Initial revision

lib/float/fif8.c

@@ -0,0 +1,48 @@
+/*
+  (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
+  See the copyright notice in the ACK home directory, in the file "Copyright".
+*/
+
+/* $Header$ */
+
+/*
+	MULTIPLY AND DISMEMBER PARTS (FIF 8)
+*/
+
+#include "FP_types.h"
+#include "FP_shift.h"
+
+void
+fif8(p,x,y)
+DOUBLE	x,y;
+struct fif8_returns *p;
+{
+
+	EXTEND	e1,e2;
+
+	extend(&y.d[0],&e1,sizeof(DOUBLE));
+	extend(&x.d[0],&e2,sizeof(DOUBLE));
+		/* do a multiply */
+	mul_ext(&e1,&e2);
+	e2 = e1;
+	compact(&e2, &y.d[0], sizeof(DOUBLE));
+	if (e1.exp < 0) {
+		p->ipart.d[0] = 0;
+		p->ipart.d[1] = 0;
+		p->fpart = y;
+		return;
+	}
+	if (e1.exp > 62 - DBL_M1LEFT) {
+		p->ipart = y;
+		p->fpart.d[0] = 0;
+		p->fpart.d[1] = 0;
+		return;
+	}
+	b64_sft(&e1.mantissa, 63 - e1.exp);
+	b64_sft(&e1.mantissa, e1.exp - 63);	/* "loose" low order bits */
+	compact(&e1, &(p->ipart.d[0]), sizeof(DOUBLE));
+	extend(&(p->ipart.d[0]), &e2, sizeof(DOUBLE));
+	extend(&y.d[0], &e1, sizeof(DOUBLE));
+	sub_ext(&e1, &e2);
+	compact(&e1, &(p->fpart.d[0]), sizeof(DOUBLE));
+}