supporting quads on 32 bit Perl

bulk88 has asked for the wisdom of the Perl Monks concerning the following question:

This is related to supporting SSE 128 bit data in Perl. 32 bit Perl doesn't come with quads/Q/q pack letter. I have a C library that uses 64 bit ints. I use perl on windows. My C compiler also has no problems with 64 bit ints. Perl NVs don't loose integer precision until 2^53. 53 is not 64. What should my XS wrapper around this C library return the 64 bit ints as in 32 bit perl? There seems to be alot negativity over Math::BigInt's bloatedness. Also how to do you load packed little endian numbers into Math::BigInt, it seems bigint only knows what big endian ASCII hex is for importing numbers. The solution should be CPAN grade. Quads are very rarely used by this C library but they need to be exposed somehow for the rare case someone wants to call that function. The simplest thing is, on 32 bits, a 64 bit int is a 8 byte packed LE PV string, conversion routines warn() and pads if under 8 bytes long. On 64 bits its a IV/UV. Is this last solution the best solution?

Comment on supporting quads on 32 bit Perl

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Re: supporting quads on 32 bit Perl by BrowserUk (Patriarch) on May 31, 2012 at 21:42 UTC
See Math::Int64 With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply]
Re^2: supporting quads on 32 bit Perl by bulk88 (Priest) on May 31, 2012 at 21:49 UTC
I saw that already. Its not available on 32 bit Windows through packagers http://code.activestate.com/ppm/Math-Int64/.	[reply]
Re^3: supporting quads on 32 bit Perl by BrowserUk (Patriarch) on May 31, 2012 at 22:01 UTC
I was thinking more along the lines of you could steal the initialisation code from it to add to your XS wrapper of the C library you are trying to access. However, you should also be able to compile it with CPAN or manually without difficulty. With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. The start of some sanity?	[reply]
Re^4: supporting quads on 32 bit Perl by bulk88 (Priest) on Jun 01, 2012 at 04:31 UTC
Re^5: supporting quads on 32 bit Perl by salva (Canon) on Jun 01, 2012 at 06:00 UTC
Some notes below your chosen depth have not been shown here
Re^3: supporting quads on 32 bit Perl by syphilis (Archbishop) on Jun 01, 2012 at 00:36 UTC
Its not available on 32 bit Windows through packagers For the record, both bribes and sisyphusion repos provide ppm packages for Math::Int64. Cheers, Rob	[reply]
Re: supporting quads on 32 bit Perl (0.23) by ikegami (Patriarch) on Jun 04, 2012 at 17:35 UTC
[ The thread was getting too deep. ] The third test of MSC.t is failing for me. Math-Int64-0.23 ActivePerl build 1402 Perl 5.14.2, 32 bit, threaded. Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.40219.01 for 80x86 `t/MSC.t ................. 1/3 # Failed test 'uint64 to NV conversion 3' # at t/MSC.t line 15. # Looks like you failed 1 test of 3. t/MSC.t ................. Dubious, test returned 1 (wstat 256, 0x100) Failed 1/3 subtests t/MSC.t (Wstat: 256 Tests: 3 Failed: 1) Failed test: 3 Non-zero exit status: 1` [download] I changed the test from `ok` to `is` tests to get more info: `t/MSC.t ................. 1/3 # Failed test 'uint64 to NV conversion 3' # at t/MSC.t line 15. # got: '1.83746864796716e+019' # expected: '18374686479671623680' # Looks like you failed 1 test of 3.` [download] The thing is I can't see any different between the two by looking at them using `sprintf` or `pack 'd'`. `nv: 1.837468647967162400000000000000e+019 u: 1.837468647967162400000000000000e+019 nv: 43efe00000000000 u: 43efe00000000000` [download] The warnings I get: Int64.xs(256) : warning C4244: 'return' : conversion from 'NV' to 'int +64_t', possible loss of data Int64.xs(335) : warning C4244: 'return' : conversion from 'NV' to 'uin +t64_t', possible loss of data Int64.xs(345) : warning C4244: 'initializing' : conversion from 'int64 +_t' to 'IV', possible loss of data Int64.xs(350) : warning C4244: 'initializing' : conversion from 'int64 +_t' to 'UV', possible loss of data Int64.xs(354) : warning C4244: 'function' : conversion from 'int64_t' +to 'const NV', possible loss of data Int64.xs(360) : warning C4244: 'initializing' : conversion from 'uint6 +4_t' to 'UV', possible loss of data Int64.xs(363) : warning C4244: 'function' : conversion from 'uint64_t' + to 'const NV', possible loss of data Int64.xs(375) : warning C4244: 'initializing' : conversion from 'uint6 +4_t' to 'char', possible loss of data Int64.xs(492) : warning C4244: 'function' : conversion from 'int64_t' +to 'const IV', possible loss of data Int64.xs(516) : warning C4244: 'function' : conversion from 'uint64_t' + to 'const UV', possible loss of data Int64.xs(535) : warning C4244: '=' : conversion from 'int64_t' to 'cha +r', possible loss of data Int64.xs(553) : warning C4244: '=' : conversion from 'uint64_t' to 'ch +ar', possible loss of data Int64.xs(669) : warning C4244: 'function' : conversion from 'uint64_t' + to 'const IV', possible loss of data Int64.xs(680) : warning C4244: 'function' : conversion from 'uint64_t' + to 'const UV', possible loss of data Int64.xs(690) : warning C4244: 'function' : conversion from 'uint64_t' + to 'const IV', possible loss of data Int64.xs(700) : warning C4244: 'function' : conversion from 'uint64_t' + to 'const UV', possible loss of data Int64.xs(712) : warning C4244: 'function' : conversion from 'int64_t' +to 'const IV', possible loss of data Int64.xs(723) : warning C4244: 'function' : conversion from 'uint64_t' + to 'const IV', possible loss of data Int64.c(1288) : warning C4101: 'rev' : unreferenced local variable Int64.c(1287) : warning C4101: 'other' : unreferenced local variable Int64.c(1317) : warning C4101: 'rev' : unreferenced local variable Int64.c(1316) : warning C4101: 'other' : unreferenced local variable Int64.c(1782) : warning C4101: 'rev' : unreferenced local variable Int64.c(1811) : warning C4101: 'rev' : unreferenced local variable Int64.c(2107) : warning C4101: 'rev' : unreferenced local variable Int64.c(2106) : warning C4101: 'other' : unreferenced local variable Int64.c(2133) : warning C4101: 'rev' : unreferenced local variable Int64.c(2132) : warning C4101: 'other' : unreferenced local variable Int64.c(2159) : warning C4101: 'rev' : unreferenced local variable Int64.c(2158) : warning C4101: 'other' : unreferenced local variable Int64.c(2185) : warning C4101: 'rev' : unreferenced local variable Int64.c(2184) : warning C4101: 'other' : unreferenced local variable Int64.c(2211) : warning C4101: 'rev' : unreferenced local variable Int64.c(2210) : warning C4101: 'other' : unreferenced local variable Int64.c(2237) : warning C4101: 'rev' : unreferenced local variable Int64.c(2236) : warning C4101: 'other' : unreferenced local variable Int64.c(2263) : warning C4101: 'rev' : unreferenced local variable Int64.c(2262) : warning C4101: 'other' : unreferenced local variable Int64.c(2289) : warning C4101: 'rev' : unreferenced local variable Int64.c(2288) : warning C4101: 'other' : unreferenced local variable Int64.c(2317) : warning C4101: 'rev' : unreferenced local variable Int64.c(2316) : warning C4101: 'other' : unreferenced local variable Int64.c(2763) : warning C4101: 'rev' : unreferenced local variable Int64.c(2792) : warning C4101: 'rev' : unreferenced local variable Int64.c(3088) : warning C4101: 'rev' : unreferenced local variable Int64.c(3087) : warning C4101: 'other' : unreferenced local variable Int64.c(3114) : warning C4101: 'rev' : unreferenced local variable Int64.c(3113) : warning C4101: 'other' : unreferenced local variable Int64.c(3140) : warning C4101: 'rev' : unreferenced local variable Int64.c(3139) : warning C4101: 'other' : unreferenced local variable Int64.c(3166) : warning C4101: 'rev' : unreferenced local variable Int64.c(3165) : warning C4101: 'other' : unreferenced local variable Int64.c(3192) : warning C4101: 'rev' : unreferenced local variable Int64.c(3191) : warning C4101: 'other' : unreferenced local variable Int64.c(3218) : warning C4101: 'rev' : unreferenced local variable Int64.c(3217) : warning C4101: 'other' : unreferenced local variable Int64.c(3244) : warning C4101: 'rev' : unreferenced local variable Int64.c(3243) : warning C4101: 'other' : unreferenced local variable ...\int64.xs(170) : warning C4715: 'SvSI64' : not all control paths re +turn a value ...\int64.xs(180) : warning C4715: 'SvSU64' : not all control paths re +turn a value [download]	[reply] [d/l] [select]
Re^2: supporting quads on 32 bit Perl (0.23) by salva (Canon) on Jun 04, 2012 at 21:42 UTC
The thing is I can't see any different between the two by looking at them using sprintf or pack 'd'. That's because `sprintf` and `pack` first convert the uint64 into an NV implicitly. On the other hand, `is` converts its operands into strings and compares them. The NV is represented in scientific notation and the uint64 in decimal and so they differ.	[reply] [d/l] [select]
Re: supporting quads on 32 bit Perl by sundialsvc4 (Abbot) on May 31, 2012 at 23:22 UTC
Frankly, I would say that before you do anything else you should use that “C compiler that has no problems with 64-bit ints” to compile a version of Perl. In other words, sidestep completely the issue of providing a 64-bit quantity to a Perl that can’t handle it. You will gain absolutely nothing by solving that curious technical problem ... In whatever form of XS-magic that you ultimately do, require a 64-bit Perl and ignore the rest. These days you can run 64-bit ints just as easily as you can run 32-bit; therefore, do so.	[reply]
Re^2: supporting quads on 32 bit Perl by bulk88 (Priest) on Jun 01, 2012 at 02:29 UTC
The solution should be CPAN grade. Frankly, I would say that before you do anything else you should use that �C compiler that has no problems with 64-bit ints� to compile a version of Perl. In other words, sidestep completely the issue of providing a 64-bit quantity to a Perl that can�t handle it. ........................ These days you can run 64-bit ints just as easily as you can run 32-bit; therefore, do so. I understand you're being frank. 64 bit Windows users are currently a minority, http://www.itsnyc.com/index.php/blog/item/windows-7s-64-bit-adoption. I think you know the status and support of Perl 32 bit pointers with 64 bit ints on Windows.	[reply]

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