--- Comment #11 from vincent at vinc17 dot org 2010-02-19 13:08 ---
(In reply to comment #10)
This issue was discussed on the WG14 reflector in October 2008, and the
general
view was that the standard should not make INT_MIN % -1 well defined (as this
would impose a significant
--- Comment #10 from jsm28 at gcc dot gnu dot org 2009-02-21 18:45 ---
This issue was discussed on the WG14 reflector in October 2008, and the general
view was that the standard should not make INT_MIN % -1 well defined (as this
would impose a significant performance cost on many
--- Comment #7 from nightstrike at gmail dot com 2008-09-12 20:32 ---
*** Bug 37503 has been marked as a duplicate of this bug. ***
--
nightstrike at gmail dot com changed:
What|Removed |Added
--- Comment #9 from jsm28 at gcc dot gnu dot org 2008-09-12 20:41 ---
Note libgcc functions would only need to get it right for CPUs defining the
macro, if in other cases the source checks would be inserted anyway. Or the
macro could depend on the mode of the division/modulo operation.
--- Comment #8 from jsm28 at gcc dot gnu dot org 2008-09-12 20:39 ---
I suggest an option such as -fdivide-checks, off by default. -std=c99 and
other conformance options, for languages where INT_MIN % -1 is defined, would
enable this option unless -fno-divide-checks is specified by the
--- Comment #6 from veksler at il dot ibm dot com 2007-01-17 08:49 ---
(In reply to comment #0)
The program below shows (at all the optimization levels) a miscompilation of
the remainder expression that causes INT_MIN % -1 to cause a SIGFPE on CPUs of
the i386 family.
For the record
--- Comment #1 from vincent at vinc17 dot org 2007-01-16 22:03 ---
Is this specific to x86? On PowerPC (gcc 4.0.1 from Mac OS X), I get:
-2147483648 % -1 - -2147483648
Ditto with:
#include limits.h
#include stdio.h
int main (void)
{
volatile int i = INT_MIN, j = -1;
printf
--- Comment #2 from vincent at vinc17 dot org 2007-01-16 22:10 ---
-2147483648, this was on a G5, with gcc 4.0.1 under Mac OS X. On a G4 under
Linux, with gcc 4.1.2 prerelease (Debian), I get 2147483647.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30484
--- Comment #3 from pinskia at gcc dot gnu dot org 2007-01-16 22:11 ---
(In reply to comment #1)
Is this specific to x86? On PowerPC (gcc 4.0.1 from Mac OS X), I get:
This is because the PPC ISA says for divide:
If an attempt is made to perform either of the divisions -- 0x8000_ /
--- Comment #4 from pinskia at gcc dot gnu dot org 2007-01-16 22:15 ---
(In reply to comment #3)
So the ISA in fact even mentions this case :).
But the PPC compiler writers guide does not talk about that case, hmmm.
--
pinskia at gcc dot gnu dot org changed:
What
--- Comment #5 from jv244 at cam dot ac dot uk 2007-01-17 07:14 ---
(In reply to comment #0)
The program below shows (at all the optimization levels) a miscompilation of
the remainder expression that causes INT_MIN % -1 to cause a SIGFPE on CPUs of
the i386 family.
notice that this
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