[Bug tree-optimization/58926] New: -Wstrict-overflow unwanted warning comparing variables initialized from one of static duration

[gabe.jones at ni dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58926

            Bug ID: 58926
           Summary: -Wstrict-overflow unwanted warning comparing variables
                    initialized from one of static duration
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gabe.jones at ni dot com

The following code produces a warning when compiled -O2 -Wstrict-overflow with
gcc 4.8.1:

   int k = 0;

   int main(void)
   {
     int i = k++, j = k;
     return (j >= i);
   }

> gcc -Wstrict-overflow -O2 main.cc

main.cpp: In function 'int func()':
main.cpp:6:13: warning: assuming signed overflow does not occur when assuming
that (X + c) >= X is always true [-Wstrict-overflow]
   return (j >= i);
             ^
                      ^