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Diffstat (limited to 'BLAS/SRC/zaxpy.f')
| -rw-r--r-- | BLAS/SRC/zaxpy.f | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/BLAS/SRC/zaxpy.f b/BLAS/SRC/zaxpy.f new file mode 100644 index 00000000..b33794c3 --- /dev/null +++ b/BLAS/SRC/zaxpy.f @@ -0,0 +1,49 @@ + SUBROUTINE ZAXPY(N,ZA,ZX,INCX,ZY,INCY) +* .. Scalar Arguments .. + DOUBLE COMPLEX ZA + INTEGER INCX,INCY,N +* .. +* .. Array Arguments .. + DOUBLE COMPLEX ZX(*),ZY(*) +* .. +* +* Purpose +* ======= +* +* constant times a vector plus a vector. +* jack dongarra, 3/11/78. +* modified 12/3/93, array(1) declarations changed to array(*) +* + +* .. Local Scalars .. + INTEGER I,IX,IY +* .. +* .. External Functions .. + DOUBLE PRECISION DCABS1 + EXTERNAL DCABS1 +* .. + IF (N.LE.0) RETURN + IF (DCABS1(ZA).EQ.0.0d0) RETURN + IF (INCX.EQ.1 .AND. INCY.EQ.1) GO TO 20 +* +* code for unequal increments or equal increments +* not equal to 1 +* + IX = 1 + IY = 1 + IF (INCX.LT.0) IX = (-N+1)*INCX + 1 + IF (INCY.LT.0) IY = (-N+1)*INCY + 1 + DO 10 I = 1,N + ZY(IY) = ZY(IY) + ZA*ZX(IX) + IX = IX + INCX + IY = IY + INCY + 10 CONTINUE + RETURN +* +* code for both increments equal to 1 +* + 20 DO 30 I = 1,N + ZY(I) = ZY(I) + ZA*ZX(I) + 30 CONTINUE + RETURN + END |