Re: [Qemu-devel] [PATCH] target/s390x: Use tcg_gen_gvec_bitsel

[David Hildenbrand]

On 03.06.19 23:59, Richard Henderson wrote:
> On 6/3/19 2:41 PM, David Hildenbrand wrote:
>>> -static void gen_sel_vec(unsigned vece, TCGv_vec d, TCGv_vec a, TCGv_vec b,
>>> -                        TCGv_vec c)
>>> -{
>>> -    TCGv_vec t = tcg_temp_new_vec_matching(d);
>>> -
>>> -    tcg_gen_andc_vec(vece, t, b, c);
>>> -    tcg_gen_and_vec(vece, d, a, c);
>>> -    tcg_gen_or_vec(vece, d, d, t);
>>> -    tcg_temp_free_vec(t);
>>> -}
>>> -
>>
>> Comparing against tcg_gen_bitsel_i64()
>>
>> 1. a and c are switched
>> 2. b is _not_ switched (and() and andc() are switched)
> 
> Not quite.  {a,b,c} from your s390 implementation becomes {c,a,b} for tcg.
> 
> Running tests would show for sure; I guess you have those later in your vx
> patch set?

I only have a small selection of tests for now

84fa6254e4 tests/tcg: target/s390x: Test VECTOR ADD *
9e9a9e5246 tests/tcg: target/s390x: Test VECTOR UNPACK *
9d2b7184c6 tests/tcg: target/s390x: Test VECTOR PACK *
4872c1b6bd tests/tcg: target/s390x: Test VECTOR MERGE (HIGH|LOW)
914502d1d1 tests/tcg: target/s390x: Test VECTOR LOAD AND REPLICATE
7d01bbca17 tests/tcg: target/s390x: Test VECTOR GENERATE MASK
dc107ebdf7 tests/tcg: target/s390x: Test VECTOR GENERATE BYTE MASK
17212a732d tests/tcg: target/s390x: Test VECTOR LOAD GR FROM VR ELEMENT
f120e93c15 tests/tcg: target/s390x: Test VECTOR GATHER ELEMENT

But I just added a simple

6c43fe6a8c tests/tcg: target/s390x: Test VECTOR SELECT

That test confirmed that your implementation works correctly. :)

> 
>> Should I send this patch with the next s390x/tcg pull request?
> 
> Yes please.

I'll change the subject to "s390x/tcg: Use tcg_gen_gvec_bitsel for
VECTOR SELECT" if you don't object. Thanks!

> 
> 
> r~
> 


-- 

Thanks,

David / dhildenb