1 files changed, 53 insertions, 0 deletions
diff --git a/deps/lightning/doc/rfib.c b/deps/lightning/doc/rfib.c
new file mode 100644
index 0000000..f14da42
--- /dev/null
+++ b/deps/lightning/doc/rfib.c
@@ -0,0 +1,53 @@
+#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 *label;
+  jit_node_t *call;
+  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 */
+
+  init_jit(argv[0]);
+  _jit = jit_new_state();
+
+  label = jit_label();
+        jit_prolog   ();
+  in =  jit_arg      ();
+        jit_getarg   (JIT_R0, in);              /* R0 = n */
+ zero = jit_beqi     (JIT_R0, 0);
+        jit_movr     (JIT_V0, JIT_R0);          /* V0 = R0 */
+        jit_movi     (JIT_R0, 1);
+  ref = jit_blei     (JIT_V0, 2);
+        jit_subi     (JIT_V1, JIT_V0, 1);       /* V1 = n-1 */
+        jit_subi     (JIT_V2, JIT_V0, 2);       /* V2 = n-2 */
+        jit_prepare();
+          jit_pushargr(JIT_V1);
+        call = jit_finishi(NULL);
+        jit_patch_at(call, label);
+        jit_retval(JIT_V1);                     /* V1 = fib(n-1) */
+        jit_prepare();
+          jit_pushargr(JIT_V2);
+        call = jit_finishi(NULL);
+        jit_patch_at(call, label);
+        jit_retval(JIT_R0);                     /* R0 = fib(n-2) */
+        jit_addr(JIT_R0, JIT_R0, JIT_V1);       /* R0 = R0 + V1 */
+
+  jit_patch(ref);                               /* patch jump */
+  jit_patch(zero);                              /* patch jump */
+        jit_retr(JIT_R0);
+
+  /* call the generated code, passing 32 as an argument */
+  fib = jit_emit();
+  jit_clear_state();
+  printf("fib(%d) = %d\n", 32, fib(32));
+  jit_destroy_state();
+  finish_jit();
+  return 0;
+}