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BSR and BSF correctly set zero flag now and 0 source for scan

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@1176
This commit is contained in:
Sjoerd van der Berg 2003-07-31 16:05:16 +00:00
parent 76ec14475b
commit f97b4bb800
1 changed files with 40 additions and 28 deletions
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68
src/cpu/core_full/op.h
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@ -479,53 +479,65 @@ switch (inst.code.op) {
case O_BSFw:
{
FILLFLAGS;
if (!inst.op1.w) SETFLAGBIT(ZF,true);
Bitu count=0;
while (count<16) {
if ((inst.op1.w>>count) & 1) break;
count++;
if (!inst.op1.w) {
SETFLAGBIT(ZF,true);
} else {
Bitu count=0;
while (count<16) {
if ((inst.op1.w>>count) & 1) break;
count++;
}
inst.op1.d=count;
SETFLAGBIT(ZF,false);
}
inst.op1.d=count;
SETFLAGBIT(ZF,false);
}
break;
case O_BSFd:
{
FILLFLAGS;
if (!inst.op1.d) SETFLAGBIT(ZF,true);
Bitu count=0;
while (count<32) {
if ((inst.op1.d>>count) & 1) break;
count++;
if (!inst.op1.d) {
SETFLAGBIT(ZF,true);
} else {
Bitu count=0;
while (count<32) {
if ((inst.op1.d>>count) & 1) break;
count++;
}
inst.op1.d=count;
SETFLAGBIT(ZF,false);
}
inst.op1.d=count;
SETFLAGBIT(ZF,false);
}
break;
case O_BSRw:
{
FILLFLAGS;
if (!inst.op1.w) SETFLAGBIT(ZF,true);
Bits count=15;
while (count>0) {
if ((inst.op1.w>>count) & 1) break;
count--;
if (!inst.op1.w) {
SETFLAGBIT(ZF,true);
} else {
Bits count=15;
while (count>0) {
if ((inst.op1.w>>count) & 1) break;
count--;
}
inst.op1.d=count;
SETFLAGBIT(ZF,false);
}
inst.op1.d=count;
SETFLAGBIT(ZF,false);
}
break;
case O_BSRd:
{
FILLFLAGS;
if (!inst.op1.d) SETFLAGBIT(ZF,true);
Bits count=31;
while (count>0) {
if ((inst.op1.d>>count) & 1) break;
count--;
if (!inst.op1.d) {
SETFLAGBIT(ZF,true);
} else {
Bits count=31;
while (count>0) {
if ((inst.op1.d>>count) & 1) break;
count--;
}
inst.op1.d=count;
SETFLAGBIT(ZF,false);
}
inst.op1.d=count;
SETFLAGBIT(ZF,false);
}
break;
case O_BTw: