Commit | Line | Data |
0716bf9b |
1 | package Math::BigInt::Calc; |
2 | |
3 | use 5.005; |
4 | use strict; |
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5 | # use warnings; # dont use warnings for older Perls |
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6 | |
7 | require Exporter; |
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8 | use vars qw/@ISA $VERSION/; |
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9 | @ISA = qw(Exporter); |
10 | |
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11 | $VERSION = '0.28'; |
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12 | |
13 | # Package to store unsigned big integers in decimal and do math with them |
14 | |
15 | # Internally the numbers are stored in an array with at least 1 element, no |
027dc388 |
16 | # leading zero parts (except the first) and in base 1eX where X is determined |
17 | # automatically at loading time to be the maximum possible value |
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18 | |
19 | # todo: |
20 | # - fully remove funky $# stuff (maybe) |
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21 | |
22 | # USE_MUL: due to problems on certain os (os390, posix-bc) "* 1e-5" is used |
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23 | # instead of "/ 1e5" at some places, (marked with USE_MUL). Other platforms |
24 | # BS2000, some Crays need USE_DIV instead. |
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25 | # The BEGIN block is used to determine which of the two variants gives the |
26 | # correct result. |
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27 | |
28 | ############################################################################## |
29 | # global constants, flags and accessory |
30 | |
31 | # constants for easier life |
32 | my $nan = 'NaN'; |
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33 | my ($MBASE,$BASE,$RBASE,$BASE_LEN,$MAX_VAL,$BASE_LEN2,$BASE_LEN_SMALL); |
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34 | my ($AND_BITS,$XOR_BITS,$OR_BITS); |
35 | my ($AND_MASK,$XOR_MASK,$OR_MASK); |
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36 | my ($LEN_CONVERT); |
ee15d750 |
37 | |
38 | sub _base_len |
39 | { |
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40 | # set/get the BASE_LEN and assorted other, connected values |
41 | # used only be the testsuite, set is used only by the BEGIN block below |
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42 | shift; |
43 | |
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44 | my $b = shift; |
45 | if (defined $b) |
46 | { |
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47 | # find whether we can use mul or div or none in mul()/div() |
48 | # (in last case reduce BASE_LEN_SMALL) |
49 | $BASE_LEN_SMALL = $b+1; |
50 | my $caught = 0; |
51 | while (--$BASE_LEN_SMALL > 5) |
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52 | { |
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53 | $MBASE = int("1e".$BASE_LEN_SMALL); |
54 | $RBASE = abs('1e-'.$BASE_LEN_SMALL); # see USE_MUL |
394e6ffb |
55 | $caught = 0; |
61f5c3f5 |
56 | $caught += 1 if (int($MBASE * $RBASE) != 1); # should be 1 |
57 | $caught += 2 if (int($MBASE / $MBASE) != 1); # should be 1 |
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58 | last if $caught != 3; |
59 | } |
61f5c3f5 |
60 | # BASE_LEN is used for anything else than mul()/div() |
61 | $BASE_LEN = $BASE_LEN_SMALL; |
62 | $BASE_LEN = shift if (defined $_[0]); # one more arg? |
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63 | $BASE = int("1e".$BASE_LEN); |
61f5c3f5 |
64 | |
65 | $BASE_LEN2 = int($BASE_LEN_SMALL / 2); # for mul shortcut |
66 | $MBASE = int("1e".$BASE_LEN_SMALL); |
67 | $RBASE = abs('1e-'.$BASE_LEN_SMALL); # see USE_MUL |
68 | $MAX_VAL = $MBASE-1; |
69 | $LEN_CONVERT = 0; |
70 | $LEN_CONVERT = 1 if $BASE_LEN_SMALL != $BASE_LEN; |
71 | |
72 | #print "BASE_LEN: $BASE_LEN MAX_VAL: $MAX_VAL BASE: $BASE RBASE: $RBASE "; |
73 | #print "BASE_LEN_SMALL: $BASE_LEN_SMALL MBASE: $MBASE\n"; |
74 | |
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75 | undef &_mul; |
76 | undef &_div; |
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77 | if ($caught & 1 != 0) |
ee15d750 |
78 | { |
79 | # must USE_MUL |
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80 | *{_mul} = \&_mul_use_mul; |
81 | *{_div} = \&_div_use_mul; |
82 | } |
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83 | else # $caught must be 2, since it can't be 1 nor 3 |
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84 | { |
ee15d750 |
85 | # can USE_DIV instead |
86 | *{_mul} = \&_mul_use_div; |
87 | *{_div} = \&_div_use_div; |
88 | } |
89 | } |
61f5c3f5 |
90 | return $BASE_LEN unless wantarray; |
91 | return ($BASE_LEN, $AND_BITS, $XOR_BITS, $OR_BITS, $BASE_LEN_SMALL, $MAX_VAL); |
ee15d750 |
92 | } |
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93 | |
94 | BEGIN |
95 | { |
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96 | # from Daniel Pfeiffer: determine largest group of digits that is precisely |
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97 | # multipliable with itself plus carry |
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98 | # Test now changed to expect the proper pattern, not a result off by 1 or 2 |
99 | my ($e, $num) = 3; # lowest value we will use is 3+1-1 = 3 |
bd05a461 |
100 | do |
101 | { |
102 | $num = ('9' x ++$e) + 0; |
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103 | $num *= $num + 1.0; |
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104 | } while ("$num" =~ /9{$e}0{$e}/); # must be a certain pattern |
105 | $e--; # last test failed, so retract one step |
106 | # the limits below brush the problems with the test above under the rug: |
107 | # the test should be able to find the proper $e automatically |
108 | $e = 5 if $^O =~ /^uts/; # UTS get's some special treatment |
109 | $e = 5 if $^O =~ /^unicos/; # unicos is also problematic (6 seems to work |
110 | # there, but we play safe) |
2e507a43 |
111 | $e = 7 if $e > 7; # cap, for VMS, OS/390 and other 64 bit systems |
112 | # 8 fails inside random testsuite, so take 7 |
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113 | |
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114 | # determine how many digits fit into an integer and can be safely added |
115 | # together plus carry w/o causing an overflow |
116 | |
117 | # this below detects 15 on a 64 bit system, because after that it becomes |
118 | # 1e16 and not 1000000 :/ I can make it detect 18, but then I get a lot of |
119 | # test failures. Ugh! (Tomake detect 18: uncomment lines marked with *) |
120 | use integer; |
121 | my $bi = 5; # approx. 16 bit |
122 | $num = int('9' x $bi); |
123 | # $num = 99999; # * |
124 | # while ( ($num+$num+1) eq '1' . '9' x $bi) # * |
125 | while ( int($num+$num+1) eq '1' . '9' x $bi) |
126 | { |
127 | $bi++; $num = int('9' x $bi); |
128 | # $bi++; $num *= 10; $num += 9; # * |
129 | } |
130 | $bi--; # back off one step |
131 | # by setting them equal, we ignore the findings and use the default |
132 | # one-size-fits-all approach from former versions |
133 | $bi = $e; # XXX, this should work always |
134 | |
135 | __PACKAGE__->_base_len($e,$bi); # set and store |
394e6ffb |
136 | |
137 | # find out how many bits _and, _or and _xor can take (old default = 16) |
138 | # I don't think anybody has yet 128 bit scalars, so let's play safe. |
394e6ffb |
139 | local $^W = 0; # don't warn about 'nonportable number' |
140 | $AND_BITS = 15; $XOR_BITS = 15; $OR_BITS = 15; |
141 | |
142 | # find max bits, we will not go higher than numberofbits that fit into $BASE |
143 | # to make _and etc simpler (and faster for smaller, slower for large numbers) |
144 | my $max = 16; |
145 | while (2 ** $max < $BASE) { $max++; } |
146 | my ($x,$y,$z); |
147 | do { |
148 | $AND_BITS++; |
149 | $x = oct('0b' . '1' x $AND_BITS); $y = $x & $x; |
150 | $z = (2 ** $AND_BITS) - 1; |
151 | } while ($AND_BITS < $max && $x == $z && $y == $x); |
152 | $AND_BITS --; # retreat one step |
153 | do { |
154 | $XOR_BITS++; |
155 | $x = oct('0b' . '1' x $XOR_BITS); $y = $x ^ 0; |
156 | $z = (2 ** $XOR_BITS) - 1; |
157 | } while ($XOR_BITS < $max && $x == $z && $y == $x); |
158 | $XOR_BITS --; # retreat one step |
159 | do { |
160 | $OR_BITS++; |
161 | $x = oct('0b' . '1' x $OR_BITS); $y = $x | $x; |
162 | $z = (2 ** $OR_BITS) - 1; |
163 | } while ($OR_BITS < $max && $x == $z && $y == $x); |
164 | $OR_BITS --; # retreat one step |
165 | |
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166 | } |
167 | |
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168 | ############################################################################## |
61f5c3f5 |
169 | # convert between the "small" and the "large" representation |
170 | |
171 | sub _to_large |
172 | { |
173 | # take an array in base $BASE_LEN_SMALL and convert it in-place to $BASE_LEN |
174 | my ($c,$x) = @_; |
175 | |
176 | # print "_to_large $BASE_LEN_SMALL => $BASE_LEN\n"; |
177 | |
178 | return $x if $LEN_CONVERT == 0 || # nothing to converconvertor |
179 | @$x == 1; # only one element => early out |
180 | |
181 | # 12345 67890 12345 67890 contents |
182 | # to 3 2 1 0 index |
183 | # 123456 7890123 4567890 contents |
184 | |
185 | # # faster variant |
186 | # my @d; my $str = ''; |
187 | # my $z = '0' x $BASE_LEN_SMALL; |
188 | # foreach (@$x) |
189 | # { |
190 | # # ... . 04321 . 000321 |
191 | # $str = substr($z.$_,-$BASE_LEN_SMALL,$BASE_LEN_SMALL) . $str; |
192 | # if (length($str) > $BASE_LEN) |
193 | # { |
194 | # push @d, substr($str,-$BASE_LEN,$BASE_LEN); # extract one piece |
195 | # substr($str,-$BASE_LEN,$BASE_LEN) = ''; # remove it |
196 | # } |
197 | # } |
198 | # push @d, $str if $str !~ /^0*$/; # extract last piece |
199 | # @$x = @d; |
200 | # $x->[-1] = int($x->[-1]); # strip leading zero |
201 | # $x; |
202 | |
203 | my $ret = ""; |
204 | my $l = scalar @$x; # number of parts |
205 | $l --; $ret .= int($x->[$l]); $l--; |
206 | my $z = '0' x ($BASE_LEN_SMALL-1); |
207 | while ($l >= 0) |
208 | { |
209 | $ret .= substr($z.$x->[$l],-$BASE_LEN_SMALL); |
210 | $l--; |
211 | } |
212 | my $str = _new($c,\$ret); # make array |
213 | @$x = @$str; # clobber contents of $x |
214 | $x->[-1] = int($x->[-1]); # strip leading zero |
215 | } |
216 | |
217 | sub _to_small |
218 | { |
219 | # take an array in base $BASE_LEN and convert it in-place to $BASE_LEN_SMALL |
220 | my ($c,$x) = @_; |
221 | |
222 | return $x if $LEN_CONVERT == 0; # nothing to do |
223 | return $x if @$x == 1 && length(int($x->[0])) <= $BASE_LEN_SMALL; |
224 | |
225 | my $d = _str($c,$x); |
226 | my $il = length($$d)-1; |
227 | ## this leaves '00000' instead of int 0 and will be corrected after any op |
228 | # clobber contents of $x |
229 | @$x = reverse(unpack("a" . ($il % $BASE_LEN_SMALL+1) |
230 | . ("a$BASE_LEN_SMALL" x ($il / $BASE_LEN_SMALL)), $$d)); |
231 | |
232 | $x->[-1] = int($x->[-1]); # strip leading zero |
233 | } |
234 | |
235 | ############################################################################### |
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236 | |
237 | sub _new |
238 | { |
394e6ffb |
239 | # (ref to string) return ref to num_array |
9393ace2 |
240 | # Convert a number from string format (without sign) to internal base |
241 | # 1ex format. Assumes normalized value as input. |
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242 | my $d = $_[1]; |
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243 | my $il = length($$d)-1; |
244 | # this leaves '00000' instead of int 0 and will be corrected after any op |
245 | [ reverse(unpack("a" . ($il % $BASE_LEN+1) |
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246 | . ("a$BASE_LEN" x ($il / $BASE_LEN)), $$d)) ]; |
0716bf9b |
247 | } |
394e6ffb |
248 | |
249 | BEGIN |
250 | { |
251 | $AND_MASK = __PACKAGE__->_new( \( 2 ** $AND_BITS )); |
252 | $XOR_MASK = __PACKAGE__->_new( \( 2 ** $XOR_BITS )); |
253 | $OR_MASK = __PACKAGE__->_new( \( 2 ** $OR_BITS )); |
254 | } |
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255 | |
256 | sub _zero |
257 | { |
258 | # create a zero |
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259 | [ 0 ]; |
0716bf9b |
260 | } |
261 | |
262 | sub _one |
263 | { |
264 | # create a one |
61f5c3f5 |
265 | [ 1 ]; |
0716bf9b |
266 | } |
267 | |
027dc388 |
268 | sub _two |
269 | { |
270 | # create a two (for _pow) |
61f5c3f5 |
271 | [ 2 ]; |
027dc388 |
272 | } |
273 | |
0716bf9b |
274 | sub _copy |
275 | { |
61f5c3f5 |
276 | [ @{$_[1]} ]; |
0716bf9b |
277 | } |
278 | |
bd05a461 |
279 | # catch and throw away |
280 | sub import { } |
281 | |
0716bf9b |
282 | ############################################################################## |
283 | # convert back to string and number |
284 | |
285 | sub _str |
286 | { |
287 | # (ref to BINT) return num_str |
288 | # Convert number from internal base 100000 format to string format. |
289 | # internal format is always normalized (no leading zeros, "-0" => "+0") |
574bacfe |
290 | my $ar = $_[1]; |
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291 | my $ret = ""; |
61f5c3f5 |
292 | |
293 | my $l = scalar @$ar; # number of parts |
294 | return $nan if $l < 1; # should not happen |
295 | |
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296 | # handle first one different to strip leading zeros from it (there are no |
297 | # leading zero parts in internal representation) |
61f5c3f5 |
298 | $l --; $ret .= int($ar->[$l]); $l--; |
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299 | # Interestingly, the pre-padd method uses more time |
574bacfe |
300 | # the old grep variant takes longer (14 to 10 sec) |
301 | my $z = '0' x ($BASE_LEN-1); |
0716bf9b |
302 | while ($l >= 0) |
303 | { |
574bacfe |
304 | $ret .= substr($z.$ar->[$l],-$BASE_LEN); # fastest way I could think of |
0716bf9b |
305 | $l--; |
306 | } |
61f5c3f5 |
307 | \$ret; |
0716bf9b |
308 | } |
309 | |
310 | sub _num |
311 | { |
312 | # Make a number (scalar int/float) from a BigInt object |
574bacfe |
313 | my $x = $_[1]; |
0716bf9b |
314 | return $x->[0] if scalar @$x == 1; # below $BASE |
315 | my $fac = 1; |
316 | my $num = 0; |
317 | foreach (@$x) |
318 | { |
319 | $num += $fac*$_; $fac *= $BASE; |
320 | } |
61f5c3f5 |
321 | $num; |
0716bf9b |
322 | } |
323 | |
324 | ############################################################################## |
325 | # actual math code |
326 | |
327 | sub _add |
328 | { |
329 | # (ref to int_num_array, ref to int_num_array) |
574bacfe |
330 | # routine to add two base 1eX numbers |
0716bf9b |
331 | # stolen from Knuth Vol 2 Algorithm A pg 231 |
b22b3e31 |
332 | # there are separate routines to add and sub as per Knuth pg 233 |
0716bf9b |
333 | # This routine clobbers up array x, but not y. |
334 | |
574bacfe |
335 | my ($c,$x,$y) = @_; |
b3abae2a |
336 | |
337 | return $x if (@$y == 1) && $y->[0] == 0; # $x + 0 => $x |
338 | if ((@$x == 1) && $x->[0] == 0) # 0 + $y => $y->copy |
339 | { |
340 | # twice as slow as $x = [ @$y ], but necc. to retain $x as ref :( |
341 | @$x = @$y; return $x; |
342 | } |
0716bf9b |
343 | |
344 | # for each in Y, add Y to X and carry. If after that, something is left in |
345 | # X, foreach in X add carry to X and then return X, carry |
346 | # Trades one "$j++" for having to shift arrays, $j could be made integer |
b22b3e31 |
347 | # but this would impose a limit to number-length of 2**32. |
0716bf9b |
348 | my $i; my $car = 0; my $j = 0; |
349 | for $i (@$y) |
350 | { |
e745a66c |
351 | $x->[$j] -= $BASE if $car = (($x->[$j] += $i + $car) >= $BASE) ? 1 : 0; |
0716bf9b |
352 | $j++; |
353 | } |
354 | while ($car != 0) |
355 | { |
356 | $x->[$j] -= $BASE if $car = (($x->[$j] += $car) >= $BASE) ? 1 : 0; $j++; |
357 | } |
61f5c3f5 |
358 | $x; |
e745a66c |
359 | } |
360 | |
361 | sub _inc |
362 | { |
363 | # (ref to int_num_array, ref to int_num_array) |
364 | # routine to add 1 to a base 1eX numbers |
365 | # This routine clobbers up array x, but not y. |
366 | my ($c,$x) = @_; |
367 | |
368 | for my $i (@$x) |
369 | { |
370 | return $x if (($i += 1) < $BASE); # early out |
61f5c3f5 |
371 | $i = 0; # overflow, next |
e745a66c |
372 | } |
61f5c3f5 |
373 | push @$x,1 if ($x->[-1] == 0); # last overflowed, so extend |
374 | $x; |
e745a66c |
375 | } |
376 | |
377 | sub _dec |
378 | { |
379 | # (ref to int_num_array, ref to int_num_array) |
380 | # routine to add 1 to a base 1eX numbers |
381 | # This routine clobbers up array x, but not y. |
382 | my ($c,$x) = @_; |
383 | |
61f5c3f5 |
384 | my $MAX = $BASE-1; # since MAX_VAL based on MBASE |
e745a66c |
385 | for my $i (@$x) |
386 | { |
387 | last if (($i -= 1) >= 0); # early out |
61f5c3f5 |
388 | $i = $MAX; # overflow, next |
e745a66c |
389 | } |
390 | pop @$x if $x->[-1] == 0 && @$x > 1; # last overflowed (but leave 0) |
61f5c3f5 |
391 | $x; |
0716bf9b |
392 | } |
393 | |
394 | sub _sub |
395 | { |
9393ace2 |
396 | # (ref to int_num_array, ref to int_num_array, swap) |
574bacfe |
397 | # subtract base 1eX numbers -- stolen from Knuth Vol 2 pg 232, $x > $y |
56b9c951 |
398 | # subtract Y from X by modifying x in place |
574bacfe |
399 | my ($c,$sx,$sy,$s) = @_; |
0716bf9b |
400 | |
401 | my $car = 0; my $i; my $j = 0; |
402 | if (!$s) |
403 | { |
404 | #print "case 2\n"; |
405 | for $i (@$sx) |
406 | { |
407 | last unless defined $sy->[$j] || $car; |
0716bf9b |
408 | $i += $BASE if $car = (($i -= ($sy->[$j] || 0) + $car) < 0); $j++; |
0716bf9b |
409 | } |
410 | # might leave leading zeros, so fix that |
394e6ffb |
411 | return __strip_zeros($sx); |
0716bf9b |
412 | } |
394e6ffb |
413 | #print "case 1 (swap)\n"; |
414 | for $i (@$sx) |
0716bf9b |
415 | { |
56b9c951 |
416 | # we can't do an early out if $x is than $y, since we |
417 | # need to copy the high chunks from $y. Found by Bob Mathews. |
418 | #last unless defined $sy->[$j] || $car; |
394e6ffb |
419 | $sy->[$j] += $BASE |
420 | if $car = (($sy->[$j] = $i-($sy->[$j]||0) - $car) < 0); |
421 | $j++; |
0716bf9b |
422 | } |
394e6ffb |
423 | # might leave leading zeros, so fix that |
424 | __strip_zeros($sy); |
0716bf9b |
425 | } |
426 | |
9393ace2 |
427 | sub _square_use_mul |
428 | { |
429 | # compute $x ** 2 or $x * $x in-place and return $x |
430 | my ($c,$x) = @_; |
431 | |
432 | # From: Handbook of Applied Cryptography by A. Menezes, P. van Oorschot and |
433 | # S. Vanstone., Chapter 14 |
434 | |
435 | #14.16 Algorithm Multiple-precision squaring |
436 | #INPUT: positive integer x = (xt 1 xt 2 ... x1 x0)b. |
437 | #OUTPUT: x * x = x ** 2 in radix b representation. |
438 | #1. For i from 0 to (2t - 1) do: wi <- 0. |
439 | #2. For i from 0 to (t - 1) do the following: |
440 | # 2.1 (uv)b w2i + xi * xi, w2i v, c u. |
441 | # 2.2 For j from (i + 1)to (t - 1) do the following: |
442 | # (uv)b <- wi+j + 2*xj * xi + c, wi+j <- v, c <- u. |
443 | # 2.3 wi+t <- u. |
444 | #3. Return((w2t-1 w2t-2 ... w1 w0)b). |
445 | |
446 | # # Note: That description is crap. Half of the symbols are not explained or |
447 | # # used with out beeing set. |
448 | # my $t = scalar @$x; # count |
449 | # my ($c,$i,$j); |
450 | # for ($i = 0; $i < $t; $i++) |
451 | # { |
452 | # $x->[$i] = $x->[$i*2] + $x[$i]*$x[$i]; |
453 | # $x->[$i*2] = $x[$i]; $c = $x[$i]; |
454 | # for ($j = $i+1; $j < $t; $j++) |
455 | # { |
456 | # $x->[$i] = $x->[$i+$j] + 2 * $x->[$i] * $x->[$j]; |
457 | # $x->[$i+$j] = $x[$j]; $c = $x[$i]; |
458 | # } |
459 | # $x->[$i+$t] = $x[$i]; |
460 | # } |
461 | $x; |
462 | } |
463 | |
ee15d750 |
464 | sub _mul_use_mul |
0716bf9b |
465 | { |
9393ace2 |
466 | # (ref to int_num_array, ref to int_num_array) |
0716bf9b |
467 | # multiply two numbers in internal representation |
b22b3e31 |
468 | # modifies first arg, second need not be different from first |
574bacfe |
469 | my ($c,$xv,$yv) = @_; |
dccbb853 |
470 | |
b3abae2a |
471 | # shortcut for two very short numbers (improved by Nathan Zook) |
61f5c3f5 |
472 | # works also if xv and yv are the same reference |
b3abae2a |
473 | if ((@$xv == 1) && (@$yv == 1)) |
474 | { |
475 | if (($xv->[0] *= $yv->[0]) >= $MBASE) |
476 | { |
477 | $xv->[0] = $xv->[0] - ($xv->[1] = int($xv->[0] * $RBASE)) * $MBASE; |
478 | }; |
479 | return $xv; |
480 | } |
481 | # shortcut for result == 0 |
482 | if ( ((@$xv == 1) && ($xv->[0] == 0)) || |
483 | ((@$yv == 1) && ($yv->[0] == 0)) ) |
484 | { |
485 | @$xv = (0); |
486 | return $xv; |
487 | } |
488 | |
0716bf9b |
489 | # since multiplying $x with $x fails, make copy in this case |
d614cd8b |
490 | $yv = [@$xv] if $xv == $yv; # same references? |
491 | # $yv = [@$xv] if "$xv" eq "$yv"; # same references? |
492 | |
9393ace2 |
493 | # since multiplying $x with $x would fail here, use the faster squaring |
d614cd8b |
494 | # return _square($c,$xv) if $xv == $yv; # same reference? |
9393ace2 |
495 | |
61f5c3f5 |
496 | if ($LEN_CONVERT != 0) |
497 | { |
498 | $c->_to_small($xv); $c->_to_small($yv); |
499 | } |
500 | |
501 | my @prod = (); my ($prod,$car,$cty,$xi,$yi); |
502 | |
0716bf9b |
503 | for $xi (@$xv) |
504 | { |
505 | $car = 0; $cty = 0; |
574bacfe |
506 | |
507 | # slow variant |
508 | # for $yi (@$yv) |
509 | # { |
510 | # $prod = $xi * $yi + ($prod[$cty] || 0) + $car; |
511 | # $prod[$cty++] = |
61f5c3f5 |
512 | # $prod - ($car = int($prod * RBASE)) * $MBASE; # see USE_MUL |
574bacfe |
513 | # } |
514 | # $prod[$cty] += $car if $car; # need really to check for 0? |
515 | # $xi = shift @prod; |
516 | |
517 | # faster variant |
518 | # looping through this if $xi == 0 is silly - so optimize it away! |
519 | $xi = (shift @prod || 0), next if $xi == 0; |
0716bf9b |
520 | for $yi (@$yv) |
521 | { |
522 | $prod = $xi * $yi + ($prod[$cty] || 0) + $car; |
574bacfe |
523 | ## this is actually a tad slower |
524 | ## $prod = $prod[$cty]; $prod += ($car + $xi * $yi); # no ||0 here |
0716bf9b |
525 | $prod[$cty++] = |
61f5c3f5 |
526 | $prod - ($car = int($prod * $RBASE)) * $MBASE; # see USE_MUL |
0716bf9b |
527 | } |
528 | $prod[$cty] += $car if $car; # need really to check for 0? |
027dc388 |
529 | $xi = shift @prod || 0; # || 0 makes v5.005_3 happy |
0716bf9b |
530 | } |
0716bf9b |
531 | push @$xv, @prod; |
61f5c3f5 |
532 | if ($LEN_CONVERT != 0) |
533 | { |
534 | $c->_to_large($yv); |
535 | $c->_to_large($xv); |
536 | } |
537 | else |
538 | { |
539 | __strip_zeros($xv); |
540 | } |
541 | $xv; |
0716bf9b |
542 | } |
543 | |
ee15d750 |
544 | sub _mul_use_div |
545 | { |
9393ace2 |
546 | # (ref to int_num_array, ref to int_num_array) |
ee15d750 |
547 | # multiply two numbers in internal representation |
548 | # modifies first arg, second need not be different from first |
549 | my ($c,$xv,$yv) = @_; |
550 | |
b3abae2a |
551 | # shortcut for two very short numbers (improved by Nathan Zook) |
61f5c3f5 |
552 | # works also if xv and yv are the same reference |
b3abae2a |
553 | if ((@$xv == 1) && (@$yv == 1)) |
554 | { |
555 | if (($xv->[0] *= $yv->[0]) >= $MBASE) |
556 | { |
557 | $xv->[0] = |
558 | $xv->[0] - ($xv->[1] = int($xv->[0] / $MBASE)) * $MBASE; |
559 | }; |
560 | return $xv; |
561 | } |
562 | # shortcut for result == 0 |
563 | if ( ((@$xv == 1) && ($xv->[0] == 0)) || |
564 | ((@$yv == 1) && ($yv->[0] == 0)) ) |
565 | { |
566 | @$xv = (0); |
567 | return $xv; |
568 | } |
569 | |
61f5c3f5 |
570 | |
ee15d750 |
571 | # since multiplying $x with $x fails, make copy in this case |
d614cd8b |
572 | $yv = [@$xv] if $xv == $yv; # same references? |
573 | # $yv = [@$xv] if "$xv" eq "$yv"; # same references? |
9393ace2 |
574 | # since multiplying $x with $x would fail here, use the faster squaring |
d614cd8b |
575 | # return _square($c,$xv) if $xv == $yv; # same reference? |
9393ace2 |
576 | |
61f5c3f5 |
577 | if ($LEN_CONVERT != 0) |
578 | { |
579 | $c->_to_small($xv); $c->_to_small($yv); |
580 | } |
581 | |
582 | my @prod = (); my ($prod,$car,$cty,$xi,$yi); |
ee15d750 |
583 | for $xi (@$xv) |
584 | { |
585 | $car = 0; $cty = 0; |
586 | # looping through this if $xi == 0 is silly - so optimize it away! |
587 | $xi = (shift @prod || 0), next if $xi == 0; |
588 | for $yi (@$yv) |
589 | { |
590 | $prod = $xi * $yi + ($prod[$cty] || 0) + $car; |
591 | $prod[$cty++] = |
61f5c3f5 |
592 | $prod - ($car = int($prod / $MBASE)) * $MBASE; |
ee15d750 |
593 | } |
594 | $prod[$cty] += $car if $car; # need really to check for 0? |
027dc388 |
595 | $xi = shift @prod || 0; # || 0 makes v5.005_3 happy |
ee15d750 |
596 | } |
597 | push @$xv, @prod; |
61f5c3f5 |
598 | if ($LEN_CONVERT != 0) |
599 | { |
600 | $c->_to_large($yv); |
601 | $c->_to_large($xv); |
602 | } |
603 | else |
604 | { |
605 | __strip_zeros($xv); |
606 | } |
607 | $xv; |
ee15d750 |
608 | } |
609 | |
610 | sub _div_use_mul |
0716bf9b |
611 | { |
b22b3e31 |
612 | # ref to array, ref to array, modify first array and return remainder if |
0716bf9b |
613 | # in list context |
574bacfe |
614 | my ($c,$x,$yorg) = @_; |
0716bf9b |
615 | |
61f5c3f5 |
616 | if (@$x == 1 && @$yorg == 1) |
617 | { |
13a12e00 |
618 | # shortcut, $yorg and $x are two small numbers |
61f5c3f5 |
619 | if (wantarray) |
620 | { |
621 | my $r = [ $x->[0] % $yorg->[0] ]; |
622 | $x->[0] = int($x->[0] / $yorg->[0]); |
623 | return ($x,$r); |
624 | } |
625 | else |
626 | { |
627 | $x->[0] = int($x->[0] / $yorg->[0]); |
628 | return $x; |
629 | } |
630 | } |
28df3e88 |
631 | if (@$yorg == 1) |
632 | { |
633 | my $rem; |
634 | $rem = _mod($c,[ @$x ],$yorg) if wantarray; |
13a12e00 |
635 | |
28df3e88 |
636 | # shortcut, $y is < $BASE |
637 | my $j = scalar @$x; my $r = 0; |
638 | my $y = $yorg->[0]; my $b; |
639 | while ($j-- > 0) |
640 | { |
641 | $b = $r * $MBASE + $x->[$j]; |
642 | $x->[$j] = int($b/$y); |
643 | $r = $b % $y; |
644 | } |
645 | pop @$x if @$x > 1 && $x->[-1] == 0; # splice up a leading zero |
646 | return ($x,$rem) if wantarray; |
647 | return $x; |
648 | } |
0716bf9b |
649 | |
d614cd8b |
650 | my $y = [ @$yorg ]; # always make copy to preserve |
61f5c3f5 |
651 | if ($LEN_CONVERT != 0) |
652 | { |
653 | $c->_to_small($x); $c->_to_small($y); |
654 | } |
655 | |
656 | my ($car,$bar,$prd,$dd,$xi,$yi,@q,$v2,$v1,@d,$tmp,$q,$u2,$u1,$u0); |
657 | |
658 | $car = $bar = $prd = 0; |
659 | if (($dd = int($MBASE/($y->[-1]+1))) != 1) |
0716bf9b |
660 | { |
661 | for $xi (@$x) |
662 | { |
663 | $xi = $xi * $dd + $car; |
61f5c3f5 |
664 | $xi -= ($car = int($xi * $RBASE)) * $MBASE; # see USE_MUL |
0716bf9b |
665 | } |
666 | push(@$x, $car); $car = 0; |
667 | for $yi (@$y) |
668 | { |
669 | $yi = $yi * $dd + $car; |
61f5c3f5 |
670 | $yi -= ($car = int($yi * $RBASE)) * $MBASE; # see USE_MUL |
0716bf9b |
671 | } |
672 | } |
673 | else |
674 | { |
675 | push(@$x, 0); |
676 | } |
677 | @q = (); ($v2,$v1) = @$y[-2,-1]; |
678 | $v2 = 0 unless $v2; |
679 | while ($#$x > $#$y) |
680 | { |
681 | ($u2,$u1,$u0) = @$x[-3..-1]; |
682 | $u2 = 0 unless $u2; |
683 | #warn "oups v1 is 0, u0: $u0 $y->[-2] $y->[-1] l ",scalar @$y,"\n" |
684 | # if $v1 == 0; |
61f5c3f5 |
685 | $q = (($u0 == $v1) ? $MAX_VAL : int(($u0*$MBASE+$u1)/$v1)); |
686 | --$q while ($v2*$q > ($u0*$MBASE+$u1-$q*$v1)*$MBASE+$u2); |
0716bf9b |
687 | if ($q) |
688 | { |
689 | ($car, $bar) = (0,0); |
690 | for ($yi = 0, $xi = $#$x-$#$y-1; $yi <= $#$y; ++$yi,++$xi) |
691 | { |
692 | $prd = $q * $y->[$yi] + $car; |
61f5c3f5 |
693 | $prd -= ($car = int($prd * $RBASE)) * $MBASE; # see USE_MUL |
694 | $x->[$xi] += $MBASE if ($bar = (($x->[$xi] -= $prd + $bar) < 0)); |
0716bf9b |
695 | } |
696 | if ($x->[-1] < $car + $bar) |
697 | { |
698 | $car = 0; --$q; |
699 | for ($yi = 0, $xi = $#$x-$#$y-1; $yi <= $#$y; ++$yi,++$xi) |
700 | { |
61f5c3f5 |
701 | $x->[$xi] -= $MBASE |
702 | if ($car = (($x->[$xi] += $y->[$yi] + $car) > $MBASE)); |
0716bf9b |
703 | } |
704 | } |
705 | } |
706 | pop(@$x); unshift(@q, $q); |
707 | } |
708 | if (wantarray) |
709 | { |
710 | @d = (); |
711 | if ($dd != 1) |
712 | { |
713 | $car = 0; |
714 | for $xi (reverse @$x) |
715 | { |
61f5c3f5 |
716 | $prd = $car * $MBASE + $xi; |
0716bf9b |
717 | $car = $prd - ($tmp = int($prd / $dd)) * $dd; # see USE_MUL |
718 | unshift(@d, $tmp); |
719 | } |
720 | } |
721 | else |
722 | { |
723 | @d = @$x; |
724 | } |
725 | @$x = @q; |
61f5c3f5 |
726 | my $d = \@d; |
727 | if ($LEN_CONVERT != 0) |
728 | { |
729 | $c->_to_large($x); $c->_to_large($d); |
730 | } |
731 | else |
732 | { |
733 | __strip_zeros($x); |
734 | __strip_zeros($d); |
735 | } |
736 | return ($x,$d); |
0716bf9b |
737 | } |
738 | @$x = @q; |
61f5c3f5 |
739 | if ($LEN_CONVERT != 0) |
740 | { |
741 | $c->_to_large($x); |
742 | } |
743 | else |
744 | { |
745 | __strip_zeros($x); |
746 | } |
747 | $x; |
0716bf9b |
748 | } |
749 | |
ee15d750 |
750 | sub _div_use_div |
751 | { |
752 | # ref to array, ref to array, modify first array and return remainder if |
753 | # in list context |
ee15d750 |
754 | my ($c,$x,$yorg) = @_; |
ee15d750 |
755 | |
61f5c3f5 |
756 | if (@$x == 1 && @$yorg == 1) |
757 | { |
13a12e00 |
758 | # shortcut, $yorg and $x are two small numbers |
61f5c3f5 |
759 | if (wantarray) |
760 | { |
761 | my $r = [ $x->[0] % $yorg->[0] ]; |
762 | $x->[0] = int($x->[0] / $yorg->[0]); |
763 | return ($x,$r); |
764 | } |
765 | else |
766 | { |
767 | $x->[0] = int($x->[0] / $yorg->[0]); |
768 | return $x; |
769 | } |
770 | } |
28df3e88 |
771 | if (@$yorg == 1) |
772 | { |
773 | my $rem; |
774 | $rem = _mod($c,[ @$x ],$yorg) if wantarray; |
775 | |
776 | # shortcut, $y is < $BASE |
777 | my $j = scalar @$x; my $r = 0; |
778 | my $y = $yorg->[0]; my $b; |
779 | while ($j-- > 0) |
780 | { |
781 | $b = $r * $MBASE + $x->[$j]; |
782 | $x->[$j] = int($b/$y); |
783 | $r = $b % $y; |
784 | } |
785 | pop @$x if @$x > 1 && $x->[-1] == 0; # splice up a leading zero |
786 | return ($x,$rem) if wantarray; |
787 | return $x; |
788 | } |
ee15d750 |
789 | |
d614cd8b |
790 | my $y = [ @$yorg ]; # always make copy to preserve |
61f5c3f5 |
791 | if ($LEN_CONVERT != 0) |
792 | { |
793 | $c->_to_small($x); $c->_to_small($y); |
794 | } |
795 | |
796 | my ($car,$bar,$prd,$dd,$xi,$yi,@q,$v2,$v1,@d,$tmp,$q,$u2,$u1,$u0); |
797 | |
798 | $car = $bar = $prd = 0; |
799 | if (($dd = int($MBASE/($y->[-1]+1))) != 1) |
ee15d750 |
800 | { |
801 | for $xi (@$x) |
802 | { |
803 | $xi = $xi * $dd + $car; |
61f5c3f5 |
804 | $xi -= ($car = int($xi / $MBASE)) * $MBASE; |
ee15d750 |
805 | } |
806 | push(@$x, $car); $car = 0; |
807 | for $yi (@$y) |
808 | { |
809 | $yi = $yi * $dd + $car; |
61f5c3f5 |
810 | $yi -= ($car = int($yi / $MBASE)) * $MBASE; |
ee15d750 |
811 | } |
812 | } |
813 | else |
814 | { |
815 | push(@$x, 0); |
816 | } |
817 | @q = (); ($v2,$v1) = @$y[-2,-1]; |
818 | $v2 = 0 unless $v2; |
819 | while ($#$x > $#$y) |
820 | { |
821 | ($u2,$u1,$u0) = @$x[-3..-1]; |
822 | $u2 = 0 unless $u2; |
823 | #warn "oups v1 is 0, u0: $u0 $y->[-2] $y->[-1] l ",scalar @$y,"\n" |
824 | # if $v1 == 0; |
61f5c3f5 |
825 | $q = (($u0 == $v1) ? $MAX_VAL : int(($u0*$MBASE+$u1)/$v1)); |
826 | --$q while ($v2*$q > ($u0*$MBASE+$u1-$q*$v1)*$MBASE+$u2); |
ee15d750 |
827 | if ($q) |
828 | { |
829 | ($car, $bar) = (0,0); |
830 | for ($yi = 0, $xi = $#$x-$#$y-1; $yi <= $#$y; ++$yi,++$xi) |
831 | { |
832 | $prd = $q * $y->[$yi] + $car; |
61f5c3f5 |
833 | $prd -= ($car = int($prd / $MBASE)) * $MBASE; |
834 | $x->[$xi] += $MBASE if ($bar = (($x->[$xi] -= $prd + $bar) < 0)); |
ee15d750 |
835 | } |
836 | if ($x->[-1] < $car + $bar) |
837 | { |
838 | $car = 0; --$q; |
839 | for ($yi = 0, $xi = $#$x-$#$y-1; $yi <= $#$y; ++$yi,++$xi) |
840 | { |
61f5c3f5 |
841 | $x->[$xi] -= $MBASE |
842 | if ($car = (($x->[$xi] += $y->[$yi] + $car) > $MBASE)); |
ee15d750 |
843 | } |
844 | } |
845 | } |
61f5c3f5 |
846 | pop(@$x); unshift(@q, $q); |
ee15d750 |
847 | } |
848 | if (wantarray) |
849 | { |
850 | @d = (); |
851 | if ($dd != 1) |
852 | { |
853 | $car = 0; |
854 | for $xi (reverse @$x) |
855 | { |
61f5c3f5 |
856 | $prd = $car * $MBASE + $xi; |
ee15d750 |
857 | $car = $prd - ($tmp = int($prd / $dd)) * $dd; |
858 | unshift(@d, $tmp); |
859 | } |
860 | } |
861 | else |
862 | { |
863 | @d = @$x; |
864 | } |
865 | @$x = @q; |
61f5c3f5 |
866 | my $d = \@d; |
867 | if ($LEN_CONVERT != 0) |
868 | { |
869 | $c->_to_large($x); $c->_to_large($d); |
870 | } |
871 | else |
872 | { |
873 | __strip_zeros($x); |
874 | __strip_zeros($d); |
875 | } |
876 | return ($x,$d); |
ee15d750 |
877 | } |
878 | @$x = @q; |
61f5c3f5 |
879 | if ($LEN_CONVERT != 0) |
880 | { |
881 | $c->_to_large($x); |
882 | } |
883 | else |
884 | { |
885 | __strip_zeros($x); |
886 | } |
887 | $x; |
ee15d750 |
888 | } |
889 | |
394e6ffb |
890 | ############################################################################## |
891 | # testing |
892 | |
893 | sub _acmp |
894 | { |
895 | # internal absolute post-normalized compare (ignore signs) |
896 | # ref to array, ref to array, return <0, 0, >0 |
897 | # arrays must have at least one entry; this is not checked for |
898 | |
899 | my ($c,$cx,$cy) = @_; |
900 | |
61f5c3f5 |
901 | # fast comp based on array elements |
394e6ffb |
902 | my $lxy = scalar @$cx - scalar @$cy; |
903 | return -1 if $lxy < 0; # already differs, ret |
904 | return 1 if $lxy > 0; # ditto |
905 | |
906 | # now calculate length based on digits, not parts |
907 | $lxy = _len($c,$cx) - _len($c,$cy); # difference |
908 | return -1 if $lxy < 0; |
909 | return 1 if $lxy > 0; |
910 | |
911 | # hm, same lengths, but same contents? |
912 | my $i = 0; my $a; |
913 | # first way takes 5.49 sec instead of 4.87, but has the early out advantage |
914 | # so grep is slightly faster, but more inflexible. hm. $_ instead of $k |
915 | # yields 5.6 instead of 5.5 sec huh? |
916 | # manual way (abort if unequal, good for early ne) |
917 | my $j = scalar @$cx - 1; |
918 | while ($j >= 0) |
9393ace2 |
919 | { |
920 | last if ($a = $cx->[$j] - $cy->[$j]); $j--; |
921 | } |
922 | # my $j = scalar @$cx; |
923 | # while (--$j >= 0) |
924 | # { |
925 | # last if ($a = $cx->[$j] - $cy->[$j]); |
926 | # } |
394e6ffb |
927 | return 1 if $a > 0; |
928 | return -1 if $a < 0; |
61f5c3f5 |
929 | 0; # equal |
930 | |
394e6ffb |
931 | # while it early aborts, it is even slower than the manual variant |
932 | #grep { return $a if ($a = $_ - $cy->[$i++]); } @$cx; |
933 | # grep way, go trough all (bad for early ne) |
934 | #grep { $a = $_ - $cy->[$i++]; } @$cx; |
935 | #return $a; |
936 | } |
937 | |
938 | sub _len |
939 | { |
940 | # compute number of digits in bigint, minus the sign |
941 | |
942 | # int() because add/sub sometimes leaves strings (like '00005') instead of |
943 | # '5' in this place, thus causing length() to report wrong length |
944 | my $cx = $_[1]; |
945 | |
946 | return (@$cx-1)*$BASE_LEN+length(int($cx->[-1])); |
947 | } |
948 | |
949 | sub _digit |
950 | { |
951 | # return the nth digit, negative values count backward |
952 | # zero is rightmost, so _digit(123,0) will give 3 |
953 | my ($c,$x,$n) = @_; |
954 | |
955 | my $len = _len('',$x); |
956 | |
957 | $n = $len+$n if $n < 0; # -1 last, -2 second-to-last |
958 | $n = abs($n); # if negative was too big |
959 | $len--; $n = $len if $n > $len; # n to big? |
960 | |
961 | my $elem = int($n / $BASE_LEN); # which array element |
962 | my $digit = $n % $BASE_LEN; # which digit in this element |
963 | $elem = '0000'.@$x[$elem]; # get element padded with 0's |
964 | return substr($elem,-$digit-1,1); |
965 | } |
966 | |
967 | sub _zeros |
968 | { |
969 | # return amount of trailing zeros in decimal |
970 | # check each array elem in _m for having 0 at end as long as elem == 0 |
971 | # Upon finding a elem != 0, stop |
972 | my $x = $_[1]; |
973 | my $zeros = 0; my $elem; |
974 | foreach my $e (@$x) |
975 | { |
976 | if ($e != 0) |
977 | { |
978 | $elem = "$e"; # preserve x |
979 | $elem =~ s/.*?(0*$)/$1/; # strip anything not zero |
980 | $zeros *= $BASE_LEN; # elems * 5 |
61f5c3f5 |
981 | $zeros += length($elem); # count trailing zeros |
394e6ffb |
982 | last; # early out |
983 | } |
984 | $zeros ++; # real else branch: 50% slower! |
985 | } |
61f5c3f5 |
986 | $zeros; |
394e6ffb |
987 | } |
988 | |
989 | ############################################################################## |
990 | # _is_* routines |
991 | |
992 | sub _is_zero |
993 | { |
994 | # return true if arg (BINT or num_str) is zero (array '+', '0') |
995 | my $x = $_[1]; |
61f5c3f5 |
996 | |
997 | (((scalar @$x == 1) && ($x->[0] == 0))) <=> 0; |
394e6ffb |
998 | } |
999 | |
1000 | sub _is_even |
1001 | { |
1002 | # return true if arg (BINT or num_str) is even |
1003 | my $x = $_[1]; |
61f5c3f5 |
1004 | (!($x->[0] & 1)) <=> 0; |
394e6ffb |
1005 | } |
1006 | |
1007 | sub _is_odd |
1008 | { |
1009 | # return true if arg (BINT or num_str) is even |
1010 | my $x = $_[1]; |
61f5c3f5 |
1011 | |
1012 | (($x->[0] & 1)) <=> 0; |
394e6ffb |
1013 | } |
1014 | |
1015 | sub _is_one |
1016 | { |
1017 | # return true if arg (BINT or num_str) is one (array '+', '1') |
1018 | my $x = $_[1]; |
61f5c3f5 |
1019 | |
1020 | (scalar @$x == 1) && ($x->[0] == 1) <=> 0; |
394e6ffb |
1021 | } |
1022 | |
1023 | sub __strip_zeros |
1024 | { |
1025 | # internal normalization function that strips leading zeros from the array |
1026 | # args: ref to array |
1027 | my $s = shift; |
1028 | |
1029 | my $cnt = scalar @$s; # get count of parts |
1030 | my $i = $cnt-1; |
1031 | push @$s,0 if $i < 0; # div might return empty results, so fix it |
1032 | |
61f5c3f5 |
1033 | return $s if @$s == 1; # early out |
1034 | |
394e6ffb |
1035 | #print "strip: cnt $cnt i $i\n"; |
1036 | # '0', '3', '4', '0', '0', |
1037 | # 0 1 2 3 4 |
1038 | # cnt = 5, i = 4 |
1039 | # i = 4 |
1040 | # i = 3 |
1041 | # => fcnt = cnt - i (5-2 => 3, cnt => 5-1 = 4, throw away from 4th pos) |
1042 | # >= 1: skip first part (this can be zero) |
1043 | while ($i > 0) { last if $s->[$i] != 0; $i--; } |
1044 | $i++; splice @$s,$i if ($i < $cnt); # $i cant be 0 |
1045 | $s; |
1046 | } |
1047 | |
1048 | ############################################################################### |
1049 | # check routine to test internal state of corruptions |
1050 | |
1051 | sub _check |
1052 | { |
1053 | # used by the test suite |
1054 | my $x = $_[1]; |
1055 | |
1056 | return "$x is not a reference" if !ref($x); |
1057 | |
1058 | # are all parts are valid? |
1059 | my $i = 0; my $j = scalar @$x; my ($e,$try); |
1060 | while ($i < $j) |
1061 | { |
1062 | $e = $x->[$i]; $e = 'undef' unless defined $e; |
1063 | $try = '=~ /^[\+]?[0-9]+\$/; '."($x, $e)"; |
1064 | last if $e !~ /^[+]?[0-9]+$/; |
1065 | $try = '=~ /^[\+]?[0-9]+\$/; '."($x, $e) (stringify)"; |
1066 | last if "$e" !~ /^[+]?[0-9]+$/; |
1067 | $try = '=~ /^[\+]?[0-9]+\$/; '."($x, $e) (cat-stringify)"; |
1068 | last if '' . "$e" !~ /^[+]?[0-9]+$/; |
1069 | $try = ' < 0 || >= $BASE; '."($x, $e)"; |
1070 | last if $e <0 || $e >= $BASE; |
1071 | # this test is disabled, since new/bnorm and certain ops (like early out |
1072 | # in add/sub) are allowed/expected to leave '00000' in some elements |
1073 | #$try = '=~ /^00+/; '."($x, $e)"; |
1074 | #last if $e =~ /^00+/; |
1075 | $i++; |
1076 | } |
1077 | return "Illegal part '$e' at pos $i (tested: $try)" if $i < $j; |
1078 | return 0; |
1079 | } |
1080 | |
1081 | |
1082 | ############################################################################### |
1083 | ############################################################################### |
1084 | # some optional routines to make BigInt faster |
1085 | |
dccbb853 |
1086 | sub _mod |
1087 | { |
1088 | # if possible, use mod shortcut |
1089 | my ($c,$x,$yo) = @_; |
1090 | |
1091 | # slow way since $y to big |
1092 | if (scalar @$yo > 1) |
1093 | { |
1094 | my ($xo,$rem) = _div($c,$x,$yo); |
1095 | return $rem; |
1096 | } |
1097 | my $y = $yo->[0]; |
027dc388 |
1098 | # both are single element arrays |
dccbb853 |
1099 | if (scalar @$x == 1) |
1100 | { |
1101 | $x->[0] %= $y; |
1102 | return $x; |
1103 | } |
1104 | |
61f5c3f5 |
1105 | # @y is single element, but @x has more than one |
dccbb853 |
1106 | my $b = $BASE % $y; |
1107 | if ($b == 0) |
1108 | { |
1109 | # when BASE % Y == 0 then (B * BASE) % Y == 0 |
1110 | # (B * BASE) % $y + A % Y => A % Y |
1111 | # so need to consider only last element: O(1) |
1112 | $x->[0] %= $y; |
1113 | } |
027dc388 |
1114 | elsif ($b == 1) |
1115 | { |
28df3e88 |
1116 | # else need to go trough all elements: O(N), but loop is a bit simplified |
027dc388 |
1117 | my $r = 0; |
1118 | foreach (@$x) |
1119 | { |
28df3e88 |
1120 | $r = ($r + $_) % $y; # not much faster, but heh... |
1121 | #$r += $_ % $y; $r %= $y; |
027dc388 |
1122 | } |
1123 | $r = 0 if $r == $y; |
1124 | $x->[0] = $r; |
1125 | } |
dccbb853 |
1126 | else |
1127 | { |
027dc388 |
1128 | # else need to go trough all elements: O(N) |
1129 | my $r = 0; my $bm = 1; |
1130 | foreach (@$x) |
1131 | { |
28df3e88 |
1132 | $r = ($_ * $bm + $r) % $y; |
1133 | $bm = ($bm * $b) % $y; |
1134 | |
1135 | #$r += ($_ % $y) * $bm; |
1136 | #$bm *= $b; |
1137 | #$bm %= $y; |
1138 | #$r %= $y; |
027dc388 |
1139 | } |
1140 | $r = 0 if $r == $y; |
1141 | $x->[0] = $r; |
dccbb853 |
1142 | } |
1143 | splice (@$x,1); |
61f5c3f5 |
1144 | $x; |
dccbb853 |
1145 | } |
1146 | |
0716bf9b |
1147 | ############################################################################## |
574bacfe |
1148 | # shifts |
1149 | |
1150 | sub _rsft |
1151 | { |
1152 | my ($c,$x,$y,$n) = @_; |
1153 | |
1154 | if ($n != 10) |
1155 | { |
61f5c3f5 |
1156 | $n = _new($c,\$n); return _div($c,$x, _pow($c,$n,$y)); |
1157 | } |
1158 | |
1159 | # shortcut (faster) for shifting by 10) |
1160 | # multiples of $BASE_LEN |
1161 | my $dst = 0; # destination |
1162 | my $src = _num($c,$y); # as normal int |
1163 | my $rem = $src % $BASE_LEN; # remainder to shift |
1164 | $src = int($src / $BASE_LEN); # source |
1165 | if ($rem == 0) |
1166 | { |
1167 | splice (@$x,0,$src); # even faster, 38.4 => 39.3 |
574bacfe |
1168 | } |
1169 | else |
1170 | { |
61f5c3f5 |
1171 | my $len = scalar @$x - $src; # elems to go |
1172 | my $vd; my $z = '0'x $BASE_LEN; |
1173 | $x->[scalar @$x] = 0; # avoid || 0 test inside loop |
1174 | while ($dst < $len) |
574bacfe |
1175 | { |
61f5c3f5 |
1176 | $vd = $z.$x->[$src]; |
1177 | $vd = substr($vd,-$BASE_LEN,$BASE_LEN-$rem); |
1178 | $src++; |
1179 | $vd = substr($z.$x->[$src],-$rem,$rem) . $vd; |
1180 | $vd = substr($vd,-$BASE_LEN,$BASE_LEN) if length($vd) > $BASE_LEN; |
1181 | $x->[$dst] = int($vd); |
1182 | $dst++; |
574bacfe |
1183 | } |
61f5c3f5 |
1184 | splice (@$x,$dst) if $dst > 0; # kill left-over array elems |
56b9c951 |
1185 | pop @$x if $x->[-1] == 0 && @$x > 1; # kill last element if 0 |
61f5c3f5 |
1186 | } # else rem == 0 |
574bacfe |
1187 | $x; |
1188 | } |
1189 | |
1190 | sub _lsft |
1191 | { |
1192 | my ($c,$x,$y,$n) = @_; |
1193 | |
1194 | if ($n != 10) |
1195 | { |
61f5c3f5 |
1196 | $n = _new($c,\$n); return _mul($c,$x, _pow($c,$n,$y)); |
574bacfe |
1197 | } |
61f5c3f5 |
1198 | |
1199 | # shortcut (faster) for shifting by 10) since we are in base 10eX |
1200 | # multiples of $BASE_LEN: |
1201 | my $src = scalar @$x; # source |
1202 | my $len = _num($c,$y); # shift-len as normal int |
1203 | my $rem = $len % $BASE_LEN; # remainder to shift |
1204 | my $dst = $src + int($len/$BASE_LEN); # destination |
1205 | my $vd; # further speedup |
1206 | $x->[$src] = 0; # avoid first ||0 for speed |
1207 | my $z = '0' x $BASE_LEN; |
1208 | while ($src >= 0) |
574bacfe |
1209 | { |
61f5c3f5 |
1210 | $vd = $x->[$src]; $vd = $z.$vd; |
1211 | $vd = substr($vd,-$BASE_LEN+$rem,$BASE_LEN-$rem); |
1212 | $vd .= $src > 0 ? substr($z.$x->[$src-1],-$BASE_LEN,$rem) : '0' x $rem; |
1213 | $vd = substr($vd,-$BASE_LEN,$BASE_LEN) if length($vd) > $BASE_LEN; |
1214 | $x->[$dst] = int($vd); |
1215 | $dst--; $src--; |
574bacfe |
1216 | } |
61f5c3f5 |
1217 | # set lowest parts to 0 |
1218 | while ($dst >= 0) { $x->[$dst--] = 0; } |
1219 | # fix spurios last zero element |
1220 | splice @$x,-1 if $x->[-1] == 0; |
574bacfe |
1221 | $x; |
1222 | } |
1223 | |
027dc388 |
1224 | sub _pow |
1225 | { |
1226 | # power of $x to $y |
1227 | # ref to array, ref to array, return ref to array |
1228 | my ($c,$cx,$cy) = @_; |
1229 | |
1230 | my $pow2 = _one(); |
1231 | my $two = _two(); |
1232 | my $y1 = _copy($c,$cy); |
1233 | while (!_is_one($c,$y1)) |
1234 | { |
1235 | _mul($c,$pow2,$cx) if _is_odd($c,$y1); |
1236 | _div($c,$y1,$two); |
1237 | _mul($c,$cx,$cx); |
1238 | } |
1239 | _mul($c,$cx,$pow2) unless _is_one($c,$pow2); |
61f5c3f5 |
1240 | $cx; |
027dc388 |
1241 | } |
1242 | |
b3abae2a |
1243 | sub _fac |
1244 | { |
1245 | # factorial of $x |
1246 | # ref to array, return ref to array |
1247 | my ($c,$cx) = @_; |
1248 | |
1249 | if ((@$cx == 1) && ($cx->[0] <= 2)) |
1250 | { |
1251 | $cx->[0] = 1 * ($cx->[0]||1); # 0,1 => 1, 2 => 2 |
1252 | return $cx; |
1253 | } |
1254 | |
1255 | # go forward until $base is exceeded |
1256 | # limit is either $x or $base (x == 100 means as result too high) |
1257 | my $steps = 100; $steps = $cx->[0] if @$cx == 1; |
1258 | my $r = 2; my $cf = 3; my $step = 1; my $last = $r; |
1259 | while ($r < $BASE && $step < $steps) |
1260 | { |
1261 | $last = $r; $r *= $cf++; $step++; |
1262 | } |
1263 | if ((@$cx == 1) && ($step == $cx->[0])) |
1264 | { |
1265 | # completely done |
1266 | $cx = [$last]; |
1267 | return $cx; |
1268 | } |
1269 | my $n = _copy($c,$cx); |
1270 | $cx = [$last]; |
1271 | |
1272 | #$cx = _one(); |
1273 | while (!(@$n == 1 && $n->[0] == $step)) |
1274 | { |
1275 | _mul($c,$cx,$n); _dec($c,$n); |
1276 | } |
1277 | $cx; |
1278 | } |
1279 | |
1280 | use constant DEBUG => 0; |
1281 | |
1282 | my $steps = 0; |
1283 | |
1284 | sub steps { $steps }; |
1285 | |
1286 | sub _sqrt |
0716bf9b |
1287 | { |
394e6ffb |
1288 | # square-root of $x |
1289 | # ref to array, return ref to array |
1290 | my ($c,$x) = @_; |
0716bf9b |
1291 | |
394e6ffb |
1292 | if (scalar @$x == 1) |
1293 | { |
1294 | # fit's into one Perl scalar |
1295 | $x->[0] = int(sqrt($x->[0])); |
1296 | return $x; |
1297 | } |
1298 | my $y = _copy($c,$x); |
b3abae2a |
1299 | # hopefully _len/2 is < $BASE, the -1 is to always undershot the guess |
1300 | # since our guess will "grow" |
1301 | my $l = int((_len($c,$x)-1) / 2); |
1302 | |
1303 | my $lastelem = $x->[-1]; # for guess |
1304 | my $elems = scalar @$x - 1; |
1305 | # not enough digits, but could have more? |
1306 | if ((length($lastelem) <= 3) && ($elems > 1)) |
1307 | { |
1308 | # right-align with zero pad |
1309 | my $len = length($lastelem) & 1; |
1310 | print "$lastelem => " if DEBUG; |
1311 | $lastelem .= substr($x->[-2] . '0' x $BASE_LEN,0,$BASE_LEN); |
1312 | # former odd => make odd again, or former even to even again |
1313 | $lastelem = $lastelem / 10 if (length($lastelem) & 1) != $len; |
1314 | print "$lastelem\n" if DEBUG; |
1315 | } |
0716bf9b |
1316 | |
61f5c3f5 |
1317 | # construct $x (instead of _lsft($c,$x,$l,10) |
1318 | my $r = $l % $BASE_LEN; # 10000 00000 00000 00000 ($BASE_LEN=5) |
1319 | $l = int($l / $BASE_LEN); |
b3abae2a |
1320 | print "l = $l " if DEBUG; |
1321 | |
1322 | splice @$x,$l; # keep ref($x), but modify it |
1323 | |
1324 | # we make the first part of the guess not '1000...0' but int(sqrt($lastelem)) |
1325 | # that gives us: |
1326 | # 14400 00000 => sqrt(14400) => 120 |
1327 | # 144000 000000 => sqrt(144000) => 379 |
1328 | |
1329 | # $x->[$l--] = int('1' . '0' x $r); # old way of guessing |
1330 | print "$lastelem (elems $elems) => " if DEBUG; |
1331 | $lastelem = $lastelem / 10 if ($elems & 1 == 1); # odd or even? |
1332 | my $g = sqrt($lastelem); $g =~ s/\.//; # 2.345 => 2345 |
1333 | $r -= 1 if $elems & 1 == 0; # 70 => 7 |
1334 | |
1335 | # padd with zeros if result is too short |
1336 | $x->[$l--] = int(substr($g . '0' x $r,0,$r+1)); |
1337 | print "now ",$x->[-1] if DEBUG; |
1338 | print " would have been ", int('1' . '0' x $r),"\n" if DEBUG; |
1339 | |
1340 | # If @$x > 1, we could compute the second elem of the guess, too, to create |
1341 | # an even better guess. Not implemented yet. |
1342 | $x->[$l--] = 0 while ($l >= 0); # all other digits of guess are zero |
61f5c3f5 |
1343 | |
b3abae2a |
1344 | print "start x= ",${_str($c,$x)},"\n" if DEBUG; |
394e6ffb |
1345 | my $two = _two(); |
1346 | my $last = _zero(); |
1347 | my $lastlast = _zero(); |
b3abae2a |
1348 | $steps = 0 if DEBUG; |
394e6ffb |
1349 | while (_acmp($c,$last,$x) != 0 && _acmp($c,$lastlast,$x) != 0) |
1350 | { |
b3abae2a |
1351 | $steps++ if DEBUG; |
394e6ffb |
1352 | $lastlast = _copy($c,$last); |
1353 | $last = _copy($c,$x); |
1354 | _add($c,$x, _div($c,_copy($c,$y),$x)); |
1355 | _div($c,$x, $two ); |
b3abae2a |
1356 | print " x= ",${_str($c,$x)},"\n" if DEBUG; |
394e6ffb |
1357 | } |
b3abae2a |
1358 | print "\nsteps in sqrt: $steps, " if DEBUG; |
394e6ffb |
1359 | _dec($c,$x) if _acmp($c,$y,_mul($c,_copy($c,$x),$x)) < 0; # overshot? |
b3abae2a |
1360 | print " final ",$x->[-1],"\n" if DEBUG; |
394e6ffb |
1361 | $x; |
0716bf9b |
1362 | } |
1363 | |
394e6ffb |
1364 | ############################################################################## |
1365 | # binary stuff |
0716bf9b |
1366 | |
394e6ffb |
1367 | sub _and |
1368 | { |
1369 | my ($c,$x,$y) = @_; |
0716bf9b |
1370 | |
394e6ffb |
1371 | # the shortcut makes equal, large numbers _really_ fast, and makes only a |
1372 | # very small performance drop for small numbers (e.g. something with less |
1373 | # than 32 bit) Since we optimize for large numbers, this is enabled. |
1374 | return $x if _acmp($c,$x,$y) == 0; # shortcut |
0716bf9b |
1375 | |
394e6ffb |
1376 | my $m = _one(); my ($xr,$yr); |
1377 | my $mask = $AND_MASK; |
1378 | |
1379 | my $x1 = $x; |
1380 | my $y1 = _copy($c,$y); # make copy |
1381 | $x = _zero(); |
1382 | my ($b,$xrr,$yrr); |
1383 | use integer; |
1384 | while (!_is_zero($c,$x1) && !_is_zero($c,$y1)) |
1385 | { |
1386 | ($x1, $xr) = _div($c,$x1,$mask); |
1387 | ($y1, $yr) = _div($c,$y1,$mask); |
1388 | |
1389 | # make ints() from $xr, $yr |
1390 | # this is when the AND_BITS are greater tahn $BASE and is slower for |
1391 | # small (<256 bits) numbers, but faster for large numbers. Disabled |
1392 | # due to KISS principle |
1393 | |
1394 | # $b = 1; $xrr = 0; foreach (@$xr) { $xrr += $_ * $b; $b *= $BASE; } |
1395 | # $b = 1; $yrr = 0; foreach (@$yr) { $yrr += $_ * $b; $b *= $BASE; } |
1396 | # _add($c,$x, _mul($c, _new( $c, \($xrr & $yrr) ), $m) ); |
1397 | |
61f5c3f5 |
1398 | # 0+ due to '&' doesn't work in strings |
1399 | _add($c,$x, _mul($c, [ 0+$xr->[0] & 0+$yr->[0] ], $m) ); |
394e6ffb |
1400 | _mul($c,$m,$mask); |
1401 | } |
1402 | $x; |
0716bf9b |
1403 | } |
1404 | |
394e6ffb |
1405 | sub _xor |
0716bf9b |
1406 | { |
394e6ffb |
1407 | my ($c,$x,$y) = @_; |
1408 | |
1409 | return _zero() if _acmp($c,$x,$y) == 0; # shortcut (see -and) |
1410 | |
1411 | my $m = _one(); my ($xr,$yr); |
1412 | my $mask = $XOR_MASK; |
1413 | |
1414 | my $x1 = $x; |
1415 | my $y1 = _copy($c,$y); # make copy |
1416 | $x = _zero(); |
1417 | my ($b,$xrr,$yrr); |
1418 | use integer; |
1419 | while (!_is_zero($c,$x1) && !_is_zero($c,$y1)) |
0716bf9b |
1420 | { |
394e6ffb |
1421 | ($x1, $xr) = _div($c,$x1,$mask); |
1422 | ($y1, $yr) = _div($c,$y1,$mask); |
1423 | # make ints() from $xr, $yr (see _and()) |
1424 | #$b = 1; $xrr = 0; foreach (@$xr) { $xrr += $_ * $b; $b *= $BASE; } |
1425 | #$b = 1; $yrr = 0; foreach (@$yr) { $yrr += $_ * $b; $b *= $BASE; } |
1426 | #_add($c,$x, _mul($c, _new( $c, \($xrr ^ $yrr) ), $m) ); |
61f5c3f5 |
1427 | |
1428 | # 0+ due to '^' doesn't work in strings |
1429 | _add($c,$x, _mul($c, [ 0+$xr->[0] ^ 0+$yr->[0] ], $m) ); |
394e6ffb |
1430 | _mul($c,$m,$mask); |
0716bf9b |
1431 | } |
394e6ffb |
1432 | # the loop stops when the shorter of the two numbers is exhausted |
1433 | # the remainder of the longer one will survive bit-by-bit, so we simple |
1434 | # multiply-add it in |
1435 | _add($c,$x, _mul($c, $x1, $m) ) if !_is_zero($c,$x1); |
1436 | _add($c,$x, _mul($c, $y1, $m) ) if !_is_zero($c,$y1); |
1437 | |
1438 | $x; |
0716bf9b |
1439 | } |
1440 | |
394e6ffb |
1441 | sub _or |
0716bf9b |
1442 | { |
394e6ffb |
1443 | my ($c,$x,$y) = @_; |
0716bf9b |
1444 | |
394e6ffb |
1445 | return $x if _acmp($c,$x,$y) == 0; # shortcut (see _and) |
0716bf9b |
1446 | |
394e6ffb |
1447 | my $m = _one(); my ($xr,$yr); |
1448 | my $mask = $OR_MASK; |
0716bf9b |
1449 | |
394e6ffb |
1450 | my $x1 = $x; |
1451 | my $y1 = _copy($c,$y); # make copy |
1452 | $x = _zero(); |
1453 | my ($b,$xrr,$yrr); |
1454 | use integer; |
1455 | while (!_is_zero($c,$x1) && !_is_zero($c,$y1)) |
1456 | { |
1457 | ($x1, $xr) = _div($c,$x1,$mask); |
1458 | ($y1, $yr) = _div($c,$y1,$mask); |
1459 | # make ints() from $xr, $yr (see _and()) |
1460 | # $b = 1; $xrr = 0; foreach (@$xr) { $xrr += $_ * $b; $b *= $BASE; } |
1461 | # $b = 1; $yrr = 0; foreach (@$yr) { $yrr += $_ * $b; $b *= $BASE; } |
1462 | # _add($c,$x, _mul($c, _new( $c, \($xrr | $yrr) ), $m) ); |
1463 | |
61f5c3f5 |
1464 | # 0+ due to '|' doesn't work in strings |
1465 | _add($c,$x, _mul($c, [ 0+$xr->[0] | 0+$yr->[0] ], $m) ); |
394e6ffb |
1466 | _mul($c,$m,$mask); |
1467 | } |
1468 | # the loop stops when the shorter of the two numbers is exhausted |
1469 | # the remainder of the longer one will survive bit-by-bit, so we simple |
1470 | # multiply-add it in |
1471 | _add($c,$x, _mul($c, $x1, $m) ) if !_is_zero($c,$x1); |
1472 | _add($c,$x, _mul($c, $y1, $m) ) if !_is_zero($c,$y1); |
1473 | |
1474 | $x; |
0716bf9b |
1475 | } |
1476 | |
61f5c3f5 |
1477 | sub _as_hex |
1478 | { |
1479 | # convert a decimal number to hex (ref to array, return ref to string) |
1480 | my ($c,$x) = @_; |
1481 | |
1482 | my $x1 = _copy($c,$x); |
1483 | |
1484 | my $es = ''; |
1485 | my $xr; |
1486 | my $x10000 = [ 0x10000 ]; |
1487 | while (! _is_zero($c,$x1)) |
1488 | { |
1489 | ($x1, $xr) = _div($c,$x1,$x10000); |
1490 | $es .= unpack('h4',pack('v',$xr->[0])); |
1491 | } |
1492 | $es = reverse $es; |
1493 | $es =~ s/^[0]+//; # strip leading zeros |
1494 | $es = '0x' . $es; |
1495 | \$es; |
1496 | } |
1497 | |
1498 | sub _as_bin |
1499 | { |
1500 | # convert a decimal number to bin (ref to array, return ref to string) |
1501 | my ($c,$x) = @_; |
1502 | |
1503 | my $x1 = _copy($c,$x); |
1504 | |
1505 | my $es = ''; |
1506 | my $xr; |
1507 | my $x10000 = [ 0x10000 ]; |
1508 | while (! _is_zero($c,$x1)) |
1509 | { |
1510 | ($x1, $xr) = _div($c,$x1,$x10000); |
1511 | $es .= unpack('b16',pack('v',$xr->[0])); |
1512 | } |
1513 | $es = reverse $es; |
1514 | $es =~ s/^[0]+//; # strip leading zeros |
1515 | $es = '0b' . $es; |
1516 | \$es; |
1517 | } |
1518 | |
394e6ffb |
1519 | sub _from_hex |
0716bf9b |
1520 | { |
394e6ffb |
1521 | # convert a hex number to decimal (ref to string, return ref to array) |
1522 | my ($c,$hs) = @_; |
0716bf9b |
1523 | |
394e6ffb |
1524 | my $mul = _one(); |
1525 | my $m = [ 0x10000 ]; # 16 bit at a time |
1526 | my $x = _zero(); |
0716bf9b |
1527 | |
61f5c3f5 |
1528 | my $len = length($$hs)-2; |
394e6ffb |
1529 | $len = int($len/4); # 4-digit parts, w/o '0x' |
1530 | my $val; my $i = -4; |
1531 | while ($len >= 0) |
1532 | { |
1533 | $val = substr($$hs,$i,4); |
1534 | $val =~ s/^[+-]?0x// if $len == 0; # for last part only because |
1535 | $val = hex($val); # hex does not like wrong chars |
1536 | $i -= 4; $len --; |
1537 | _add ($c, $x, _mul ($c, [ $val ], $mul ) ) if $val != 0; |
1538 | _mul ($c, $mul, $m ) if $len >= 0; # skip last mul |
1539 | } |
1540 | $x; |
1541 | } |
1542 | |
1543 | sub _from_bin |
0716bf9b |
1544 | { |
394e6ffb |
1545 | # convert a hex number to decimal (ref to string, return ref to array) |
1546 | my ($c,$bs) = @_; |
0716bf9b |
1547 | |
13a12e00 |
1548 | # instead of converting 8 bit at a time, it is faster to convert the |
1549 | # number to hex, and then call _from_hex. |
1550 | |
1551 | my $hs = $$bs; |
1552 | $hs =~ s/^[+-]?0b//; # remove sign and 0b |
1553 | my $l = length($hs); # bits |
1554 | $hs = '0' x (8-($l % 8)) . $hs if ($l % 8) != 0; # padd left side w/ 0 |
1555 | my $h = unpack('H*', pack ('B*', $hs)); # repack as hex |
1556 | return $c->_from_hex(\('0x'.$h)); |
1557 | |
394e6ffb |
1558 | my $mul = _one(); |
1559 | my $m = [ 0x100 ]; # 8 bit at a time |
1560 | my $x = _zero(); |
0716bf9b |
1561 | |
61f5c3f5 |
1562 | my $len = length($$bs)-2; |
394e6ffb |
1563 | $len = int($len/8); # 4-digit parts, w/o '0x' |
1564 | my $val; my $i = -8; |
1565 | while ($len >= 0) |
0716bf9b |
1566 | { |
394e6ffb |
1567 | $val = substr($$bs,$i,8); |
1568 | $val =~ s/^[+-]?0b// if $len == 0; # for last part only |
1569 | |
394e6ffb |
1570 | $val = ord(pack('B8',substr('00000000'.$val,-8,8))); |
1571 | |
1572 | $i -= 8; $len --; |
1573 | _add ($c, $x, _mul ($c, [ $val ], $mul ) ) if $val != 0; |
1574 | _mul ($c, $mul, $m ) if $len >= 0; # skip last mul |
0716bf9b |
1575 | } |
394e6ffb |
1576 | $x; |
0716bf9b |
1577 | } |
1578 | |
d614cd8b |
1579 | sub _modinv |
1580 | { |
1581 | # inverse modulus |
1582 | } |
1583 | |
1584 | sub _modpow |
1585 | { |
1586 | # modulus of power ($x ** $y) % $z |
1587 | } |
1588 | |
394e6ffb |
1589 | ############################################################################## |
1590 | ############################################################################## |
1591 | |
0716bf9b |
1592 | 1; |
1593 | __END__ |
1594 | |
1595 | =head1 NAME |
1596 | |
1597 | Math::BigInt::Calc - Pure Perl module to support Math::BigInt |
1598 | |
1599 | =head1 SYNOPSIS |
1600 | |
ee15d750 |
1601 | Provides support for big integer calculations. Not intended to be used by other |
1602 | modules (except Math::BigInt::Cached). Other modules which sport the same |
1603 | functions can also be used to support Math::Bigint, like Math::BigInt::Pari. |
0716bf9b |
1604 | |
1605 | =head1 DESCRIPTION |
1606 | |
027dc388 |
1607 | In order to allow for multiple big integer libraries, Math::BigInt was |
1608 | rewritten to use library modules for core math routines. Any module which |
1609 | follows the same API as this can be used instead by using the following: |
0716bf9b |
1610 | |
ee15d750 |
1611 | use Math::BigInt lib => 'libname'; |
0716bf9b |
1612 | |
027dc388 |
1613 | 'libname' is either the long name ('Math::BigInt::Pari'), or only the short |
1614 | version like 'Pari'. |
1615 | |
0716bf9b |
1616 | =head1 EXPORT |
1617 | |
027dc388 |
1618 | The following functions MUST be defined in order to support the use by |
1619 | Math::BigInt: |
0716bf9b |
1620 | |
1621 | _new(string) return ref to new object from ref to decimal string |
1622 | _zero() return a new object with value 0 |
1623 | _one() return a new object with value 1 |
1624 | |
1625 | _str(obj) return ref to a string representing the object |
1626 | _num(obj) returns a Perl integer/floating point number |
1627 | NOTE: because of Perl numeric notation defaults, |
1628 | the _num'ified obj may lose accuracy due to |
1629 | machine-dependend floating point size limitations |
1630 | |
1631 | _add(obj,obj) Simple addition of two objects |
1632 | _mul(obj,obj) Multiplication of two objects |
1633 | _div(obj,obj) Division of the 1st object by the 2nd |
b22b3e31 |
1634 | In list context, returns (result,remainder). |
1635 | NOTE: this is integer math, so no |
1636 | fractional part will be returned. |
1637 | _sub(obj,obj) Simple subtraction of 1 object from another |
0716bf9b |
1638 | a third, optional parameter indicates that the params |
1639 | are swapped. In this case, the first param needs to |
1640 | be preserved, while you can destroy the second. |
1641 | sub (x,y,1) => return x - y and keep x intact! |
e745a66c |
1642 | _dec(obj) decrement object by one (input is garant. to be > 0) |
1643 | _inc(obj) increment object by one |
1644 | |
0716bf9b |
1645 | |
1646 | _acmp(obj,obj) <=> operator for objects (return -1, 0 or 1) |
1647 | |
1648 | _len(obj) returns count of the decimal digits of the object |
1649 | _digit(obj,n) returns the n'th decimal digit of object |
1650 | |
1651 | _is_one(obj) return true if argument is +1 |
1652 | _is_zero(obj) return true if argument is 0 |
1653 | _is_even(obj) return true if argument is even (0,2,4,6..) |
1654 | _is_odd(obj) return true if argument is odd (1,3,5,7..) |
1655 | |
1656 | _copy return a ref to a true copy of the object |
1657 | |
1658 | _check(obj) check whether internal representation is still intact |
1659 | return 0 for ok, otherwise error message as string |
1660 | |
bd05a461 |
1661 | The following functions are optional, and can be defined if the underlying lib |
027dc388 |
1662 | has a fast way to do them. If undefined, Math::BigInt will use pure Perl (hence |
1663 | slow) fallback routines to emulate these: |
0716bf9b |
1664 | |
1665 | _from_hex(str) return ref to new object from ref to hexadecimal string |
1666 | _from_bin(str) return ref to new object from ref to binary string |
1667 | |
ee15d750 |
1668 | _as_hex(str) return ref to scalar string containing the value as |
1669 | unsigned hex string, with the '0x' prepended. |
1670 | Leading zeros must be stripped. |
1671 | _as_bin(str) Like as_hex, only as binary string containing only |
1672 | zeros and ones. Leading zeros must be stripped and a |
1673 | '0b' must be prepended. |
1674 | |
0716bf9b |
1675 | _rsft(obj,N,B) shift object in base B by N 'digits' right |
dccbb853 |
1676 | For unsupported bases B, return undef to signal failure |
0716bf9b |
1677 | _lsft(obj,N,B) shift object in base B by N 'digits' left |
dccbb853 |
1678 | For unsupported bases B, return undef to signal failure |
0716bf9b |
1679 | |
1680 | _xor(obj1,obj2) XOR (bit-wise) object 1 with object 2 |
dccbb853 |
1681 | Note: XOR, AND and OR pad with zeros if size mismatches |
0716bf9b |
1682 | _and(obj1,obj2) AND (bit-wise) object 1 with object 2 |
1683 | _or(obj1,obj2) OR (bit-wise) object 1 with object 2 |
1684 | |
dccbb853 |
1685 | _mod(obj,obj) Return remainder of div of the 1st by the 2nd object |
394e6ffb |
1686 | _sqrt(obj) return the square root of object (truncate to int) |
b3abae2a |
1687 | _fac(obj) return factorial of object 1 (1*2*3*4..) |
0716bf9b |
1688 | _pow(obj,obj) return object 1 to the power of object 2 |
1689 | _gcd(obj,obj) return Greatest Common Divisor of two objects |
1690 | |
b22b3e31 |
1691 | _zeros(obj) return number of trailing decimal zeros |
d614cd8b |
1692 | _modinv return inverse modulus |
1693 | _modpow return modulus of power ($x ** $y) % $z |
0716bf9b |
1694 | |
b22b3e31 |
1695 | Input strings come in as unsigned but with prefix (i.e. as '123', '0xabc' |
0716bf9b |
1696 | or '0b1101'). |
1697 | |
b22b3e31 |
1698 | Testing of input parameter validity is done by the caller, so you need not |
574bacfe |
1699 | worry about underflow (f.i. in C<_sub()>, C<_dec()>) nor about division by |
1700 | zero or similar cases. |
1701 | |
1702 | The first parameter can be modified, that includes the possibility that you |
1703 | return a reference to a completely different object instead. Although keeping |
dccbb853 |
1704 | the reference and just changing it's contents is prefered over creating and |
1705 | returning a different reference. |
574bacfe |
1706 | |
1707 | Return values are always references to objects or strings. Exceptions are |
1708 | C<_lsft()> and C<_rsft()>, which return undef if they can not shift the |
027dc388 |
1709 | argument. This is used to delegate shifting of bases different than the one |
1710 | you can support back to Math::BigInt, which will use some generic code to |
1711 | calculate the result. |
574bacfe |
1712 | |
1713 | =head1 WRAP YOUR OWN |
1714 | |
1715 | If you want to port your own favourite c-lib for big numbers to the |
1716 | Math::BigInt interface, you can take any of the already existing modules as |
1717 | a rough guideline. You should really wrap up the latest BigInt and BigFloat |
bd05a461 |
1718 | testsuites with your module, and replace in them any of the following: |
574bacfe |
1719 | |
1720 | use Math::BigInt; |
1721 | |
bd05a461 |
1722 | by this: |
574bacfe |
1723 | |
1724 | use Math::BigInt lib => 'yourlib'; |
1725 | |
1726 | This way you ensure that your library really works 100% within Math::BigInt. |
0716bf9b |
1727 | |
1728 | =head1 LICENSE |
1729 | |
1730 | This program is free software; you may redistribute it and/or modify it under |
1731 | the same terms as Perl itself. |
1732 | |
1733 | =head1 AUTHORS |
1734 | |
1735 | Original math code by Mark Biggar, rewritten by Tels L<http://bloodgate.com/> |
1736 | in late 2000, 2001. |
1737 | Seperated from BigInt and shaped API with the help of John Peacock. |
1738 | |
1739 | =head1 SEE ALSO |
1740 | |
ee15d750 |
1741 | L<Math::BigInt>, L<Math::BigFloat>, L<Math::BigInt::BitVect>, |
1742 | L<Math::BigInt::GMP>, L<Math::BigInt::Cached> and L<Math::BigInt::Pari>. |
0716bf9b |
1743 | |
1744 | =cut |