Vector API Get Implementation patch

Thu Jun 21 00:37:57 UTC 2018

> I left those out initially because extract1D/1L is going to be scalar, I can include them.
> I think extract1D may look something like this:

Double64Vector/Long64Vector are still there and even though they are 
1-element vectors, the operations have to be intrinsified to get 
reliable vectorbox elimination.

Yeah, a plain move should be enough. Shouldn't it be also guarded by 
"$dst$$reg != $src$$reg"?

Another observation: shouldn't 64-bit vector operands be represented by 
VecD and not VecX?

The same applies to:

+instruct extract2i(rRegI dst, vecX src, immI idx) %{

+instruct extract4s(rRegI dst, vecX src, immI idx) %{

+instruct extract8b(rRegI dst, vecX src, immI idx) %{

Best regards,
Vladimir Ivanov

> 
> instruct extract1d(regD dst, vecX src, immI idx) %{
>    predicate(UseAVX > 0 && n->as_Vector()->length() == 1 && n->bottom_type()->basic_type() == T_DOUBLE);
>    match(Set dst (ExtractD src idx));
>    ins_encode %{
>      int vector_len = 0;
>      int midx = 0x1 & $idx$$constant;
>      __ vmovdqu($dst$$XMMRegister, $src$$XMMRegister);
>    %}
>    ins_pipe( pipe_slow );
> %}
> 
> -----Original Message-----
> From: Vladimir Ivanov [mailto:vladimir.x.ivanov at oracle.com]
> Sent: Wednesday, June 20, 2018 3:38 PM
> To: Kandu, Rahul <rahul.kandu at intel.com>; panama-dev at openjdk.java.net
> Subject: Re: Vector API Get Implementation patch
> 
> 
>> I'll add the extract2f. Thanks for the suggestion. Let me send another webrev shortly with the extract2f.
> 
> What about extract1d & extract1l? Is there any reason why they aren't needed?
> 
>> I'm not quite sure why missing intrinsic(s) are not caught by tests- even so earlier when ExtractI rules were missing. I can find out.
> 
> Yes, please.
> 
> Best regards,
> Vladimir Ivanov
> 
>> -----Original Message-----
>> From: Vladimir Ivanov [mailto:vladimir.x.ivanov at oracle.com]
>> Sent: Wednesday, June 20, 2018 2:54 PM
>> To: Kandu, Rahul <rahul.kandu at intel.com>; panama-dev at openjdk.java.net
>> Subject: Re: Vector API Get Implementation patch
>>
>> Rahul,
>>
>>> Please find the updated patch for the Get Implementation
>>> http://cr.openjdk.java.net/~vdeshpande/webrevGetImplF620/webrev/
>>>
>>> in this patch, I made the following modifications.
>>>     
>>> 1. fixed AVX-512 rules with predicate "UseAVX >2"
>>> 2. added ExtractI rules
>>> 3. fixed tabulation issues in the instructs in the x86.ad file.
>>> 4. Includes all test types- all tests passed, including Int128/256/512 etc.
>>> 5. removed extract4b rule
>>
>> Thanks. I noticed that some 64-bit variants are missing as well while JDK implementation still calls the intrinsic [1]:
>>
>>      extract1d, extract2f, extract1l
>>
>> Do you have an idea why the tests don't catch that? I believe intinsics don't kick in, but I don't see why (just by staring at the code).
>>
>> Otherwise, looks good.
>>
>>> This patch covers for AVX rules.
>>>
>>> If its fine, I can add the Non-AVX rules (UseAVX==0 && UseSSE>3) in a patch for all the types and submit it separately.
>>
>> Sounds good.
>>
>> Best regards,
>> Vladimir Ivanov
>>
>> [1]
>> src/jdk.incubator.vector/share/classes/jdk/incubator/vector/Double64Vector.java:
>>
>>        public double get(int i) {
>>            if (i < 0 || i >= LENGTH) {
>>                throw new IllegalArgumentException("Index " + i + " must be zero or positive, and less than " + LENGTH);
>>            }
>>            long bits = (long) VectorIntrinsics.extract(
>>                                    Double64Vector.class, double.class, LENGTH,
>>                                    this, i,
>>                                    (vec, ix) -> {
>>                                        double[] vecarr = vec.getElements();
>>                                        return (long)Double.doubleToLongBits(vecarr[ix]);
>>                                    });
>>            return Double.longBitsToDouble(bits);
>>        }
>>
>>
>>
>>> -----Original Message-----
>>> From: panama-dev [mailto:panama-dev-bounces at openjdk.java.net] On
>>> Behalf Of Kandu, Rahul
>>> Sent: Monday, June 18, 2018 8:58 AM
>>> To: Vladimir Ivanov <vladimir.x.ivanov at oracle.com>;
>>> panama-dev at openjdk.java.net
>>> Subject: RE: Vector API Get Implementation patch
>>>
>>> Vladimir,
>>>
>>> Thanks for your input. I'll upload the updated patch shortly.
>>>
>>> Rahul
>>>
>>> -----Original Message-----
>>> From: Vladimir Ivanov [mailto:vladimir.x.ivanov at oracle.com]
>>> Sent: Thursday, June 14, 2018 9:44 AM
>>> To: Kandu, Rahul <rahul.kandu at intel.com>; panama-dev at openjdk.java.net
>>> Subject: Re: Vector API Get Implementation patch
>>>
>>> Rahul,
>>>
>>> Some comments/questions/ suggestions:
>>>
>>>       (1) I don't see any non-AVX rules. Do you plan to add them later?
>>>
>>>
>>>       (2) No matcher rules for ExtractI as well. Same question: left for later?
>>>
>>>
>>>       (3) AVX-512 rules should be guarded by "UseAVX > 2" predicate:
>>>
>>> +instruct extract32s(rRegI dst, vecZ src, vecZ tmp, immI idx) %{
>>> +  predicate(UseAVX > 0 && n->as_Vector()->length() == 32 &&
>>> n->bottom_type()->basic_type() == T_SHORT);
>>>
>>>
>>>       (4) Is extract4b ever used? I don't see any 32-bit vectors present.
>>>
>>> +instruct extract4b(rRegI dst, vecX src, immI idx) %{
>>> +  predicate(UseAVX > 0 && n->as_Vector()->length() == 4 &&
>>> n->bottom_type()->basic_type() == T_BYTE);
>>>
>>>
>>>        (5) I suggest to migrate to immU? (recently introduced) and get
>>> rid of index masking (see [1] for examples):
>>>        +    int midx = 0x3F & $idx$$constant;
>>>
>>> Applying similar refactorings to rvinsert64B, the following:
>>>
>>> +instruct extract64b(rRegI dst, vecZ src, vecZ tmp, immI idx) %{
>>> ...
>>> +    int midx = 0x3F & $idx$$constant;
>>> +    if (midx == 0) {
>>> +      __ movdl($dst$$Register, $src$$XMMRegister);
>>> +          __ movsbl($dst$$Register, $dst$$Register);
>>> +    }
>>> +    else if (midx >= 1 && midx <= 15) {
>>> +      __ pextrb($dst$$Register, $src$$XMMRegister, midx);
>>> +          __ movsbl($dst$$Register, $dst$$Register);
>>> +    }
>>> +    else {
>>> +      int extr_idx1 = midx / 16;
>>> +      int extr_idx2 = midx % 16;
>>> +      __ vextracti32x4($tmp$$XMMRegister, $src$$XMMRegister, extr_idx1);
>>> +      __ pextrb($dst$$Register, $tmp$$XMMRegister, extr_idx2);
>>> +          __ movsbl($dst$$Register, $dst$$Register);
>>> +    }
>>>
>>> can be converted to into:
>>>
>>> +instruct extract64b(rRegI dst, vecZ src, vecZ tmp, immU6 idx) %{
>>> ...
>>> +    uint x_idx = $idx$$constant & right_n_bits(4);
>>> +    uint z_idx = ($idx$$constant >> 4) & 2;
>>> +    if (z_idx == 0) {
>>> +      if (x_idx == 0) {
>>> +        __ movdl($dst$$Register, $src$$XMMRegister);
>>> +      } else {
>>> +        __ pextrb($dst$$Register, $src$$XMMRegister, x_idx);
>>> +      }
>>> +    } else { // z_idx > 0
>>> +      __ vextracti32x4($tmp$$XMMRegister, $src$$XMMRegister, z_idx);
>>> +      __ pextrb($dst$$Register, $tmp$$XMMRegister, x_idx);
>>> +    }
>>> +    __ movsbl($dst$$Register, $dst$$Register);
>>>
>>> or even:
>>>
>>> +    uint x_idx = $idx$$constant & right_n_bits(4);
>>> +    uint z_idx = ($idx$$constant >> 4) & 2;
>>> +    Register r_i32 = $src$$XMMRegister;
>>> +    if (z_idx > 0) {
>>> +      r_i32 = $tmp$$XMMRegister;
>>> +      __ vextracti32x4(r_i32, $src$$XMMRegister, z_idx);
>>> +    }
>>> +    if (x_idx == 0) {
>>> +      __ movdl($dst$$Register, r_i32);
>>> +    } else {
>>> +      __ pextrb($dst$$Register, r_i32, x_idx);
>>> +    }
>>> +    __ movsbl($dst$$Register, $dst$$Register);
>>>
>>>
>>> Also, please, fix code formatting. Many lines have wrong indentation.
>>>
>>> Best regards,
>>> Vladimir Ivanov
>>>
>>> [1] http://hg.openjdk.java.net/panama/dev/rev/e00750ed585a
>>>
>>> On 14/06/2018 03:10, Kandu, Rahul wrote:
>>>> Hi All,
>>>>
>>>> Please find the Get Implementation patch for the Vector API. The following patch also includes Tests for Get operations.
>>>>
>>>> http://cr.openjdk.java.net/~rlupusoru/panama/webrevrGetImplF/
>>>>
>>>> regards,
>>>> Rahul
>>>>