RFR: 8354242: VectorAPI: combine vector not operation with compare [v3]
Emanuel Peter
epeter at openjdk.org
Tue Apr 29 10:24:47 UTC 2025
On Fri, 25 Apr 2025 07:24:15 GMT, erifan <duke at openjdk.org> wrote:
>> This patch optimizes the following patterns:
>> For integer types:
>>
>> (XorV (VectorMaskCmp src1 src2 cond) (Replicate -1))
>> => (VectorMaskCmp src1 src2 ncond)
>> (XorVMask (VectorMaskCmp src1 src2 cond) (MaskAll m1))
>> => (VectorMaskCmp src1 src2 ncond)
>>
>> cond can be eq, ne, le, ge, lt, gt, ule, uge, ult and ugt, ncond is the negative comparison of cond.
>>
>> For float and double types:
>>
>> (XorV (VectorMaskCast (VectorMaskCmp src1 src2 cond)) (Replicate -1))
>> => (VectorMaskCast (VectorMaskCmp src1 src2 ncond))
>> (XorVMask (VectorMaskCast (VectorMaskCmp src1 src2 cond)) (MaskAll m1))
>> => (VectorMaskCast (VectorMaskCmp src1 src2 ncond))
>>
>> cond can be eq or ne.
>>
>> Benchmarks on Nvidia Grace machine with 128-bit SVE2: With option `-XX:UseSVE=2`:
>>
>> Benchmark Unit Before Score Error After Score Error Uplift
>> testCompareEQMaskNotByte ops/s 7912127.225 2677.289518 10266136.26 8955.008548 1.29
>> testCompareEQMaskNotDouble ops/s 884737.6799 446.963779 1179760.772 448.031844 1.33
>> testCompareEQMaskNotFloat ops/s 1765045.787 682.332214 2359520.803 896.305743 1.33
>> testCompareEQMaskNotInt ops/s 1787221.411 977.743935 2353952.519 960.069976 1.31
>> testCompareEQMaskNotLong ops/s 895297.1974 673.44808 1178449.02 323.804205 1.31
>> testCompareEQMaskNotShort ops/s 3339987.002 3415.2226 4712761.965 2110.862053 1.41
>> testCompareGEMaskNotByte ops/s 7907615.16 4094.243652 10251646.9 9486.699831 1.29
>> testCompareGEMaskNotInt ops/s 1683738.958 4233.813092 2352855.205 1251.952546 1.39
>> testCompareGEMaskNotLong ops/s 854496.1561 8594.598885 1177811.493 521.1229 1.37
>> testCompareGEMaskNotShort ops/s 3341860.309 1578.975338 4714008.434 1681.10365 1.41
>> testCompareGTMaskNotByte ops/s 7910823.674 2993.367032 10245063.58 9774.75138 1.29
>> testCompareGTMaskNotInt ops/s 1673393.928 3153.099431 2353654.521 1190.848583 1.4
>> testCompareGTMaskNotLong ops/s 849405.9159 2432.858159 1177952.041 359.96413 1.38
>> testCompareGTMaskNotShort ops/s 3339509.141 3339.976585 4711442.496 2673.364893 1.41
>> testCompareLEMaskNotByte ops/s 7911340.004 3114.69191 10231626.5 27134.20035 1.29
>> testCompareLEMaskNotInt ops/s 1675812.113 1340.969885 2353255.341 1452.4522 1.4
>> testCompareLEMaskNotLong ops/s 848862.8036 6564.841731 1177763.623 539.290106 1.38
>> testCompareLEMaskNotShort ops/s 3324951.54 2380.29473 4712116.251 1544.559684 1.41
>> testCompareLTMaskNotByte ops/s 7910390.844 2630.861436 10239567.69 6487.441672 1.29
>> testCompareLTMaskNotInt ops/s 16721...
>
> erifan has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:
>
> - Addressed some review comments
>
> 1. Call VectorNode::Ideal() only once in XorVNode::Ideal.
> 2. Improve code comments.
> - Merge branch 'master' into JDK-8354242
> - Merge branch 'master' into JDK-8354242
> - 8354242: VectorAPI: combine vector not operation with compare
>
> This patch optimizes the following patterns:
> For integer types:
> ```
> (XorV (VectorMaskCmp src1 src2 cond) (Replicate -1))
> => (VectorMaskCmp src1 src2 ncond)
> (XorVMask (VectorMaskCmp src1 src2 cond) (MaskAll m1))
> => (VectorMaskCmp src1 src2 ncond)
> ```
> cond can be eq, ne, le, ge, lt, gt, ule, uge, ult and ugt, ncond is the
> negative comparison of cond.
>
> For float and double types:
> ```
> (XorV (VectorMaskCast (VectorMaskCmp src1 src2 cond)) (Replicate -1))
> => (VectorMaskCast (VectorMaskCmp src1 src2 ncond))
> (XorVMask (VectorMaskCast (VectorMaskCmp src1 src2 cond)) (MaskAll m1))
> => (VectorMaskCast (VectorMaskCmp src1 src2 ncond))
> ```
> cond can be eq or ne.
>
> Benchmarks on Nvidia Grace machine with 128-bit SVE2:
> With option `-XX:UseSVE=2`:
> ```
> Benchmark Unit Before Score Error After Score Error Uplift
> testCompareEQMaskNotByte ops/s 7912127.225 2677.289518 10266136.26 8955.008548 1.29
> testCompareEQMaskNotDouble ops/s 884737.6799 446.963779 1179760.772 448.031844 1.33
> testCompareEQMaskNotFloat ops/s 1765045.787 682.332214 2359520.803 896.305743 1.33
> testCompareEQMaskNotInt ops/s 1787221.411 977.743935 2353952.519 960.069976 1.31
> testCompareEQMaskNotLong ops/s 895297.1974 673.44808 1178449.02 323.804205 1.31
> testCompareEQMaskNotShort ops/s 3339987.002 3415.2226 4712761.965 2110.862053 1.41
> testCompareGEMaskNotByte ops/s 7907615.16 4094.243652 10251646.9 9486.699831 1.29
> testCompareGEMaskNotInt ops/s 1683738.958 4233.813092 2352855.205 1251.952546 1.39
> testCompareGEMaskNotLong ops/s 854496.1561 8594.598885 1177811.493 521.1229 1.37
> testCompareGEMaskNotShort ops/s 3341860.309 1578.975338 4714008.434 1681.10365 1.41
> testCompareGTMaskNotByte ops/s 7910823.674 2993.367032 10245063.58 9774.75138 1.29
> testCompareGTMaskNotInt ops/s 1673393.928 3153.099431 2353654.521 1190.848583 1.4
> testCompareGTMaskNotLong ops/s 849405.9159 2...
Yes, this discussion is down to `requires` vs `applyIf`. This is my argument for `applyIf`, quoted from above, I have not yet seen an argument against it:
> If you use @require, then the person does not realize there is a test AND the test is not run. If you use applyIf, the person does not realize there is a test, but it is run at least for result verifiation - and then the person MIGHT realize if the test catches a wrong result / crash.
In my understanding, `requires` should only be used if the test really **requires** a certain platform or feature. That can be because some flags are only available under certain platforms for example. But for IR tests, we should try to always use `applyIf`, because it allows testing on other platforms.
Actually, I filed this RFE a while ago: https://bugs.openjdk.org/browse/JDK-8310891
We should try to move as many tests from using `requires` to `applyIf`, so that we have an increased test coverage.
-------------
PR Comment: https://git.openjdk.org/jdk/pull/24674#issuecomment-2838240704
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