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Groups > comp.lang.python > #57300
| From | Grant Edwards <invalid@invalid.invalid> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Python Front-end to GCC |
| Date | 2013-10-22 18:58 +0000 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <l46hsb$h4j$2@reader1.panix.com> (permalink) |
| References | (5 earlier) <mailman.1345.1382433285.18130.python-list@python.org> <526668e5$0$29981$c3e8da3$5496439d@news.astraweb.com> <mailman.1354.1382450725.18130.python-list@python.org> <52669852$0$29981$c3e8da3$5496439d@news.astraweb.com> <bcnq66Fk2qnU1@mid.individual.net> |
On 2013-10-22, Neil Cerutti <neilc@norwich.edu> wrote:
> On 2013-10-22, Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote:
>> On Tue, 22 Oct 2013 14:04:57 +0000, Dave Angel wrote:
>>> but here you go on to say the C code is unsafely skipping
>>> initialization, which is not the case.
>>
>> Are you talking generically, or specifically about the C code
>> referenced in the link I gave?
>>
>> "Memory is always zeroed" is one of the advantages of Go over C and C++,
>> at least according to Rob Pike:
>>
>> http://commandcenter.blogspot.com.au/2012/06/less-is-exponentially-
>> more.html
>
> Go initializes variables to defined zero values, not simply to
> all-bits zero as (I think) C does.
C initializes to defined zero values. For most machines in use today,
those values _happen_ to be all-bits-zero.
This makes the implementation trivial: chuck them all into some
pre-defined section (e.g. ".bss"), and then on startup, you zero-out
all the bits in the section without having to know what's where within
that section. If you design a machine such that integer, pointer, and
FP representations where 0, NULL, and 0.0 are all zero-bits, then life
get's tougher for the guys writing the compiler and startup code.
But the language doesn't require or assume that initializer values are
all-bits-zero. FP values have to be initizliaed to 0.0. Int's have
to be initialized to integer value 0, pointers have to be initialized
to (void*)0. Nowhere it the languauge is it required or assumed that
any or all of those values are all represented by contiguous blocks of
all-zero-bits.
> This isn't as great a feature as it seems, since the zero value for
> some built in types, e.g., map, is unusable without manual
> construction. In addition, you can't define a zero value for your own
> types.
--
Grant Edwards grant.b.edwards Yow! Oh my GOD -- the
at SUN just fell into YANKEE
gmail.com STADIUM!!
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Python Front-end to GCC Philip Herron <herron.philip@googlemail.com> - 2013-10-20 10:56 -0700
Re: Python Front-end to GCC victorgarcianet@gmail.com - 2013-10-20 15:10 -0700
Re: Python Front-end to GCC John Nagle <nagle@animats.com> - 2013-10-22 23:48 -0700
Re: Python Front-end to GCC Philip Herron <herron.philip@googlemail.com> - 2013-10-23 00:25 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-23 09:42 +0100
Re: Python Front-end to GCC John Nagle <nagle@animats.com> - 2013-10-23 13:51 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-20 20:35 -0700
Re: Python Front-end to GCC Steven D'Aprano <steve@pearwood.info> - 2013-10-21 07:46 +0000
Re: Python Front-end to GCC Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-10-21 10:55 +0100
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-21 23:41 +0000
Re: Python Front-end to GCC Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-10-22 10:14 +0100
Re: Python Front-end to GCC Philip Herron <herron.philip@googlemail.com> - 2013-10-22 02:32 -0700
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-22 12:00 +0000
Re: Python Front-end to GCC Chris Angelico <rosuav@gmail.com> - 2013-10-22 23:20 +1100
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-22 17:27 +0000
Re: Python Front-end to GCC Chris Angelico <rosuav@gmail.com> - 2013-10-23 08:43 +1100
Re: Python Front-end to GCC Dave Angel <davea@davea.name> - 2013-10-22 14:04 +0000
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-22 15:22 +0000
Re: Python Front-end to GCC Grant Edwards <invalid@invalid.invalid> - 2013-10-22 15:39 +0000
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-22 16:40 +0000
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-22 17:50 +0100
Re: Python Front-end to GCC Chris Kaynor <ckaynor@zindagigames.com> - 2013-10-22 09:52 -0700
Re: Python Front-end to GCC Frank Miles <fpm@u.washington.edu> - 2013-10-22 16:53 +0000
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-22 17:23 +0000
Re: Python Front-end to GCC Chris Kaynor <ckaynor@zindagigames.com> - 2013-10-22 10:35 -0700
Re: Python Front-end to GCC Neil Cerutti <neilc@norwich.edu> - 2013-10-22 17:37 +0000
Re: Python Front-end to GCC Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-10-22 18:37 +0100
Re: Python Front-end to GCC MRAB <python@mrabarnett.plus.com> - 2013-10-22 18:42 +0100
Re: Python Front-end to GCC Grant Edwards <invalid@invalid.invalid> - 2013-10-22 18:49 +0000
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 04:40 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 04:55 -0700
Re: Python Front-end to GCC Dan Sommers <dan@tombstonezero.net> - 2013-10-25 12:55 +0000
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 15:18 +0100
Re: Python Front-end to GCC Ned Batchelder <ned@nedbatchelder.com> - 2013-10-25 10:35 -0400
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 11:26 -0700
Re: Python Front-end to GCC Grant Edwards <invalid@invalid.invalid> - 2013-10-25 19:06 +0000
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 19:40 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 11:45 -0700
Re: Python Front-end to GCC rusi <rustompmody@gmail.com> - 2013-10-25 11:59 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 12:09 -0700
Re: Python Front-end to GCC rusi <rustompmody@gmail.com> - 2013-10-25 12:15 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 20:02 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 12:18 -0700
Re: Python Front-end to GCC John Nagle <nagle@animats.com> - 2013-10-26 14:31 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-26 15:10 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-27 15:14 -0700
Re: Python Front-end to GCC rusi <rustompmody@gmail.com> - 2013-10-27 19:15 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-28 08:44 +0000
Re: Python Front-end to GCC rusi <rustompmody@gmail.com> - 2013-10-28 02:31 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 20:36 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 12:49 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 21:14 +0100
Re: Python Front-end to GCC Tim Delaney <timothy.c.delaney@gmail.com> - 2013-10-26 07:11 +1100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 13:29 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 21:36 +0100
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-26 02:42 +0000
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 21:44 +0100
Re: Python Front-end to GCC Tim Delaney <timothy.c.delaney@gmail.com> - 2013-10-26 07:48 +1100
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 21:56 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 14:02 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 22:11 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-25 14:37 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-25 22:56 +0100
Re: Python Front-end to GCC Chris Angelico <rosuav@gmail.com> - 2013-10-26 13:36 +1100
Re: Python Front-end to GCC Neil Cerutti <neilc@norwich.edu> - 2013-10-22 17:15 +0000
Re: Python Front-end to GCC Grant Edwards <invalid@invalid.invalid> - 2013-10-22 18:58 +0000
Re: Python Front-end to GCC Grant Edwards <invalid@invalid.invalid> - 2013-10-22 20:26 +0000
Re: Python Front-end to GCC Grant Edwards <invalid@invalid.invalid> - 2013-10-22 15:36 +0000
Re: Python Front-end to GCC Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-10-22 15:15 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-21 13:14 -0700
Re: Python Front-end to GCC Ned Batchelder <ned@nedbatchelder.com> - 2013-10-21 16:29 -0400
Re: Python Front-end to GCC rusi <rustompmody@gmail.com> - 2013-10-21 20:40 -0700
Re: Python Front-end to GCC Philip Herron <herron.philip@googlemail.com> - 2013-10-21 04:08 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-21 13:26 -0700
Re: Python Front-end to GCC Philip Herron <herron.philip@googlemail.com> - 2013-10-21 14:03 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-21 16:04 -0700
Re: Python Front-end to GCC Piet van Oostrum <piet@vanoostrum.org> - 2013-10-21 23:45 -0400
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-21 21:24 -0700
Re: Python Front-end to GCC Steven D'Aprano <steve@pearwood.info> - 2013-10-22 05:25 +0000
Re: Python Front-end to GCC Dave Angel <davea@davea.name> - 2013-10-22 04:39 +0000
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-22 08:04 -0700
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-22 17:09 +0000
Re: Python Front-end to GCC Piet van Oostrum <piet@vanoostrum.org> - 2013-10-22 13:20 -0400
Re: Python Front-end to GCC Ned Batchelder <ned@nedbatchelder.com> - 2013-10-22 11:46 -0400
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-22 16:52 +0100
Re: Python Front-end to GCC Benjamin Kaplan <benjamin.kaplan@case.edu> - 2013-10-22 09:03 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-22 10:50 -0700
Re: Python Front-end to GCC rusi <rustompmody@gmail.com> - 2013-10-22 11:11 -0700
Re: Python Front-end to GCC Neil Cerutti <neilc@norwich.edu> - 2013-10-22 18:18 +0000
Re: Python Front-end to GCC Piet van Oostrum <piet@vanoostrum.org> - 2013-10-22 15:20 -0400
Re: Python Front-end to GCC Neil Cerutti <neilc@norwich.edu> - 2013-10-22 19:27 +0000
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-22 20:38 +0100
Re: Python Front-end to GCC Neil Cerutti <neilc@norwich.edu> - 2013-10-22 20:00 +0000
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-22 20:32 +0100
Re: Python Front-end to GCC Skip Montanaro <skip@pobox.com> - 2013-10-22 13:08 -0500
Re: Python Front-end to GCC MRAB <python@mrabarnett.plus.com> - 2013-10-22 19:16 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-22 11:16 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-22 11:22 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-22 11:28 -0700
Re: Python Front-end to GCC Piet van Oostrum <piet@vanoostrum.org> - 2013-10-22 18:11 -0400
Re: Python Front-end to GCC Chris Angelico <rosuav@gmail.com> - 2013-10-23 17:28 +1100
Re: Python Front-end to GCC Grant Edwards <invalid@invalid.invalid> - 2013-10-22 22:47 +0000
Re: Python Front-end to GCC Ned Batchelder <ned@nedbatchelder.com> - 2013-10-22 14:23 -0400
Re: Python Front-end to GCC rusi <rustompmody@gmail.com> - 2013-10-22 11:40 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-22 19:58 +0100
Re: Python Front-end to GCC Ned Batchelder <ned@nedbatchelder.com> - 2013-10-22 14:40 -0400
Re: Python Front-end to GCC alex23 <wuwei23@gmail.com> - 2013-10-23 11:36 +1000
Re: Python Front-end to GCC rusi <rustompmody@gmail.com> - 2013-10-22 21:04 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-23 07:06 +0100
Re: Python Front-end to GCC MRAB <python@mrabarnett.plus.com> - 2013-10-22 19:47 +0100
Re: Python Front-end to GCC Ned Batchelder <ned@nedbatchelder.com> - 2013-10-22 13:56 -0400
Re: Python Front-end to GCC Michael Torrie <torriem@gmail.com> - 2013-10-22 22:05 -0600
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-23 07:13 +0100
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-26 14:25 -0700
Re: Python Front-end to GCC Mark Janssen <dreamingforward@gmail.com> - 2013-10-26 14:33 -0700
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-26 22:38 +0100
Re: Python Front-end to GCC Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-10-26 22:35 +0100
Re: Python Front-end to GCC Antoine Pitrou <solipsis@pitrou.net> - 2013-10-22 08:55 +0000
Re: Python Front-end to GCC Philip Herron <herron.philip@googlemail.com> - 2013-10-22 02:08 -0700
Re: Python Front-end to GCC Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-10-22 10:10 +0000
Re: Python Front-end to GCC Antoine Pitrou <solipsis@pitrou.net> - 2013-10-22 15:51 +0000
Re: Python Front-end to GCC Stefan Behnel <stefan_ml@behnel.de> - 2013-10-24 08:47 +0200
Re: Python Front-end to GCC xDog Walker <thudfoo@gmail.com> - 2013-10-25 14:49 -0700
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