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CPM OPERATING SYSTEMS/CPM 68K/1.0X SOURCES/v102a/orglibf/ftoffp.c

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+/*
+	Copyright 1982
+	Alcyon Corporation
+	8716 Production Ave.
+	San Diego, Ca.  92121
+*/
+
+/*char *version "@(#)ftoffp.c	1.2    10/19/83"; */
+
+/*
+ *	Floating Point to FFP Floating Point Routine :
+ *		FFP Standard Single Precision Representation Floating Point
+ *
+ *	long
+ *	fptoffp(f)
+ *	float f;
+ *
+ *	Rely's on the fact that a long and a float are both 32 bits.
+ */
+
+long
+fptoffp(f)			/* convert current machine float to ffp rep */
+float f;			/* unsigned input, guaranteed positive */
+{
+	register int exp, count, sign;
+	long l;
+
+	if (f == 0.0)
+		return(0L);
+	if (f < 0.0) {
+		f = -f;
+		sign = 1;
+	}
+	else
+		sign = 0;
+	exp = 0L;
+	for( ; f >= 1.0; f = f / 2.0)
+		exp++;
+	for( ; f < 0.5; f = f * 2.0)
+		exp--;
+	f = f * 16777216.0;	/* 2 ^ 24 */
+	l = f;
+	l <<= 8;
+	exp += 0x40;
+	l |= (exp & 0x7f);
+	if (sign)
+		l |= 0x80;
+	return(l);
+}