[multiple changes]

2009-07-23  Olivier Hainque  <hainque@adacore.com>

	* g-ssinty.ads: New unit. GNAT.SSE.Internal_Types. Factorize
	low level internal type definitions for distinct higher level
	binding development activities (user type definitions and
	operations).
	* gnat_rm.texi: Document it.
	* g-ssvety.ads: Use it.
	* gcc-interface/Makefile.in: (x86 32/64 linux, cygwin32 sections): Add
	g-ssinty.o to EXTRA_GNATRTL_NONTASKING_OBJS.
	* gcc-interface/utils.c (gnat_internal_attribute_table): Add entry
	for the "may_alias" attribute.

2009-07-23  Thomas Quinot  <quinot@adacore.com>

	* scos.ads: Minor typo fix
	* gcc-interface/decl.c (validate_alignment): For the case of an
	implicit array base type, look for alignment clause on first subtype.
	Code clean up.

2009-07-23  Ed Schonberg  <schonberg@adacore.com>

	* sem.adb (Walk_Library_Units): Handle properly the case where a unit
	in the context depends on the spec of the main unit, by delaying
	processing of the main unit body until all other units have been
	processed.

From-SVN: r149993

8 files changed, 200 insertions, 62 deletions

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index c07e719..dc4d8a5 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,30 @@
+2009-07-23  Olivier Hainque  <hainque@adacore.com>
+
+	* g-ssinty.ads: New unit. GNAT.SSE.Internal_Types. Factorize
+	low level internal type definitions for distinct higher level
+	binding development activities (user type definitions and
+	operations).
+	* gnat_rm.texi: Document it.
+	* g-ssvety.ads: Use it.
+	* gcc-interface/Makefile.in: (x86 32/64 linux, cygwin32 sections): Add
+	g-ssinty.o to EXTRA_GNATRTL_NONTASKING_OBJS.
+	* gcc-interface/utils.c (gnat_internal_attribute_table): Add entry
+	for the "may_alias" attribute.
+
+2009-07-23  Thomas Quinot  <quinot@adacore.com>
+
+	* scos.ads: Minor typo fix
+	* gcc-interface/decl.c (validate_alignment): For the case of an
+	implicit array base type, look for alignment clause on first subtype.
+	Code clean up.
+
+2009-07-23  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem.adb (Walk_Library_Units): Handle properly the case where a unit
+	in the context depends on the spec of the main unit, by delaying
+	processing of the main unit body until all other units have been
+	processed.
+
 2009-07-23  Arnaud Charlet  <charlet@adacore.com>
 
 	* a-convec.adb: Add comments about suspicious/subtle code.
diff --git a/gcc/ada/g-ssinty.ads b/gcc/ada/g-ssinty.ads
new file mode 100644
index 0000000..becdc76
--- /dev/null
+++ b/gcc/ada/g-ssinty.ads
@@ -0,0 +1,77 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT COMPILER COMPONENTS                         --
+--                                                                          --
+--               G N A T . S S E . I N T E R N A L _ T Y P E S              --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--             Copyright (C) 2009, Free Software Foundation, Inc.           --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This unit exposes low level types to interface with the GCC vector
+--  builtins directly. These are useful for the development of higher level
+--  bindings to the reference Intel intrinsic operations.
+
+--  See GNAT.SSE for the list of targets where this facility is supported.
+
+package GNAT.SSE.Internal_Types is
+
+   type v4sf is private;
+   type v2df is private;
+   type v2di is private;
+
+private
+
+   --  GCC'wise, vector operations operate on objects of vector modes,
+   --  conveyed through vector types obtained in C by setting an attribute on
+   --  what looks like a component typedef.  For example, in xmmintrin.h:
+   --
+   --    typedef float __v4sf __attribute__ ((__vector_size__ (16)));
+
+   --  Applying a 'vector_size' machine attribute in Ada, as in
+   --
+   --    type Vf is new Float;
+   --    pragma Machine_Attribute (Vf,  "vector_size", 16);
+   --
+   --  makes Vf a 16bytes long V4SFmode GCC type but the effect on the type
+   --  layout is not conveyed to the front-end.  The latter still sees "Vf"
+   --  as a 4bytes long single float, with numerous potential pitfalls.
+
+   --  We devised a 'vector_type' alternate machine attribute, which applies
+   --  to array types of the proper size and alignment from the front-end
+   --  perspective:
+
+   type v4sf is array (1 .. 4) of GNAT.SSE.Float32;
+   for v4sf'Alignment use GNAT.SSE.VECTOR_ALIGN;
+   pragma Machine_Attribute (v4sf, "vector_type");
+
+   type v2di is array (1 .. 2) of GNAT.SSE.Integer64;
+   for v2di'Alignment use GNAT.SSE.VECTOR_ALIGN;
+   pragma Machine_Attribute (v2di, "vector_type");
+
+   type v2df is array (1 .. 2) of GNAT.SSE.Float64;
+   for v2df'Alignment use GNAT.SSE.VECTOR_ALIGN;
+   pragma Machine_Attribute (v2df, "vector_type");
+
+end GNAT.SSE.Internal_Types;
diff --git a/gcc/ada/g-ssvety.ads b/gcc/ada/g-ssvety.ads
index eb7d590..42cd24b 100644
--- a/gcc/ada/g-ssvety.ads
+++ b/gcc/ada/g-ssvety.ads
@@ -30,7 +30,9 @@
 ------------------------------------------------------------------------------
 
 --  This unit exposes the Ada __m128 like data types to represent the contents
---  of SSE registers, for use by the SSE intrinsics.
+--  of SSE registers, for use by bindings to the SSE intrinsic operations.
+
+--  See GNAT.SSE for the list of targets where this facility is supported.
 
 package GNAT.SSE.Vector_Types is
 
@@ -49,32 +51,23 @@ package GNAT.SSE.Vector_Types is
    --     * Use new data types only with the respective intrinsics described
    --       in this documentation. >>
 
-   type M128 is private;   --  SSE >= 1
-   type M128d is private;  --  SSE >= 2
-   type M128i is private;  --  SSE >= 2
+   type m128 is private;   --  SSE >= 1
+   type m128d is private;  --  SSE >= 2
+   type m128i is private;  --  SSE >= 2
 
 private
-   --  GCC'wise, vector operations operate on objects of vector modes,
-   --  conveyed through vector types obtained by setting an attribute on what
-   --  looks like a component typedef.  For example, in C (xmmintrin.h):
-   --
-   --    typedef float __v4sf __attribute__ ((__vector_size__ (16)));
 
-   --  We can obtain the same low level GCC effect in Ada with
-   --  Machine_Attribute pragmas, as in
+   --  Each of the m128 types maps to a specific vector_type with
+   --  an extra "may_alias" attribute as in GCC's definitions for C,
+   --  for instance in xmmintrin.h:
    --
-   --    type Vf is new Float;
-   --    pragma Machine_Attribute (Vf,  "vector_size", 16);
+   --  /* The Intel API is flexible enough that we must allow aliasing
+   --     with other vector types, and their scalar components.  */
+   --  typedef float __m128
+   --    __attribute__ ((__vector_size__ (16), __may_alias__));
    --
-   --  which makes Vf a 16bytes long V4SFmode type for GCC. The effect on the
-   --  type layout is not conveyed to the front-end, however, so the latter
-   --  still sees "Vf" as a 4bytes long single float. This leads to numerous
-   --  potential pitfalls if this type is directly exposed user land, so we
-   --  add wrapper records with rep clauses to compensate.
-
-   --  The wrapper records all have a single component of the twisted low
-   --  level type, so they inherit the mode while the rep clauses convey the
-   --  size and alignment information to the front-end.
+   --  /* Internal data types for implementing the intrinsics.  */
+   --  typedef float __v4sf __attribute__ ((__vector_size__ (16)));
 
    ------------
    --  M128  --
@@ -82,44 +75,32 @@ private
 
    --  << The __m128 data type can hold four 32-bit floating-point values. >>
 
-   type V4sf is new Float32;
-   pragma Machine_Attribute (V4sf, "vector_size", VECTOR_BYTES);
-
-   type M128 is record
-      Value : V4sf;
-   end record;
-   for M128'Size use VECTOR_BYTES * 8;
-   for M128'Alignment use VECTOR_ALIGN;
+   type m128 is array (1 .. 4) of Float32;
+   for m128'Alignment use VECTOR_ALIGN;
+   pragma Machine_Attribute (m128, "vector_type");
+   pragma Machine_Attribute (m128, "may_alias");
 
    -------------
-   --  M128d  --
+   --  m128d  --
    -------------
 
    --  << The __m128d data type can hold two 64-bit floating-point values. >>
 
-   type V2df is new Float64;
-   pragma Machine_Attribute (V2df, "vector_size", VECTOR_BYTES);
-
-   type M128d is record
-      Value : V2df;
-   end record;
-   for M128d'Size use VECTOR_BYTES * 8;
-   for M128d'Alignment use VECTOR_ALIGN;
+   type m128d is array (1 .. 2) of Float64;
+   for m128d'Alignment use VECTOR_ALIGN;
+   pragma Machine_Attribute (m128d, "vector_type");
+   pragma Machine_Attribute (m128d, "may_alias");
 
    -------------
-   --  M128i  --
+   --  m128i  --
    -------------
 
    --  << The __m128i data type can hold sixteen 8-bit, eight 16-bit, four
    --     32-bit, or two 64-bit integer values. >>
 
-   type V2di is new Integer64;
-   pragma Machine_Attribute (V2di, "vector_size", VECTOR_BYTES);
-
-   type M128i is record
-      Value : V2di;
-   end record;
-   for M128i'Size use VECTOR_BYTES * 8;
-   for M128i'Alignment use VECTOR_ALIGN;
+   type m128i is array (1 .. 2) of Integer64;
+   for m128i'Alignment use VECTOR_ALIGN;
+   pragma Machine_Attribute (m128i, "vector_type");
+   pragma Machine_Attribute (m128i, "may_alias");
 
 end GNAT.SSE.Vector_Types;
diff --git a/gcc/ada/gcc-interface/Makefile.in b/gcc/ada/gcc-interface/Makefile.in
index d487716..0e80808 100644
--- a/gcc/ada/gcc-interface/Makefile.in
+++ b/gcc/ada/gcc-interface/Makefile.in
@@ -1052,7 +1052,7 @@ ifeq ($(strip $(filter-out %86 linux%,$(arch) $(osys))),)
     endif
 
     THREADSLIB = -lpthread
-    EXTRA_GNATRTL_NONTASKING_OBJS=g-sse.o g-ssvety.o
+    EXTRA_GNATRTL_NONTASKING_OBJS=g-sse.o g-ssvety.o g-ssinty.o
     EXTRA_GNATRTL_TASKING_OBJS=s-linux.o
   endif
 
@@ -1593,7 +1593,7 @@ ifeq ($(strip $(filter-out cygwin32% mingw32% pe,$(osys))),)
     endif
 
     EXTRA_GNATRTL_NONTASKING_OBJS = \
-	s-win32.o s-winext.o g-regist.o g-sse.o g-ssvety.o
+	s-win32.o s-winext.o g-regist.o g-sse.o g-ssvety.o g-ssinty.o
     EXTRA_GNATRTL_TASKING_OBJS = a-exetim.o
 
     MISCLIB = -lws2_32
@@ -2003,7 +2003,7 @@ ifeq ($(strip $(filter-out %x86_64 linux%,$(arch) $(osys))),)
     mlib-tgt-specific.adb<mlib-tgt-specific-linux.adb \
     indepsw.adb<indepsw-gnu.adb
 
-  EXTRA_GNATRTL_NONTASKING_OBJS=g-sse.o g-ssvety.o
+  EXTRA_GNATRTL_NONTASKING_OBJS=g-sse.o g-ssvety.o g-ssinty.o
   EXTRA_GNATRTL_TASKING_OBJS=s-linux.o
   EH_MECHANISM=-gcc
   THREADSLIB=-lpthread
diff --git a/gcc/ada/gcc-interface/utils.c b/gcc/ada/gcc-interface/utils.c
index 59d9477..1548f6d 100644
--- a/gcc/ada/gcc-interface/utils.c
+++ b/gcc/ada/gcc-interface/utils.c
@@ -122,6 +122,7 @@ const struct attribute_spec gnat_internal_attribute_table[] =
   { "type generic", 0, 0,  false, true, true, handle_type_generic_attribute },
 
   { "vector_size",  1, 1,  false, true, false,  handle_vector_size_attribute },
+  { "may_alias",    0, 0, false, true, false, NULL },
 
   /* ??? format and format_arg are heavy and not supported, which actually
      prevents support for stdio builtins, which we however declare as part
diff --git a/gcc/ada/gnat_rm.texi b/gcc/ada/gnat_rm.texi
index 1f26563..14a7a8f 100644
--- a/gcc/ada/gnat_rm.texi
+++ b/gcc/ada/gnat_rm.texi
@@ -382,6 +382,7 @@ The GNAT Library
 * GNAT.Spitbol.Table_Integer (g-sptain.ads)::
 * GNAT.Spitbol.Table_VString (g-sptavs.ads)::
 * GNAT.SSE (g-sse.ads)::
+* GNAT.SSE.Internal_Types (g-ssinty.ads)::
 * GNAT.SSE.Vector_Types (g-ssvety.ads)::
 * GNAT.Strings (g-string.ads)::
 * GNAT.String_Split (g-strspl.ads)::
@@ -13571,6 +13572,7 @@ of GNAT, and will generate a warning message.
 * GNAT.Spitbol.Table_Integer (g-sptain.ads)::
 * GNAT.Spitbol.Table_VString (g-sptavs.ads)::
 * GNAT.SSE (g-sse.ads)::
+* GNAT.SSE.Internal_Types (g-ssinty.ads)::
 * GNAT.SSE.Vector_Types (g-ssvety.ads)::
 * GNAT.Strings (g-string.ads)::
 * GNAT.String_Split (g-strspl.ads)::
@@ -14641,6 +14643,15 @@ the Intel(r) Streaming SIMD Extensions with GNAT on the x86 family of
 targets.  It exposes vector component types together with a general
 introduction to the binding contents and use.
 
+@node GNAT.SSE.Internal_Types (g-ssinty.ads)
+@section @code{GNAT.SSE.Internal_Types} (@file{g-ssinty.ads})
+@cindex @code{GNAT.SSE.Internal_Types} (@file{g-ssinty.ads})
+
+@noindent
+Low level GCC vector types for direct use of the vector related
+builtins, required for the development of higher level bindings to SSE
+intrinsic operations.
+
 @node GNAT.SSE.Vector_Types (g-ssvety.ads)
 @section @code{GNAT.SSE.Vector_Types} (@file{g-ssvety.ads})
 @cindex @code{GNAT.SSE.Vector_Types} (@file{g-ssvety.ads})
diff --git a/gcc/ada/scos.ads b/gcc/ada/scos.ads
index fa039a5..15c2053 100644
--- a/gcc/ada/scos.ads
+++ b/gcc/ada/scos.ads
@@ -103,7 +103,7 @@ package SCOs is
    --  Statement lines
 
    --    These lines correspond to a sequence of one or more statements which
-   --    are always exeecuted in sequence, The first statement may be an entry
+   --    are always executed in sequence, The first statement may be an entry
    --    point (e.g. statement after a label), and the last statement may be
    --    an exit point (e.g. an exit statement), but no other entry or exit
    --    points may occur within the sequence of statements. The idea is that
diff --git a/gcc/ada/sem.adb b/gcc/ada/sem.adb
index f5beda4..f60c143 100644
--- a/gcc/ada/sem.adb
+++ b/gcc/ada/sem.adb
@@ -107,7 +107,6 @@ package body Sem is
    procedure Analyze (N : Node_Id) is
    begin
       Debug_A_Entry ("analyzing  ", N);
-
       --  Immediate return if already analyzed
 
       if Analyzed (N) then
@@ -1510,6 +1509,12 @@ package body Sem is
       --  after we have fully processed X, and is used only for debugging
       --  printouts and assertions.
 
+      Do_Main : Boolean := False;
+      --  Flag to delay processing the main body until after all other units.
+      --  This is needed because the spec of the main unit may appear in the
+      --  context of some other unit. We do not want this to force processing
+      --  of the main body before all other units have been processed.
+
       procedure Do_Action (CU : Node_Id; Item : Node_Id);
       --  Calls Action, with some validity checks
 
@@ -1712,7 +1717,8 @@ package body Sem is
 
          if not Nkind_In (Item, N_Package_Body, N_Subprogram_Body)
            or else Acts_As_Spec (CU)
-           or else CU = Cunit (Main_Unit)
+           or else (CU = Cunit (Main_Unit) and then Do_Main)
+
          then
 
             Do_Action (CU, Item);
@@ -1733,14 +1739,47 @@ package body Sem is
          --  be possible to restrict the list to those bodies that are used
          --  in the main unit. Possible optimization ???
 
+         --  Such bodies can also appear in a circular dependency list, where
+         --  spec A depends on spec B and the body of B depends on spec A.
+         --  This is not an elaboration issue, but body B must be excluded
+         --  from the processing.
+
          if Nkind (Item) = N_Package_Declaration then
             declare
                Body_Unit : constant Node_Id := Library_Unit (CU);
 
+               function Circular_Dependence (B : Node_Id) return Boolean;
+               --  Check whether this body depends on a spec that is pending,
+               --  that is to say has been seen but not processed yet.
+
+               function Circular_Dependence (B : Node_Id) return Boolean is
+                  Item : Node_Id;
+                  UN   : Unit_Number_Type;
+
+               begin
+                  Item := First (Context_Items (B));
+                  while Present (Item) loop
+                     if Nkind (Item) = N_With_Clause then
+                        UN := Get_Cunit_Unit_Number (Library_Unit (Item));
+
+                        if Seen (UN)
+                          and then not Done (UN)
+                        then
+                           return True;
+                        end if;
+                     end if;
+
+                     Next (Item);
+                  end loop;
+
+                  return False;
+               end Circular_Dependence;
+
             begin
                if Present (Body_Unit)
                  and then Body_Unit /= Cunit (Main_Unit)
                  and then Unit_Num /= Get_Source_Unit (System_Aux_Id)
+                 and then not Circular_Dependence (Body_Unit)
                then
                   Do_Unit_And_Dependents (Body_Unit, Unit (Body_Unit));
                   Do_Action (Body_Unit, Unit (Body_Unit));
@@ -1801,16 +1840,13 @@ package body Sem is
 
             case Nkind (N) is
 
-               --  If it's a body, then ignore it, unless it's the main unit
-               --  Otherwise bodies appear in the list because of inlining or
-               --  instantiations, and they are processed immediately after
-               --  the corresponding specs.
+               --  If it's a body, ignore it. Bodies appear in the list only
+               --  because of inlining/instantiations, and they are processed
+               --  immediately after the corresponding specs.
+               --  The main unit is processed separately after all other units.
 
                when N_Package_Body | N_Subprogram_Body =>
-
-                  if CU = Cunit (Main_Unit) then
-                     Do_Unit_And_Dependents (CU, N);
-                  end if;
+                  null;
 
                --  It's a spec, so just do it
 
@@ -1822,6 +1858,11 @@ package body Sem is
          Next_Elmt (Cur);
       end loop;
 
+      if not Done (Main_Unit) then
+         Do_Main := True;
+         Do_Unit_And_Dependents (Cunit (Main_Unit), Unit (Cunit (Main_Unit)));
+      end if;
+
       if Debug_Unit_Walk then
          if Done /= (Done'Range => True) then
             Write_Eol;