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diff --git a/sys/gio/fpnormr.x b/sys/gio/fpnormr.x
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+++ b/sys/gio/fpnormr.x
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+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<mach.h>
+
+# FP_NORMR -- Normalize a single precision number x to the value NORMX, in the
+# range [1-10).  EXPON is returned such that  x = normx * (10.0E0 ** expon).
+
+procedure fp_normr (x, normx, expon)
+
+real	x			# number to be normalized
+real	normx			# X normalized to the range 1-10 (output)
+int	expon			# exponent of normalized X
+real	absx, tol
+
+begin
+	tol = EPSILONR * 10.0
+	absx = abs (x)
+	expon = 0
+
+	if (absx > 0) {
+	    while (absx < (1.0E0 - tol)) {
+		absx = absx * 10.0E0
+		expon = expon - 1
+		if (absx == 0.0) {	# check for underflow to zero
+		    normx = 0
+		    expon = 0
+		    return
+		}
+	    }
+	    while (absx >= (10.0E0 + tol)) {
+		absx = absx / 10.0E0
+		expon = expon + 1
+	    }
+	}
+
+	if (x < 0)
+	    normx = -absx
+	else
+	    normx = absx
+end