aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/timeconst.pl
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/timeconst.pl')
-rw-r--r--kernel/timeconst.pl402
1 files changed, 402 insertions, 0 deletions
diff --git a/kernel/timeconst.pl b/kernel/timeconst.pl
new file mode 100644
index 000000000000..62b1287932ed
--- /dev/null
+++ b/kernel/timeconst.pl
@@ -0,0 +1,402 @@
1#!/usr/bin/perl
2# -----------------------------------------------------------------------
3#
4# Copyright 2007 rPath, Inc. - All Rights Reserved
5#
6# This file is part of the Linux kernel, and is made available under
7# the terms of the GNU General Public License version 2 or (at your
8# option) any later version; incorporated herein by reference.
9#
10# -----------------------------------------------------------------------
11#
12
13#
14# Usage: timeconst.pl HZ > timeconst.h
15#
16
17# Precomputed values for systems without Math::BigInt
18# Generated by:
19# timeconst.pl --can 24 32 48 64 100 122 128 200 250 256 300 512 1000 1024 1200
20%canned_values = (
21 24 => [
22 '0xa6aaaaab','0x2aaaaaa',26,
23 '0xa6aaaaaaaaaaaaab','0x2aaaaaaaaaaaaaa',58,
24 125,3,
25 '0xc49ba5e4','0x1fbe76c8b4',37,
26 '0xc49ba5e353f7ceda','0x1fbe76c8b439581062',69,
27 3,125,
28 '0xa2c2aaab','0xaaaa',16,
29 '0xa2c2aaaaaaaaaaab','0xaaaaaaaaaaaa',48,
30 125000,3,
31 '0xc9539b89','0x7fffbce4217d',47,
32 '0xc9539b8887229e91','0x7fffbce4217d2849cb25',79,
33 3,125000,
34 ], 32 => [
35 '0xfa000000','0x6000000',27,
36 '0xfa00000000000000','0x600000000000000',59,
37 125,4,
38 '0x83126e98','0xfdf3b645a',36,
39 '0x83126e978d4fdf3c','0xfdf3b645a1cac0831',68,
40 4,125,
41 '0xf4240000','0x0',17,
42 '0xf424000000000000','0x0',49,
43 31250,1,
44 '0x8637bd06','0x3fff79c842fa',46,
45 '0x8637bd05af6c69b6','0x3fff79c842fa5093964a',78,
46 1,31250,
47 ], 48 => [
48 '0xa6aaaaab','0x6aaaaaa',27,
49 '0xa6aaaaaaaaaaaaab','0x6aaaaaaaaaaaaaa',59,
50 125,6,
51 '0xc49ba5e4','0xfdf3b645a',36,
52 '0xc49ba5e353f7ceda','0xfdf3b645a1cac0831',68,
53 6,125,
54 '0xa2c2aaab','0x15555',17,
55 '0xa2c2aaaaaaaaaaab','0x1555555555555',49,
56 62500,3,
57 '0xc9539b89','0x3fffbce4217d',46,
58 '0xc9539b8887229e91','0x3fffbce4217d2849cb25',78,
59 3,62500,
60 ], 64 => [
61 '0xfa000000','0xe000000',28,
62 '0xfa00000000000000','0xe00000000000000',60,
63 125,8,
64 '0x83126e98','0x7ef9db22d',35,
65 '0x83126e978d4fdf3c','0x7ef9db22d0e560418',67,
66 8,125,
67 '0xf4240000','0x0',18,
68 '0xf424000000000000','0x0',50,
69 15625,1,
70 '0x8637bd06','0x1fff79c842fa',45,
71 '0x8637bd05af6c69b6','0x1fff79c842fa5093964a',77,
72 1,15625,
73 ], 100 => [
74 '0xa0000000','0x0',28,
75 '0xa000000000000000','0x0',60,
76 10,1,
77 '0xcccccccd','0x733333333',35,
78 '0xcccccccccccccccd','0x73333333333333333',67,
79 1,10,
80 '0x9c400000','0x0',18,
81 '0x9c40000000000000','0x0',50,
82 10000,1,
83 '0xd1b71759','0x1fff2e48e8a7',45,
84 '0xd1b71758e219652c','0x1fff2e48e8a71de69ad4',77,
85 1,10000,
86 ], 122 => [
87 '0x8325c53f','0xfbcda3a',28,
88 '0x8325c53ef368eb05','0xfbcda3ac10c9714',60,
89 500,61,
90 '0xf9db22d1','0x7fbe76c8b',35,
91 '0xf9db22d0e560418a','0x7fbe76c8b43958106',67,
92 61,500,
93 '0x8012e2a0','0x3ef36',18,
94 '0x8012e29f79b47583','0x3ef368eb04325',50,
95 500000,61,
96 '0xffda4053','0x1ffffbce4217',45,
97 '0xffda4052d666a983','0x1ffffbce4217d2849cb2',77,
98 61,500000,
99 ], 128 => [
100 '0xfa000000','0x1e000000',29,
101 '0xfa00000000000000','0x1e00000000000000',61,
102 125,16,
103 '0x83126e98','0x3f7ced916',34,
104 '0x83126e978d4fdf3c','0x3f7ced916872b020c',66,
105 16,125,
106 '0xf4240000','0x40000',19,
107 '0xf424000000000000','0x4000000000000',51,
108 15625,2,
109 '0x8637bd06','0xfffbce4217d',44,
110 '0x8637bd05af6c69b6','0xfffbce4217d2849cb25',76,
111 2,15625,
112 ], 200 => [
113 '0xa0000000','0x0',29,
114 '0xa000000000000000','0x0',61,
115 5,1,
116 '0xcccccccd','0x333333333',34,
117 '0xcccccccccccccccd','0x33333333333333333',66,
118 1,5,
119 '0x9c400000','0x0',19,
120 '0x9c40000000000000','0x0',51,
121 5000,1,
122 '0xd1b71759','0xfff2e48e8a7',44,
123 '0xd1b71758e219652c','0xfff2e48e8a71de69ad4',76,
124 1,5000,
125 ], 250 => [
126 '0x80000000','0x0',29,
127 '0x8000000000000000','0x0',61,
128 4,1,
129 '0x80000000','0x180000000',33,
130 '0x8000000000000000','0x18000000000000000',65,
131 1,4,
132 '0xfa000000','0x0',20,
133 '0xfa00000000000000','0x0',52,
134 4000,1,
135 '0x83126e98','0x7ff7ced9168',43,
136 '0x83126e978d4fdf3c','0x7ff7ced916872b020c4',75,
137 1,4000,
138 ], 256 => [
139 '0xfa000000','0x3e000000',30,
140 '0xfa00000000000000','0x3e00000000000000',62,
141 125,32,
142 '0x83126e98','0x1fbe76c8b',33,
143 '0x83126e978d4fdf3c','0x1fbe76c8b43958106',65,
144 32,125,
145 '0xf4240000','0xc0000',20,
146 '0xf424000000000000','0xc000000000000',52,
147 15625,4,
148 '0x8637bd06','0x7ffde7210be',43,
149 '0x8637bd05af6c69b6','0x7ffde7210be9424e592',75,
150 4,15625,
151 ], 300 => [
152 '0xd5555556','0x2aaaaaaa',30,
153 '0xd555555555555556','0x2aaaaaaaaaaaaaaa',62,
154 10,3,
155 '0x9999999a','0x1cccccccc',33,
156 '0x999999999999999a','0x1cccccccccccccccc',65,
157 3,10,
158 '0xd0555556','0xaaaaa',20,
159 '0xd055555555555556','0xaaaaaaaaaaaaa',52,
160 10000,3,
161 '0x9d495183','0x7ffcb923a29',43,
162 '0x9d495182a9930be1','0x7ffcb923a29c779a6b5',75,
163 3,10000,
164 ], 512 => [
165 '0xfa000000','0x7e000000',31,
166 '0xfa00000000000000','0x7e00000000000000',63,
167 125,64,
168 '0x83126e98','0xfdf3b645',32,
169 '0x83126e978d4fdf3c','0xfdf3b645a1cac083',64,
170 64,125,
171 '0xf4240000','0x1c0000',21,
172 '0xf424000000000000','0x1c000000000000',53,
173 15625,8,
174 '0x8637bd06','0x3ffef39085f',42,
175 '0x8637bd05af6c69b6','0x3ffef39085f4a1272c9',74,
176 8,15625,
177 ], 1000 => [
178 '0x80000000','0x0',31,
179 '0x8000000000000000','0x0',63,
180 1,1,
181 '0x80000000','0x0',31,
182 '0x8000000000000000','0x0',63,
183 1,1,
184 '0xfa000000','0x0',22,
185 '0xfa00000000000000','0x0',54,
186 1000,1,
187 '0x83126e98','0x1ff7ced9168',41,
188 '0x83126e978d4fdf3c','0x1ff7ced916872b020c4',73,
189 1,1000,
190 ], 1024 => [
191 '0xfa000000','0xfe000000',32,
192 '0xfa00000000000000','0xfe00000000000000',64,
193 125,128,
194 '0x83126e98','0x7ef9db22',31,
195 '0x83126e978d4fdf3c','0x7ef9db22d0e56041',63,
196 128,125,
197 '0xf4240000','0x3c0000',22,
198 '0xf424000000000000','0x3c000000000000',54,
199 15625,16,
200 '0x8637bd06','0x1fff79c842f',41,
201 '0x8637bd05af6c69b6','0x1fff79c842fa5093964',73,
202 16,15625,
203 ], 1200 => [
204 '0xd5555556','0xd5555555',32,
205 '0xd555555555555556','0xd555555555555555',64,
206 5,6,
207 '0x9999999a','0x66666666',31,
208 '0x999999999999999a','0x6666666666666666',63,
209 6,5,
210 '0xd0555556','0x2aaaaa',22,
211 '0xd055555555555556','0x2aaaaaaaaaaaaa',54,
212 2500,3,
213 '0x9d495183','0x1ffcb923a29',41,
214 '0x9d495182a9930be1','0x1ffcb923a29c779a6b5',73,
215 3,2500,
216 ]
217);
218
219$has_bigint = eval 'use Math::BigInt qw(bgcd); 1;';
220
221sub bint($)
222{
223 my($x) = @_;
224 return Math::BigInt->new($x);
225}
226
227#
228# Constants for division by reciprocal multiplication.
229# (bits, numerator, denominator)
230#
231sub fmul($$$)
232{
233 my ($b,$n,$d) = @_;
234
235 $n = bint($n);
236 $d = bint($d);
237
238 return scalar (($n << $b)+$d-bint(1))/$d;
239}
240
241sub fadj($$$)
242{
243 my($b,$n,$d) = @_;
244
245 $n = bint($n);
246 $d = bint($d);
247
248 $d = $d/bgcd($n, $d);
249 return scalar (($d-bint(1)) << $b)/$d;
250}
251
252sub fmuls($$$) {
253 my($b,$n,$d) = @_;
254 my($s,$m);
255 my($thres) = bint(1) << ($b-1);
256
257 $n = bint($n);
258 $d = bint($d);
259
260 for ($s = 0; 1; $s++) {
261 $m = fmul($s,$n,$d);
262 return $s if ($m >= $thres);
263 }
264 return 0;
265}
266
267# Provides mul, adj, and shr factors for a specific
268# (bit, time, hz) combination
269sub muladj($$$) {
270 my($b, $t, $hz) = @_;
271 my $s = fmuls($b, $t, $hz);
272 my $m = fmul($s, $t, $hz);
273 my $a = fadj($s, $t, $hz);
274 return ($m->as_hex(), $a->as_hex(), $s);
275}
276
277# Provides numerator, denominator values
278sub numden($$) {
279 my($n, $d) = @_;
280 my $g = bgcd($n, $d);
281 return ($n/$g, $d/$g);
282}
283
284# All values for a specific (time, hz) combo
285sub conversions($$) {
286 my ($t, $hz) = @_;
287 my @val = ();
288
289 # HZ_TO_xx
290 push(@val, muladj(32, $t, $hz));
291 push(@val, muladj(64, $t, $hz));
292 push(@val, numden($t, $hz));
293
294 # xx_TO_HZ
295 push(@val, muladj(32, $hz, $t));
296 push(@val, muladj(64, $hz, $t));
297 push(@val, numden($hz, $t));
298
299 return @val;
300}
301
302sub compute_values($) {
303 my($hz) = @_;
304 my @val = ();
305 my $s, $m, $a, $g;
306
307 if (!$has_bigint) {
308 die "$0: HZ == $hz not canned and ".
309 "Math::BigInt not available\n";
310 }
311
312 # MSEC conversions
313 push(@val, conversions(1000, $hz));
314
315 # USEC conversions
316 push(@val, conversions(1000000, $hz));
317
318 return @val;
319}
320
321sub output($@)
322{
323 my($hz, @val) = @_;
324 my $pfx, $bit, $suf, $s, $m, $a;
325
326 print "/* Automatically generated by kernel/timeconst.pl */\n";
327 print "/* Conversion constants for HZ == $hz */\n";
328 print "\n";
329 print "#ifndef KERNEL_TIMECONST_H\n";
330 print "#define KERNEL_TIMECONST_H\n";
331 print "\n";
332
333 print "#include <linux/param.h>\n";
334
335 print "\n";
336 print "#if HZ != $hz\n";
337 print "#error \"kernel/timeconst.h has the wrong HZ value!\"\n";
338 print "#endif\n";
339 print "\n";
340
341 foreach $pfx ('HZ_TO_MSEC','MSEC_TO_HZ',
342 'USEC_TO_HZ','HZ_TO_USEC') {
343 foreach $bit (32, 64) {
344 foreach $suf ('MUL', 'ADJ', 'SHR') {
345 printf "#define %-23s %s\n",
346 "${pfx}_$suf$bit", shift(@val);
347 }
348 }
349 foreach $suf ('NUM', 'DEN') {
350 printf "#define %-23s %s\n",
351 "${pfx}_$suf", shift(@val);
352 }
353 }
354
355 print "\n";
356 print "#endif /* KERNEL_TIMECONST_H */\n";
357}
358
359($hz) = @ARGV;
360
361# Use this to generate the %canned_values structure
362if ($hz eq '--can') {
363 shift(@ARGV);
364 @hzlist = sort {$a <=> $b} (@ARGV);
365
366 print "# Precomputed values for systems without Math::BigInt\n";
367 print "# Generated by:\n";
368 print "# timeconst.pl --can ", join(' ', @hzlist), "\n";
369 print "\%canned_values = (\n";
370 my $pf = "\t";
371 foreach $hz (@hzlist) {
372 my @values = compute_values($hz);
373 print "$pf$hz => [\n";
374 while (scalar(@values)) {
375 my $bit;
376 foreach $bit (32, 64) {
377 my $m = shift(@values);
378 my $a = shift(@values);
379 my $s = shift(@values);
380 print "\t\t\'",$m,"\',\'",$a,"\',",$s,",\n";
381 }
382 my $n = shift(@values);
383 my $d = shift(@values);
384 print "\t\t",$n,',',$d,",\n";
385 }
386 print "\t]";
387 $pf = ', ';
388 }
389 print "\n);\n";
390} else {
391 $hz += 0; # Force to number
392 if ($hz < 1) {
393 die "Usage: $0 HZ\n";
394 }
395
396 @val = @{$canned_values{$hz}};
397 if (!defined(@val)) {
398 @val = compute_values($hz);
399 }
400 output($hz, @val);
401}
402exit 0;
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-05 14:12:47 -0500