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fix edge cases with add/sub carry and overflow flag

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This commit is contained in:
Michaël Banaan Ananas 2012-07-18 04:37:04 +00:00
parent efb5a45086
commit fea905713a
1 changed files with 10 additions and 12 deletions
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22
src/emu/cpu/tms32025/tms32025.c
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@ -413,9 +413,6 @@ INLINE void MODIFY_AR_ARP(tms32025_state *cpustate)
case 0x70: /* 111 *BR0+ */
cpustate->AR[ARP] += reverse_carry_add(cpustate->AR[ARP],cpustate->AR[0]);
break;
default:
break;
}
if( !cpustate->mHackIgnoreARP )
@ -449,7 +446,7 @@ INLINE void CALCULATE_SUB_CARRY(tms32025_state *cpustate)
INLINE void CALCULATE_ADD_OVERFLOW(tms32025_state *cpustate, INT32 addval)
{
if ((INT32)(~(cpustate->oldacc.d ^ addval) & (cpustate->oldacc.d ^ cpustate->ACC.d)) < 0)
if ((INT32)((cpustate->ACC.d ^ addval) & (cpustate->oldacc.d ^ cpustate->ACC.d)) < 0)
{
SET0(cpustate, OV_FLAG);
if (OVM)
@ -587,12 +584,11 @@ static void abst(tms32025_state *cpustate)
}
CLR1(cpustate, C_FLAG);
}
static void add(tms32025_state *cpustate) /* #### add carry support - see page 3-31 (70) #### */
{ /* page 10-13 (348) spru031d */
static void add(tms32025_state *cpustate)
{
cpustate->oldacc.d = cpustate->ACC.d;
GETDATA(cpustate, (cpustate->opcode.b.h & 0xf), SXM);
cpustate->ACC.d += cpustate->ALU.d;
CALCULATE_ADD_OVERFLOW(cpustate, cpustate->ALU.d);
CALCULATE_ADD_CARRY(cpustate);
}
@ -600,17 +596,18 @@ static void addc(tms32025_state *cpustate)
{
cpustate->oldacc.d = cpustate->ACC.d;
GETDATA(cpustate, 0, 0);
if (CARRY) cpustate->ALU.d++;
if (CARRY) cpustate->ACC.d++;
cpustate->ACC.d += cpustate->ALU.d;
CALCULATE_ADD_OVERFLOW(cpustate, cpustate->ALU.d);
CALCULATE_ADD_CARRY(cpustate);
if (cpustate->ACC.d == cpustate->oldacc.d) {} /* edge case, carry remains same */
else CALCULATE_ADD_CARRY(cpustate);
}
static void addh(tms32025_state *cpustate)
{
cpustate->oldacc.d = cpustate->ACC.d;
GETDATA(cpustate, 0, 0);
cpustate->ACC.w.h += cpustate->ALU.w.l;
if ((INT16)(~(cpustate->oldacc.w.h ^ cpustate->ALU.w.l) & (cpustate->oldacc.w.h ^ cpustate->ACC.w.h)) < 0) {
if ((INT16)((cpustate->ACC.w.h ^ cpustate->ALU.w.l) & (cpustate->oldacc.w.h ^ cpustate->ACC.w.h)) < 0) {
SET0(cpustate, OV_FLAG);
if (OVM)
cpustate->ACC.w.h = ((INT16)cpustate->oldacc.w.h < 0) ? 0x8000 : 0x7fff;
@ -1486,10 +1483,11 @@ static void subb(tms32025_state *cpustate)
{
cpustate->oldacc.d = cpustate->ACC.d;
GETDATA(cpustate, 0, 0);
if (CARRY == 0) cpustate->ALU.d--;
if (CARRY == 0) cpustate->ACC.d--;
cpustate->ACC.d -= cpustate->ALU.d;
CALCULATE_SUB_OVERFLOW(cpustate, cpustate->ALU.d);
CALCULATE_SUB_CARRY(cpustate);
if (cpustate->ACC.d == cpustate->oldacc.d) {} /* edge case, carry remains same */
else CALCULATE_SUB_CARRY(cpustate);
}
static void subc(tms32025_state *cpustate)
{