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! { dg-do compile }
! { dg-options "-O2 -fcheck=bounds" }
FUNCTION F06FKFN(N,W,INCW,X,INCX)
IMPLICIT NONE
INTEGER, PARAMETER :: WP = KIND(0.0D0)
REAL (KIND=WP) :: F06FKFN
REAL (KIND=WP), PARAMETER :: ONE = 1.0E+0_WP
REAL (KIND=WP), PARAMETER :: ZERO = 0.0E+0_WP
INTEGER, INTENT (IN) :: INCW, INCX, N
REAL (KIND=WP), INTENT (IN) :: W(*), X(*)
REAL (KIND=WP) :: ABSYI, NORM, SCALE, SSQ
INTEGER :: I, IW, IX
REAL (KIND=WP), EXTERNAL :: F06BMFN
INTRINSIC ABS, SQRT
IF (N<1) THEN
NORM = ZERO
ELSE IF (N==1) THEN
NORM = SQRT(W(1))*ABS(X(1))
ELSE
IF (INCW>0) THEN
IW = 1
ELSE
IW = 1 - (N-1)*INCW
END IF
IF (INCX>0) THEN
IX = 1
ELSE
IX = 1 - (N-1)*INCX
END IF
SCALE = ZERO
SSQ = ONE
DO I = 1, N
IF ((W(IW)/=ZERO) .AND. (X(IX)/=ZERO)) THEN
ABSYI = SQRT(W(IW))*ABS(X(IX))
IF (SCALE<ABSYI) THEN
SSQ = 1 + SSQ*(SCALE/ABSYI)**2
SCALE = ABSYI
ELSE
SSQ = SSQ + (ABSYI/SCALE)**2
END IF
END IF
IW = IW + INCW
IX = IX + INCX
END DO
NORM = F06BMFN(SCALE,SSQ)
END IF
F06FKFN = NORM
RETURN
END FUNCTION F06FKFN
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