| 1 | #include <stdio.h> |
| 2 | #include <lightning.h> |
| 3 | |
| 4 | static jit_state_t *_jit; |
| 5 | |
| 6 | typedef int (*pifi)(int); /* Pointer to Int Function of Int */ |
| 7 | |
| 8 | int main(int argc, char *argv[]) |
| 9 | { |
| 10 | pifi fib; |
| 11 | jit_node_t *label; |
| 12 | jit_node_t *call; |
| 13 | jit_node_t *in; /* offset of the argument */ |
| 14 | jit_node_t *ref; /* to patch the forward reference */ |
| 15 | jit_node_t *zero; /* to patch the forward reference */ |
| 16 | |
| 17 | init_jit(argv[0]); |
| 18 | _jit = jit_new_state(); |
| 19 | |
| 20 | label = jit_label(); |
| 21 | jit_prolog (); |
| 22 | in = jit_arg (); |
| 23 | jit_getarg (JIT_R0, in); /* R0 = n */ |
| 24 | zero = jit_beqi (JIT_R0, 0); |
| 25 | jit_movr (JIT_V0, JIT_R0); /* V0 = R0 */ |
| 26 | jit_movi (JIT_R0, 1); |
| 27 | ref = jit_blei (JIT_V0, 2); |
| 28 | jit_subi (JIT_V1, JIT_V0, 1); /* V1 = n-1 */ |
| 29 | jit_subi (JIT_V2, JIT_V0, 2); /* V2 = n-2 */ |
| 30 | jit_prepare(); |
| 31 | jit_pushargr(JIT_V1); |
| 32 | call = jit_finishi(NULL); |
| 33 | jit_patch_at(call, label); |
| 34 | jit_retval(JIT_V1); /* V1 = fib(n-1) */ |
| 35 | jit_prepare(); |
| 36 | jit_pushargr(JIT_V2); |
| 37 | call = jit_finishi(NULL); |
| 38 | jit_patch_at(call, label); |
| 39 | jit_retval(JIT_R0); /* R0 = fib(n-2) */ |
| 40 | jit_addr(JIT_R0, JIT_R0, JIT_V1); /* R0 = R0 + V1 */ |
| 41 | |
| 42 | jit_patch(ref); /* patch jump */ |
| 43 | jit_patch(zero); /* patch jump */ |
| 44 | jit_retr(JIT_R0); |
| 45 | |
| 46 | /* call the generated code, passing 32 as an argument */ |
| 47 | fib = jit_emit(); |
| 48 | jit_clear_state(); |
| 49 | printf("fib(%d) = %d\n", 32, fib(32)); |
| 50 | jit_destroy_state(); |
| 51 | finish_jit(); |
| 52 | return 0; |
| 53 | } |