Re: [PATCH 13/13] rs6000, remove vector set and vector init built-ins.

[Carl Love <cel@linux.ibm.com>]

Kewen:

On 5/13/24 22:44, Kewen.Lin wrote:
>> perform the same operation as setting a specific element in the vector in
>> C code.  For example:
>>
>>   src_v4si = __builtin_vec_set_v4si (src_v4si, int_val, index);
>>   src_v4si[index] = int_val;
>>
>> The built-in actually generates more instructions than the inline C code
>> with no optimization but is identical with -O3 optimizations.
>>
>> All of the above built-ins that are removed do not have test cases and
>> are not documented.
>>
>> Built-ins   __builtin_vec_set_v1ti __builtin_vec_set_v2di,
>> __builtin_vec_set_v2df are not removed as they are used in function
>> resolve_vec_insert() in file rs6000-c.cc.
> I think we can replace these calls with the equivalent gimple codes
> (early expanding it) and then we can get rid of these instances.

Hmm, going to need a little coaching here.  I am not sure how to do this.  Looks like I get to lean some  something new.

                   Carl