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, 10 insertions, 0 deletions

diff --git a/lib/compiler/src/genop.tab b/lib/compiler/src/genop.tab
index 397e478e1e..d59bb241a8 100755
--- a/lib/compiler/src/genop.tab
+++ b/lib/compiler/src/genop.tab
@@ -554,3 +554,13 @@ BEAM_FORMAT_NUMBER=0
 ##       Do a garbage collection if necessary to allocate space on the heap
 ##       for the result.
 160: build_stacktrace/0
+
+## @spec raw_raise
+## @doc  This instruction works like the erlang:raise/3 BIF, except that the
+##       stacktrace in x(2) must be a raw stacktrace.
+##       x(0) is the class of the exception (error, exit, or throw),
+##       x(1) is the exception term, and x(2) is the raw stackframe.
+##       If x(0) is not a valid class, the instruction will not throw an
+##       exception, but store the atom 'badarg' in x(0) and execute the
+##       next instruction.
+161: raw_raise/0