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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [gcc/] [ada/] [i-pacdec.adb] - Blame information for rev 706

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1 706 jeremybenn
------------------------------------------------------------------------------
2
--                                                                          --
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--                         GNAT COMPILER COMPONENTS                         --
4
--                                                                          --
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--            I N T E R F A C E S . P A C K E D _ D E C I M A L             --
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--                                                                          --
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--                                 B o d y                                  --
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--            (Version for IBM Mainframe Packed Decimal Format)             --
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--                                                                          --
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--          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
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--                                                                          --
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-- GNAT is free software;  you can  redistribute it  and/or modify it under --
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-- terms of the  GNU General Public License as published  by the Free Soft- --
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-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
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-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
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--                                                                          --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception,   --
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-- version 3.1, as published by the Free Software Foundation.               --
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--                                                                          --
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-- You should have received a copy of the GNU General Public License and    --
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-- a copy of the GCC Runtime Library Exception along with this program;     --
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-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
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-- <http://www.gnu.org/licenses/>.                                          --
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--                                                                          --
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-- GNAT was originally developed  by the GNAT team at  New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc.      --
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--                                                                          --
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------------------------------------------------------------------------------
32
 
33
with System; use System;
34
 
35
with Ada.Unchecked_Conversion;
36
 
37
package body Interfaces.Packed_Decimal is
38
 
39
   type Packed is array (Byte_Length) of Unsigned_8;
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   --  The type used internally to represent packed decimal
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42
   type Packed_Ptr is access Packed;
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   function To_Packed_Ptr is
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     new Ada.Unchecked_Conversion (Address, Packed_Ptr);
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   --  The following array is used to convert a value in the range 0-99 to
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   --  a packed decimal format with two hexadecimal nibbles. It is worth
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   --  using table look up in this direction because divides are expensive.
49
 
50
   Packed_Byte : constant array (00 .. 99) of Unsigned_8 :=
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      (16#00#, 16#01#, 16#02#, 16#03#, 16#04#,
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       16#05#, 16#06#, 16#07#, 16#08#, 16#09#,
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       16#10#, 16#11#, 16#12#, 16#13#, 16#14#,
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       16#15#, 16#16#, 16#17#, 16#18#, 16#19#,
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       16#20#, 16#21#, 16#22#, 16#23#, 16#24#,
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       16#25#, 16#26#, 16#27#, 16#28#, 16#29#,
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       16#30#, 16#31#, 16#32#, 16#33#, 16#34#,
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       16#35#, 16#36#, 16#37#, 16#38#, 16#39#,
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       16#40#, 16#41#, 16#42#, 16#43#, 16#44#,
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       16#45#, 16#46#, 16#47#, 16#48#, 16#49#,
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       16#50#, 16#51#, 16#52#, 16#53#, 16#54#,
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       16#55#, 16#56#, 16#57#, 16#58#, 16#59#,
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       16#60#, 16#61#, 16#62#, 16#63#, 16#64#,
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       16#65#, 16#66#, 16#67#, 16#68#, 16#69#,
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       16#70#, 16#71#, 16#72#, 16#73#, 16#74#,
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       16#75#, 16#76#, 16#77#, 16#78#, 16#79#,
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       16#80#, 16#81#, 16#82#, 16#83#, 16#84#,
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       16#85#, 16#86#, 16#87#, 16#88#, 16#89#,
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       16#90#, 16#91#, 16#92#, 16#93#, 16#94#,
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       16#95#, 16#96#, 16#97#, 16#98#, 16#99#);
71
 
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   ---------------------
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   -- Int32_To_Packed --
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   ---------------------
75
 
76
   procedure Int32_To_Packed (V : Integer_32; P : System.Address; D : D32) is
77
      PP           : constant Packed_Ptr  := To_Packed_Ptr (P);
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      Empty_Nibble : constant Boolean     := ((D rem 2) = 0);
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      B            : constant Byte_Length := (D / 2) + 1;
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      VV           : Integer_32 := V;
81
 
82
   begin
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      --  Deal with sign byte first
84
 
85
      if VV >= 0 then
86
         PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#C#;
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         VV := VV / 10;
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      else
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         VV := -VV;
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         PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#D#;
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      end if;
93
 
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      for J in reverse B - 1 .. 2 loop
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         if VV = 0 then
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            for K in 1 .. J loop
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               PP (K) := 16#00#;
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            end loop;
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100
            return;
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102
         else
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            PP (J) := Packed_Byte (Integer (VV rem 100));
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            VV := VV / 100;
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         end if;
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      end loop;
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      --  Deal with leading byte
109
 
110
      if Empty_Nibble then
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         if VV > 9 then
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            raise Constraint_Error;
113
         else
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            PP (1) := Unsigned_8 (VV);
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         end if;
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117
      else
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         if VV > 99 then
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            raise Constraint_Error;
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         else
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            PP (1) := Packed_Byte (Integer (VV));
122
         end if;
123
      end if;
124
 
125
   end Int32_To_Packed;
126
 
127
   ---------------------
128
   -- Int64_To_Packed --
129
   ---------------------
130
 
131
   procedure Int64_To_Packed (V : Integer_64; P : System.Address; D : D64) is
132
      PP           : constant Packed_Ptr  := To_Packed_Ptr (P);
133
      Empty_Nibble : constant Boolean     := ((D rem 2) = 0);
134
      B            : constant Byte_Length := (D / 2) + 1;
135
      VV           : Integer_64 := V;
136
 
137
   begin
138
      --  Deal with sign byte first
139
 
140
      if VV >= 0 then
141
         PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#C#;
142
         VV := VV / 10;
143
 
144
      else
145
         VV := -VV;
146
         PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#D#;
147
      end if;
148
 
149
      for J in reverse B - 1 .. 2 loop
150
         if VV = 0 then
151
            for K in 1 .. J loop
152
               PP (K) := 16#00#;
153
            end loop;
154
 
155
            return;
156
 
157
         else
158
            PP (J) := Packed_Byte (Integer (VV rem 100));
159
            VV := VV / 100;
160
         end if;
161
      end loop;
162
 
163
      --  Deal with leading byte
164
 
165
      if Empty_Nibble then
166
         if VV > 9 then
167
            raise Constraint_Error;
168
         else
169
            PP (1) := Unsigned_8 (VV);
170
         end if;
171
 
172
      else
173
         if VV > 99 then
174
            raise Constraint_Error;
175
         else
176
            PP (1) := Packed_Byte (Integer (VV));
177
         end if;
178
      end if;
179
 
180
   end Int64_To_Packed;
181
 
182
   ---------------------
183
   -- Packed_To_Int32 --
184
   ---------------------
185
 
186
   function Packed_To_Int32 (P : System.Address; D : D32) return Integer_32 is
187
      PP           : constant Packed_Ptr  := To_Packed_Ptr (P);
188
      Empty_Nibble : constant Boolean     := ((D mod 2) = 0);
189
      B            : constant Byte_Length := (D / 2) + 1;
190
      V            : Integer_32;
191
      Dig          : Unsigned_8;
192
      Sign         : Unsigned_8;
193
      J            : Positive;
194
 
195
   begin
196
      --  Cases where there is an unused (zero) nibble in the first byte.
197
      --  Deal with the single digit nibble at the right of this byte
198
 
199
      if Empty_Nibble then
200
         V := Integer_32 (PP (1));
201
         J := 2;
202
 
203
         if V > 9 then
204
            raise Constraint_Error;
205
         end if;
206
 
207
      --  Cases where all nibbles are used
208
 
209
      else
210
         V := 0;
211
         J := 1;
212
      end if;
213
 
214
      --  Loop to process bytes containing two digit nibbles
215
 
216
      while J < B loop
217
         Dig := Shift_Right (PP (J), 4);
218
 
219
         if Dig > 9 then
220
            raise Constraint_Error;
221
         else
222
            V := V * 10 + Integer_32 (Dig);
223
         end if;
224
 
225
         Dig := PP (J) and 16#0F#;
226
 
227
         if Dig > 9 then
228
            raise Constraint_Error;
229
         else
230
            V := V * 10 + Integer_32 (Dig);
231
         end if;
232
 
233
         J := J + 1;
234
      end loop;
235
 
236
      --  Deal with digit nibble in sign byte
237
 
238
      Dig := Shift_Right (PP (J), 4);
239
 
240
      if Dig > 9 then
241
         raise Constraint_Error;
242
      else
243
         V := V * 10 + Integer_32 (Dig);
244
      end if;
245
 
246
      Sign :=  PP (J) and 16#0F#;
247
 
248
      --  Process sign nibble (deal with most common cases first)
249
 
250
      if Sign = 16#C# then
251
         return V;
252
 
253
      elsif Sign = 16#D# then
254
         return -V;
255
 
256
      elsif Sign = 16#B# then
257
         return -V;
258
 
259
      elsif Sign >= 16#A# then
260
         return V;
261
 
262
      else
263
         raise Constraint_Error;
264
      end if;
265
   end Packed_To_Int32;
266
 
267
   ---------------------
268
   -- Packed_To_Int64 --
269
   ---------------------
270
 
271
   function Packed_To_Int64 (P : System.Address; D : D64) return Integer_64 is
272
      PP           : constant Packed_Ptr  := To_Packed_Ptr (P);
273
      Empty_Nibble : constant Boolean     := ((D mod 2) = 0);
274
      B            : constant Byte_Length := (D / 2) + 1;
275
      V            : Integer_64;
276
      Dig          : Unsigned_8;
277
      Sign         : Unsigned_8;
278
      J            : Positive;
279
 
280
   begin
281
      --  Cases where there is an unused (zero) nibble in the first byte.
282
      --  Deal with the single digit nibble at the right of this byte
283
 
284
      if Empty_Nibble then
285
         V := Integer_64 (PP (1));
286
         J := 2;
287
 
288
         if V > 9 then
289
            raise Constraint_Error;
290
         end if;
291
 
292
      --  Cases where all nibbles are used
293
 
294
      else
295
         J := 1;
296
         V := 0;
297
      end if;
298
 
299
      --  Loop to process bytes containing two digit nibbles
300
 
301
      while J < B loop
302
         Dig := Shift_Right (PP (J), 4);
303
 
304
         if Dig > 9 then
305
            raise Constraint_Error;
306
         else
307
            V := V * 10 + Integer_64 (Dig);
308
         end if;
309
 
310
         Dig := PP (J) and 16#0F#;
311
 
312
         if Dig > 9 then
313
            raise Constraint_Error;
314
         else
315
            V := V * 10 + Integer_64 (Dig);
316
         end if;
317
 
318
         J := J + 1;
319
      end loop;
320
 
321
      --  Deal with digit nibble in sign byte
322
 
323
      Dig := Shift_Right (PP (J), 4);
324
 
325
      if Dig > 9 then
326
         raise Constraint_Error;
327
      else
328
         V := V * 10 + Integer_64 (Dig);
329
      end if;
330
 
331
      Sign :=  PP (J) and 16#0F#;
332
 
333
      --  Process sign nibble (deal with most common cases first)
334
 
335
      if Sign = 16#C# then
336
         return V;
337
 
338
      elsif Sign = 16#D# then
339
         return -V;
340
 
341
      elsif Sign = 16#B# then
342
         return -V;
343
 
344
      elsif Sign >= 16#A# then
345
         return V;
346
 
347
      else
348
         raise Constraint_Error;
349
      end if;
350
   end Packed_To_Int64;
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352
end Interfaces.Packed_Decimal;

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