IntVector.fromValues is not optimized away ?

Tue May 12 14:57:30 UTC 2020

Right, much of a muchness (“swings and roundabouts”), perhaps marginally worse.

Paul.

> On May 12, 2020, at 5:05 AM, Remi Forax <forax at univ-mlv.fr> wrote:
> 
> Nope,
> doesn't work, i still see the array allocation :(
> 
> Rémi
> 
> ----- Mail original -----
>> De: "Remi Forax" <forax at univ-mlv.fr>
>> À: "Paul Sandoz" <paul.sandoz at oracle.com>
>> Cc: "panama-dev at openjdk.java.net'" <panama-dev at openjdk.java.net>
>> Envoyé: Lundi 11 Mai 2020 22:00:17
>> Objet: Re: IntVector.fromValues is not optimized away ?
> 
>> Ok, will test !
>> 
>> Rémi
>> 
>>> De: "Paul Sandoz" <paul.sandoz at oracle.com>
>>> À: "Remi Forax" <forax at univ-mlv.fr>
>>> Cc: "panama-dev at openjdk.java.net'" <panama-dev at openjdk.java.net>
>>> Envoyé: Lundi 11 Mai 2020 20:02:14
>>> Objet: Re: IntVector.fromValues is not optimized away ?
>> 
>>> Hi Remi,
>> 
>>> For some reason this method does not defer to the fromArray equivalent.
>> 
>>> Can you try with the following patch?
>> 
>>> [
>>> http://cr.openjdk.java.net/~psandoz/panama/vector-from-values-using-from-array/webrev/ <http://cr.openjdk.java.net/~psandoz/panama/vector-from-values-using-from-array/webrev/>
>>> |
>>> http://cr.openjdk.java.net/~psandoz/panama/vector-from-values-using-from-array/webrev/ <http://cr.openjdk.java.net/~psandoz/panama/vector-from-values-using-from-array/webrev/>
>>> ]
>> 
>>> I shall also investigate further.
>> 
>>> Paul.
>> 
>>>> On May 9, 2020, at 11:52 AM, Remi Forax < [ mailto:forax at univ-mlv.fr <mailto:forax at univ-mlv.fr> |
>>>> forax at univ-mlv.fr ] > wrote:
>> 
>>>> Hi all,
>>>> this may be obvious but do we agree that IntVector.fromValues is not optimized
>>>> thus really create an array destroying any hope of perf ?
>> 
>>>> I'm trying to see the difference between
>> 
>>>> public int hashCode() {
>>>> return i1 ^ i2 ^ i3 ^ i4;
>>>> }
>> 
>>>> and
>> 
>>>> public int hashCode() {
>>>> var v1 = IntVector.fromValues(IntVector.SPECIES_64, i1, i3);
>>>> var v2 = IntVector.fromValues(IntVector.SPECIES_64, i2, i4);
>>>> var result = v1.lanewise(VectorOperators.XOR, v2);
>>>> return result.lane(0) ^ result.lane(1);
>>>> }
>> 
>>>> but taking a look to the generated assembly (below), the allocation of the two
>>>> arrays are still there,
>>>> too bad because the last 6 instructions are more or less what i was expecting.
>> 
>>>> 0x00007fbb383324dc: mov 0x14(%rsi),%r11d ;*getfield i3 {reexecute=0 rethrow=0
>>>> return_oop=0}
>>>> ; - fr.umlv.vector.VectorizedHashCode$Data::hashCode2 at 16 (line 14)
>>>> 0x00007fbb383324e0: mov 0xc(%rsi),%ebp
>>>> 0x00007fbb383324e3: mov 0x120(%r15),%r8
>>>> 0x00007fbb383324ea: mov %r8,%r10
>>>> 0x00007fbb383324ed: add $0x18,%r10
>>>> 0x00007fbb383324f1: cmp 0x130(%r15),%r10
>>>> 0x00007fbb383324f8: jae 0x00007fbb383325db
>>>> 0x00007fbb383324fe: mov %r10,0x120(%r15)
>>>> 0x00007fbb38332505: prefetchw 0xc0(%r10)
>>>> 0x00007fbb3833250d: movq $0x1,(%r8)
>>>> 0x00007fbb38332514: prefetchw 0x100(%r10)
>>>> 0x00007fbb3833251c: movl $0x70cb1,0x8(%r8) ; {metadata({type array int})}
>>>> 0x00007fbb38332524: prefetchw 0x140(%r10)
>>>> 0x00007fbb3833252c: movl $0x2,0xc(%r8)
>>>> 0x00007fbb38332534: prefetchw 0x180(%r10)
>>>> 0x00007fbb3833253c: mov %ebp,0x10(%r8)
>>>> 0x00007fbb38332540: mov %r11d,0x14(%r8) ;*newarray {reexecute=0 rethrow=0
>>>> return_oop=0}
>>>> ; - java.util.Arrays::copyOf at 1 (line 3584)
>>>> ; - jdk.incubator.vector.IntVector::fromValues at 19 (line 553)
>>>> ; - fr.umlv.vector.VectorizedHashCode$Data::hashCode2 at 20 (line 14)
>>>> 0x00007fbb38332544: mov 0x18(%rsi),%r9d
>>>> 0x00007fbb38332548: mov 0x120(%r15),%rax ;*invokestatic extract {reexecute=0
>>>> rethrow=0 return_oop=0}
>>>> ; - jdk.incubator.vector.Int64Vector::laneHelper at 16 (line 482)
>>>> ; - jdk.incubator.vector.Int64Vector::lane at 36 (line 476)
>>>> ; - fr.umlv.vector.VectorizedHashCode$Data::hashCode2 at 64 (line 17)
>>>> 0x00007fbb3833254f: mov 0x10(%rsi),%ebp ;*getfield i2 {reexecute=0 rethrow=0
>>>> return_oop=0}
>>>> ; - fr.umlv.vector.VectorizedHashCode$Data::hashCode2 at 33 (line 15)
>>>> 0x00007fbb38332552: mov %rax,%r10
>>>> 0x00007fbb38332555: add $0x18,%r10
>>>> 0x00007fbb38332559: nopl 0x0(%rax)
>>>> 0x00007fbb38332560: cmp 0x130(%r15),%r10
>>>> 0x00007fbb38332567: jae 0x00007fbb3833260d
>>>> 0x00007fbb3833256d: mov %r10,0x120(%r15)
>>>> 0x00007fbb38332574: prefetchw 0xc0(%r10)
>>>> 0x00007fbb3833257c: movq $0x1,(%rax)
>>>> 0x00007fbb38332583: prefetchw 0x100(%r10)
>>>> 0x00007fbb3833258b: movl $0x70cb1,0x8(%rax) ; {metadata({type array int})}
>>>> 0x00007fbb38332592: prefetchw 0x140(%r10)
>>>> 0x00007fbb3833259a: movl $0x2,0xc(%rax)
>>>> 0x00007fbb383325a1: prefetchw 0x180(%r10)
>>>> 0x00007fbb383325a9: mov %ebp,0x10(%rax)
>>>> 0x00007fbb383325ac: mov %r9d,0x14(%rax) ;*newarray {reexecute=0 rethrow=0
>>>> return_oop=0}
>>>> ; - java.util.Arrays::copyOf at 1 (line 3584)
>>>> ; - jdk.incubator.vector.IntVector::fromValues at 19 (line 553)
>>>> ; - fr.umlv.vector.VectorizedHashCode$Data::hashCode2 at 44 (line 15)
>>>> 0x00007fbb383325b0: vmovq 0x10(%rax),%xmm0 ;*invokestatic extract {reexecute=0
>>>> rethrow=0 return_oop=0}
>>>> ; - jdk.incubator.vector.Int64Vector::laneHelper at 16 (line 482)
>>>> ; - jdk.incubator.vector.Int64Vector::lane at 36 (line 476)
>>>> ; - fr.umlv.vector.VectorizedHashCode$Data::hashCode2 at 64 (line 17)
>>>> 0x00007fbb383325b5: vpxor 0x10(%r8),%xmm0,%xmm0 ;*invokespecial <init>
>>>> {reexecute=0 rethrow=0 return_oop=0}
>>>> ; - jdk.internal.vm.vector.VectorSupport$Vector::<init>@2 (line 104)
>>>> ; - jdk.incubator.vector.Vector::<init>@2 (line 1122)
>>>> ; - jdk.incubator.vector.AbstractVector::<init>@2 (line 67)
>>>> ; - jdk.incubator.vector.IntVector::<init>@2 (line 55)
>>>> ; - jdk.incubator.vector.Int64Vector::<init>@2 (line 58)
>>>> ; - jdk.incubator.vector.Int64Vector::vectorFactory at 5 (line 169)
>>>> ; - jdk.incubator.vector.Int64Vector::vectorFactory at 2 (line 41)
>>>> ; - jdk.incubator.vector.IntVector$IntSpecies::vectorFactory at 5 (line 3718)
>>>> ; - jdk.incubator.vector.IntVector::fromValues at 22 (line 553)
>>>> ; - fr.umlv.vector.VectorizedHashCode$Data::hashCode2 at 44 (line 15)
>>>> 0x00007fbb383325bb: vpextrd $0x1,%xmm0,%r11d
>>>> 0x00007fbb383325c1: vmovd %xmm0,%eax
>>>> 0x00007fbb383325c5: xor %r11d,%eax
>>>> 0x00007fbb383325c8: vzeroupper
>> 
>>>> regards,
>>>> Rémi