Re: [PATCH 04/18] rs6000: Handle some recent MMA builtin changes

[Bill Schmidt <wschmidt@linux.ibm.com>]

Thanks!  I'll remove the elses in the committed patch, along with a TODO 
comment for the additional factoring opportunity for when I get to that 
stage.

Thanks for all the reviews!
Bill

On 9/16/21 6:38 PM, Segher Boessenkool wrote:
> Hi!
>
> On Wed, Sep 01, 2021 at 11:13:40AM -0500, Bill Schmidt wrote:
>> Peter Bergner recently added two new builtins __builtin_vsx_lxvp and
>> __builtin_vsx_stxvp.  These happened to break a pattern in MMA builtins that
>> I had been using to automate gimple folding of MMA builtins.  Previously,
>> every MMA function that could be folded had an associated internal function
>> that it was folded into.  The LXVP/STXVP builtins are just folded directly
>> into memory operations.
>>
>> Instead of relying on this pattern, this patch adds a new attribute to
>> builtins called "mmaint," which is set for all MMA builtins that have an
>> associated internal builtin.  The naming convention that adds _INTERNAL to
>> the builtin index name remains.
>>
>> The rest of the patch is just duplicating Peter's patch, using the new
>> builtin infrastructure.
>> 	* config/rs6000/rs6000-call.c
>> 	(rs6000_gimple_fold_new_mma_builtin): Handle RS6000_BIF_LXVP and
>> 	RS6000_BIF_STXVP.
> It is fine to end a changelog line in a colon.
>
>> +  else if (fncode == RS6000_BIF_LXVP)
>> +    {
>> +      push_gimplify_context (true);
>> +      tree offset = gimple_call_arg (stmt, 0);
>> +      tree ptr = gimple_call_arg (stmt, 1);
>> +      tree lhs = gimple_call_lhs (stmt);
>> +      if (TREE_TYPE (TREE_TYPE (ptr)) != vector_pair_type_node)
>> +	ptr = build1 (VIEW_CONVERT_EXPR,
>> +		      build_pointer_type (vector_pair_type_node), ptr);
>> +      tree mem = build_simple_mem_ref (build2 (POINTER_PLUS_EXPR,
>> +					       TREE_TYPE (ptr), ptr, offset));
>> +      gimplify_assign (lhs, mem, &new_seq);
>> +      pop_gimplify_context (NULL);
>> +      gsi_replace_with_seq (gsi, new_seq, true);
>> +      return true;
>> +    }
> Fwiw, all those cases return, so those "else" are not needed.  Also it
> would be nice if this could be factored a bit better, hrm.
>
> Is that "if" in there useful?  Maybe add a helper function for it, then?
>
> Anyway: okay for trunk.  Thanks!
>
>
> Segher