28: * Arguments
! 29: * =========
! 30: *
! 31: * N (input) INTEGER
! 32: * The length of vectors X, Y, and W.
! 33: *
! 34: * X (input/output) COMPLEX*16 array, dimension (N)
! 35: * The first part of the doubled-single accumulation vector.
! 36: *
! 37: * Y (input/output) COMPLEX*16 array, dimension (N)
! 38: * The second part of the doubled-single accumulation vector.
! 39: *
! 40: * W (input) COMPLEX*16 array, dimension (N)
! 41: * The vector to be added.
! 42: *
! 43: * =====================================================================
! 44: *
! 45: * .. Local Scalars ..
! 46: COMPLEX*16 S
! 47: INTEGER I
! 48: * ..
! 49: * .. Executable Statements ..
! 50: DO 10 I = 1, N
! 51: S = X(I) + W(I)
! 52: S = (S + S) - S
! 53: Y(I) = ((X(I) - S) + W(I)) + Y(I)
! 54: X(I) = S
! 55: 10 CONTINUE
! 56: RETURN
! 57: END
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