[Bug tree-optimization/51275] New: CLOBBERS can be optimized if they are right before the return (or RESX)

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51275

             Bug #: 51275
           Summary: CLOBBERS can be optimized if they are right before the
                    return (or RESX)
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: pins...@gcc.gnu.org


Created attachment 25890
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25890
Patch which optimizes the clobbers

As mentioned in Bug #51264 comment #10, clobbers can be optimized but only
after inlining.  I attached a patch which does the optimization in
fold_all_builtins.  With this patch, most of the reason for adding
-fno-exceptions to compiling GCC is gone (though inlining is still different).