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Arithmetic safety.

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This commit is contained in:
redcode
2018-08-09 04:46:22 +02:00
parent 34a2bff1ed
commit 53aa30b287
1 changed files with 13 additions and 13 deletions
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26
sources/Z80.c
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@@ -366,19 +366,19 @@ static void __uuu___(Z80 *object, zuint8 offset, zuint8 value)
case 0: /* ADD */
t = A + value;
F = ((zuint)A + (zuint)value > 255) /* CF = Carry */
| pf_overflow_add8(A, value) /* PF = Overflow */
| ((A ^ value ^ t) & HF); /* HF = Half-carry */
A = t; /* NF = 0 */
F = ((zuint)A + value > 255) /* CF = Carry */
| pf_overflow_add8(A, value) /* PF = Overflow */
| ((A ^ value ^ t) & HF); /* HF = Half-carry */
A = t; /* NF = 0 */
break;
case 1: /* ADC */
t = F_C;
F = ((zuint)A + (zuint)value + (zuint)t > 255) /* CF = Carry */
| pf_overflow_adc8(A, value, t) /* PF = Overflow */
| (((A & 0xF) + (value & 0xF) + t) & HF); /* HF = Half-carry */
/* NF = 0 */
F = ((zuint)A + value + t > 255) /* CF = Carry */
| pf_overflow_adc8(A, value, t) /* PF = Overflow */
| (((A & 0xF) + (value & 0xF) + t) & HF); /* HF = Half-carry */
/* NF = 0 */
A += value + t;
break;
@@ -682,11 +682,11 @@ static Z_INLINE void add_RR_NN(Z80 *object, zuint16 *r, zuint16 v)
{
zuint16 t = *r + v;
F = F_SZP /* SF, ZF, PF unchanged */
| ((t >> 8) & YXF) /* YF = RR.13; XF = RR.11 */
| (((*r ^ v ^ t) >> 8) & HF) /* HF = RRh half-carry */
| ((zuint32)*r + (zuint32)v > 65535); /* CF = Carry */
*r = t; /* NF = 0 */
F = F_SZP /* SF, ZF, PF unchanged */
| ((t >> 8) & YXF) /* YF = RR.13; XF = RR.11 */
| (((*r ^ v ^ t) >> 8) & HF) /* HF = RRh half-carry */
| ((zuint32)*r + v > 65535); /* CF = Carry */
*r = t; /* NF = 0 */
}