X-Git-Url: http://git.vpit.fr/?a=blobdiff_plain;f=lib%2FScalar%2FVec%2FUtil.pm;h=1435972a64b3c2ab4beeb2de254dc932a2728ed0;hb=82dcef98c2b9fa6b67b9912a6f4e566b4fd7e155;hp=2c0f723f0361dbfc8cd8403d7d7bca0c9e5e09e6;hpb=5d190c195e99dcfbbe49786e190b0922e24432b0;p=perl%2Fmodules%2FScalar-Vec-Util.git diff --git a/lib/Scalar/Vec/Util.pm b/lib/Scalar/Vec/Util.pm index 2c0f723..1435972 100644 --- a/lib/Scalar/Vec/Util.pm +++ b/lib/Scalar/Vec/Util.pm @@ -11,13 +11,13 @@ Scalar::Vec::Util - Utility routines for vec strings. =head1 VERSION -Version 0.05 +Version 0.06 =cut our $VERSION; BEGIN { - $VERSION = '0.05'; + $VERSION = '0.06'; eval { require XSLoader; XSLoader::load(__PACKAGE__, $VERSION); @@ -45,9 +45,11 @@ BEGIN { =head1 DESCRIPTION -A set of utilities to manipulate bits in vec strings. Highly optimized XS routines are used when available, but straightforward pure perl replacements are also provided for platforms without a C compiler. +A set of utilities to manipulate bits in vec strings. +Highly optimized XS routines are used when available, but straightforward pure perl replacements are also provided for platforms without a C compiler. -This module doesn't reimplement bit vectors. It can be used on the very same scalars that C builds, or actually on any Perl string (C). +This module doesn't reimplement bit vectors. +It can be used on the very same scalars that C builds, or actually on any Perl string (C). =head1 CONSTANTS @@ -57,39 +59,51 @@ True when pure perl fallbacks are used instead of XS functions. =head2 C -Size in bits of the unit used for moves. The higher this value is, the faster the XS functions are. It's usually C, except on non-little-endian architectures where it currently falls back to C (e.g. SPARC). +Size in bits of the unit used for moves. +The higher this value is, the faster the XS functions are. +It's usually C, except on non-little-endian architectures where it currently falls back to C (e.g. SPARC). =head1 FUNCTIONS =head2 C -Starting at C<$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 -sub _alldef { - for (@_) { return 0 unless defined } - return 1; -} - -sub vfill_pp { - (undef, my $s, my $l, my $x) = @_; - croak "Invalid argument" unless _alldef @_; +sub vfill_pp ($$$$) { + my ($s, $l, $x) = @_[1 .. 3]; return unless $l; - $x = 1 if $x; - vec($_[0], $_, 1) = $x for $s .. $s + $l - 1; + croak 'Invalid negative offset' if $s < 0; + croak 'Invalid negative length' if $l < 0; + $x = ~0 if $x; + my $SIZE = 32; + my $t = int($s / $SIZE) + 1; + my $u = int(($s + $l) / $SIZE); + if ($SIZE * $t < $s + $l) { # implies $t <= $u + vec($_[0], $_, 1) = $x for $s .. $SIZE * $t - 1; + vec($_[0], $_, $SIZE) = $x for $t .. $u - 1; + vec($_[0], $_, 1) = $x for $SIZE * $u .. $s + $l - 1; + } else { + vec($_[0], $_, 1) = $x for $s .. $s + $l - 1; + } } =head2 C<< vcopy $from => $from_start, $to => $to_start, $length >> -Copies C<$length> bits starting at C<$from_start> in C<$from> to C<$to_start> in C<$to>. If C<$from_start + $length> is too long for C<$from>, zeros are copied past C<$length>. Grows C<$to> if necessary. +Copies C<$length> bits starting at C<$from_start> in C<$from> to C<$to_start> in C<$to>. +If C<$from_start + $length> is too long for C<$from>, zeros are copied past C<$length>. +Grows C<$to> if necessary. +Doesn't need to allocate any extra memory. =cut -sub vcopy_pp { +sub vcopy_pp ($$$$$) { my ($fs, $ts, $l) = @_[1, 3, 4]; - croak "Invalid argument" unless _alldef @_; return unless $l; + croak 'Invalid negative offset' if $fs < 0 or $ts < 0; + croak 'Invalid negative length' if $l < 0; my $step = $ts - $fs; if ($step <= 0) { vec($_[2], $_ + $step, 1) = vec($_[0], $_, 1) for $fs .. $fs + $l - 1; @@ -98,15 +112,83 @@ sub vcopy_pp { } } +=head2 C<< vshift $v, $start, $length => $bits [, $insert ] >> + +In the area starting at C<$start> and of length C<$length> in C<$v>, shift bits C positions left if C<< $bits > 0 >> and right otherwise. +If C<$insert> is defined, also fills the resulting gap with ones if C<$insert> is true and zeros if it's false. +Bits outside of the specified area are left untouched. +Doesn't need to allocate any extra memory. + +=cut + +sub vshift ($$$$;$) { + my ($start, $length, $bits, $insert) = @_[1 .. 4]; + return unless $length and $bits; + croak 'Invalid negative offset' if $start < 0; + croak 'Invalid negative length' if $length < 0; + my $left = 1; + if ($bits < 0) { + $left = 0; + $bits = -$bits; + } + if ($bits < $length) { + $length -= $bits; + if ($left) { + vcopy($_[0], $start, $_[0], $start + $bits, $length); + vfill($_[0], $start, $bits, $insert) if defined $insert; + } else { + vcopy($_[0], $start + $bits, $_[0], $start, $length); + vfill($_[0], $start + $length, $bits, $insert) if defined $insert; + } + } else { + vfill($_[0], $start, $length, $insert) if defined $insert; + } +} + +=head2 C<< vrot $v, $start, $length, $bits >> + +In the area starting at C<$start> and of length C<$length> in C<$v>, rotates bits C positions left if C<< $bits > 0 >> and right otherwise. +Bits outside of the specified area are left untouched. +Currently allocates an extra buffer of size C. + +=cut + +sub vrot ($$$$) { + my ($start, $length, $bits) = @_[1 .. 3]; + return unless $length and $bits; + croak 'Invalid negative offset' if $start < 0; + croak 'Invalid negative length' if $length < 0; + my $left = 1; + if ($bits < 0) { + $left = 0; + $bits = -$bits; + } + $bits %= $length; + return unless $bits; + $length -= $bits; + my $buf = ''; + if ($left) { + vcopy($_[0], $start + $length, $buf, 0, $bits); + vcopy($_[0], $start, $_[0], $start + $bits, $length); + vcopy($buf, 0, $_[0], $start, $bits); + } else { + vcopy($_[0], $start, $buf, 0, $bits); + vcopy($_[0], $start + $bits, $_[0], $start, $length); + vcopy($buf, 0, $_[0], $start + $length, $bits); + } +} + =head2 C<< veq $v1 => $v1_start, $v2 => $v2_start, $length >> -Returns true if the C<$length> bits starting at C<$v1_start> in C<$v1> and C<$v2_start> in C<$v2> are equal, and false otherwise. If needed, C<$length> is decreased to fit inside C<$v1> and C<$v2> boundaries. +Returns true if the C<$length> bits starting at C<$v1_start> in C<$v1> and C<$v2_start> in C<$v2> are equal, and false otherwise. +If needed, C<$length> is decreased to fit inside C<$v1> and C<$v2> boundaries. =cut -sub veq_pp { +sub veq_pp ($$$$$) { my ($s1, $s2, $l) = @_[1, 3, 4]; - croak "Invalid argument" unless _alldef @_; + croak 'Invalid negative offset' if $s1 < 0 or $s2 < 0; + croak 'Invalid negative length' if $l < 0; my $i = 0; while ($i < $l) { return 0 if vec($_[0], $s1 + $i, 1) != vec($_[2], $s2 + $i, 1); @@ -117,9 +199,11 @@ sub veq_pp { =head1 EXPORT -The functions L, L and L are only exported on request. All of them are exported by the tags C<':funcs'> and C<':all'>. +The functions L, L, L, L and L are only exported on request. +All of them are exported by the tags C<':funcs'> and C<':all'>. -The constants L and L are also only exported on request. They are all exported by the tags C<':consts'> and C<':all'>. +The constants L and L are also only exported on request. +They are all exported by the tags C<':consts'> and C<':all'>. =cut @@ -127,7 +211,7 @@ use base qw/Exporter/; our @EXPORT = (); our %EXPORT_TAGS = ( - 'funcs' => [ qw/vfill vcopy veq/ ], + 'funcs' => [ qw/vfill vcopy vshift vrot veq/ ], 'consts' => [ qw/SVU_PP SVU_SIZE/ ] ); our @EXPORT_OK = map { @$_ } values %EXPORT_TAGS; @@ -135,7 +219,8 @@ $EXPORT_TAGS{'all'} = [ @EXPORT_OK ]; =head1 BENCHMARKS -The following timings were obtained by running the C script. The C<_pp> entries are the pure Perl versions, while C<_bv> are L versions. +The following timings were obtained by running the C script. +The C<_pp> entries are the pure Perl versions, whereas C<_bv> are L versions. =over 4 @@ -213,7 +298,8 @@ The following timings were obtained by running the C script. T =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 @@ -231,7 +317,8 @@ You can contact me by mail or on C (vincent). =head1 BUGS -Please report any bugs or feature requests to C, or through the web interface at L. 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, or through the web interface at L. +I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. =head1 SUPPORT @@ -243,7 +330,7 @@ Tests code coverage report is available at L