Vector API Get Implementation patch

[Vladimir Ivanov]

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
>>