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VAX: Fixed WordLshift (ASHP left overflow calc)

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As observed by EVKAB diagnostic and reported in #319
This commit is contained in:
Mark Pizzolato 2016-05-30 14:43:35 -07:00
parent 8b08e6c2d9
commit 8d7e8f4d30
1 changed files with 15 additions and 14 deletions
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29
VAX/vax_cis.c
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@ -1,6 +1,6 @@
/* vax_cis.c: VAX CIS instructions
Copyright (c) 2004-2008, Robert M Supnik
Copyright (c) 2004-2016, Robert M Supnik
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
@ -26,7 +26,8 @@
On a full VAX, this module simulates the VAX commercial instruction set (CIS).
On a subset VAX, this module implements the emulated instruction fault.
16-Oct-08 RMS Fixed bug in ASHP left overflow calc (Word/NibbleLShift)
30-May-16 RMS Fixed WorldLshift FOR REAL
16-Oct-08 RMS Fixed bug in ASHP left overflow calc (Word/NibbleLshift)
Fixed bug in DIVx (LntDstr calculation)
28-May-08 RMS Inlined physical memory routines
16-May-06 RMS Fixed bug in length calculation (Tim Stark)
@ -1494,7 +1495,7 @@ void WordRshift (DSTR *dsrc, int32 sc)
{
int32 i;
if (sc) {
if (sc != 0) {
for (i = 0; i < DSTRLNT; i++) {
if ((i + sc) < DSTRLNT)
dsrc->val[i] = dsrc->val[i + sc];
@ -1513,18 +1514,18 @@ return;
int32 WordLshift (DSTR *dsrc, int32 sc)
{
int32 i, c;
int32 i, c, zc;
c = 0;
if (sc) {
for (i = DSTRMAX; i >= 0; i--) {
if (i >= sc)
dsrc->val[i] = dsrc->val[i - sc];
else {
c |= dsrc->val[i];
dsrc->val[i] = 0;
}
if (sc != 0) {
for (i = DSTRMAX; i >= 0; i--) { /* work hi to low */
if ((i + sc) <= DSTRMAX) /* move in range? */
dsrc->val[i + sc] = dsrc->val[i];
else c |= dsrc->val[i]; /* no, count as ovflo */
}
zc = (sc >= DSTRLNT)? DSTRLNT: sc; /* cap fill */
for (i = 0; i < zc; i++) /* fill with 0s */
dsrc->val[i] = 0;
}
return c;
}
@ -1541,7 +1542,7 @@ uint32 NibbleRshift (DSTR *dsrc, int32 sc, uint32 cin)
{
int32 i, s, nc;
if ((s = sc * 4)) {
if ((s = sc * 4) != 0) {
for (i = DSTRMAX; i >= 0; i--) {
nc = (dsrc->val[i] << (32 - s)) & LMASK;
dsrc->val[i] = ((dsrc->val[i] >> s) |
@ -1565,7 +1566,7 @@ uint32 NibbleLshift (DSTR *dsrc, int32 sc, uint32 cin)
{
int32 i, s, nc;
if ((s = sc * 4)) {
if ((s = sc * 4) != 0) {
for (i = 0; i < DSTRLNT; i++) {
nc = dsrc->val[i] >> (32 - s);
dsrc->val[i] = ((dsrc->val[i] << s) |