Re: [PATCH] Make SRA tolerate most throwing statements

[Eric Botcazou <ebotcazou at adacore dot com>]

> back in January in
> http://gcc.gnu.org/ml/gcc-patches/2014-01/msg00848.html Eric pointed
> out a testcase where the problem was SRA not scalarizing an aggregate
> because it was involved in a throwing statement.  The reason is that
> SRA is likely to need to append new statements after each one where a
> replaced aggregate is present, but throwing statements must end their
> BBs.  This patch comes up with a fix for most such situations by
> adding these new statements onto a single successor non-EH edge, if
> there is one and only one such edge.

Thanks for working on this.

> I have bootstrapped and tested a very similar version on x86_64-linux,
> bootstrap and testing of this exact one is currently underway.  OK for
> trunk?  Eric, if and once this gets in, can you please add the
> testcase from your original post to the suite?

Reduced testcase attached, you can install it with the patch.


	* gnat.dg/opt34.adb: New test.
	* gnat.dg/opt34_pkg.ads: New helper.


-- 
Eric Botcazou

-- { dg-do compile }
-- { dg-options "-O -fdump-tree-esra" }

with Opt34_Pkg; use Opt34_Pkg;

procedure Opt34 is

   function Local_Fun (Arg : T_Private) return T_Private is
      Result : T_Private;
   begin

      case Get_Integer (Arg) is
         when 1 =>
            Result := Get_Private (100);
         when 2 =>
            Result := T_Private_Zero;
         when others =>
            null;
      end case;

      return Result;
   end Local_Fun;

begin
   Assert (Get_Integer (Local_Fun (Get_Private (1))) = 100);
end;

-- { dg-final { scan-tree-dump "Created a replacement for result" "esra" } }
-- { dg-final { cleanup-tree-dump "esra" } }

package Opt34_Pkg is

   type T_Private is record
      I : Integer := 0;
   end record;

   T_Private_Zero : constant T_Private := (I => 0);

   function Get_Private (I : Integer) return T_Private;
   function Get_Integer (X : T_Private) return Integer;

   procedure Assert (Cond : Boolean);

end Opt34_Pkg;