Initial revision

mach/proto/fp/adf4.c

@@ -0,0 +1,48 @@
+/*
+	ADD TWO FLOATS - SINGLE
+*/
+
+#include	"FP_types.h"
+
+_float
+adf4(s2,s1)
+_float	s1,s2;
+{
+	EXTEND	e1,e2;
+	int	swap = 0;
+
+	extend((_double *)&s1,&e1,sizeof(SINGLE));
+	extend((_double *)&s2,&e2,sizeof(SINGLE));
+			/* if signs differ do subtraction	*/
+			/* result in e1 */
+	if (e1.sign ^ e2.sign)	{
+#ifdef	DEBUG
+		printf("\t\t\tADF calls SUBTRACT\n");
+#endif	DEBUG
+			/* set sign of e1 to sign of largest	*/
+		swap = (e2.exp >  e1.exp) ? 1 : (e2.exp < e1.exp) ? 0 :
+		       (e2.m1  >  e1.m1 ) ? 1 : 0;
+			/* adjust mantissas to equal powers */
+		sft_ext(&e1,&e2);
+			/* subtract the extended formats	*/
+		if (swap)	{
+#ifdef	DEBUG
+			printf("\t\t\t\tSWAP\n");
+#endif	DEBUG
+			sub_ext(&e2,&e1);
+			e1 = e2;
+		}
+		else
+			sub_ext(&e1,&e2);
+	}
+	else	{
+#ifdef	DEBUG
+		printf("\t\t\tADF calls ADDITION\n");
+#endif	DEBUG
+			/* adjust mantissas to equal powers */
+		sft_ext(&e1,&e2);
+		add_ext(&e1,&e2);
+	}
+	compact(&e1,(_double *)&s1,sizeof(SINGLE));
+	return(s1);
+}