This queue is for tickets about the Digest-CRC CPAN distribution.

Report information
The Basics
Id:
70674
Status:
resolved
Priority:
Low/Low
Queue:

People
Owner:
OLIMAUL [...] cpan.org
Requestors:
pebolle [...] tiscali.nl
Cc:
AdminCc:

BugTracker
Severity:
Normal
Broken in:
0.17
Fixed in:
(no value)



Subject: Fix a few issues with CRC.xs
0) crc2.pl is a (silly) test that uses several methods to compute identical CRC32 checksums. It uses the convenience wrappers I suggested in buh #70672. Output currently is: crc8 : 244 crc8 : 244 crc8i : 4 crc8i : 179 crc8o : 0 crc8o : 0 crc8r : 32 crc8r : 32 crcccitt : 10673 crcccitt : 10673 crcccitti: 35318 crcccitti: 45368 crcccitto: 0 crcccitto: 0 crcccittr: 28561 crcccittr: 28561 crc16n : 65256 crc16n : 65256 crc16i : 48349 crc16i : 25117 crc16o : 0 crc16o : 0 crc16 : 47933 crc16 : 47933 crc32n : 4236843288 crc32n : 4236843288 crc32i : 1687957459 crc32i : 3600338594 crc32o : 4294967295 crc32o : 4294967295 crc32 : 3421780262 crc32 : 3421780262 crc64 : 5090661014116757502 crc64 : 5090661014116757502 testn : 339470139 testn : 339470139 testi : 2351878640 testi : 2930071031 testo : 4294967295 testo : 4294967295 testr : 260797489 testr : 260797489 (The n, i, o and r suffixes mean no reflect, in reflect, out reflect and reflect twice.) Note that out reflect is broken and in reflect is broken in two step mode. 1) refin_refout.patch adds the few fixes needed to address these issues in CRC.xs. Feel free to ask to to break down what they do individually. Boring output using this patch: crc8 : 244 crc8 : 244 crc8i : 4 crc8i : 4 crc8o : 47 crc8o : 47 crc8r : 32 crc8r : 32 crcccitt : 10673 crcccitt : 10673 crcccitti: 35318 crcccitti: 35318 crcccitto: 36244 crcccitto: 36244 crcccittr: 28561 crcccittr: 28561 crc16n : 65256 crc16n : 65256 crc16i : 48349 crc16i : 48349 crc16o : 6015 crc16o : 6015 crc16 : 47933 crc16 : 47933 crc32n : 4236843288 crc32n : 4236843288 crc32i : 1687957459 crc32i : 1687957459 crc32o : 412651839 crc32o : 412651839 crc32 : 3421780262 crc32 : 3421780262 crc64 : 5090661014116757502 crc64 : 5090661014116757502 testn : 339470139 testn : 339470139 testi : 2351878640 testi : 2351878640 testo : 3706182696 testo : 3706182696 testr : 260797489 testr : 260797489 (Note that I cross checked these checksums using the crcmodel.[ch] reference code.) 2) If (something like) this patch is acceptable, I might be tempted to: - fix the non-xs code too. (How does one trigger the usage of that code?); - make sure the documentation is updated (ie, inludes some recent enhancements).
Subject: crc2.pl
#! /usr/bin/env perl use 5.010; use strict; use warnings; use Digest::CRC 0.17 qw( crc crc8 crcccitt crc16 crc32 crc64 ); my $in0 = "12345"; my $in1 = "6789"; my $out; $out = crc8( $in0 . $in1); printf "crc8 : %u\n", $out; $out = crc8( $in0 ); $out = crc8( $in1, $out ); printf "crc8 : %u\n", $out; $out = crc( $in0 . $in1, 8, 0x00, 0x00, 0, 0x7, 1, 0 ); printf "crc8i : %u\n", $out; $out = crc( $in0 , 8, 0x00, 0x00, 0, 0x7, 1, 0 ); $out = crc( $in1 , 8, $out, 0x00, 0, 0x7, 1, 1 ); printf "crc8i : %u\n", $out; $out = crc( $in0 . $in1, 8, 0x00, 0x00, 1, 0x7, 0, 0 ); printf "crc8o : %u\n", $out; $out = crc( $in0 , 8, 0x00, 0x00, 1, 0x7, 0, 0 ); $out = crc( $in1 , 8, $out, 0x00, 1, 0x7, 0, 1 ); printf "crc8o : %u\n", $out; $out = crc( $in0 . $in1, 8, 0x00, 0x00, 1, 0x7, 1, 0 ); printf "crc8r : %u\n", $out; $out = crc( $in0 , 8, 0x00, 0x00, 1, 0x7, 1, 0 ); $out = crc( $in1 , 8, $out, 0x00, 1, 0x7, 1, 1 ); printf "crc8r : %u\n", $out; $out = crcccitt( $in0 . $in1); printf "crcccitt : %u\n", $out; $out = crcccitt( $in0 ); $out = crcccitt( $in1, $out ); printf "crcccitt : %u\n", $out; $out = crc( $in0 . $in1, 16, 0xFFFF, 0x0000, 0, 0x1021, 1, 0); printf "crcccitti: %u\n", $out; $out = crc( $in0 , 16, 0xFFFF, 0x0000, 0, 0x1021, 1, 0); $out = crc( $in1 , 16, $out , 0x0000, 0, 0x1021, 1, 1); printf "crcccitti: %u\n", $out; $out = crc( $in0 . $in1, 16, 0xFFFF, 0x0000, 1, 0x1021, 0, 0); printf "crcccitto: %u\n", $out; $out = crc( $in0 , 16, 0xFFFF, 0x0000, 1, 0x1021, 0, 0); $out = crc( $in1 , 16, $out , 0x0000, 1, 0x1021, 0, 1); printf "crcccitto: %u\n", $out; $out = crc( $in0 . $in1, 16, 0xFFFF, 0x0000, 1, 0x1021, 1, 0); printf "crcccittr: %u\n", $out; $out = crc( $in0 , 16, 0xFFFF, 0x0000, 1, 0x1021, 1, 0); $out = crc( $in1 , 16, $out , 0x0000, 1, 0x1021, 1, 1); printf "crcccittr: %u\n", $out; $out = crc( $in0 . $in1, 16, 0x0000, 0x0000, 0, 0x8005, 0, 0); printf "crc16n : %u\n", $out; $out = crc( $in0 , 16, 0x0000, 0x0000, 0, 0x8005, 0, 0); $out = crc( $in1 , 16, $out , 0x0000, 0, 0x8005, 0, 1); printf "crc16n : %u\n", $out; $out = crc( $in0 . $in1, 16, 0x0000, 0x0000, 0, 0x8005, 1, 0); printf "crc16i : %u\n", $out; $out = crc( $in0 , 16, 0x0000, 0x0000, 0, 0x8005, 1, 0); $out = crc( $in1 , 16, $out , 0x0000, 0, 0x8005, 1, 1); printf "crc16i : %u\n", $out; $out = crc( $in0 . $in1, 16, 0x0000, 0x0000, 1, 0x8005, 0, 0); printf "crc16o : %u\n", $out; $out = crc( $in0 , 16, 0x0000, 0x0000, 1, 0x8005, 0, 0); $out = crc( $in1 , 16, $out , 0x0000, 1, 0x8005, 0, 1); printf "crc16o : %u\n", $out; $out = crc16( $in0 . $in1); printf "crc16 : %u\n", $out; $out = crc16( $in0 ); $out = crc16( $in1, $out ); printf "crc16 : %u\n", $out; $out = crc( $in0 . $in1, 32, 0xFFFFFFFF, 0xFFFFFFFF, 0, 0x04C11DB7, 0, 0); printf "crc32n : %u\n", $out; $out = crc( $in0 , 32, 0xFFFFFFFF, 0xFFFFFFFF, 0, 0x04C11DB7, 0, 0); $out = crc( $in1 , 32, $out , 0xFFFFFFFF, 0, 0x04C11DB7, 0, 1); printf "crc32n : %u\n", $out; $out = crc( $in0 . $in1, 32, 0xFFFFFFFF, 0xFFFFFFFF, 0, 0x04C11DB7, 1, 0); printf "crc32i : %u\n", $out; $out = crc( $in0 , 32, 0xFFFFFFFF, 0xFFFFFFFF, 0, 0x04C11DB7, 1, 0); $out = crc( $in1 , 32, $out , 0xFFFFFFFF, 0, 0x04C11DB7, 1, 1); printf "crc32i : %u\n", $out; $out = crc( $in0 . $in1, 32, 0xFFFFFFFF, 0xFFFFFFFF, 1, 0x04C11DB7, 0, 0); printf "crc32o : %u\n", $out; $out = crc( $in0 , 32, 0xFFFFFFFF, 0xFFFFFFFF, 1, 0x04C11DB7, 0, 0); $out = crc( $in1 , 32, $out , 0xFFFFFFFF, 1, 0x04C11DB7, 0, 1); printf "crc32o : %u\n", $out; $out = crc32( $in0 . $in1); printf "crc32 : %u\n", $out; $out = crc32( $in0 ); $out = crc32( $in1, $out ); printf "crc32 : %u\n", $out; $out = crc64( $in0 . $in1); printf "crc64 : %u\n", $out; $out = crc64( $in0 ); $out = crc64( $in1, $out ); printf "crc64 : %u\n", $out; $out = crc( $in0 . $in1, 32, 0x12345678, 0xFFFFFFFF, 0, 0x04C11DB7, 0, 0); printf "testn : %u\n", $out; $out = crc( $in0 , 32, 0x12345678, 0xFFFFFFFF, 0, 0x04C11DB7, 0, 0); $out = crc( $in1 , 32, $out , 0xFFFFFFFF, 0, 0x04C11DB7, 0, 1); printf "testn : %u\n", $out; $out = crc( $in0 . $in1, 32, 0x12345678, 0xFFFFFFFF, 0, 0x04C11DB7, 1, 0); printf "testi : %u\n", $out; $out = crc( $in0 , 32, 0x12345678, 0xFFFFFFFF, 0, 0x04C11DB7, 1, 0); $out = crc( $in1 , 32, $out , 0xFFFFFFFF, 0, 0x04C11DB7, 1, 1); printf "testi : %u\n", $out; $out = crc( $in0 . $in1, 32, 0x12345678, 0xFFFFFFFF, 1, 0x04C11DB7, 0, 0); printf "testo : %u\n", $out; $out = crc( $in0 , 32, 0x12345678, 0xFFFFFFFF, 1, 0x04C11DB7, 0, 0); $out = crc( $in1 , 32, $out , 0xFFFFFFFF, 1, 0x04C11DB7, 0, 1); printf "testo : %u\n", $out; $out = crc( $in0 . $in1, 32, 0x12345678, 0xFFFFFFFF, 1, 0x04C11DB7, 1, 0); printf "testr : %u\n", $out; $out = crc( $in0 , 32, 0x12345678, 0xFFFFFFFF, 1, 0x04C11DB7, 1, 0); $out = crc( $in1 , 32, $out , 0xFFFFFFFF, 1, 0x04C11DB7, 1, 1); printf "testr : %u\n", $out;
From: pebolle@tiscali.nl
This actually adds the promised patch.
Subject: refin_refout.patch
diff -up Digest-CRC-0.17/CRC.xs.ref Digest-CRC-0.17/CRC.xs --- Digest-CRC-0.17/CRC.xs.ref 2011-09-01 17:56:21.332059946 +0200 +++ Digest-CRC-0.17/CRC.xs 2011-09-01 18:11:13.790194360 +0200 @@ -31,7 +31,7 @@ static UV reflect(UV in, int width) int i; UV out = 0; - for (i = width; in; i--, in >>= 1) + for (i = width; in && i; i--, in >>= 1) out = (out << 1) | (in & 1); return out << i; @@ -123,18 +123,19 @@ _crc(message, width, init, xorout, refin CODE: SvGETMAGIC(message); - if (cont) { - init = (init ^ xorout); - if (refin) - init = reflect(init, width); - } - crc = refin ? reflect(init, width) : init; msg = SvPV(message, len); end = msg + len; mask = ((UV)1)<<(width-1); mask = mask + (mask-1); tab = (UV *) SvPVX(table); + crc = refin ? reflect(init, width) : init; + if (cont) { + crc = (init ^ xorout) & mask; + if (refout ^ refin) + crc = reflect(crc, width); + } + if (refin) { while (msg < end) crc = (crc >> 8) ^ tab[(crc ^ *msg++) & 0xFF];
Hi, thanks for the patch. It is part of version 0.18 which I uploaded a few minutes ago. It seems the non-xs code calculates correct values. You can force the non-xs code using "perl Makefile.pm -pm" Oliver


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