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Re: [Patch emit-rtl.h] Update comment about is_leaf


On 15/06/17 09:16, Ramana Radhakrishnan wrote:
> crtl->is_leaf has a comment above it referring to "Local Register
> Allocation". However this is set by IRA and not LRA since the meaning of
> Local Register Allocator in GCC has changed quite drastically since 1999
> when this comment was introduced above the variable
> current_function_is_leaf. From memory gcc in those days had "local" and
> "global" register allocation - however all of this has changed quite a
> bit drastically since.
> 
> This patch merely updates the comment as I did some head scratching this
> morning about how this could be set before Local Register Allocator
> especially given the comment in ira.c as below.
> 
> 
>  /* Determine if the current function is a leaf before running IRA
>      since this can impact optimizations done by the prologue and
>      epilogue thus changing register elimination offsets.  */
>   crtl->is_leaf = leaf_function_p ();
> 
> 
> Ok to apply ?
> 
> 
> * emit-rtl.h (is_leaf): Update comment about local register allocator.
> 

OK.

R.

> 
> Thanks,
> Ramana
> 
> 
> update-comment.txt
> 
> 
> diff --git a/gcc/emit-rtl.h b/gcc/emit-rtl.h
> index 0a242b1..86fec77 100644
> --- a/gcc/emit-rtl.h
> +++ b/gcc/emit-rtl.h
> @@ -265,7 +265,7 @@ struct GTY(()) rtl_data {
>  
>    /* Nonzero if function being compiled doesn't contain any calls
>       (ignoring the prologue and epilogue).  This is set prior to
> -     local register allocation and is valid for the remaining
> +     register allocation in IRA and is valid for the remaining
>       compiler passes.  */
>    bool is_leaf;
>  
> 


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