On 17.05.19 18:16, Richard Henderson wrote:
> On 5/15/19 1:31 PM, David Hildenbrand wrote:
>> +#define DEF_VFAE(BITS)
>> \
>> +static int vfae##BITS(void *v1, const void *v2, const void *v3, uint8_t m5)
>>
>
>
> First, because this *is* complicated stuff, can we find a way to use inline
> functions instead of an undebuggable macro for this? Perhaps a different set
> of wrappers than s390_vec_read_element##BITS, which always return uint32_t, so
> that they have a constant signature?
For vfene I have for now
+static inline uint64_t s390_vec_read_element(const S390Vector *v,
uint8_t enr,
+ uint8_t es)
+{
+ switch (es) {
+ case MO_8:
+ return s390_vec_read_element8(v, enr);
+ case MO_16:
+ return s390_vec_read_element16(v, enr);
+ case MO_32:
+ return s390_vec_read_element32(v, enr);
+ case MO_64:
+ return s390_vec_read_element64(v, enr);
+ default:
+ g_assert_not_reached();
+ }
+}
+
Which we could reuse here.
I'll try to look into using a inline function instead, passing in the
element size and other flags, so the compiler can specialize.
Thanks!
>
>> + if (zs && !data) {
>> + if (cc == 3) {
>> + first_byte = i * (BITS / 8);
>> + cc = 0; /* match for zero */
>> + } else if (cc != 0) {
>> + cc = 2; /* matching elements before match for zero */
>> + }
>> + if (!rt) {
>> + break;
>> + }
>> + }
>
> So here we are computing the second intermediate result.
>
>> + /* try to match with any other element from the other vector */
>> + for (j = 0; j < (128 / BITS); j++) {
>> + if (data == s390_vec_read_element##BITS(v3, j)) {
>> + any_equal = true;
>> + break;
>> + }
>> + }
>
> And here the first intermediate result,
>
>> + /* invert the result if requested */
>> + any_equal = in ^ any_equal;
>
> ... inverted, if requested,
>
>> + if (cc == 3 && any_equal) {
>> + first_byte = i * (BITS / 8);
>> + cc = 1; /* matching elements, no match for zero */
>> + if (!zs && !rt) {
>> + break;
>> + }
>> + }
>
>> + /* indicate bit vector if requested */
>> + if (rt && any_equal) {
>> + s390_vec_write_element##BITS(&tmp, i, (uint##BITS##_t)-1ull);
>> + }
>
> ... writing out (some of) the results of the first intermediate result.
>
>> + }
>> + if (!rt) {
>> + s390_vec_write_element8(&tmp, 7, first_byte);
>> + }
>
> ... writing out the rest of the first intermediate result.
>
> I wonder if it wouldn't be clearer, within the loop, to do
>
> if (any_equal) {
> if (cc == 3) {
> first_byte = ...;
> cc = 1;
> }
> if (rt) {
> write element -1;
> } else if (!zs) {
> break;
> }
> }
>
> I also think that, if we create a bunch more of these wrappers:
>
>> +DEF_VFAE_HELPER(8)
>> +DEF_VFAE_HELPER(16)
>> +DEF_VFAE_HELPER(32)
>
> then RT and ZS can be passed in as constant parameters to the above, and then
> the compiler will fold away all of the stuff that's not needed for each
> different case. Which, I think, is significant. These are practically
> different instructions with the different modifiers.
>
>
> r~
>
--
Thanks,
David / dhildenb
