[PATCH] Cleanup TODO handling for CFG clenaup & SSA update

[Richard Biener]

On March 8, 2019 3:52:36 PM GMT+01:00, Jeff Law <law@redhat.com> wrote:
>On 3/8/19 7:23 AM, Richard Biener wrote:
>> 
>> There's an old comment
>> 
>>       /* When cleanup_tree_cfg merges consecutive blocks, it may
>>          perform some simplistic propagation when removing single
>>          valued PHI nodes.  This propagation may, in turn, cause the
>>          SSA form to become out-of-date (see PR 22037).  So, even
>>          if the parent pass had not scheduled an SSA update, we may
>>          still need to do one.  */
>>       if (!(flags & TODO_update_ssa_any) && need_ssa_update_p (cfun))
>>         flags |= TODO_update_ssa;
>> 
>> which is from times we've had multiple virtual operands.  After
>> those went away we could still run into this for example when
>> propagating a non-const function address into an indirect call
>> through a const function type.  This has been fixed as well
>> (we retain the const-ness of the call).  Thus the above is
>> no longer necessary and we can simplify the code.
>> 
>> Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
>> 
>> I'm not really nervous about this change but if you think it
>> should wait for GCC 10 speak up.
>> 
>> Richard.
>> 
>> 2019-03-08  Richard Biener  <rguenther@suse.de>
>> 
>> 	* passes.c (execute_function_todo): Remove dead code.
>What's driving the desire to change this for gcc-9?  I think it's a
>fine
>cleanup for gcc-10, but it's not clear to me we want to push it into
>gcc-9.

Just that I came along this with the previous related CFG cleanup fix and got the time to test it. 

Queued for GCC 10 instead. 

Richard. 

>jeff