I personally would never dare to write any code that could result in an
expression like:
1 << -1
Unfortunately I found some code that uses it.
Eventually I learned that the following code behaves differently on i386 and
ppc64:
#include <stdio.h>
int main(int argc, char *argv[])
{
int shifter = 0;
unsigned int target = 0;
target |= (1 << (shifter -1));
printf("%x\n", target);
}
On i386, it prints 80000000.
On ppc64, it prints 0.
Should gcc be changed to be consistent across platforms?
It might help those that platforms that are being used less frequently.
--
Summary: 1 << -1 inconsistent across platforms
Product: gcc
Version: 4.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: kengert at redhat dot com
GCC build triplet: ppc64-yellowdog-linux
GCC host triplet: ppc64-yellowdog-linux
GCC target triplet: ppc64-yellowdog-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35213
