From b91af798bca6bd963185151799a347e7efbb68e9 Mon Sep 17 00:00:00 2001
From: ceriel <none@none>
Date: Mon, 27 Nov 1989 16:26:02 +0000
Subject: [PATCH] fixed rounding on ties to round to even, and fixed extend bug
 (test for 0 was wrong)

---
 mach/proto/fp/compact.c | 10 ++++++++--
 mach/proto/fp/extend.c  | 24 ++++++++++++++----------
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/mach/proto/fp/compact.c b/mach/proto/fp/compact.c
index 55c3c22eb..c2dea192d 100644
--- a/mach/proto/fp/compact.c
+++ b/mach/proto/fp/compact.c
@@ -63,12 +63,15 @@ dbl_over:			trap(EFOVFL);
 		DBL->_s.p2      |= (f->m1 << DBL_LUNPACK); /* plus 10 == 32 */
 
 		/* if not exact then round to nearest	*/
+		/* on a tie, round to even */
 
 #ifdef EXCEPTION_INEXACT
 		if ((f->m2 & DBL_EXACT) != 0) {
 		    INEXACT();
 #endif
-		    if (f->m2 & DBL_ROUNDUP)	{
+		    if (((f->m2 & DBL_EXACT) > DBL_ROUNDUP)
+			|| ((f->m2 & DBL_EXACT) == DBL_ROUNDUP
+			    && (f->m2 & (DBL_ROUNDUP << 1)))) {
 			DBL->_s.p2++;	/* rounding up	*/
 			if (DBL->_s.p2 == 0L) { /* carry out	*/
 			    DBL->_s.p1.fract++;
@@ -153,12 +156,15 @@ sgl_over:			trap(EFOVFL);
 		SGL->fract = (f->m1 >> SGL_RUNPACK);
 
 		/* check for rounding to nearest	*/
+		/* on a tie, round to even		*/
 #ifdef EXCEPTION_INEXACT
 		if (f->m2 != 0 ||
 		    (f->m1 & SGL_EXACT) != 0L) {
 			INEXACT();
 #endif
-			if (f->m1 & SGL_ROUNDUP) {
+		        if (((f->m1 & SGL_EXACT) > SGL_ROUNDUP)
+			    || ((f->m1 & SGL_EXACT) == SGL_ROUNDUP
+			        && (f->m1 & (SGL_ROUNDUP << 1)))) {
 				SGL->fract++;
 				if (f->exp == 0 && (f->m1 & ~SGL_MASK)) {
 					f->exp++;
diff --git a/mach/proto/fp/extend.c b/mach/proto/fp/extend.c
index a7199e6ae..d2286aa8a 100644
--- a/mach/proto/fp/extend.c
+++ b/mach/proto/fp/extend.c
@@ -42,16 +42,6 @@ int	size;
 	int	leadbit = 0;
 
 	cpt1 = (char *) from;
-	if (((DOUBLE *) cpt1)->_s.p1.fract == 0L ||
-	    ((DOUBLE *) cpt1)->_s.p1.fract == 0x80000000) 	{
-		if (size == sizeof(SINGLE))	{
-zero:			zrf_ext(to);
-			return;
-		}
-		else if (((DOUBLE *) cpt1)->_s.p2 == 0L)
-			goto zero;
-	}
-/*	there is a number to convert so lets get started	*/
 
 #if FL_MSL_AT_LOW_ADDRESS
 #if FL_MSW_AT_LOW_ADDRESS
@@ -86,6 +76,13 @@ zero:			zrf_ext(to);
 		cpt1 += 4;
 		to->m1 = get4(cpt1);
 #endif
+		if (to->exp == 1 && to->m1 == 0 && tmp == 0) {
+			to->exp = 0;
+			to->sign = 0;
+			to->m1 = 0;
+			to->m2 = 0;
+			return;
+		}
 		to->m1 <<= DBL_M1LEFT;		/* shift	*/
 		to->exp -= DBL_BIAS;		/* remove bias	*/
 		to->m1 |= (tmp>>DBL_RPACK);	/* plus 10 == 32	*/
@@ -94,6 +91,13 @@ zero:			zrf_ext(to);
 	else	{	/* size == sizeof(SINGLE)		*/
 		to->m1 = get4(cpt1);
 		to->m1  <<= SGL_M1LEFT;	/* shift	*/
+		if (to->exp == 1 && to->m1 == 0) {
+			to->exp = 0;
+			to->sign = 0;
+			to->m1 = 0;
+			to->m2 = 0;
+			return;
+		}
 		to->exp -= SGL_BIAS;		/* remove bias	*/
 		to->m2 = 0L;
 	}
-- 
2.34.1