[patch] Set TREE_THIS_NOTRAP throughout tree-nested.c

[Martin Liška]

On 7/24/19 11:14 AM, Eric Botcazou wrote:
> Hi,
> 
> stack memory is considered non-trapping by the compiler once the frame has 
> been established so TREE_THIS_NOTRAP can be set on the dereferences built 
> during the unnesting pass.
> 
> Tested on x86_64-suse-linux, OK for the mainline?
> 
> 
> 2019-07-24  Eric Botcazou  <ebotcazou@adacore.com>
> 
> 	* tree-nested.c (build_simple_mem_ref_notrap): New function.
> 	(get_static_chain): Call it instead of (build_simple_mem_ref.
> 	(get_frame_field): Likewise.
> 	(get_nonlocal_debug_decl): Likewise.
> 	(convert_nonlocal_reference_op): Likewise.
> 

Note that the revision caused size increase of 548.exchange2_r SPEC 2017 benchmark:
https://lnt.opensuse.org/db_default/v4/SPEC/graph?plot.0=35.398.4

Martin