| void __attribute__((naked)) incomplete_cas(int *a, int *b) { | |
| // Stop at the first instruction (an lr without a corresponding sc), then make | |
| // a step instruction and ensure that execution stops at the next instruction | |
| // (and a5, a2, a4). | |
| asm volatile("1:\n\t" | |
| "lr.w a2, (a0)\n\t" | |
| "and a5, a2, a4\n\t" | |
| "beq a5, a1, 2f\n\t" | |
| "xor a5, a2, a0\n\t" | |
| "and a5, a5, a4\n\t" | |
| "xor a5, a2, a5\n\t" | |
| "bnez a5, 1b\n\t" | |
| "2:\n\t" | |
| "ret\n\t"); | |
| } | |
| int main() { | |
| int a = 4; | |
| int b = 2; | |
| incomplete_cas(&a, &b); | |
| } |