gcc/ada/g-sse.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             G N A T . S S E                              --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --             Copyright (C) 2009, Free Software Foundation, Inc.           --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 --  This package is the root of a set aimed at offering Ada bindings to a
  33 --  subset of the Intel(r) Streaming SIMD Extensions with GNAT. The purpose
  34 --  is to allow access from Ada to the SSE facilities defined in the Intel(r)
  35 --  compiler manuals, in particular in the Intrinsics Reference of the C++
  36 --  Compiler User's Guide, available from http://www.intel.com.
  37
  38 --  Assuming actual hardware support is available, this capability is
  39 --  currently supported on the following set of targets:
  40
  41 --     GNU/Linux x86 and x86_64
  42 --     Windows XP/Vista x86 and x86_64
  43
  44 --  This unit exposes vector _component_ types together with general comments
  45 --  on the binding contents.
  46
  47 --  One other unit is offered as of today: GNAT.SSE.Vector_Types, which
  48 --  exposes Ada types corresponding to the reference types (__m128 and the
  49 --  like) over which a binding to the SSE GCC builtins may operate.
  50
  51 --  The exposed Ada types are private. Object initializations or value
  52 --  observations may be performed with unchecked conversions or address
  53 --  overlays, for example:
  54
  55 --  with Ada.Unchecked_Conversion;
  56 --  with GNAT.SSE.Vector_Types; use GNAT.SSE, GNAT.SSE.Vector_Types;
  57
  58 --  procedure SSE_Base is
  59
  60 --     --  Core operations
  61
  62 --     function ia32_addps (A, B : m128) return m128;
  63 --     pragma Import (Intrinsic, ia32_addps, "__builtin_ia32_addps");
  64
  65 --     --  User views & conversions
  66
  67 --     type Vf32_View is array (1 .. 4) of GNAT.SSE.Float32;
  68 --     for Vf32_View'Alignment use VECTOR_ALIGN;
  69
  70 --     function To_m128 is new Ada.Unchecked_Conversion (Vf32_View, m128);
  71
  72 --     Xf32 : constant Vf32_View := (1.0, 1.0, 2.0, 2.0);
  73 --     Yf32 : constant Vf32_View := (2.0, 2.0, 1.0, 1.0);
  74
  75 --     X128 : constant m128 := To_m128 (Xf32);
  76 --     Y128 : constant m128 := To_m128 (Yf32);
  77
  78 --  begin
  79 --     --  Operations & overlays
  80
  81 --     declare
  82 --        Z128 : m128;
  83 --        Zf32 : Vf32_View;
  84 --        for Zf32'Address use Z128'Address;
  85 --     begin
  86 --        Z128 := ia32_addps (X128, Y128);
  87 --        if Zf32 /= (3.0, 3.0, 3.0, 3.0) then
  88 --           raise Program_Error;
  89 --        end if;
  90 --     end;
  91
  92 --     declare
  93 --        type m128_View_Kind is (SSE, F32);
  94 --        type m128_Object (View : m128_View_Kind := F32) is record
  95 --           case View is
  96 --              when SSE  => V128 : m128;
  97 --              when F32  => Vf32 : Vf32_View;
  98 --           end case;
  99 --        end record;
 100 --        pragma Unchecked_Union (m128_Object);
 101
 102 --        O1 : constant m128_Object := (View => SSE, V128 => X128);
 103 --     begin
 104 --        if O1.Vf32 /= Xf32 then
 105 --           raise Program_Error;
 106 --        end if;
 107 --     end;
 108 --  end SSE_Base;
 109
 110 package GNAT.SSE is
 111
 112    -----------------------------------
 113    -- Common vector characteristics --
 114    -----------------------------------
 115
 116    VECTOR_BYTES : constant := 16;
 117    --  Common size of all the SSE vector types, in bytes.
 118
 119    VECTOR_ALIGN : constant := 16;
 120    --  Common alignment of all the SSE vector types, in bytes.
 121
 122    --  Alignment-wise, the reference document reads:
 123    --  << The compiler aligns __m128d and _m128i local and global data to
 124    --     16-byte boundaries on the stack. >>
 125    --
 126    --  We apply that consistently to all the Ada vector types, as GCC does
 127    --  for the corresponding C types.
 128
 129    ----------------------------
 130    -- Vector component types --
 131    ----------------------------
 132
 133    type Float32 is new Float;
 134    type Float64 is new Long_Float;
 135    type Integer64 is new Long_Long_Integer;
 136
 137 end GNAT.SSE;