Re: [PATCH-1v2, rs6000] Enable SImode in FP registers on P7 [PR88558]

[HAO CHEN GUI <guihaoc@linux.ibm.com>]

Hi Kewen,

在 2023/9/18 15:34, Kewen.Lin 写道:
> hanks for checking!  So for P7, this patch looks neutral, but for P8 and
> later, it may cause some few differences in code gen.  I'm curious that how
> many total object files and different object files were checked and found
> on P8?  
P8 with -O2, following object files are different.
507.cactuBSSN_r datestamp.o
511.povray_r colutils.o
521.wrf_r module_cu_kfeta.fppized.o
526.blender_r particle_edit.o
526.blender_r glutil.o
526.blender_r displist.o
526.blender_r CCGSubSurf.o

P8 with -O3, following object files are different.
502.gcc_r ifcvt.o
502.gcc_r rtlanal.o
548.exchange2_r exchange2.fppized.o
507.cactuBSSN_r datestamp.o
511.povray_r colutils.o
521.wrf_r module_bc.fppized.o
521.wrf_r module_cu_kfeta.fppized.o
526.blender_r particle_edit.o
526.blender_r displist.o
526.blender_r CCGSubSurf.o
526.blender_r sketch.o




> https://gcc.gnu.org/pipermail/gcc-patches/2023-February/612821.html
> I also wonder if it's easy to reduce some of them further as small test cases.
> 
> Since xxlor is better than fmr at least on Power10, could you also evaluate
> the affected bmks on P10 (even P8/P9) to ensure no performance degradation?
There is no performance recession on P10/P9/P8. The detail data is listed on
internal issue.

Thanks
Gui Haochen