1 files changed, 49 insertions, 0 deletions
diff --git a/deps/lightning/doc/ifib.c b/deps/lightning/doc/ifib.c
new file mode 100644
index 0000000..745c80b
--- /dev/null
+++ b/deps/lightning/doc/ifib.c
@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <lightning.h>
+
+static jit_state_t *_jit;
+
+typedef int (*pifi)(int);       /* Pointer to Int Function of Int */
+
+int main(int argc, char *argv[])
+{
+  pifi       fib;
+  jit_node_t *in;               /* offset of the argument */
+  jit_node_t *ref;              /* to patch the forward reference */
+  jit_node_t *zero;             /* to patch the forward reference */
+  jit_node_t *jump;             /* jump to start of loop */
+  jit_node_t *loop;             /* start of the loop */
+
+  init_jit(argv[0]);
+  _jit = jit_new_state();
+
+        jit_prolog   ();
+  in =  jit_arg      ();
+        jit_getarg   (JIT_R0, in);              /* R0 = n */
+ zero = jit_beqi     (JIT_R0, 0);
+        jit_movr     (JIT_R1, JIT_R0);
+        jit_movi     (JIT_R0, 1);
+  ref = jit_blei     (JIT_R1, 2);
+        jit_subi     (JIT_R2, JIT_R1, 2);
+        jit_movr     (JIT_R1, JIT_R0);
+
+  loop= jit_label();
+        jit_subi     (JIT_R2, JIT_R2, 1);       /* decr. counter */
+        jit_movr     (JIT_V0, JIT_R0);          /* V0 = R0 */
+        jit_addr     (JIT_R0, JIT_R0, JIT_R1);  /* R0 = R0 + R1 */
+        jit_movr     (JIT_R1, JIT_V0);          /* R1 = V0 */
+  jump= jit_bnei     (JIT_R2, 0);               /* if (R2) goto loop; */
+  jit_patch_at(jump, loop);
+
+  jit_patch(ref);                               /* patch forward jump */
+  jit_patch(zero);                              /* patch forward jump */
+        jit_retr     (JIT_R0);
+
+  /* call the generated code, passing 36 as an argument */
+  fib = jit_emit();
+  jit_clear_state();
+  printf("fib(%d) = %d\n", 36, fib(36));
+  jit_destroy_state();
+  finish_jit();
+  return 0;
+}