[Bug c++/58717] New: Pre-calculation optimization is omitted

[masoud_mxm at yahoo dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58717

            Bug ID: 58717
           Summary: Pre-calculation optimization is omitted
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: masoud_mxm at yahoo dot com

Created attachment 30997
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30997&action=edit
Two .cpp source code

It seems newer versions of gcc (4.8+) don't pre-calculate functions for
constant inputs (Asked the issue here:
http://stackoverflow.com/q/19350097/952747). Two source codes attached.


unsigned long long s(unsigned long long n)
{
    auto s = 0ULL;
    for (auto i = 0ULL; i < n; i++)
        s += i;
    return s;
}

const auto N = 1000000000ULL;

auto x = s(N); // It computes in run-time and dose NOT compute in compile-time!