| #!/usr/bin/perl |
| # ----------------------------------------------------------------------- |
| # |
| # Copyright 2007-2008 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, |
| 125,3, |
| '0xc49ba5e4','0x1fbe76c8b4',37, |
| 3,125, |
| '0xa2c2aaab','0xaaaa',16, |
| 125000,3, |
| '0xc9539b89','0x7fffbce4217d',47, |
| 3,125000, |
| ], 32 => [ |
| '0xfa000000','0x6000000',27, |
| 125,4, |
| '0x83126e98','0xfdf3b645a',36, |
| 4,125, |
| '0xf4240000','0x0',17, |
| 31250,1, |
| '0x8637bd06','0x3fff79c842fa',46, |
| 1,31250, |
| ], 48 => [ |
| '0xa6aaaaab','0x6aaaaaa',27, |
| 125,6, |
| '0xc49ba5e4','0xfdf3b645a',36, |
| 6,125, |
| '0xa2c2aaab','0x15555',17, |
| 62500,3, |
| '0xc9539b89','0x3fffbce4217d',46, |
| 3,62500, |
| ], 64 => [ |
| '0xfa000000','0xe000000',28, |
| 125,8, |
| '0x83126e98','0x7ef9db22d',35, |
| 8,125, |
| '0xf4240000','0x0',18, |
| 15625,1, |
| '0x8637bd06','0x1fff79c842fa',45, |
| 1,15625, |
| ], 100 => [ |
| '0xa0000000','0x0',28, |
| 10,1, |
| '0xcccccccd','0x733333333',35, |
| 1,10, |
| '0x9c400000','0x0',18, |
| 10000,1, |
| '0xd1b71759','0x1fff2e48e8a7',45, |
| 1,10000, |
| ], 122 => [ |
| '0x8325c53f','0xfbcda3a',28, |
| 500,61, |
| '0xf9db22d1','0x7fbe76c8b',35, |
| 61,500, |
| '0x8012e2a0','0x3ef36',18, |
| 500000,61, |
| '0xffda4053','0x1ffffbce4217',45, |
| 61,500000, |
| ], 128 => [ |
| '0xfa000000','0x1e000000',29, |
| 125,16, |
| '0x83126e98','0x3f7ced916',34, |
| 16,125, |
| '0xf4240000','0x40000',19, |
| 15625,2, |
| '0x8637bd06','0xfffbce4217d',44, |
| 2,15625, |
| ], 200 => [ |
| '0xa0000000','0x0',29, |
| 5,1, |
| '0xcccccccd','0x333333333',34, |
| 1,5, |
| '0x9c400000','0x0',19, |
| 5000,1, |
| '0xd1b71759','0xfff2e48e8a7',44, |
| 1,5000, |
| ], 250 => [ |
| '0x80000000','0x0',29, |
| 4,1, |
| '0x80000000','0x180000000',33, |
| 1,4, |
| '0xfa000000','0x0',20, |
| 4000,1, |
| '0x83126e98','0x7ff7ced9168',43, |
| 1,4000, |
| ], 256 => [ |
| '0xfa000000','0x3e000000',30, |
| 125,32, |
| '0x83126e98','0x1fbe76c8b',33, |
| 32,125, |
| '0xf4240000','0xc0000',20, |
| 15625,4, |
| '0x8637bd06','0x7ffde7210be',43, |
| 4,15625, |
| ], 300 => [ |
| '0xd5555556','0x2aaaaaaa',30, |
| 10,3, |
| '0x9999999a','0x1cccccccc',33, |
| 3,10, |
| '0xd0555556','0xaaaaa',20, |
| 10000,3, |
| '0x9d495183','0x7ffcb923a29',43, |
| 3,10000, |
| ], 512 => [ |
| '0xfa000000','0x7e000000',31, |
| 125,64, |
| '0x83126e98','0xfdf3b645',32, |
| 64,125, |
| '0xf4240000','0x1c0000',21, |
| 15625,8, |
| '0x8637bd06','0x3ffef39085f',42, |
| 8,15625, |
| ], 1000 => [ |
| '0x80000000','0x0',31, |
| 1,1, |
| '0x80000000','0x0',31, |
| 1,1, |
| '0xfa000000','0x0',22, |
| 1000,1, |
| '0x83126e98','0x1ff7ced9168',41, |
| 1,1000, |
| ], 1024 => [ |
| '0xfa000000','0xfe000000',32, |
| 125,128, |
| '0x83126e98','0x7ef9db22',31, |
| 128,125, |
| '0xf4240000','0x3c0000',22, |
| 15625,16, |
| '0x8637bd06','0x1fff79c842f',41, |
| 16,15625, |
| ], 1200 => [ |
| '0xd5555556','0xd5555555',32, |
| 5,6, |
| '0x9999999a','0x66666666',31, |
| 6,5, |
| '0xd0555556','0x2aaaaa',22, |
| 2500,3, |
| '0x9d495183','0x1ffcb923a29',41, |
| 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($$$) { |
| my($b,$n,$d) = @_; |
| my($s,$m); |
| my($thres) = bint(1) << ($b-1); |
| |
| $n = bint($n); |
| $d = bint($d); |
| |
| for ($s = 0; 1; $s++) { |
| $m = fmul($s,$n,$d); |
| return $s if ($m >= $thres); |
| } |
| return 0; |
| } |
| |
| # Generate a hex value if the result fits in 64 bits; |
| # otherwise skip. |
| sub bignum_hex($) { |
| my($x) = @_; |
| my $s = $x->as_hex(); |
| |
| return (length($s) > 18) ? undef : $s; |
| } |
| |
| # Provides mul, adj, and shr factors for a specific |
| # (bit, time, hz) combination |
| sub muladj($$$) { |
| my($b, $t, $hz) = @_; |
| my $s = fmuls($b, $t, $hz); |
| my $m = fmul($s, $t, $hz); |
| my $a = fadj($s, $t, $hz); |
| return (bignum_hex($m), bignum_hex($a), $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, $hz)); |
| push(@val, numden($t, $hz)); |
| |
| # xx_TO_HZ |
| push(@val, muladj(32, $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 outputval($$) |
| { |
| my($name, $val) = @_; |
| my $csuf; |
| |
| if (defined($val)) { |
| if ($name !~ /SHR/) { |
| $val = "U64_C($val)"; |
| } |
| printf "#define %-23s %s\n", $name.$csuf, $val.$csuf; |
| } |
| } |
| |
| 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 "#include <linux/types.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) { |
| foreach $suf ('MUL', 'ADJ', 'SHR') { |
| outputval("${pfx}_$suf$bit", shift(@val)); |
| } |
| } |
| foreach $suf ('NUM', 'DEN') { |
| outputval("${pfx}_$suf", shift(@val)); |
| } |
| } |
| |
| print "\n"; |
| print "#endif /* KERNEL_TIMECONST_H */\n"; |
| } |
| |
| # Pretty-print Perl values |
| sub perlvals(@) { |
| my $v; |
| my @l = (); |
| |
| foreach $v (@_) { |
| if (!defined($v)) { |
| push(@l, 'undef'); |
| } elsif ($v =~ /^0x/) { |
| push(@l, "\'".$v."\'"); |
| } else { |
| push(@l, $v.''); |
| } |
| } |
| return join(',', @l); |
| } |
| |
| ($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) { |
| my $m = shift(@values); |
| my $a = shift(@values); |
| my $s = shift(@values); |
| print "\t\t", perlvals($m,$a,$s), ",\n"; |
| } |
| my $n = shift(@values); |
| my $d = shift(@values); |
| print "\t\t", perlvals($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{$hz}}; |
| if (!@val) { |
| @val = compute_values($hz); |
| } |
| output($hz, @val); |
| } |
| exit 0; |