Richard Biener <richard.guent...@gmail.com> writes:
> On Tue, Jun 2, 2020 at 4:10 AM Jiufu Guo <guoji...@linux.ibm.com> wrote:
>>
>> Jiufu Guo <guoji...@linux.ibm.com> writes:
>>
>> Hi,
>>
>> I updated the patch just a little accordinlgy. Thanks!
>>
>> diff --git a/gcc/common.opt b/gcc/common.opt
>> index 4464049fc1f..570e2aa53c8 100644
>> --- a/gcc/common.opt
>> +++ b/gcc/common.opt
>> @@ -2856,6 +2856,10 @@ funroll-all-loops
>> Common Report Var(flag_unroll_all_loops) Optimization
>> Perform loop unrolling for all loops.
>>
>> +funroll-completely-grow-size
>> +Common Undocumented Var(flag_cunroll_grow_size) Init(2) Optimization
>> +; Internal undocumented flag, allow size growth during complete unrolling
>> +
>> ; Nonzero means that loop optimizer may assume that the induction variables
>> ; that control loops do not overflow and that the loops with nontrivial
>> ; exit condition are not infinite
>> diff --git a/gcc/toplev.c b/gcc/toplev.c
>> index 96316fbd23b..8d52358efdd 100644
>> --- a/gcc/toplev.c
>> +++ b/gcc/toplev.c
>> @@ -1474,6 +1474,10 @@ process_options (void)
>> if (flag_unroll_all_loops)
>> flag_unroll_loops = 1;
>>
>> + /* Allow cunroll to grow size accordingly. */
>> + if (flag_cunroll_grow_size == AUTODETECT_VALUE)
>> + flag_cunroll_grow_size = flag_unroll_loops || flag_peel_loops;
>> +
>
> (*)
>
>> /* web and rename-registers help when run after loop unrolling. */
>> if (flag_web == AUTODETECT_VALUE)
>> flag_web = flag_unroll_loops;
>> diff --git a/gcc/tree-ssa-loop-ivcanon.c b/gcc/tree-ssa-loop-ivcanon.c
>> index 8ab6ab3330c..298ab215530 100644
>> --- a/gcc/tree-ssa-loop-ivcanon.c
>> +++ b/gcc/tree-ssa-loop-ivcanon.c
>> @@ -1603,9 +1603,8 @@ pass_complete_unroll::execute (function *fun)
>> re-peeling the same loop multiple times. */
>> if (flag_peel_loops)
>> peeled_loops = BITMAP_ALLOC (NULL);
>> - unsigned int val = tree_unroll_loops_completely (flag_unroll_loops
>> - || flag_peel_loops
>> - || optimize >= 3, true);
>> + unsigned int val = tree_unroll_loops_completely (flag_cunroll_grow_size,
>
> With -O3 -fno-peel-loops this does not have the same effect anymore.
> So above (*) you'd need to check || optimize >= 3 as well.
Oh, yes. Thanks for your kindly review!
BR,
Jiufu
>
>> + true);
>> if (peeled_loops)
>> {
>> BITMAP_FREE (peeled_loops);
>>
>> BR,
>> Jiufu
>>
>> > Richard Biener <richard.guent...@gmail.com> writes:
>> >
>>
>> >>> >> From: Jiufu Guo <guoji...@linux.ibm.com>
>> >>> >>
>> >>> >> Currently GIMPLE complete unroller(cunroll) is checking
>> >>> >> flag_unroll_loops and flag_peel_loops to see if allow size growth.
>> >>> >> Beside affects curnoll, flag_unroll_loops also controls RTL unroler.
>> >>> >> To have more freedom to control cunroll and RTL unroller, this patch
>> >>> >> introduces flag_cunroll_grow_size. With this patch, we can control
>> >>> >> cunroll and RTL unroller indepently.
>> >>> >>
>> >>> >> Bootstrap/regtest pass on powerpc64le. OK for trunk? And backport to
>> >>> >> GCC10 after week?
>> >>> >>
>> >>> >>
>> >>> >> +funroll-completely-grow-size
>> >>> >> +Var(flag_cunroll_grow_size) Init(2)
>> >>> >> +; Control cunroll to allow size growth during complete unrolling
>> >>> >> +
>> >>> >
>> >>
>> >> It won't work without adjusting the awk scripts. So go with
>> >>
>> >> funroll-completely-grow-size
>> >> Undocumented Optimization Var(flag_cunroll_grow_size)
>> >> EnabledBy(funroll-loops || fpeel-loops)
>> >> ; ...
>> >>
>> > EnabledBy(funroll-loops || fpeel-loops) does not works as we expected:
>> > "-funroll-loops -fno-peel-loops" turns off flag_cunroll_grow_size.
>> >
>> > Through "EnabledBy", a flag can be turned, and also can be turned off by
>> > the "EnabledBy option", only if the flag is not specifed through commond
>> > line.
>> >
>> >> and enable it at O3+. AUTODETECT_VALUE doesn't make sense for
>> >> an option not supposed to be set by users?
>> >>
>> >
>> > global_options_set.x_flagxxx can be used to check if option is set by
>> > user. But it does not work well here neither, because we also care of
>> > if the flag is override by OPTION_OPTIMIZATION_TABLE or
>> > OPTION_OVERRIDE.
>> >
>> > AUTODETECT_VALUE(value is 2) is used for some flags like flag_web,
>> > flag_rename_registers, flag_var_tracking, flag_tree_cselim...
>> > And this way could be used to check if the flag is effective(on/off)
>> > either explicit set by command line or implicit set through
>> > OPTION_OVERRIDE or OPTION_OPTIMIZATION_TABLE.
>> > So, I use it here.
>>
>>
