Hi:
use gcc4.1.2 on x86_64/linux, for example:
main()
{
long long int a;
double b;
a=4607182418800017408;
b=*(double *)&a;
printf("%f\n",b);
}
if using -O0/-O1 optimization, the result is 1.000000;
but if using -O2/-O3 optimization,the result is 0.000000.
i have try to close -fno-strict-aliasing in -O2/-O3, the result will be same as
-O0/-O1.
so i think the strict-aliasing may have some bug!!!
--
Summary: strict-aliasing error
Product: gcc
Version: 4.1.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: baisjing at yahoo dot com dot cn
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38588
