--- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-27
15:21 ---
INT_MAX/-1 is undefined.
and signed overflow is undefined.
Why file this bug when the comments on the list say this is not a bug?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22200
--- Additional Comments From veksler at il dot ibm dot com 2005-06-27
15:33 ---
This is a bug because std::numeric_limitssigned::is_modulo
should be true only if singed overflow is defined.
This is not the case with gcc, because gcc does not have the
extension signed oveflow == module
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-27
15:40 ---
I think we need to read:
ISO/IEC 10967-1 Language Independent Arithmetic, part 1 since that is what
the standard references
for is_modulo.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22200
--- Additional Comments From gdr at integrable-solutions dot net
2005-06-27 16:06 ---
Subject: Re: numeric_limitssigned::is_modulo is inconsistend with gcc
pinskia at gcc dot gnu dot org [EMAIL PROTECTED] writes:
| INT_MAX/-1 is undefined.
| and signed overflow is undefined.
|
| Why
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-27
16:07 ---
Actually it is modulo for all operations.
and INT_MAX/-1 does not raise a trap.
--
What|Removed |Added
--- Additional Comments From gdr at integrable-solutions dot net
2005-06-27 16:09 ---
Subject: Re: numeric_limitssigned::is_modulo is inconsistend with gcc
pinskia at gcc dot gnu dot org [EMAIL PROTECTED] writes:
| I think we need to read:
| ISO/IEC 10967-1 Language Independent
--- Additional Comments From gdr at gcc dot gnu dot org 2005-06-27 16:21
---
(In reply to comment #1)
INT_MAX/-1 is undefined.
and signed overflow is undefined.
Why file this bug when the comments on the list say this is not a bug?
(In reply to comment #5)
Actually it is modulo
pinskia at gcc dot gnu dot org [EMAIL PROTECTED] writes:
| Actually it is modulo for all operations.
But then do read the comment as far as the loop optimizer is
concerned. It does not seem like it understands that it is modulo
arithmetic.
| and INT_MAX/-1 does not raise a trap.
It that is
--- Additional Comments From gdr at integrable-solutions dot net
2005-06-27 16:25 ---
Subject: Re: numeric_limitssigned::is_modulo is inconsistend with gcc
pinskia at gcc dot gnu dot org [EMAIL PROTECTED] writes:
| Actually it is modulo for all operations.
But then do read the
--- Additional Comments From themis_hv at yahoo dot co dot uk 2005-06-27
16:32 ---
(In reply to comment #1)
Why file this bug when the comments on the list say this is not a bug?
It's for the potentially long debate.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22200
--- Additional Comments From veksler at il dot ibm dot com 2005-06-27
16:35 ---
In Comment #5 Andrew Pinski writes:
Actually it is modulo for all operations.
and INT_MAX/-1 does not raise a trap.
That was a typo on my part.
It was supposed to be INT_MIN/-1
INT_MAX/-1 does not
On Jun 27, 2005, at 12:25 PM, gdr at integrable-solutions dot net wrote:
| Actually it is modulo for all operations.
But then do read the comment as far as the loop optimizer is
concerned. It does not seem like it understands that it is modulo
arithmetic.
But that is because overflow is
--- Additional Comments From pinskia at physics dot uc dot edu 2005-06-27
16:53 ---
Subject: Re: numeric_limitssigned::is_modulo is inconsistend with gcc
On Jun 27, 2005, at 12:25 PM, gdr at integrable-solutions dot net wrote:
| Actually it is modulo for all operations.
But then
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-27
17:29 ---
(In reply to comment #7)
Andrew --
You do not seem to understand this PR. Please DO NOT close it.
Your eagerness to close PRs is doing harms -- that was already debated
last couple o weeks and I do
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-27
17:34 ---
Invalid as the C++ standard says:
True if the type is modulo.203) A type is modulo if it is possible to add two
positive numbers and
have a result that wraps around to a third number that is less.
--- Additional Comments From schlie at comcast dot net 2005-06-27 18:00
---
(In reply to comment #13)
Invalid as the C++ standard says:
True if the type is modulo.203) A type is modulo if it is possible to add
two positive numbers and
have a result that wraps around to a third
--- Additional Comments From gdr at integrable-solutions dot net
2005-06-27 18:19 ---
Subject: Re: numeric_limitssigned::is_modulo is inconsistend with gcc
pinskia at physics dot uc dot edu [EMAIL PROTECTED] writes:
| Subject: Re: numeric_limitssigned::is_modulo is inconsistend with
--- Additional Comments From gdr at integrable-solutions dot net
2005-06-27 18:23 ---
Subject: Re: numeric_limitssigned::is_modulo is inconsistend with gcc
pinskia at gcc dot gnu dot org [EMAIL PROTECTED] writes:
| --- Additional Comments From pinskia at gcc dot gnu dot org
--- Additional Comments From gdr at gcc dot gnu dot org 2005-06-27 18:25
---
Andrew is being silly.
--
What|Removed |Added
Status|RESOLVED
--- Additional Comments From gdr at integrable-solutions dot net
2005-06-27 18:27 ---
Subject: Re: numeric_limitssigned::is_modulo is inconsistend with gcc
pinskia at gcc dot gnu dot org [EMAIL PROTECTED] writes:
| --- Additional Comments From pinskia at gcc dot gnu dot org
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-27
18:34 ---
(In reply to comment #16)
Thanks, I'm the author of limits. For all useful purposes, please
Andrew go back and read the link I gave to RTH's message.
Yes and RTH's comment about trapping is wrong,
--- Additional Comments From gdr at integrable-solutions dot net
2005-06-27 18:46 ---
Subject: Re: numeric_limitssigned::is_modulo is inconsistend with gcc
pinskia at gcc dot gnu dot org [EMAIL PROTECTED] writes:
| --- Additional Comments From pinskia at gcc dot gnu dot org
--- Additional Comments From veksler at il dot ibm dot com 2005-06-27
20:28 ---
(In reply to comment #13)
Invalid as the C++ standard says:
True if the type is modulo.203) A type is modulo if it is possible to add
two positive numbers and
have a result that wraps around to a third
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-27
21:02 ---
(In reply to comment #21)
1. Sometimes using undefined simplifies the compiler and improves
generated code.
2. (OTOH) Undefind situations are unhelpful the the users, they complicate
debugging,
--- Additional Comments From veksler at il dot ibm dot com 2005-06-27
22:00 ---
(In reply to comment #22)
(In reply to comment #21)
2. (OTOH) Undefind situations are unhelpful the the users, they complicate
debugging, and make programming harder. Reducing rules that imply
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