Optimize the is_function/2 guard test

The is_function2 instruction is executed surprisingly
frequently when running dialyzer or the compiler. It
cannot hurt to optimize it a little.

1 files changed, 7 insertions, 1 deletions

diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index df60e889f3..e55c4a112d 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -709,12 +709,18 @@ is_function(Fail, Src) {
     }
 }
 
-is_function2(Fail, Fun, Arity) {
+cold_is_function2(Fail, Fun, Arity) {
     if (erl_is_function(c_p, $Fun, $Arity) != am_true ) {
         $FAIL($Fail);
     }
 }
 
+hot_is_function2(Fail, Fun, Arity) {
+    if (!is_function2($Fun, $Arity)) {
+        $FAIL($Fail);
+    }
+}
+
 is_integer(Fail, Src) {
     if (is_not_integer($Src)) {
         $FAIL($Fail);