[PATCH 1/2] make vect_finish_stmt_generation work w/o stmt_vec_info

[Richard Sandiford]

Richard Biener <rguenther@suse.de> writes:
> This makes the call chain below vec_init_vector happy with a NULL
> stmt_vec_info which is used as "context".
>
> 2020-05-27  Richard Biener  <rguenther@suse.de>
>
> 	* tree-vect-stmts.c (vect_finish_stmt_generation_1):
> 	Conditionalize stmt_info use, assert the new stmt cannot throw
> 	when not specified.
> 	(vect_finish_stmt_generation): Adjust assert.

Wasn't sure from this patch in isolation: when's it valid to pass a null
stmt_info?  Felt weird that we suddenly needed this now, when we already
have so many callers that follow the existing interface.

Or is this because you want to remove the stmt_info argument entirely
at some point, and this is a step towards that?

Thanks,
Richard

> ---
>  gcc/tree-vect-stmts.c | 21 +++++++++++++--------
>  1 file changed, 13 insertions(+), 8 deletions(-)
>
> diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
> index 35043ecd0f9..901999be058 100644
> --- a/gcc/tree-vect-stmts.c
> +++ b/gcc/tree-vect-stmts.c
> @@ -1668,14 +1668,19 @@ vect_finish_stmt_generation_1 (vec_info *vinfo,
>    if (dump_enabled_p ())
>      dump_printf_loc (MSG_NOTE, vect_location, "add new stmt: %G", vec_stmt);
>  
> -  gimple_set_location (vec_stmt, gimple_location (stmt_info->stmt));
> +  if (stmt_info)
> +    {
> +      gimple_set_location (vec_stmt, gimple_location (stmt_info->stmt));
>  
> -  /* While EH edges will generally prevent vectorization, stmt might
> -     e.g. be in a must-not-throw region.  Ensure newly created stmts
> -     that could throw are part of the same region.  */
> -  int lp_nr = lookup_stmt_eh_lp (stmt_info->stmt);
> -  if (lp_nr != 0 && stmt_could_throw_p (cfun, vec_stmt))
> -    add_stmt_to_eh_lp (vec_stmt, lp_nr);
> +      /* While EH edges will generally prevent vectorization, stmt might
> +	 e.g. be in a must-not-throw region.  Ensure newly created stmts
> +	 that could throw are part of the same region.  */
> +      int lp_nr = lookup_stmt_eh_lp (stmt_info->stmt);
> +      if (lp_nr != 0 && stmt_could_throw_p (cfun, vec_stmt))
> +	add_stmt_to_eh_lp (vec_stmt, lp_nr);
> +    }
> +  else
> +    gcc_assert (!stmt_could_throw_p (cfun, vec_stmt));
>  
>    return vec_stmt_info;
>  }
> @@ -1705,7 +1710,7 @@ vect_finish_stmt_generation (vec_info *vinfo,
>  			     stmt_vec_info stmt_info, gimple *vec_stmt,
>  			     gimple_stmt_iterator *gsi)
>  {
> -  gcc_assert (gimple_code (stmt_info->stmt) != GIMPLE_LABEL);
> +  gcc_assert (!stmt_info || gimple_code (stmt_info->stmt) != GIMPLE_LABEL);
>  
>    if (!gsi_end_p (*gsi)
>        && gimple_has_mem_ops (vec_stmt))