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ocpu: Add CMP instruction

This commit is contained in:
g1n 2022-05-08 13:23:09 +03:00
parent 05914bb508
commit 055f16d956
Signed by: g1n
GPG Key ID: 8D352193D65D4E2C
2 changed files with 30 additions and 0 deletions
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2
src/include/yemu/ocpu.h
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@ -59,6 +59,8 @@
#define INS_XOR_REG 0xC4
#define INS_NAND_IM 0x25
#define INS_NAND_REG 0xC5
#define INS_CMP_IM 0x26
#define INS_CMP_REG 0xC6
#define INS_OCPU_NOP 0x90
#define INS_OCPU_SEC 0x61
#define INS_OCPU_CLC 0x62

28
src/ocpu/ocpu.c
View File

@ -420,6 +420,34 @@ void ocpu_execute() {
write_register(reg, 0, word_value);
}
break;
case INS_CMP_IM:
int reg_value = match_register(ocpu_fetch_byte());
value = ocpu_fetch_byte();
if (reg_value == value) {
ocpu.ZF = 1;
ocpu.CF = 0;
} else if (reg_value < value) {
ocpu.ZF = 0;
ocpu.CF = 1;
} else {
ocpu.ZF = 0;
ocpu.CF = 0;
}
break;
case INS_CMP_REG:
int reg1_value = match_register(ocpu_fetch_byte());
int reg2_value = match_register(ocpu_fetch_byte());
if (reg1_value == reg2_value) {
ocpu.ZF = 1;
ocpu.CF = 0;
} else if (reg1_value < reg2_value) {
ocpu.ZF = 0;
ocpu.CF = 1;
} else {
ocpu.ZF = 0;
ocpu.CF = 0;
}
break;
case INS_OCPU_NOP:
break;
case INS_OCPU_SEC: