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   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --               G N A T . S S E . I N T E R N A L _ T Y P E S              --
   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 unit exposes low level types to interface with the GCC vector
  33 --  builtins directly. These are useful for the development of higher level
  34 --  bindings to the reference Intel intrinsic operations.
  35
  36 --  See GNAT.SSE for the list of targets where this facility is supported.
  37
  38 package GNAT.SSE.Internal_Types is
  39
  40    type v4sf is private;
  41    type v2df is private;
  42    type v2di is private;
  43
  44 private
  45
  46    --  GCC'wise, vector operations operate on objects of vector modes,
  47    --  conveyed through vector types obtained in C by setting an attribute on
  48    --  what looks like a component typedef.  For example, in xmmintrin.h:
  49    --
  50    --    typedef float __v4sf __attribute__ ((__vector_size__ (16)));
  51
  52    --  Applying a 'vector_size' machine attribute in Ada, as in
  53    --
  54    --    type Vf is new Float;
  55    --    pragma Machine_Attribute (Vf,  "vector_size", 16);
  56    --
  57    --  makes Vf a 16bytes long V4SFmode GCC type but the effect on the type
  58    --  layout is not conveyed to the front-end.  The latter still sees "Vf"
  59    --  as a 4bytes long single float, with numerous potential pitfalls.
  60
  61    --  We devised a 'vector_type' alternate machine attribute, which applies
  62    --  to array types of the proper size and alignment from the front-end
  63    --  perspective:
  64
  65    type v4sf is array (1 .. 4) of GNAT.SSE.Float32;
  66    for v4sf'Alignment use GNAT.SSE.VECTOR_ALIGN;
  67    pragma Machine_Attribute (v4sf, "vector_type");
  68
  69    type v2di is array (1 .. 2) of GNAT.SSE.Integer64;
  70    for v2di'Alignment use GNAT.SSE.VECTOR_ALIGN;
  71    pragma Machine_Attribute (v2di, "vector_type");
  72
  73    type v2df is array (1 .. 2) of GNAT.SSE.Float64;
  74    for v2df'Alignment use GNAT.SSE.VECTOR_ALIGN;
  75    pragma Machine_Attribute (v2df, "vector_type");
  76
  77 end GNAT.SSE.Internal_Types;