Re: [PATCH] lower-bitint: Force some arrays corresponding to large/huge _BitInt SSA_NAMEs to BLKmode

[Richard Biener <rguenther@suse.de>]

On Thu, 18 Jan 2024, Jakub Jelinek wrote:

> On Thu, Jan 18, 2024 at 02:13:55PM +0100, Jakub Jelinek wrote:
> > The == BITINT_TYPE check is non-essential, was just trying to keep existing
> > behavior otherwise.  I can certainly drop that.
> 
> So following then?

OK.

Thanks,
Richard.

> 2024-01-18  Jakub Jelinek  <jakub@redhat.com>
> 	    Richard Biener  <rguenther@suse.de>
> 
> 	* cfgexpand.cc (discover_nonconstant_array_refs_r): Force non-BLKmode
> 	VAR_DECLs referenced in BLKmode VIEW_CONVERT_EXPRs into memory.
> 	* expr.cc (expand_expr_real_1) <case VIEW_CONVERT_EXPR>: Do nothing
> 	but adjust_address also for BLKmode mode and MEM op0.
> 
> --- gcc/cfgexpand.cc.jj	2024-01-16 11:45:16.159326506 +0100
> +++ gcc/cfgexpand.cc	2024-01-18 14:15:54.853008586 +0100
> @@ -6380,11 +6380,15 @@ discover_nonconstant_array_refs_r (tree
>    /* References of size POLY_INT_CST to a fixed-size object must go
>       through memory.  It's more efficient to force that here than
>       to create temporary slots on the fly.
> -     RTL expansion expectes TARGET_MEM_REF to always address actual memory.  */
> +     RTL expansion expectes TARGET_MEM_REF to always address actual memory.
> +     Also, force to stack non-BLKmode vars accessed through VIEW_CONVERT_EXPR
> +     to BLKmode type.  */
>    else if (TREE_CODE (t) == TARGET_MEM_REF
>  	   || (TREE_CODE (t) == MEM_REF
>  	       && TYPE_SIZE (TREE_TYPE (t))
> -	       && POLY_INT_CST_P (TYPE_SIZE (TREE_TYPE (t)))))
> +	       && POLY_INT_CST_P (TYPE_SIZE (TREE_TYPE (t))))
> +	   || (TREE_CODE (t) == VIEW_CONVERT_EXPR
> +	       && TYPE_MODE (TREE_TYPE (t)) == BLKmode))
>      {
>        tree base = get_base_address (t);
>        if (base
> --- gcc/expr.cc.jj	2024-01-12 10:07:58.194851657 +0100
> +++ gcc/expr.cc	2024-01-18 14:15:31.970328685 +0100
> @@ -12389,6 +12389,10 @@ expand_expr_real_1 (tree exp, rtx target
>        /* If the input and output modes are both the same, we are done.  */
>        if (mode == GET_MODE (op0))
>  	;
> +      /* Similarly if the output mode is BLKmode and input is a MEM,
> +	 adjust_address done below is all we need.  */
> +      else if (mode == BLKmode && MEM_P (op0))
> +	;
>        /* If neither mode is BLKmode, and both modes are the same size
>  	 then we can use gen_lowpart.  */
>        else if (mode != BLKmode
> 
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
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