Re: [PATCH] treat argp-based mem as frame related in dse

[Hans-Peter Nilsson]

> From: Jiufu Guo <guoji...@linux.ibm.com>
> Date: Wed,  6 Dec 2023 17:27:58 +0800

> Hi,
> 
> The issue mentioned in PR112525 would be able to be handled by                
>              
> updating dse.cc to treat arg_pointer_rtx similarly with frame_pointer_rtx.    
>                          
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=30271#c10 also mentioned         
>                      
> this idea.                                                           
>                                                                 
> One thing, arpg area may be used to pass argument to callee. So, it would     
>                        
> be needed to check if call insns are using that mem.
> 
> Bootstrap &regtest pass on ppc64{,le} and x86_64.
> Is this ok for trunk?
> 
> BR,
> Jeff (Jiufu Guo)
> 
> 
>       PR rtl-optimization/112525
> 
> gcc/ChangeLog:
> 
>       * dse.cc (get_group_info): Add arg_pointer_rtx as frame_related.
>       (check_mem_read_rtx): Add parameter to indicate if it is checking mem
>       for call insn.
>       (scan_insn): Add mem checking on call usage.

This, when committed as r14-6674-g4759383245ac97, caused all
or most test that "throw" to fail for cris-elf at execution
time, but I don't see other targets failing (cf. gcc-testresults
archives).  I opened PR113109 and will dig a little deeper.

brgds, H-P