FSF GCC merge 02/23/03
[official-gcc.git] / gcc / ada / uintp.ads
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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- U I N T P --
6 -- --
7 -- S p e c --
8 -- --
9 -- --
10 -- Copyright (C) 1992-2002, Free Software Foundation, Inc. --
11 -- --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
22 -- --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
29 -- --
30 -- GNAT was originally developed by the GNAT team at New York University. --
31 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 -- --
33 ------------------------------------------------------------------------------
35 -- Support for universal integer arithmetic
37 -- WARNING: There is a C version of this package. Any changes to this
38 -- source file must be properly reflected in the C header file sinfo.h
40 with Alloc;
41 with Table;
42 pragma Elaborate_All (Table);
43 with Types; use Types;
45 package Uintp is
47 -------------------------------------------------
48 -- Basic Types and Constants for Uintp Package --
49 -------------------------------------------------
51 type Uint is private;
52 -- The basic universal integer type
54 No_Uint : constant Uint;
55 -- A constant value indicating a missing or unset Uint value
57 Uint_0 : constant Uint;
58 Uint_1 : constant Uint;
59 Uint_2 : constant Uint;
60 Uint_3 : constant Uint;
61 Uint_4 : constant Uint;
62 Uint_5 : constant Uint;
63 Uint_6 : constant Uint;
64 Uint_7 : constant Uint;
65 Uint_8 : constant Uint;
66 Uint_9 : constant Uint;
67 Uint_10 : constant Uint;
68 Uint_12 : constant Uint;
69 Uint_15 : constant Uint;
70 Uint_16 : constant Uint;
71 Uint_24 : constant Uint;
72 Uint_32 : constant Uint;
73 Uint_63 : constant Uint;
74 Uint_64 : constant Uint;
75 Uint_128 : constant Uint;
77 Uint_Minus_1 : constant Uint;
78 Uint_Minus_2 : constant Uint;
79 Uint_Minus_3 : constant Uint;
80 Uint_Minus_4 : constant Uint;
81 Uint_Minus_5 : constant Uint;
82 Uint_Minus_6 : constant Uint;
83 Uint_Minus_7 : constant Uint;
84 Uint_Minus_8 : constant Uint;
85 Uint_Minus_9 : constant Uint;
86 Uint_Minus_12 : constant Uint;
87 Uint_Minus_128 : constant Uint;
89 -----------------
90 -- Subprograms --
91 -----------------
93 procedure Initialize;
94 -- Initialize Uint tables. Note that Initialize must not be called if
95 -- Tree_Read is used. Note also that there is no lock routine in this
96 -- unit, these are among the few tables that can be expanded during
97 -- gigi processing.
99 procedure Tree_Read;
100 -- Initializes internal tables from current tree file using Tree_Read.
101 -- Note that Initialize should not be called if Tree_Read is used.
102 -- Tree_Read includes all necessary initialization.
104 procedure Tree_Write;
105 -- Writes out internal tables to current tree file using Tree_Write.
107 function UI_Abs (Right : Uint) return Uint;
108 pragma Inline (UI_Abs);
109 -- Returns abs function of universal integer.
111 function UI_Add (Left : Uint; Right : Uint) return Uint;
112 function UI_Add (Left : Int; Right : Uint) return Uint;
113 function UI_Add (Left : Uint; Right : Int) return Uint;
114 -- Returns sum of two integer values.
116 function UI_Decimal_Digits_Hi (U : Uint) return Nat;
117 -- Returns an estimate of the number of decimal digits required to
118 -- represent the absolute value of U. This estimate is correct or high,
119 -- i.e. it never returns a value that is too low. The accuracy of the
120 -- estimate affects only the effectiveness of comparison optimizations
121 -- in Urealp.
123 function UI_Decimal_Digits_Lo (U : Uint) return Nat;
124 -- Returns an estimate of the number of decimal digits required to
125 -- represent the absolute value of U. This estimate is correct or low,
126 -- i.e. it never returns a value that is too high. The accuracy of the
127 -- estimate affects only the effectiveness of comparison optimizations
128 -- in Urealp.
130 function UI_Div (Left : Uint; Right : Uint) return Uint;
131 function UI_Div (Left : Int; Right : Uint) return Uint;
132 function UI_Div (Left : Uint; Right : Int) return Uint;
133 -- Returns quotient of two integer values. Fatal error if Right = 0
135 function UI_Eq (Left : Uint; Right : Uint) return Boolean;
136 function UI_Eq (Left : Int; Right : Uint) return Boolean;
137 function UI_Eq (Left : Uint; Right : Int) return Boolean;
138 pragma Inline (UI_Eq);
139 -- Compares integer values for equality.
141 function UI_Expon (Left : Uint; Right : Uint) return Uint;
142 function UI_Expon (Left : Int; Right : Uint) return Uint;
143 function UI_Expon (Left : Uint; Right : Int) return Uint;
144 function UI_Expon (Left : Int; Right : Int) return Uint;
145 -- Returns result of exponentiating two integer values
146 -- Fatal error if Right is negative.
148 function UI_GCD (Uin, Vin : Uint) return Uint;
149 -- Computes GCD of input values. Assumes Uin >= Vin >= 0.
151 function UI_Ge (Left : Uint; Right : Uint) return Boolean;
152 function UI_Ge (Left : Int; Right : Uint) return Boolean;
153 function UI_Ge (Left : Uint; Right : Int) return Boolean;
154 pragma Inline (UI_Ge);
155 -- Compares integer values for greater than or equal.
157 function UI_Gt (Left : Uint; Right : Uint) return Boolean;
158 function UI_Gt (Left : Int; Right : Uint) return Boolean;
159 function UI_Gt (Left : Uint; Right : Int) return Boolean;
160 pragma Inline (UI_Gt);
161 -- Compares integer values for greater than.
163 function UI_Is_In_Int_Range (Input : Uint) return Boolean;
164 pragma Inline (UI_Is_In_Int_Range);
165 -- Determines if universal integer is in Int range.
167 function UI_Le (Left : Uint; Right : Uint) return Boolean;
168 function UI_Le (Left : Int; Right : Uint) return Boolean;
169 function UI_Le (Left : Uint; Right : Int) return Boolean;
170 pragma Inline (UI_Le);
171 -- Compares integer values for less than or equal.
173 function UI_Lt (Left : Uint; Right : Uint) return Boolean;
174 function UI_Lt (Left : Int; Right : Uint) return Boolean;
175 function UI_Lt (Left : Uint; Right : Int) return Boolean;
176 -- Compares integer values for less than.
178 function UI_Max (Left : Uint; Right : Uint) return Uint;
179 function UI_Max (Left : Int; Right : Uint) return Uint;
180 function UI_Max (Left : Uint; Right : Int) return Uint;
181 -- Returns maximum of two integer values
183 function UI_Min (Left : Uint; Right : Uint) return Uint;
184 function UI_Min (Left : Int; Right : Uint) return Uint;
185 function UI_Min (Left : Uint; Right : Int) return Uint;
186 -- Returns minimum of two integer values.
188 function UI_Mod (Left : Uint; Right : Uint) return Uint;
189 function UI_Mod (Left : Int; Right : Uint) return Uint;
190 function UI_Mod (Left : Uint; Right : Int) return Uint;
191 pragma Inline (UI_Mod);
192 -- Returns mod function of two integer values.
194 function UI_Mul (Left : Uint; Right : Uint) return Uint;
195 function UI_Mul (Left : Int; Right : Uint) return Uint;
196 function UI_Mul (Left : Uint; Right : Int) return Uint;
197 -- Returns product of two integer values
199 function UI_Ne (Left : Uint; Right : Uint) return Boolean;
200 function UI_Ne (Left : Int; Right : Uint) return Boolean;
201 function UI_Ne (Left : Uint; Right : Int) return Boolean;
202 pragma Inline (UI_Ne);
203 -- Compares integer values for inequality.
205 function UI_Negate (Right : Uint) return Uint;
206 pragma Inline (UI_Negate);
207 -- Returns negative of universal integer.
209 function UI_Rem (Left : Uint; Right : Uint) return Uint;
210 function UI_Rem (Left : Int; Right : Uint) return Uint;
211 function UI_Rem (Left : Uint; Right : Int) return Uint;
212 -- Returns rem of two integer values.
214 function UI_Sub (Left : Uint; Right : Uint) return Uint;
215 function UI_Sub (Left : Int; Right : Uint) return Uint;
216 function UI_Sub (Left : Uint; Right : Int) return Uint;
217 pragma Inline (UI_Sub);
218 -- Returns difference of two integer values
220 function UI_From_Dint (Input : Dint) return Uint;
221 -- Converts Dint value to universal integer form.
223 function UI_From_Int (Input : Int) return Uint;
224 -- Converts Int value to universal integer form.
226 function UI_To_Int (Input : Uint) return Int;
227 -- Converts universal integer value to Int. Fatal error
228 -- if value is not in appropriate range.
230 function Num_Bits (Input : Uint) return Nat;
231 -- Approximate number of binary bits in given universal integer.
232 -- This function is used for capacity checks, and it can be one
233 -- bit off without affecting its usage.
235 ---------------------
236 -- Output Routines --
237 ---------------------
239 type UI_Format is (Hex, Decimal, Auto);
240 -- Used to determine whether UI_Image/UI_Write output is in hexadecimal
241 -- or decimal format. Auto, the default setting, lets the routine make
242 -- a decision based on the value.
244 UI_Image_Max : constant := 32;
245 UI_Image_Buffer : String (1 .. UI_Image_Max);
246 UI_Image_Length : Natural;
247 -- Buffer used for UI_Image as described below
249 procedure UI_Image (Input : Uint; Format : UI_Format := Auto);
250 -- Places a representation of Uint, consisting of a possible minus sign,
251 -- followed by the value in UI_Image_Buffer. The form of the value is an
252 -- integer literal in either decimal (no base) or hexadecimal (base 16)
253 -- format. If Hex is True on entry, then hex mode is forced, otherwise
254 -- UI_Image makes a guess at which output format is more convenient. The
255 -- value must fit in UI_Image_Buffer. If necessary, the result is an
256 -- approximation of the proper value, using an exponential format. The
257 -- image of No_Uint is output as a single question mark.
259 procedure UI_Write (Input : Uint; Format : UI_Format := Auto);
260 -- Writes a representation of Uint, consisting of a possible minus sign,
261 -- followed by the value to the output file. The form of the value is an
262 -- integer literal in either decimal (no base) or hexadecimal (base 16)
263 -- format as appropriate. UI_Format shows which format to use. Auto,
264 -- the default, asks UI_Write to make a guess at which output format
265 -- will be more convenient to read.
267 procedure pid (Input : Uint);
268 pragma Export (Ada, pid);
269 -- Writes representation of Uint in decimal with a terminating line
270 -- return. This is intended for use from the debugger.
272 procedure pih (Input : Uint);
273 pragma Export (Ada, pih);
274 -- Writes representation of Uint in hex with a terminating line return.
275 -- This is intended for use from the debugger.
277 ------------------------
278 -- Operator Renamings --
279 ------------------------
281 function "+" (Left : Uint; Right : Uint) return Uint renames UI_Add;
282 function "+" (Left : Int; Right : Uint) return Uint renames UI_Add;
283 function "+" (Left : Uint; Right : Int) return Uint renames UI_Add;
285 function "/" (Left : Uint; Right : Uint) return Uint renames UI_Div;
286 function "/" (Left : Int; Right : Uint) return Uint renames UI_Div;
287 function "/" (Left : Uint; Right : Int) return Uint renames UI_Div;
289 function "*" (Left : Uint; Right : Uint) return Uint renames UI_Mul;
290 function "*" (Left : Int; Right : Uint) return Uint renames UI_Mul;
291 function "*" (Left : Uint; Right : Int) return Uint renames UI_Mul;
293 function "-" (Left : Uint; Right : Uint) return Uint renames UI_Sub;
294 function "-" (Left : Int; Right : Uint) return Uint renames UI_Sub;
295 function "-" (Left : Uint; Right : Int) return Uint renames UI_Sub;
297 function "**" (Left : Uint; Right : Uint) return Uint renames UI_Expon;
298 function "**" (Left : Uint; Right : Int) return Uint renames UI_Expon;
299 function "**" (Left : Int; Right : Uint) return Uint renames UI_Expon;
300 function "**" (Left : Int; Right : Int) return Uint renames UI_Expon;
302 function "abs" (Real : Uint) return Uint renames UI_Abs;
304 function "mod" (Left : Uint; Right : Uint) return Uint renames UI_Mod;
305 function "mod" (Left : Int; Right : Uint) return Uint renames UI_Mod;
306 function "mod" (Left : Uint; Right : Int) return Uint renames UI_Mod;
308 function "rem" (Left : Uint; Right : Uint) return Uint renames UI_Rem;
309 function "rem" (Left : Int; Right : Uint) return Uint renames UI_Rem;
310 function "rem" (Left : Uint; Right : Int) return Uint renames UI_Rem;
312 function "-" (Real : Uint) return Uint renames UI_Negate;
314 function "=" (Left : Uint; Right : Uint) return Boolean renames UI_Eq;
315 function "=" (Left : Int; Right : Uint) return Boolean renames UI_Eq;
316 function "=" (Left : Uint; Right : Int) return Boolean renames UI_Eq;
318 function ">=" (Left : Uint; Right : Uint) return Boolean renames UI_Ge;
319 function ">=" (Left : Int; Right : Uint) return Boolean renames UI_Ge;
320 function ">=" (Left : Uint; Right : Int) return Boolean renames UI_Ge;
322 function ">" (Left : Uint; Right : Uint) return Boolean renames UI_Gt;
323 function ">" (Left : Int; Right : Uint) return Boolean renames UI_Gt;
324 function ">" (Left : Uint; Right : Int) return Boolean renames UI_Gt;
326 function "<=" (Left : Uint; Right : Uint) return Boolean renames UI_Le;
327 function "<=" (Left : Int; Right : Uint) return Boolean renames UI_Le;
328 function "<=" (Left : Uint; Right : Int) return Boolean renames UI_Le;
330 function "<" (Left : Uint; Right : Uint) return Boolean renames UI_Lt;
331 function "<" (Left : Int; Right : Uint) return Boolean renames UI_Lt;
332 function "<" (Left : Uint; Right : Int) return Boolean renames UI_Lt;
334 -----------------------------
335 -- Mark/Release Processing --
336 -----------------------------
338 -- The space used by Uint data is not automatically reclaimed. However,
339 -- a mark-release regime is implemented which allows storage to be
340 -- released back to a previously noted mark. This is used for example
341 -- when doing comparisons, where only intermediate results get stored
342 -- that do not need to be saved for future use.
344 type Save_Mark is private;
346 function Mark return Save_Mark;
347 -- Note mark point for future release
349 procedure Release (M : Save_Mark);
350 -- Release storage allocated since mark was noted
352 procedure Release_And_Save (M : Save_Mark; UI : in out Uint);
353 -- Like Release, except that the given Uint value (which is typically
354 -- among the data being released) is recopied after the release, so
355 -- that it is the most recent item, and UI is updated to point to
356 -- its copied location.
358 procedure Release_And_Save (M : Save_Mark; UI1, UI2 : in out Uint);
359 -- Like Release, except that the given Uint values (which are typically
360 -- among the data being released) are recopied after the release, so
361 -- that they are the most recent items, and UI1 and UI2 are updated if
362 -- necessary to point to the copied locations. This routine is careful
363 -- to do things in the right order, so that the values do not clobber
364 -- one another.
366 -----------------------------------
367 -- Representation of Uint Values --
368 -----------------------------------
370 private
372 type Uint is new Int range Uint_Low_Bound .. Uint_High_Bound;
373 for Uint'Size use 32;
375 No_Uint : constant Uint := Uint (Uint_Low_Bound);
377 -- Uint values are represented as multiple precision integers stored in
378 -- a multi-digit format using Base as the base. This value is chosen so
379 -- that the product Base*Base is within the range of allowed Int values.
381 -- Base is defined to allow efficient execution of the primitive
382 -- operations (a0, b0, c0) defined in the section "The Classical
383 -- Algorithms" (sec. 4.3.1) of Donald Knuth's "The Art of Computer
384 -- Programming", Vol. 2. These algorithms are used in this package.
386 Base_Bits : constant := 15;
387 -- Number of bits in base value
389 Base : constant Int := 2 ** Base_Bits;
391 -- Values in the range -(Base+1) .. maxdirect are encoded directly as
392 -- Uint values by adding a bias value. The value of maxdirect is chosen
393 -- so that a directly represented number always fits in two digits when
394 -- represented in base format.
396 Min_Direct : constant Int := -(Base - 1);
397 Max_Direct : constant Int := (Base - 1) * (Base - 1);
399 -- The following values define the bias used to store Uint values which
400 -- are in this range, as well as the biased values for the first and
401 -- last values in this range. We use a new derived type for these
402 -- constants to avoid accidental use of Uint arithmetic on these
403 -- values, which is never correct.
405 type Ctrl is range Int'First .. Int'Last;
407 Uint_Direct_Bias : constant Ctrl := Ctrl (Uint_Low_Bound) + Ctrl (Base);
408 Uint_Direct_First : constant Ctrl := Uint_Direct_Bias + Ctrl (Min_Direct);
409 Uint_Direct_Last : constant Ctrl := Uint_Direct_Bias + Ctrl (Max_Direct);
411 Uint_0 : constant Uint := Uint (Uint_Direct_Bias);
412 Uint_1 : constant Uint := Uint (Uint_Direct_Bias + 1);
413 Uint_2 : constant Uint := Uint (Uint_Direct_Bias + 2);
414 Uint_3 : constant Uint := Uint (Uint_Direct_Bias + 3);
415 Uint_4 : constant Uint := Uint (Uint_Direct_Bias + 4);
416 Uint_5 : constant Uint := Uint (Uint_Direct_Bias + 5);
417 Uint_6 : constant Uint := Uint (Uint_Direct_Bias + 6);
418 Uint_7 : constant Uint := Uint (Uint_Direct_Bias + 7);
419 Uint_8 : constant Uint := Uint (Uint_Direct_Bias + 8);
420 Uint_9 : constant Uint := Uint (Uint_Direct_Bias + 9);
421 Uint_10 : constant Uint := Uint (Uint_Direct_Bias + 10);
422 Uint_12 : constant Uint := Uint (Uint_Direct_Bias + 12);
423 Uint_15 : constant Uint := Uint (Uint_Direct_Bias + 15);
424 Uint_16 : constant Uint := Uint (Uint_Direct_Bias + 16);
425 Uint_24 : constant Uint := Uint (Uint_Direct_Bias + 24);
426 Uint_32 : constant Uint := Uint (Uint_Direct_Bias + 32);
427 Uint_63 : constant Uint := Uint (Uint_Direct_Bias + 63);
428 Uint_64 : constant Uint := Uint (Uint_Direct_Bias + 64);
429 Uint_128 : constant Uint := Uint (Uint_Direct_Bias + 128);
431 Uint_Minus_1 : constant Uint := Uint (Uint_Direct_Bias - 1);
432 Uint_Minus_2 : constant Uint := Uint (Uint_Direct_Bias - 2);
433 Uint_Minus_3 : constant Uint := Uint (Uint_Direct_Bias - 3);
434 Uint_Minus_4 : constant Uint := Uint (Uint_Direct_Bias - 4);
435 Uint_Minus_5 : constant Uint := Uint (Uint_Direct_Bias - 5);
436 Uint_Minus_6 : constant Uint := Uint (Uint_Direct_Bias - 6);
437 Uint_Minus_7 : constant Uint := Uint (Uint_Direct_Bias - 7);
438 Uint_Minus_8 : constant Uint := Uint (Uint_Direct_Bias - 8);
439 Uint_Minus_9 : constant Uint := Uint (Uint_Direct_Bias - 9);
440 Uint_Minus_12 : constant Uint := Uint (Uint_Direct_Bias - 12);
441 Uint_Minus_128 : constant Uint := Uint (Uint_Direct_Bias - 128);
443 type Save_Mark is record
444 Save_Uint : Uint;
445 Save_Udigit : Int;
446 end record;
448 -- Values outside the range that is represented directly are stored
449 -- using two tables. The secondary table Udigits contains sequences of
450 -- Int values consisting of the digits of the number in a radix Base
451 -- system. The digits are stored from most significant to least
452 -- significant with the first digit only carrying the sign.
454 -- There is one entry in the primary Uints table for each distinct Uint
455 -- value. This table entry contains the length (number of digits) and
456 -- a starting offset of the value in the Udigits table.
458 Uint_First_Entry : constant Uint := Uint (Uint_Table_Start);
460 -- Some subprograms defined in this package manipulate the Udigits
461 -- table directly, while for others it is more convenient to work with
462 -- locally defined arrays of the digits of the Universal Integers.
463 -- The type UI_Vector is defined for this purpose and some internal
464 -- subprograms used for converting from one to the other are defined.
466 type UI_Vector is array (Pos range <>) of Int;
467 -- Vector containing the integer values of a Uint value
469 -- Note: An earlier version of this package used pointers of arrays
470 -- of Ints (dynamically allocated) for the Uint type. The change
471 -- leads to a few less natural idioms used throughout this code, but
472 -- eliminates all uses of the heap except for the table package itself.
473 -- For example, Uint parameters are often converted to UI_Vectors for
474 -- internal manipulation. This is done by creating the local UI_Vector
475 -- using the function N_Digits on the Uint to find the size needed for
476 -- the vector, and then calling Init_Operand to copy the values out
477 -- of the table into the vector.
479 type Uint_Entry is record
480 Length : Pos;
481 -- Length of entry in Udigits table in digits (i.e. in words)
483 Loc : Int;
484 -- Starting location in Udigits table of this Uint value
485 end record;
487 package Uints is new Table.Table (
488 Table_Component_Type => Uint_Entry,
489 Table_Index_Type => Uint,
490 Table_Low_Bound => Uint_First_Entry,
491 Table_Initial => Alloc.Uints_Initial,
492 Table_Increment => Alloc.Uints_Increment,
493 Table_Name => "Uints");
495 package Udigits is new Table.Table (
496 Table_Component_Type => Int,
497 Table_Index_Type => Int,
498 Table_Low_Bound => 0,
499 Table_Initial => Alloc.Udigits_Initial,
500 Table_Increment => Alloc.Udigits_Increment,
501 Table_Name => "Udigits");
503 -- Note: the reason these tables are defined here in the private part of
504 -- the spec, rather than in the body, is that they are refrerenced
505 -- directly by gigi.
507 end Uintp;