1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- G N A T . A L T I V E C . C O N V E R S I O N S --
9 -- Copyright (C) 2005-2009, Free Software Foundation, Inc. --
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. --
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. --
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/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 with Ada.Unchecked_Conversion;
34 with System; use System;
36 package body GNAT.Altivec.Conversions is
38 -- All the vector/view conversions operate similarly: bare unchecked
39 -- conversion on big endian targets, and elements permutation on little
40 -- endian targets. We call "Mirroring" the elements permutation process.
42 -- We would like to provide a generic version of the conversion routines
43 -- and just have a set of "renaming as body" declarations to satisfy the
44 -- public interface. This unfortunately prevents inlining, which we must
45 -- preserve at least for the hard binding.
47 -- We instead provide a generic version of facilities needed by all the
48 -- conversion routines and use them repeatedly.
51 type Vitem_Type is private;
53 type Varray_Index_Type is range <>;
54 type Varray_Type is array (Varray_Index_Type) of Vitem_Type;
56 type Vector_Type is private;
57 type View_Type is private;
59 package Generic_Conversions is
61 subtype Varray is Varray_Type;
62 -- This provides an easy common way to refer to the type parameter
63 -- in contexts where a specific instance of this package is "use"d.
65 procedure Mirror (A : Varray_Type; Into : out Varray_Type);
66 pragma Inline (Mirror);
67 -- Mirror the elements of A into INTO, not touching the per-element
70 -- A procedure with an out parameter is a bit heavier to use than a
71 -- function but reduces the amount of temporary creations around the
72 -- call. Instances are typically not front-end inlined. They can still
73 -- be back-end inlined on request with the proper command-line option.
75 -- Below are Unchecked Conversion routines for various purposes,
76 -- relying on internal knowledge about the bits layout in the different
77 -- types (all 128 value bits blocks).
79 -- View<->Vector straight bitwise conversions on BE targets
81 function UNC_To_Vector is
82 new Ada.Unchecked_Conversion (View_Type, Vector_Type);
84 function UNC_To_View is
85 new Ada.Unchecked_Conversion (Vector_Type, View_Type);
87 -- Varray->Vector/View for returning mirrored results on LE targets
89 function UNC_To_Vector is
90 new Ada.Unchecked_Conversion (Varray_Type, Vector_Type);
92 function UNC_To_View is
93 new Ada.Unchecked_Conversion (Varray_Type, View_Type);
95 -- Vector/View->Varray for to-be-permuted source on LE targets
97 function UNC_To_Varray is
98 new Ada.Unchecked_Conversion (Vector_Type, Varray_Type);
100 function UNC_To_Varray is
101 new Ada.Unchecked_Conversion (View_Type, Varray_Type);
103 end Generic_Conversions;
105 package body Generic_Conversions is
107 procedure Mirror (A : Varray_Type; Into : out Varray_Type) is
109 for J in A'Range loop
110 Into (J) := A (A'Last - J + A'First);
114 end Generic_Conversions;
116 -- Now we declare the instances and implement the interface function
117 -- bodies simply calling the instantiated routines.
119 ---------------------
120 -- Char components --
121 ---------------------
123 package SC_Conversions is new Generic_Conversions
124 (signed_char, Vchar_Range, Varray_signed_char, VSC, VSC_View);
126 function To_Vector (S : VSC_View) return VSC is
129 if Default_Bit_Order = High_Order_First then
130 return UNC_To_Vector (S);
135 Mirror (UNC_To_Varray (S), Into => M);
136 return UNC_To_Vector (M);
141 function To_View (S : VSC) return VSC_View is
144 if Default_Bit_Order = High_Order_First then
145 return UNC_To_View (S);
150 Mirror (UNC_To_Varray (S), Into => M);
151 return UNC_To_View (M);
158 package UC_Conversions is new Generic_Conversions
159 (unsigned_char, Vchar_Range, Varray_unsigned_char, VUC, VUC_View);
161 function To_Vector (S : VUC_View) return VUC is
164 if Default_Bit_Order = High_Order_First then
165 return UNC_To_Vector (S);
170 Mirror (UNC_To_Varray (S), Into => M);
171 return UNC_To_Vector (M);
176 function To_View (S : VUC) return VUC_View is
179 if Default_Bit_Order = High_Order_First then
180 return UNC_To_View (S);
185 Mirror (UNC_To_Varray (S), Into => M);
186 return UNC_To_View (M);
193 package BC_Conversions is new Generic_Conversions
194 (bool_char, Vchar_Range, Varray_bool_char, VBC, VBC_View);
196 function To_Vector (S : VBC_View) return VBC is
199 if Default_Bit_Order = High_Order_First then
200 return UNC_To_Vector (S);
205 Mirror (UNC_To_Varray (S), Into => M);
206 return UNC_To_Vector (M);
211 function To_View (S : VBC) return VBC_View is
214 if Default_Bit_Order = High_Order_First then
215 return UNC_To_View (S);
220 Mirror (UNC_To_Varray (S), Into => M);
221 return UNC_To_View (M);
226 ----------------------
227 -- Short components --
228 ----------------------
230 package SS_Conversions is new Generic_Conversions
231 (signed_short, Vshort_Range, Varray_signed_short, VSS, VSS_View);
233 function To_Vector (S : VSS_View) return VSS is
236 if Default_Bit_Order = High_Order_First then
237 return UNC_To_Vector (S);
242 Mirror (UNC_To_Varray (S), Into => M);
243 return UNC_To_Vector (M);
248 function To_View (S : VSS) return VSS_View is
251 if Default_Bit_Order = High_Order_First then
252 return UNC_To_View (S);
257 Mirror (UNC_To_Varray (S), Into => M);
258 return UNC_To_View (M);
265 package US_Conversions is new Generic_Conversions
266 (unsigned_short, Vshort_Range, Varray_unsigned_short, VUS, VUS_View);
268 function To_Vector (S : VUS_View) return VUS is
271 if Default_Bit_Order = High_Order_First then
272 return UNC_To_Vector (S);
277 Mirror (UNC_To_Varray (S), Into => M);
278 return UNC_To_Vector (M);
283 function To_View (S : VUS) return VUS_View is
286 if Default_Bit_Order = High_Order_First then
287 return UNC_To_View (S);
292 Mirror (UNC_To_Varray (S), Into => M);
293 return UNC_To_View (M);
300 package BS_Conversions is new Generic_Conversions
301 (bool_short, Vshort_Range, Varray_bool_short, VBS, VBS_View);
303 function To_Vector (S : VBS_View) return VBS is
306 if Default_Bit_Order = High_Order_First then
307 return UNC_To_Vector (S);
312 Mirror (UNC_To_Varray (S), Into => M);
313 return UNC_To_Vector (M);
318 function To_View (S : VBS) return VBS_View is
321 if Default_Bit_Order = High_Order_First then
322 return UNC_To_View (S);
327 Mirror (UNC_To_Varray (S), Into => M);
328 return UNC_To_View (M);
337 package SI_Conversions is new Generic_Conversions
338 (signed_int, Vint_Range, Varray_signed_int, VSI, VSI_View);
340 function To_Vector (S : VSI_View) return VSI is
343 if Default_Bit_Order = High_Order_First then
344 return UNC_To_Vector (S);
349 Mirror (UNC_To_Varray (S), Into => M);
350 return UNC_To_Vector (M);
355 function To_View (S : VSI) return VSI_View is
358 if Default_Bit_Order = High_Order_First then
359 return UNC_To_View (S);
364 Mirror (UNC_To_Varray (S), Into => M);
365 return UNC_To_View (M);
372 package UI_Conversions is new Generic_Conversions
373 (unsigned_int, Vint_Range, Varray_unsigned_int, VUI, VUI_View);
375 function To_Vector (S : VUI_View) return VUI is
378 if Default_Bit_Order = High_Order_First then
379 return UNC_To_Vector (S);
384 Mirror (UNC_To_Varray (S), Into => M);
385 return UNC_To_Vector (M);
390 function To_View (S : VUI) return VUI_View is
393 if Default_Bit_Order = High_Order_First then
394 return UNC_To_View (S);
399 Mirror (UNC_To_Varray (S), Into => M);
400 return UNC_To_View (M);
407 package BI_Conversions is new Generic_Conversions
408 (bool_int, Vint_Range, Varray_bool_int, VBI, VBI_View);
410 function To_Vector (S : VBI_View) return VBI is
413 if Default_Bit_Order = High_Order_First then
414 return UNC_To_Vector (S);
419 Mirror (UNC_To_Varray (S), Into => M);
420 return UNC_To_Vector (M);
425 function To_View (S : VBI) return VBI_View is
428 if Default_Bit_Order = High_Order_First then
429 return UNC_To_View (S);
434 Mirror (UNC_To_Varray (S), Into => M);
435 return UNC_To_View (M);
440 ----------------------
441 -- Float components --
442 ----------------------
444 package F_Conversions is new Generic_Conversions
445 (C_float, Vfloat_Range, Varray_float, VF, VF_View);
447 function To_Vector (S : VF_View) return VF is
450 if Default_Bit_Order = High_Order_First then
451 return UNC_To_Vector (S);
456 Mirror (UNC_To_Varray (S), Into => M);
457 return UNC_To_Vector (M);
462 function To_View (S : VF) return VF_View is
465 if Default_Bit_Order = High_Order_First then
466 return UNC_To_View (S);
471 Mirror (UNC_To_Varray (S), Into => M);
472 return UNC_To_View (M);
477 ----------------------
478 -- Pixel components --
479 ----------------------
481 package P_Conversions is new Generic_Conversions
482 (pixel, Vpixel_Range, Varray_pixel, VP, VP_View);
484 function To_Vector (S : VP_View) return VP is
487 if Default_Bit_Order = High_Order_First then
488 return UNC_To_Vector (S);
493 Mirror (UNC_To_Varray (S), Into => M);
494 return UNC_To_Vector (M);
499 function To_View (S : VP) return VP_View is
502 if Default_Bit_Order = High_Order_First then
503 return UNC_To_View (S);
508 Mirror (UNC_To_Varray (S), Into => M);
509 return UNC_To_View (M);
514 end GNAT.Altivec.Conversions;