With this change, the compiler now supports the -gnatn[d] switch, where 'd'
is a digit and can only be '1' or '2' for the time being, to let the user
specify the level of inlining across modules. If the old form `-gnatn' is used,
the compiler will pick the inlining level based on the optimization level.
Tested on x86_64-pc-linux-gnu, committed on trunk
2012-06-12 Eric Botcazou <ebotca...@adacore.com>
* opt.ads (Inline_Level): New variable.
* gnat1drv.adb (Adjust_Global_Switches): Set it based on optimization
level if it has not been set by the user.
* switch-c.adb (Scan_Front_End_Switches): Accept -gnatn1 and -gnatn2
and set Inline_Level accordingly.
* inline.adb (Add_Inlined_Body): Declate new Inline_Level_Type type.
(Must_Inline): Return Inline_Level_T instead of Boolean to indicate
whether the package of the inlined subprogram must be compiled.
If Inline_Level is set to 1, only compile packages of subprograms
directly called from the main unit.
* usage.adb (Usage): Adjust line for -gnatn switch.
* gnat_ugn.texi (Switches for gcc): Document -gnatn1 and -gnatn2.
Index: switch-c.adb
===================================================================
--- switch-c.adb (revision 188428)
+++ switch-c.adb (working copy)
@@ -732,6 +732,16 @@
Ptr := Ptr + 1;
Inline_Active := True;
+ -- There may be a digit appended to the switch
+
+ if Ptr <= Max then
+ C := Switch_Chars (Ptr);
+ if C = '1' or C = '2' then
+ Ptr := Ptr + 1;
+ Inline_Level := Character'Pos (C) - Character'Pos ('0');
+ end if;
+ end if;
+
-- Processing for N switch
when 'N' =>
Index: inline.adb
===================================================================
--- inline.adb (revision 188428)
+++ inline.adb (working copy)
@@ -229,7 +229,13 @@
procedure Add_Inlined_Body (E : Entity_Id) is
- function Must_Inline return Boolean;
+ type Inline_Level_Type is (Dont_Inline, Inline_Call, Inline_Package);
+ -- Level of inlining for the call: Dont_Inline means no inlining,
+ -- Inline_Call means that only the call is considered for inlining,
+ -- Inline_Package means that the call is considered for inlining and
+ -- its package compiled and scanned for more inlining opportunities.
+
+ function Must_Inline return Inline_Level_Type;
-- Inlining is only done if the call statement N is in the main unit,
-- or within the body of another inlined subprogram.
@@ -237,7 +243,7 @@
-- Must_Inline --
-----------------
- function Must_Inline return Boolean is
+ function Must_Inline return Inline_Level_Type is
Scop : Entity_Id;
Comp : Node_Id;
@@ -251,7 +257,7 @@
-- trouble to try to inline at this level.
if Scop = Standard_Standard then
- return False;
+ return Dont_Inline;
end if;
-- Otherwise lookup scope stack to outer scope
@@ -267,14 +273,19 @@
Comp := Parent (Comp);
end loop;
+ -- If the call is in the main unit, inline the call and compile the
+ -- package of the subprogram to find more calls to be inlined.
+
if Comp = Cunit (Main_Unit)
or else Comp = Library_Unit (Cunit (Main_Unit))
then
Add_Call (E);
- return True;
+ return Inline_Package;
end if;
- -- Call is not in main unit. See if it's in some inlined subprogram
+ -- The call is not in the main unit. See if it is in some inlined
+ -- subprogram. If so, inline the call and, if the inlining level is
+ -- set to 1, stop there; otherwise also compile the package as above.
Scop := Current_Scope;
while Scope (Scop) /= Standard_Standard
@@ -284,15 +295,21 @@
and then Is_Inlined (Scop)
then
Add_Call (E, Scop);
- return True;
+ if Inline_Level = 1 then
+ return Inline_Call;
+ else
+ return Inline_Package;
+ end if;
end if;
Scop := Scope (Scop);
end loop;
- return False;
+ return Dont_Inline;
end Must_Inline;
+ Level : Inline_Level_Type;
+
-- Start of processing for Add_Inlined_Body
begin
@@ -309,11 +326,15 @@
-- no enclosing package to retrieve. In this case, it is the body of
-- the function that will have to be loaded.
- if not Is_Abstract_Subprogram (E)
- and then not Is_Nested (E)
- and then Convention (E) /= Convention_Protected
- and then Must_Inline
+ if Is_Abstract_Subprogram (E)
+ or else Is_Nested (E)
+ or else Convention (E) = Convention_Protected
then
+ return;
+ end if;
+
+ Level := Must_Inline;
+ if Level /= Dont_Inline then
declare
Pack : constant Entity_Id := Get_Code_Unit_Entity (E);
@@ -339,7 +360,8 @@
-- declares the type, and that body is visible to the back end.
-- Do not inline it either if it is in the main unit.
- elsif not Is_Inlined (Pack)
+ elsif Level = Inline_Package
+ and then not Is_Inlined (Pack)
and then Comes_From_Source (E)
and then not In_Main_Unit_Or_Subunit (Pack)
then
Index: usage.adb
===================================================================
--- usage.adb (revision 188428)
+++ usage.adb (working copy)
@@ -298,7 +298,7 @@
-- Line for -gnatn switch
- Write_Switch_Char ("n");
+ Write_Switch_Char ("n[d]");
Write_Line ("Enable pragma Inline (both within and across units)");
-- Line for -gnatN switch
Index: gnat_ugn.texi
===================================================================
--- gnat_ugn.texi (revision 188441)
+++ gnat_ugn.texi (working copy)
@@ -4302,11 +4302,15 @@
is abandoned. The equal sign here is optional. A value of zero
means that no limit applies.
-@item -gnatn
+@item -gnatn[12]
@cindex @option{-gnatn} (@command{gcc})
-Activate inlining for subprograms for which
-pragma @code{Inline} is specified. This inlining is performed
-by the GCC back-end.
+Activate inlining for subprograms for which pragma @code{Inline} is
+specified. This inlining is performed by the GCC back-end. An optional
+digit sets the inlining level: 1 for moderate inlining across modules,
+which is a good compromise between compilation times and performances
+at run time, and 2 for full inlining across modules, which may bring
+about longer compilation times. If no inlining level is specified,
+the compiler will pick it based on the optimization level.
@item -gnatN
@cindex @option{-gnatN} (@command{gcc})
Index: gnat1drv.adb
===================================================================
--- gnat1drv.adb (revision 188449)
+++ gnat1drv.adb (working copy)
@@ -505,6 +505,17 @@
Tagged_Type_Expansion := False;
end if;
+
+ -- If the inlining level has not been set by the user, compute it from
+ -- the optimization level: 1 at -O1/-O2 (and -Os), 2 at -O3 and above.
+
+ if Inline_Level = 0 then
+ if Optimization_Level < 3 then
+ Inline_Level := 1;
+ else
+ Inline_Level := 2;
+ end if;
+ end if;
end Adjust_Global_Switches;
--------------------
Index: opt.ads
===================================================================
--- opt.ads (revision 188428)
+++ opt.ads (working copy)
@@ -733,6 +733,12 @@
-- Set True to activate pragma Inline processing across modules. Default
-- for now is not to inline across module boundaries.
+ Inline_Level : Nat := 0;
+ -- GNAT
+ -- Set to indicate the inlining level: 0 means that an appropriate value
+ -- is to be computed by the compiler, 1 is for moderate inlining across
+ -- modules and 2 for full inlining across modules.
+
Interface_Library_Unit : Boolean := False;
-- GNATBIND
-- Set to True to indicate that at least one ALI file is an interface ALI:
