[Bug c/68311] New: gcc/ipa-icf.c:3041: possible sequence point error ?

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68311

            Bug ID: 68311
           Summary: gcc/ipa-icf.c:3041: possible sequence point error ?
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

clang compiling gcc trunk dated 20151112 says

../../src/trunk/gcc/ipa-icf.c:3041:73: warning: multiple unsequenced
modifications to 'class_id' [-Wunsequenced]

Source code is

     congruence_class* newclasses[2] = { new congruence_class (class_id++), new
congruence_class (class_id++) };

I don't recall anything about ordering of operands in this scenario.

Suggest code rework.