Re: [1/2] Add get_next_strinfo helper function

[Richard Sandiford <richard dot sandiford at linaro dot org>]

Ping

Richard Sandiford <richard.sandiford@linaro.org> writes:
> This patch just adds a helper function for getting the next strinfo
> in a chain, since part 2 adds another place where we do that.
>
> Tested on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?
>
> Thanks,
> Richard
>
>
> 2017-05-16  Richard Sandiford  <richard.sandiford@linaro.org>
>
> gcc/
> 	* tree-ssa-strlen.c (get_next_strinfo): New function.
> 	(get_stridx_plus_constant): Use it.
> 	(zero_length_string): Likewise.
> 	(adjust_related_strinfos): Likewise.
> 	(adjust_last_stmt): Likewise.
>
> Index: gcc/tree-ssa-strlen.c
> ===================================================================
> --- gcc/tree-ssa-strlen.c	2017-05-15 19:57:18.899053381 +0100
> +++ gcc/tree-ssa-strlen.c	2017-05-15 20:50:21.412511763 +0100
> @@ -156,6 +156,19 @@ get_strinfo (int idx)
>    return (*stridx_to_strinfo)[idx];
>  }
>  
> +/* Get the next strinfo in the chain after SI, or null if none.  */
> +
> +static inline strinfo *
> +get_next_strinfo (strinfo *si)
> +{
> +  if (si->next == 0)
> +    return NULL;
> +  strinfo *nextsi = get_strinfo (si->next);
> +  if (nextsi == NULL || nextsi->first != si->first || nextsi->prev != si->idx)
> +    return NULL;
> +  return nextsi;
> +}
> +
>  /* Helper function for get_stridx.  */
>  
>  static int
> @@ -665,10 +678,8 @@ get_stridx_plus_constant (strinfo *bases
>    gcc_checking_assert (compare_tree_int (si->length, off) != -1);
>    for (chainsi = si; chainsi->next; chainsi = si)
>      {
> -      si = get_strinfo (chainsi->next);
> +      si = get_next_strinfo (chainsi);
>        if (si == NULL
> -	  || si->first != chainsi->first
> -	  || si->prev != chainsi->idx
>  	  || si->length == NULL_TREE
>  	  || TREE_CODE (si->length) != INTEGER_CST)
>  	break;
> @@ -736,26 +747,18 @@ zero_length_string (tree ptr, strinfo *c
>        si = verify_related_strinfos (chainsi);
>        if (si)
>  	{
> -	  chainsi = si;
> -	  for (; chainsi->next; chainsi = si)
> +	  do
>  	    {
> -	      if (chainsi->endptr == NULL_TREE)
> +	      gcc_assert (si->length || si->stmt);
> +	      if (si->endptr == NULL_TREE)
>  		{
> -		  chainsi = unshare_strinfo (chainsi);
> -		  chainsi->endptr = ptr;
> +		  si = unshare_strinfo (si);
> +		  si->endptr = ptr;
>  		}
> -	      si = get_strinfo (chainsi->next);
> -	      if (si == NULL
> -		  || si->first != chainsi->first
> -		  || si->prev != chainsi->idx)
> -		break;
> -	    }
> -	  gcc_assert (chainsi->length || chainsi->stmt);
> -	  if (chainsi->endptr == NULL_TREE)
> -	    {
> -	      chainsi = unshare_strinfo (chainsi);
> -	      chainsi->endptr = ptr;
> +	      chainsi = si;
> +	      si = get_next_strinfo (si);
>  	    }
> +	  while (si != NULL);
>  	  if (chainsi->length && integer_zerop (chainsi->length))
>  	    {
>  	      if (chainsi->next)
> @@ -833,12 +836,8 @@ adjust_related_strinfos (location_t loc,
>  	  si->endptr = NULL_TREE;
>  	  si->dont_invalidate = true;
>  	}
> -      if (si->next == 0)
> -	return;
> -      nsi = get_strinfo (si->next);
> -      if (nsi == NULL
> -	  || nsi->first != si->first
> -	  || nsi->prev != si->idx)
> +      nsi = get_next_strinfo (si);
> +      if (nsi == NULL)
>  	return;
>        si = nsi;
>      }
> @@ -995,15 +994,9 @@ adjust_last_stmt (strinfo *si, gimple *s
>  	return;
>        while (firstsi != lastsi)
>  	{
> -	  strinfo *nextsi;
> -	  if (firstsi->next == 0)
> -	    return;
> -	  nextsi = get_strinfo (firstsi->next);
> -	  if (nextsi == NULL
> -	      || nextsi->prev != firstsi->idx
> -	      || nextsi->first != si->first)
> +	  firstsi = get_next_strinfo (firstsi);
> +	  if (firstsi == NULL)
>  	    return;
> -	  firstsi = nextsi;
>  	}
>      }
>