Re: [PATCH 2/2] fix rem_usage()

[Ramsay Jones <ramsay@ramsayjones.plus.com>]

On 27/12/2020 09:27, Luc Van Oostenryck wrote:
> rem_usage() is used to remove an element from a def-use chain. Optionally,

Hmm, rename this to 'remove_usage()' at the same time?

ATB,
Ramsay Jones

> if the chain become empty, the defining instruction can also be killed.
> 
> This optional part is currently be done on all pseudos but only those
> having a definition should be concerned.
> 
> Fix this by adding a check so that only PSEUDO_REGs and PSEUDO_PHIs are killed.
> 
> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
> ---
>  simplify.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/simplify.c b/simplify.c
> index a877b693b610..12482d787189 100644
> --- a/simplify.c
> +++ b/simplify.c
> @@ -271,7 +271,7 @@ static inline void rem_usage(pseudo_t p, pseudo_t *usep, int kill)
>  {
>  	if (has_use_list(p)) {
>  		delete_pseudo_user_list_entry(&p->users, usep, 1);
> -		if (kill && !p->users)
> +		if (kill && !p->users && has_definition(p))
>  			kill_instruction(p->def);
>  	}
>  }
>