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[/] [openrisc/] [trunk/] [gnu-src/] [gcc-4.5.1/] [gcc/] [ada/] [i-pacdec.adb] - Blame information for rev 303

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1 281 jeremybenn 
------------------------------------------------------------------------------
2 
--                                                                          --
3 
--                         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             --
6 
--                                                                          --
7 
--                                 B o d y                                  --
8 
--            (Version for IBM Mainframe Packed Decimal Format)             --
9 
--                                                                          --
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--          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
11 
--                                                                          --
12 
-- 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.               --
22 
--                                                                          --
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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;     --
25 
-- 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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--                                                                          --
31 
------------------------------------------------------------------------------
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;
40 
   --  The type used internally to represent packed decimal
41 
 
42 
   type Packed_Ptr is access Packed;
43 
   function To_Packed_Ptr is
44 
     new Ada.Unchecked_Conversion (Address, Packed_Ptr);
45 
 
46 
   --  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
48 
   --  using table look up in this direction because divides are expensive.
49 
 
50 
   Packed_Byte : constant array (00 .. 99) of Unsigned_8 :=
51 
      (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#,
56 
       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#,
70 
       16#95#, 16#96#, 16#97#, 16#98#, 16#99#);
71 
 
72 
   ---------------------
73 
   -- Int32_To_Packed --
74 
   ---------------------
75 
 
76 
   procedure Int32_To_Packed (V : Integer_32; P : System.Address; D : D32) is
77 
      PP           : constant Packed_Ptr  := To_Packed_Ptr (P);
78 
      Empty_Nibble : constant Boolean     := ((D rem 2) = 0);
79 
      B            : constant Byte_Length := (D / 2) + 1;
80 
      VV           : Integer_32 := V;
81 
 
82 
   begin
83 
      --  Deal with sign byte first
84 
 
85 
      if VV >= 0 then
86 
         PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#C#;
87 
         VV := VV / 10;
88 
 
89 
      else
90 
         VV := -VV;
91 
         PP (B) := Unsigned_8 (VV rem 10) * 16 + 16#D#;
92 
      end if;
93 
 
94 
      for J in reverse B - 1 .. 2 loop
95 
         if VV = 0 then
96 
            for K in 1 .. J loop
97 
               PP (K) := 16#00#;
98 
            end loop;
99 
 
100 
            return;
101 
 
102 
         else
103 
            PP (J) := Packed_Byte (Integer (VV rem 100));
104 
            VV := VV / 100;
105 
         end if;
106 
      end loop;
107 
 
108 
      --  Deal with leading byte
109 
 
110 
      if Empty_Nibble then
111 
         if VV > 9 then
112 
            raise Constraint_Error;
113 
         else
114 
            PP (1) := Unsigned_8 (VV);
115 
         end if;
116 
 
117 
      else
118 
         if VV > 99 then
119 
            raise Constraint_Error;
120 
         else
121 
            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;
351 
 
352 
end Interfaces.Packed_Decimal;

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