[Bug c/61902] New: signed integer overflow in real.c in real_from_integer

[zeccav at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61902

            Bug ID: 61902
           Summary: signed integer overflow in real.c in real_from_integer
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zeccav at gmail dot com

Running sanitized cc1 on testsuite files fp-int-convert-float80-timode.c
and fp-int-convert-timode.c and fp-int-convert-float128-timode.c 
I get the following
"../../gcc-4.9.1/gcc/real.c:2136:15: runtime error: 
signed integer overflow: 9223372036854775807 + 1 cannot be represented in type
'long int'

The instruction at real.c:2136 is
"high += 1;"
It seems high==LONG_MIN on x86-64.