REE: fix uninitialized registers handling

gcc/ChangeLog:

	PR rtl-optimization/66790
	* df.h (DF_MIR): New macro.
	(DF_LAST_PROBLEM_PLUS1): Update to be past DF_MIR
	(DF_MIR_INFO_BB): New macro.
	(DF_MIR_IN, DF_MIR_OUT): New macros.
	(struct df_mir_bb_info): New.
	(df_mir): New macro.
	(df_mir_add_problem, df_mir_simulate_one_insn): New forward
	declarations.
	(df_mir_get_bb_info): New.
	* df-problems.c (struct df_mir_problem_data): New.
	(df_mir_free_bb_info, df_mir_alloc, df_mir_reset,
	df_mir_bb_local_compute, df_mir_local_compute, df_mir_init,
	df_mir_confluence_0, df_mir_confluence_n,
	df_mir_transfer_function, df_mir_free, df_mir_top_dump,
	df_mir_bottom_dump, df_mir_verify_solution_start,
	df_mir_verify_solution_end): New.
	(problem_MIR): New.
	(df_mir_add_problem, df_mir_simulate_one_insn): New.
	* timevar.def (TV_DF_MIR): New.
	* ree.c: Include bitmap.h
	(add_removable_extension): Add an INIT_REGS parameter.  Use it
	to skip zero-extensions that may get an uninitialized register.
	(find_removable_extensions): Compute must-initialized registers
	using the MIR dataflow problem. Update the call to
	add_removable_extension.
	(find_and_remove_re): Call df_mir_add_problem.

gcc/testsuite/ChangeLog:

	* gnat.dg/opt50.adb: New test.
	* gnat.dg/opt50_pkg.adb: New helper.
	* gnat.dg/opt50_pkg.ads: New helper.

From-SVN: r229008

3 files changed, 83 insertions, 0 deletions

diff --git a/gcc/testsuite/gnat.dg/opt50.adb b/gcc/testsuite/gnat.dg/opt50.adb
new file mode 100644
index 0000000..f930d09
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/opt50.adb
@@ -0,0 +1,23 @@
+-- { dg-do run }
+-- { dg-options "-O3 -gnatn" }
+
+with Opt50_Pkg; use Opt50_Pkg;
+
+procedure Opt50 is
+  B : Boolean;
+  E : Enum;
+begin
+  Get ("four", E, B);
+  if B = True then
+    raise Program_Error;
+  end if;
+  Get ("three", E, B);
+  if B = False then
+    raise Program_Error;
+  end if;
+  declare
+    A : Enum_Boolean_Array (One .. E) := (others => True);
+  begin
+    Set (A);
+  end;
+end Opt50;
diff --git a/gcc/testsuite/gnat.dg/opt50_pkg.adb b/gcc/testsuite/gnat.dg/opt50_pkg.adb
new file mode 100644
index 0000000..0f92f7d
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/opt50_pkg.adb
@@ -0,0 +1,48 @@
+with Ada.Characters.Handling;
+with Ada.Containers;
+with Ada.Containers.Indefinite_Hashed_Maps;
+with Ada.Strings.Hash;
+
+package body Opt50_Pkg is
+
+   type Enum_Name is array (Enum) of access constant String;
+
+   Enum_Name_Table : constant Enum_Name := (
+      One   => new String'("one"),
+      Two   => new String'("two"),
+      Three => new String'("three"));
+
+   package String_To_Enum_Map is new Ada.Containers.Indefinite_Hashed_Maps
+      (Key_Type => String, Element_Type => Enum,
+       Hash => Ada.Strings.Hash, Equivalent_Keys => "=");
+
+   function Fill_Hashed_Map return String_To_Enum_Map.Map is
+      Res : String_To_Enum_Map.Map;
+      use String_To_Enum_Map;
+   begin
+      for I in Enum_Name_Table'Range loop
+         declare
+            Kind : constant String := Enum_Name_Table (I).all;
+         begin
+            Res.Insert(Key => Kind, New_Item => I);
+         end;
+      end loop;
+      return Res;
+   end;
+
+   String_To_Enum : constant String_To_Enum_Map.Map := Fill_Hashed_Map;
+
+   procedure Get (Kind : String; Result : out Enum; Success : out Boolean) is
+      X : constant String := Ada.Characters.Handling.To_Lower (Kind);
+      use String_To_Enum_Map;
+      Curs : constant Cursor := String_To_Enum.Find (X);
+   begin
+      Success := Curs /= No_Element;
+      if Success then
+         Result := Element(Curs);
+      end if;
+   end;
+
+   procedure Set (A : Enum_Boolean_Array) is null;
+
+end Opt50_Pkg;
diff --git a/gcc/testsuite/gnat.dg/opt50_pkg.ads b/gcc/testsuite/gnat.dg/opt50_pkg.ads
new file mode 100644
index 0000000..9faea54
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/opt50_pkg.ads
@@ -0,0 +1,12 @@
+package Opt50_Pkg is
+
+   type Enum is (One, Two, Three);
+   for Enum'Size use 16;
+
+   type Enum_Boolean_Array is array (Enum range <>) of Boolean;
+
+   procedure Get (Kind : String; Result : out Enum; Success : out Boolean);
+
+   procedure Set (A : Enum_Boolean_Array);
+
+end Opt50_Pkg;