Re: Patch to fix gcc.c-torture/compile/20010102-1.c on IA64 HP-UX

[Peter Bergner <bergner@vnet.ibm.com>]

On Tue, 2008-09-16 at 09:51 -0700, Steve Ellcey wrote:
> Index: regrename.c
> ===================================================================
> --- regrename.c	(revision 140386)
> +++ regrename.c	(working copy)
> @@ -357,11 +357,13 @@ do_replace (struct du_chain *chain, int 
>      {
>        unsigned int regno = ORIGINAL_REGNO (*chain->loc);
>        struct reg_attrs * attr = REG_ATTRS (*chain->loc);
> +      int reg_ptr = REG_POINTER (*chain->loc);
> 
>        *chain->loc = gen_raw_REG (GET_MODE (*chain->loc), reg);
>        if (regno >= FIRST_PSEUDO_REGISTER)
>  	ORIGINAL_REGNO (*chain->loc) = regno;
>        REG_ATTRS (*chain->loc) = attr;
> +      REG_POINTER (*chain->loc) = reg_ptr;
>        df_insn_rescan (chain->insn);
>        chain = chain->next_use;
>      }
> @@ -1375,6 +1377,7 @@ find_oldest_value_reg (enum reg_class cl
>  	{
>  	  ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (reg);
>  	  REG_ATTRS (new_rtx) = REG_ATTRS (reg);
> +	  REG_POINTER (new_rtx) = REG_POINTER (reg);
>  	  return new_rtx;
>  	}
>      }
> @@ -1673,6 +1676,7 @@ copyprop_hardreg_forward_1 (basic_block 
>  		    {
>  		      ORIGINAL_REGNO (new_rtx) = ORIGINAL_REGNO (src);
>  		      REG_ATTRS (new_rtx) = REG_ATTRS (src);
> +		      REG_POINTER (new_rtx) = REG_POINTER (src);
>  		      if (dump_file)
>  			fprintf (dump_file,
>  				 "insn %u: replaced reg %u with %u\n",

Would it make more sense to call gen_reg_rtx_and_attrs() and
set_reg_attrs_from_value() to get/set the REG_ATTRS and REG_POINTER
fields?  There was also a bug (PR36533), where we shouldn't set the
REG_POINTER attribute for hard registers.  I'm not sure if that's
possible here, but it doesn't seem to be checked.  Using
set_reg_attrs_from_value() would protect us from that.

Peter