Re: [PATCH v3] rs6000: Fix some issues in rs6000_can_inline_p [PR102059]

["Kewen.Lin" <linkw@linux.ibm.com>]

Hi Bill,

on 2022/2/9 上午4:29, Bill Schmidt wrote:
> Hi!
> 
> From some discussion today, I think we want to limit the scope of
> this patch to just the power8-fusion flag that's causing trouble for
> now, given stage 4.  We've talked about making power8-fusion a do-
> nothing flag, since it doesn't add much benefit now and probably
> shouldn't be a separate flag anyway.  Having it as a meaningless
> flag makes it more palatable to add an exception for it in the
> inlining path.
> 
> Others, feel free to weigh in.
> 

Many thanks for caring about this.  It's a good idea to handle this
power8-fusion specially for now.

BR,
Kewen

> Thanks,
> Bill
> 
> On 1/5/22 1:34 AM, Kewen.Lin wrote:
>> Hi,
>>
>> This patch is to fix the inconsistent behaviors for non-LTO mode
>> and LTO mode.  As Martin pointed out, currently the function
>> rs6000_can_inline_p simply makes it inlinable if callee_tree is
>> NULL, but it's unexpected, we should use the command line options
>> from target_option_default_node as default.
>>
>> It replaces rs6000_isa_flags with target_option_default_node when
>> caller_tree is NULL since it's more straightforward and doesn't
>> suffer from some bug not to keep rs6000_isa_flags as default.
>>
>> It also extends the scope of the check for the case that callee
>> has explicit set options, inlining in test case pr102059-5.c can
>> happen unexpectedly before, it's fixed accordingly.
>>
>> As Richi/Mike pointed out, some tuning flags like MASK_P8_FUSION
>> can be neglected for always inlining, this patch also takes some
>> flags when the callee is attributed by always_inline.
>>
>> v1: https://gcc.gnu.org/pipermail/gcc-patches/2021-September/578552.html
>> v2: https://gcc.gnu.org/pipermail/gcc-patches/2021-December/586112.html
>>
>> This patch is one re-post of this updated version[1] and also
>> rebased and adjusted on top of the related commit r12-6219.
>>
>> Bootstrapped and regtested on powerpc64-linux-gnu P8 and
>> powerpc64le-linux-gnu P9 and P10.
>>
>> Is it ok for trunk?
>>
>> [1] https://gcc.gnu.org/pipermail/gcc-patches/2021-December/586296.html
>>
>> BR,
>> Kewen
>> -----
>> gcc/ChangeLog:
>>
>> 	PR target/102059
>> 	* config/rs6000/rs6000.c (rs6000_can_inline_p): Adjust with
>> 	target_option_default_node and consider always_inline_safe flags.
>>
>> gcc/testsuite/ChangeLog:
>>
>> 	PR target/102059
>> 	* gcc.target/powerpc/pr102059-4.c: New test.
>> 	* gcc.target/powerpc/pr102059-5.c: New test.
>> 	* gcc.target/powerpc/pr102059-6.c: New test.
>> 	* gcc.target/powerpc/pr102059-7.c: New test.
>> 	* gcc.target/powerpc/pr102059-8.c: New test.
>> 	* gcc.dg/lto/pr102059-1_0.c: Remove unneeded option.
>>
>>