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------------------------------------------------------------------------------

--                                                                          --

--                         GNAT COMPILER COMPONENTS                         --

--                                                                          --

--                             G N A T . S S E                              --

--                                                                          --

--                                 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 package is the root of a set aimed at offering Ada bindings to a

--  subset of the Intel(r) Streaming SIMD Extensions with GNAT. The purpose

--  is to allow access from Ada to the SSE facilities defined in the Intel(r)

--  compiler manuals, in particular in the Intrinsics Reference of the C++

--  Compiler User's Guide, available from http://www.intel.com.

--  Assuming actual hardware support is available, this capability is

--  currently supported on the following set of targets:

--     GNU/Linux x86 and x86_64

--     Windows XP/Vista x86 and x86_64

--  This unit exposes vector _component_ types together with general comments

--  on the binding contents.

--  One other unit is offered as of today: GNAT.SSE.Vector_Types, which

--  exposes Ada types corresponding to the reference types (__m128 and the

--  like) over which a binding to the SSE GCC builtins may operate.

--  The exposed Ada types are private. Object initializations or value

--  observations may be performed with unchecked conversions or address

--  overlays, for example:

--  with Ada.Unchecked_Conversion;

--  with GNAT.SSE.Vector_Types; use GNAT.SSE, GNAT.SSE.Vector_Types;

--  procedure SSE_Base is

--     --  Core operations

--     function ia32_addps (A, B : m128) return m128;

--     pragma Import (Intrinsic, ia32_addps, "__builtin_ia32_addps");

--     --  User views & conversions

--     type Vf32_View is array (1 .. 4) of GNAT.SSE.Float32;

--     for Vf32_View'Alignment use VECTOR_ALIGN;

--     function To_m128 is new Ada.Unchecked_Conversion (Vf32_View, m128);

--     Xf32 : constant Vf32_View := (1.0, 1.0, 2.0, 2.0);

--     Yf32 : constant Vf32_View := (2.0, 2.0, 1.0, 1.0);

--     X128 : constant m128 := To_m128 (Xf32);

--     Y128 : constant m128 := To_m128 (Yf32);

--  begin

--     --  Operations & overlays

--     declare

--        Z128 : m128;

--        Zf32 : Vf32_View;

--        for Zf32'Address use Z128'Address;

--     begin

--        Z128 := ia32_addps (X128, Y128);

--        if Zf32 /= (3.0, 3.0, 3.0, 3.0) then

--           raise Program_Error;

--        end if;

--     end;

--     declare

--        type m128_View_Kind is (SSE, F32);

--        type m128_Object (View : m128_View_Kind := F32) is record

--           case View is

--              when SSE  => V128 : m128;

--              when F32  => Vf32 : Vf32_View;

--           end case;

--        end record;

--        pragma Unchecked_Union (m128_Object);

--        O1 : constant m128_Object := (View => SSE, V128 => X128);

--     begin

--        if O1.Vf32 /= Xf32 then

--           raise Program_Error;

--        end if;

--     end;

--  end SSE_Base;

package GNAT.SSE is

   -----------------------------------

   -- Common vector characteristics --

   -----------------------------------

   VECTOR_BYTES : constant := 16;

   --  Common size of all the SSE vector types, in bytes.

   VECTOR_ALIGN : constant := 16;

   --  Common alignment of all the SSE vector types, in bytes.

   --  Alignment-wise, the reference document reads:

   --  << The compiler aligns __m128d and _m128i local and global data to

   --     16-byte boundaries on the stack. >>

   --

   --  We apply that consistently to all the Ada vector types, as GCC does

   --  for the corresponding C types.

   ----------------------------

   -- Vector component types --

   ----------------------------

   type Float32 is new Float;

   type Float64 is new Long_Float;

   type Integer64 is new Long_Long_Integer;

end GNAT.SSE;