GCC does not have a proper modulo overflow semantics for signed
integral types.
1. The loop optimizer seems to assume that signed overflow does
not happen (or is undefined).
2. On x86 INT_MAX/-1 seems to trap (instead of implementing
modulo semantics).
In that case numeric_limits<signed>:is_modulo should be synchronized
with gcc and be set to false instead of true.
Another option, is to change gcc to fully support the modulo
arithmetics of signed integer.
--
Summary: numeric_limits<signed>::is_modulo is inconsistend with
gcc
Product: gcc
Version: 4.0.0
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: libstdc++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: veksler at il dot ibm dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22200
