--- cci/sys/tahoe/Kmuld.x	2019/07/28 12:24:19	1.1.1.1
+++ cci/sys/tahoe/Kmuld.x	2019/07/28 12:30:03	1.1.1.2
@@ -79,9 +79,6 @@ _Kmuld:	.word	0xffc
 	jmp	1b
 realshift:
 	shrq	r5,r0,r0
-	bbc	$0,r1,shiftmore
-	incl	r1		/* rounding. */
-shiftmore:
 	shrq	$1,r0,r0
 comb:
 	andl2	$CLEARHID,r0
@@ -91,8 +88,21 @@ comb:
 	jlss	1f
 	orl2	$HFS_OVF,*20(fp)	
 sign:
-1:	bbc	$0,r3,done
+1:	bbc	$0,r3,1f
 	orl2	$SIGNBIT,r0
+/*
+ * 3/31/86 - Check if rounding is needed.  If the accumulator least is
+ * 0xfffffff0-0xffffffff and the lower half of the accumulator most is
+ * 0xffff, then rounding could have significance and should be done.
+ */
+1:	andl3	$0xfffffff0,r1,r2
+	cmpl	$0xfffffff0,r2
+	jneq	done
+	andl3	$0xffff,r0,r2
+	cmpl	$0xffff,r2
+	jneq	done
+	clrl	r1
+	incl	r0
 done:	ret
 
 
@@ -103,9 +113,17 @@ done:	ret
 	  ret
   overflow:
 	orl2	$HFS_OVF,*20(fp)
+	movl	$0x7fffffff,r0
+	bbc	$0,r3,1f
+	orl2	$SIGNBIT,r0
+1:	mnegl	$1,r1
 	ret
   underflow:
 	orl2	$HFS_UNDF,*20(fp)
+	movl	$0x800000,r0
+	bbc	$0,r3,1f
+	orl2	$SIGNBIT,r0
+1:	clrl	r1
 	ret