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#!/usr/bin/perl
# -----------------------------------------------------------------------
#
# Copyright 2007 rPath, Inc. - All Rights Reserved
#
# This file is part of the Linux kernel, and is made available under
# the terms of the GNU General Public License version 2 or (at your
# option) any later version; incorporated herein by reference.
#
# -----------------------------------------------------------------------
#
#
# Usage: timeconst.pl HZ > timeconst.h
#
# Precomputed values for systems without Math::BigInt
# Generated by:
# timeconst.pl --can 24 32 48 64 100 122 128 200 250 256 300 512 1000 1024 1200
%canned_values = (
24 => [
'0xa6aaaaab','0x2aaaaaa',26,
'0xa6aaaaaaaaaaaaab','0x2aaaaaaaaaaaaaa',58,
125,3,
'0xc49ba5e4','0x1fbe76c8b4',37,
'0xc49ba5e353f7ceda','0x1fbe76c8b439581062',69,
3,125,
'0xa2c2aaab','0xaaaa',16,
'0xa2c2aaaaaaaaaaab','0xaaaaaaaaaaaa',48,
125000,3,
'0xc9539b89','0x7fffbce4217d',47,
'0xc9539b8887229e91','0x7fffbce4217d2849cb25',79,
3,125000,
], 32 => [
'0xfa000000','0x6000000',27,
'0xfa00000000000000','0x600000000000000',59,
125,4,
'0x83126e98','0xfdf3b645a',36,
'0x83126e978d4fdf3c','0xfdf3b645a1cac0831',68,
4,125,
'0xf4240000','0x0',17,
'0xf424000000000000','0x0',49,
31250,1,
'0x8637bd06','0x3fff79c842fa',46,
'0x8637bd05af6c69b6','0x3fff79c842fa5093964a',78,
1,31250,
], 48 => [
'0xa6aaaaab','0x6aaaaaa',27,
'0xa6aaaaaaaaaaaaab','0x6aaaaaaaaaaaaaa',59,
125,6,
'0xc49ba5e4','0xfdf3b645a',36,
'0xc49ba5e353f7ceda','0xfdf3b645a1cac0831',68,
6,125,
'0xa2c2aaab','0x15555',17,
'0xa2c2aaaaaaaaaaab','0x1555555555555',49,
62500,3,
'0xc9539b89','0x3fffbce4217d',46,
'0xc9539b8887229e91','0x3fffbce4217d2849cb25',78,
3,62500,
], 64 => [
'0xfa000000','0xe000000',28,
'0xfa00000000000000','0xe00000000000000',60,
125,8,
'0x83126e98','0x7ef9db22d',35,
'0x83126e978d4fdf3c','0x7ef9db22d0e560418',67,
8,125,
'0xf4240000','0x0',18,
'0xf424000000000000','0x0',50,
15625,1,
'0x8637bd06','0x1fff79c842fa',45,
'0x8637bd05af6c69b6','0x1fff79c842fa5093964a',77,
1,15625,
], 100 => [
'0xa0000000','0x0',28,
'0xa000000000000000','0x0',60,
10,1,
'0xcccccccd','0x733333333',35,
'0xcccccccccccccccd','0x73333333333333333',67,
1,10,
'0x9c400000','0x0',18,
'0x9c40000000000000','0x0',50,
10000,1,
'0xd1b71759','0x1fff2e48e8a7',45,
'0xd1b71758e219652c','0x1fff2e48e8a71de69ad4',77,
1,10000,
], 122 => [
'0x8325c53f','0xfbcda3a',28,
'0x8325c53ef368eb05','0xfbcda3ac10c9714',60,
500,61,
'0xf9db22d1','0x7fbe76c8b',35,
'0xf9db22d0e560418a','0x7fbe76c8b43958106',67,
61,500,
'0x8012e2a0','0x3ef36',18,
'0x8012e29f79b47583','0x3ef368eb04325',50,
500000,61,
'0xffda4053','0x1ffffbce4217',45,
'0xffda4052d666a983','0x1ffffbce4217d2849cb2',77,
61,500000,
], 128 => [
'0xfa000000','0x1e000000',29,
'0xfa00000000000000','0x1e00000000000000',61,
125,16,
'0x83126e98','0x3f7ced916',34,
'0x83126e978d4fdf3c','0x3f7ced916872b020c',66,
16,125,
'0xf4240000','0x40000',19,
'0xf424000000000000','0x4000000000000',51,
15625,2,
'0x8637bd06','0xfffbce4217d',44,
'0x8637bd05af6c69b6','0xfffbce4217d2849cb25',76,
2,15625,
], 200 => [
'0xa0000000','0x0',29,
'0xa000000000000000','0x0',61,
5,1,
'0xcccccccd','0x333333333',34,
'0xcccccccccccccccd','0x33333333333333333',66,
1,5,
'0x9c400000','0x0',19,
'0x9c40000000000000','0x0',51,
5000,1,
'0xd1b71759','0xfff2e48e8a7',44,
'0xd1b71758e219652c','0xfff2e48e8a71de69ad4',76,
1,5000,
], 250 => [
'0x80000000','0x0',29,
'0x8000000000000000','0x0',61,
4,1,
'0x80000000','0x180000000',33,
'0x8000000000000000','0x18000000000000000',65,
1,4,
'0xfa000000','0x0',20,
'0xfa00000000000000','0x0',52,
4000,1,
'0x83126e98','0x7ff7ced9168',43,
'0x83126e978d4fdf3c','0x7ff7ced916872b020c4',75,
1,4000,
], 256 => [
'0xfa000000','0x3e000000',30,
'0xfa00000000000000','0x3e00000000000000',62,
125,32,
'0x83126e98','0x1fbe76c8b',33,
'0x83126e978d4fdf3c','0x1fbe76c8b43958106',65,
32,125,
'0xf4240000','0xc0000',20,
'0xf424000000000000','0xc000000000000',52,
15625,4,
'0x8637bd06','0x7ffde7210be',43,
'0x8637bd05af6c69b6','0x7ffde7210be9424e592',75,
4,15625,
], 300 => [
'0xd5555556','0x2aaaaaaa',30,
'0xd555555555555556','0x2aaaaaaaaaaaaaaa',62,
10,3,
'0x9999999a','0x1cccccccc',33,
'0x999999999999999a','0x1cccccccccccccccc',65,
3,10,
'0xd0555556','0xaaaaa',20,
'0xd055555555555556','0xaaaaaaaaaaaaa',52,
10000,3,
'0x9d495183','0x7ffcb923a29',43,
'0x9d495182a9930be1','0x7ffcb923a29c779a6b5',75,
3,10000,
], 512 => [
'0xfa000000','0x7e000000',31,
'0xfa00000000000000','0x7e00000000000000',63,
125,64,
'0x83126e98','0xfdf3b645',32,
'0x83126e978d4fdf3c','0xfdf3b645a1cac083',64,
64,125,
'0xf4240000','0x1c0000',21,
'0xf424000000000000','0x1c000000000000',53,
15625,8,
'0x8637bd06','0x3ffef39085f',42,
'0x8637bd05af6c69b6','0x3ffef39085f4a1272c9',74,
8,15625,
], 1000 => [
'0x80000000','0x0',31,
'0x8000000000000000','0x0',63,
1,1,
'0x80000000','0x0',31,
'0x8000000000000000','0x0',63,
1,1,
'0xfa000000','0x0',22,
'0xfa00000000000000','0x0',54,
1000,1,
'0x83126e98','0x1ff7ced9168',41,
'0x83126e978d4fdf3c','0x1ff7ced916872b020c4',73,
1,1000,
], 1024 => [
'0xfa000000','0xfe000000',32,
'0xfa00000000000000','0xfe00000000000000',64,
125,128,
'0x83126e98','0x7ef9db22',31,
'0x83126e978d4fdf3c','0x7ef9db22d0e56041',63,
128,125,
'0xf4240000','0x3c0000',22,
'0xf424000000000000','0x3c000000000000',54,
15625,16,
'0x8637bd06','0x1fff79c842f',41,
'0x8637bd05af6c69b6','0x1fff79c842fa5093964',73,
16,15625,
], 1200 => [
'0xd5555556','0xd5555555',32,
'0xd555555555555556','0xd555555555555555',64,
5,6,
'0x9999999a','0x66666666',31,
'0x999999999999999a','0x6666666666666666',63,
6,5,
'0xd0555556','0x2aaaaa',22,
'0xd055555555555556','0x2aaaaaaaaaaaaa',54,
2500,3,
'0x9d495183','0x1ffcb923a29',41,
'0x9d495182a9930be1','0x1ffcb923a29c779a6b5',73,
3,2500,
]
);
$has_bigint = eval 'use Math::BigInt qw(bgcd); 1;';
sub bint($)
{
my($x) = @_;
return Math::BigInt->new($x);
}
#
# Constants for division by reciprocal multiplication.
# (bits, numerator, denominator)
#
sub fmul($$$)
{
my ($b,$n,$d) = @_;
$n = bint($n);
$d = bint($d);
return scalar (($n << $b)+$d-bint(1))/$d;
}
sub fadj($$$)
{
my($b,$n,$d) = @_;
$n = bint($n);
$d = bint($d);
$d = $d/bgcd($n, $d);
return scalar (($d-bint(1)) << $b)/$d;
}
sub fmuls($$$) {
my($b,$n,$d) = @_;
my($s,$m);
my($thres) = bint(1) << ($b-1);
$n = bint($n);
$d = bint($d);
for ($s = 0; 1; $s++) {
$m = fmul($s,$n,$d);
return $s if ($m >= $thres);
}
return 0;
}
# Provides mul, adj, and shr factors for a specific
# (bit, time, hz) combination
sub muladj($$$) {
my($b, $t, $hz) = @_;
my $s = fmuls($b, $t, $hz);
my $m = fmul($s, $t, $hz);
my $a = fadj($s, $t, $hz);
return ($m->as_hex(), $a->as_hex(), $s);
}
# Provides numerator, denominator values
sub numden($$) {
my($n, $d) = @_;
my $g = bgcd($n, $d);
return ($n/$g, $d/$g);
}
# All values for a specific (time, hz) combo
sub conversions($$) {
my ($t, $hz) = @_;
my @val = ();
# HZ_TO_xx
push(@val, muladj(32, $t, $hz));
push(@val, muladj(64, $t, $hz));
push(@val, numden($t, $hz));
# xx_TO_HZ
push(@val, muladj(32, $hz, $t));
push(@val, muladj(64, $hz, $t));
push(@val, numden($hz, $t));
return @val;
}
sub compute_values($) {
my($hz) = @_;
my @val = ();
my $s, $m, $a, $g;
if (!$has_bigint) {
die "$0: HZ == $hz not canned and ".
"Math::BigInt not available\n";
}
# MSEC conversions
push(@val, conversions(1000, $hz));
# USEC conversions
push(@val, conversions(1000000, $hz));
return @val;
}
sub output($@)
{
my($hz, @val) = @_;
my $pfx, $bit, $suf, $s, $m, $a;
print "/* Automatically generated by kernel/timeconst.pl */\n";
print "/* Conversion constants for HZ == $hz */\n";
print "\n";
print "#ifndef KERNEL_TIMECONST_H\n";
print "#define KERNEL_TIMECONST_H\n";
print "\n";
print "#include <linux/param.h>\n";
print "\n";
print "#if HZ != $hz\n";
print "#error \"kernel/timeconst.h has the wrong HZ value!\"\n";
print "#endif\n";
print "\n";
foreach $pfx ('HZ_TO_MSEC','MSEC_TO_HZ',
'HZ_TO_USEC','USEC_TO_HZ') {
foreach $bit (32, 64) {
foreach $suf ('MUL', 'ADJ', 'SHR') {
printf "#define %-23s %s\n",
"${pfx}_$suf$bit", shift(@val);
}
}
foreach $suf ('NUM', 'DEN') {
printf "#define %-23s %s\n",
"${pfx}_$suf", shift(@val);
}
}
print "\n";
print "#endif /* KERNEL_TIMECONST_H */\n";
}
($hz) = @ARGV;
# Use this to generate the %canned_values structure
if ($hz eq '--can') {
shift(@ARGV);
@hzlist = sort {$a <=> $b} (@ARGV);
print "# Precomputed values for systems without Math::BigInt\n";
print "# Generated by:\n";
print "# timeconst.pl --can ", join(' ', @hzlist), "\n";
print "\%canned_values = (\n";
my $pf = "\t";
foreach $hz (@hzlist) {
my @values = compute_values($hz);
print "$pf$hz => [\n";
while (scalar(@values)) {
my $bit;
foreach $bit (32, 64) {
my $m = shift(@values);
my $a = shift(@values);
my $s = shift(@values);
print "\t\t\'",$m,"\',\'",$a,"\',",$s,",\n";
}
my $n = shift(@values);
my $d = shift(@values);
print "\t\t",$n,',',$d,",\n";
}
print "\t]";
$pf = ', ';
}
print "\n);\n";
} else {
$hz += 0; # Force to number
if ($hz < 1) {
die "Usage: $0 HZ\n";
}
@val = @{$canned_values{$hz}};
if (!defined(@val)) {
@val = compute_values($hz);
}
output($hz, @val);
}
exit 0;
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