diff options
Diffstat (limited to 'sux.c')
| -rw-r--r-- | sux.c | 84 |
1 files changed, 79 insertions, 5 deletions
@@ -1,4 +1,3 @@ -#include <limits.h> #include "opcode.h" #include <stdint.h> uint64_t a; /* Accumulator. */ @@ -19,13 +18,88 @@ uint64_t alu(uint8_t opcode, uint64_t value) { break; /* Subtract with carry. */ case SBC: - sum = a-value-!carry + sum = a-value-!carry; vf = (a^value) & (a^sum) & 0x80; carry = (sum > value) ? 1 : 0; a |= sum; break; - - - + /* Multiply with accumulator. */ + case MUL: + sum = a*value+carry; + vf = (~(a^value) & (a^sum & 0x80)); + carry = (sum < value) ? 1 : 0; + a |= sum; + break; + /* Divide with accumulator. */ + case DIV: + sum = a/value-!carry; + vf = (a^value) & (a^sum) & 0x80; + carry = (sum > value) ? 1 : 0; + a |= sum; + break; + /* Bitwise AND. */ + case AND: + case AAY: + case AAX: + a &= value; + if (opcode == AAY) + y &= value; + if (opcode == AAX) + x &= value; + break; + case ANY: + y &= value; + break; + case ANX: + x &= value; + break; + /* Bitwise OR. */ + case ORA: + case OAY: + case OAX: + a |= value; + if (opcode == OAY) + y |= value; + if (opcode == OAX) + x |= value; + break; + case ORY: + y |= value; + break; + case ORX: + x |= value; + break; + /* Bitwise Exclusive OR. */ + case XOR: + case XAY: + case XAX: + a ^= value; + if (opcode == XAY) + y ^= value; + if (opcode == XAX) + x ^= value; + break; + case XRY: + y ^= value; + break; + case XRX: + x ^= value; + break; + /* Shift accumulator left. */ + case SLA: + a <<= value; + break; + /* Shift accumulator right. */ + case SRA: + a >>= value; + break; + /* Rotate accumulator left. */ + case ROL: + (a << value) | (a >> (64-value)); + break; + /* Rotate accumulator right. */ + case ROR: + (a >> value) | (a << (64-value)); + break; } } |