=head1 VERSION
-Version 0.01
+Version 0.05
=cut
our $VERSION;
BEGIN {
- $VERSION = '0.01';
+ $VERSION = '0.05';
eval {
require XSLoader;
XSLoader::load(__PACKAGE__, $VERSION);
1;
} or do {
- sub SVU_PP () { 1 }
- sub SVU_SIZE () { 1 }
- *vfill = *vfill_pp;
- *vcopy = *vcopy_pp;
- *veq = *veq_pp;
+ *SVU_PP = sub () { 1 };
+ *SVU_SIZE = sub () { 1 };
+ *vfill = *vfill_pp;
+ *vcopy = *vcopy_pp;
+ *veq = *veq_pp;
}
}
=head1 DESCRIPTION
-A set of utilities to manipulate bits in vec strings. Highly optimized XS routines are used when available, but straightforward pure perl replacements are also provided for platforms without a C compiler.
+A set of utilities to manipulate bits in vec strings.
+Highly optimized XS routines are used when available, but straightforward pure perl replacements are also provided for platforms without a C compiler.
-This module doesn't reimplement bit vectors. It can be used on the very same scalars that C<vec> builds, or actually on any Perl string (C<SVt_PV>).
+This module doesn't reimplement bit vectors.
+It can be used on the very same scalars that C<vec> builds, or actually on any Perl string (C<SVt_PV>).
=head1 CONSTANTS
=head2 C<SVU_SIZE>
-Size in bits of the unit used for moves. The higher this value is, the faster the XS functions are. It's usually C<CHAR_BIT * $Config{alignbytes}>, except on non-little-endian architectures where it currently falls back to C<CHAR_BIT> (e.g. SPARC).
+Size in bits of the unit used for moves.
+The higher this value is, the faster the XS functions are.
+It's usually C<CHAR_BIT * $Config{alignbytes}>, except on non-little-endian architectures where it currently falls back to C<CHAR_BIT> (e.g. SPARC).
=head1 FUNCTIONS
=head2 C<vfill $vec, $start, $length, $bit>
-Starting at C<$start> in C<$vec>, fills C<$length> bits with C<$bit>. Grows C<$vec> if necessary.
+Starting at C<$start> in C<$vec>, fills C<$length> bits with C<$bit>.
+Grows C<$vec> if necessary.
=cut
=head2 C<< vcopy $from => $from_start, $to => $to_start, $length >>
-Copies C<$length> bits starting at C<$from_start> in C<$from> to C<$to_start> in C<$to>. If C<$from_start + $length> is too long for C<$from>, zeros are copied past C<$length>. Grows C<$to> if necessary.
+Copies C<$length> bits starting at C<$from_start> in C<$from> to C<$to_start> in C<$to>.
+If C<$from_start + $length> is too long for C<$from>, zeros are copied past C<$length>.
+Grows C<$to> if necessary.
+Doesn't need to allocate any extra memory.
=cut
=head2 C<< veq $v1 => $v1_start, $v2 => $v2_start, $length >>
-Returns true if the C<$length> bits starting at C<$v1_start> in C<$v1> and C<$v2_start> in C<$v2> are equal, and false otherwise. If needed, C<$length> is decreased to fit inside C<$v1> and C<$v2> boundaries.
+Returns true if the C<$length> bits starting at C<$v1_start> in C<$v1> and C<$v2_start> in C<$v2> are equal, and false otherwise.
+If needed, C<$length> is decreased to fit inside C<$v1> and C<$v2> boundaries.
=cut
=head1 EXPORT
-The functions L</vfill>, L</vcopy> and L</veq> are only exported on request. All of them are exported by the tags C<':funcs'> and C<':all'>.
+The functions L</vfill>, L</vcopy> and L</veq> are only exported on request.
+All of them are exported by the tags C<':funcs'> and C<':all'>.
-The constants L</SVU_PP> and L</SVU_SIZE> are also only exported on request. They are all exported by the tags C<':consts'> and C<':all'>.
+The constants L</SVU_PP> and L</SVU_SIZE> are also only exported on request.
+They are all exported by the tags C<':consts'> and C<':all'>.
=cut
our @EXPORT_OK = map { @$_ } values %EXPORT_TAGS;
$EXPORT_TAGS{'all'} = [ @EXPORT_OK ];
+=head1 BENCHMARKS
+
+The following timings were obtained by running the C<samples/bench.pl> script.
+The C<_pp> entries are the pure Perl versions, whereas C<_bv> are L<Bit::Vector> versions.
+
+=over 4
+
+=item This is for perl 5.8.8 on a Core 2 Duo 2.66GHz machine (unit is 64 bits).
+
+ Filling bits at a given position :
+ Rate vfill_pp vfill_bv vfill
+ vfill_pp 80.3/s -- -100% -100%
+ vfill_bv 1053399/s 1312401% -- -11%
+ vfill 1180792/s 1471129% 12% --
+
+ Copying bits from a bit vector to a different one :
+ Rate vcopy_pp vcopy_bv vcopy
+ vcopy_pp 112/s -- -100% -100%
+ vcopy_bv 62599/s 55622% -- -89%
+ vcopy 558491/s 497036% 792% --
+
+ Moving bits in the same bit vector from a given position to a different one :
+ Rate vmove_pp vmove_bv vmove
+ vmove_pp 64.8/s -- -100% -100%
+ vmove_bv 64742/s 99751% -- -88%
+ vmove 547980/s 845043% 746% --
+
+ Testing bit equality from different positions of different bit vectors :
+ Rate veq_pp veq_bv veq
+ veq_pp 92.7/s -- -100% -100%
+ veq_bv 32777/s 35241% -- -94%
+ veq 505828/s 545300% 1443% --
+
+=item This is for perl 5.10.0 on a Pentium 4 3.0GHz (unit is 32 bits).
+
+ Rate vfill_pp vfill_bv vfill
+ vfill_pp 185/s -- -100% -100%
+ vfill_bv 407979/s 220068% -- -16%
+ vfill 486022/s 262184% 19% --
+
+ Rate vcopy_pp vcopy_bv vcopy
+ vcopy_pp 61.5/s -- -100% -100%
+ vcopy_bv 32548/s 52853% -- -83%
+ vcopy 187360/s 304724% 476% --
+
+ Rate vmove_pp vmove_bv vmove
+ vmove_pp 63.1/s -- -100% -100%
+ vmove_bv 32829/s 51933% -- -83%
+ vmove 188572/s 298787% 474% --
+
+ Rate veq_pp veq_bv veq
+ veq_pp 34.2/s -- -100% -100%
+ veq_bv 17518/s 51190% -- -91%
+ veq 192181/s 562591% 997% --
+
+=item This is for perl 5.10.0 on an UltraSPARC-IIi (unit is 8 bits).
+
+ Rate vfill_pp vfill vfill_bv
+ vfill_pp 4.23/s -- -100% -100%
+ vfill 30039/s 709283% -- -17%
+ vfill_bv 36022/s 850568% 20% --
+
+ Rate vcopy_pp vcopy_bv vcopy
+ vcopy_pp 2.74/s -- -100% -100%
+ vcopy_bv 8146/s 297694% -- -60%
+ vcopy 20266/s 740740% 149% --
+
+ Rate vmove_pp vmove_bv vmove
+ vmove_pp 2.66/s -- -100% -100%
+ vmove_bv 8274/s 311196% -- -59%
+ vmove 20287/s 763190% 145% --
+
+ Rate veq_pp veq_bv veq
+ veq_pp 7.33/s -- -100% -100%
+ veq_bv 2499/s 33978% -- -87%
+ veq 19675/s 268193% 687% --
+
+=back
+
=head1 CAVEATS
-Please report architectures where we can't use the alignment as the move unit. I'll add exceptions for them.
+Please report architectures where we can't use the alignment as the move unit.
+I'll add exceptions for them.
=head1 DEPENDENCIES
Vincent Pit, C<< <perl at profvince.com> >>, L<http://www.profvince.com>.
-You can contact me by mail or on #perl @ FreeNode (vincent or Prof_Vince).
+You can contact me by mail or on C<irc.perl.org> (vincent).
=head1 BUGS
-Please report any bugs or feature requests to C<bug-scalar-vec-util at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Scalar-Vec-Util>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
+Please report any bugs or feature requests to C<bug-scalar-vec-util at rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Scalar-Vec-Util>.
+I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
=head1 SUPPORT
projects / perl / modules / Scalar-Vec-Util.git / blobdiff