Don't build a stacktrace if it's only passed to erlang:raise/3

Consider the following function:

    function({function,Name,Arity,CLabel,Is0}, Lc0) ->
      try
        %% Optimize the code for the function.
      catch
        Class:Error:Stack ->
          io:format("Function: ~w/~w\n", [Name,Arity]),
          erlang:raise(Class, Error, Stack)
      end.

The stacktrace is retrieved, but it is only used in the call
to erlang:raise/3. There is no need to build a stacktrace
in this function. We can avoid the building if we introduce
an instruction called raw_raise/3 that works exactly like
the erlang:raise/3 BIF except that its third argument must
be a raw stacktrace.

1 files changed, 6 insertions, 0 deletions

diff --git a/lib/hipe/icode/hipe_beam_to_icode.erl b/lib/hipe/icode/hipe_beam_to_icode.erl
index 7ff9fd83eb..6e66ec057c 100644
--- a/lib/hipe/icode/hipe_beam_to_icode.erl
+++ b/lib/hipe/icode/hipe_beam_to_icode.erl
@@ -1164,6 +1164,12 @@ trans_fun([build_stacktrace|Instructions], Env) ->
   Vars = [mk_var({x,0})], %{x,0} is implict arg and dst
   [hipe_icode:mk_primop(Vars,build_stacktrace,Vars),
    trans_fun(Instructions, Env)];
+%%--- raw_raise ---
+trans_fun([raw_raise|Instructions], Env) ->
+  Vars = [mk_var({x,0}),mk_var({x,1}),mk_var({x,2})],
+  Dst = [mk_var({x,0})],
+  [hipe_icode:mk_primop(Dst,raw_raise,Vars) |
+   trans_fun(Instructions, Env)];
 %%--------------------------------------------------------------------
 %%--- ERROR HANDLING ---
 %%--------------------------------------------------------------------