[Bug tree-optimization/114301] New: gimple_can_duplicate_bb_p check for returns twice can be moved to the check of the last statement

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114301

            Bug ID: 114301
           Summary: gimple_can_duplicate_bb_p check for returns twice can
                    be moved to the check of the last statement
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog, internal-improvement
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: pinskia at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

It is the case that the returns twice function will always be the last
statement of the BB so the check for that can be moved up to the check of the
last statement part. This is a small optimization as gimple_call_flags (which
calls flags_from_decl_or_type) can call special_function_p and
special_function_p does string comparisons in the end. So removing as many
calls to gimple_call_flags  can speed up GCC slightly.