gcc subdir for combined gcc/ack library build

lib/gnu/ieee_float/modf.c

@@ -0,0 +1,61 @@
+/*
+libc/ieee_float/modf.c
+
+Created:	Oct 14, 1993 by Philip Homburg <philip@cs.vu.nl>
+
+Implementation of modf that directly manipulates the exponent bits in an
+ieee float
+*/
+
+#include <sys/types.h>
+#include <math.h>
+
+#include "ieee_float.h"
+
+double modf(value, iptr)
+double value;
+double *iptr;
+{
+	struct f64 *f64p;
+	double tmp;
+	int exp;
+	int mask_bits;
+	u32_t mant;
+
+	f64p= (struct f64 *)&value;
+
+	exp= F64_GET_EXP(f64p);
+	exp -= F64_EXP_BIAS;
+	if (exp < 0)
+	{
+		*iptr= 0;
+		return value;
+	}
+	mask_bits= 52-exp;
+	if (mask_bits <= 0)
+	{
+		*iptr= value;
+		return 0;
+	}
+	tmp= value;
+	if (mask_bits >= 32)
+	{
+		F64_SET_MANT_LOW(f64p, 0);
+		mask_bits -= 32;
+		mant= F64_GET_MANT_HIGH(f64p);
+		mant &= ~((1 << mask_bits)-1);
+		F64_SET_MANT_HIGH(f64p, mant);
+	}
+	else
+	{
+		mant= F64_GET_MANT_LOW(f64p);
+		mant &= ~((1 << mask_bits)-1);
+		F64_SET_MANT_LOW(f64p, mant);
+	}
+	*iptr= value;
+	return tmp-value;
+}
+
+/*
+ * $PchId: modf.c,v 1.3 1996/02/22 21:01:39 philip Exp $
+ */