[Bug rtl-optimization/82488] New: UBSAN in gcc/expr.c:4098:17: runtime error: signed integer overflow: 0 - -9223372036854775808 cannot be represented in type 'long int'

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82488

            Bug ID: 82488
           Summary: UBSAN in gcc/expr.c:4098:17: runtime error: signed
                    integer overflow: 0 - -9223372036854775808 cannot be
                    represented in type 'long int'
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---

Following overflows:

$ ./xgcc -B.
/home/marxin/Programming/gcc/gcc/testsuite/gcc.c-torture/compile/pr17397.c -c 
../../gcc/expr.c:4098:17: runtime error: signed integer overflow: 0 -
-9223372036854775808 cannot be represented in type 'long int'

(and many other where we have an array allocated with alloca (VLA).