Hi John, thanks for your review, and thanks Vladimir! I've had another go at the implementation to use a dedicated loop clause holder class with a stable array; performance is roughly on par with that of the BMHs-as-arrays approach (see below).
The new webrev is at http://cr.openjdk.java.net/~mhaupt/8161211/webrev.01/; please review. Thanks, Michael Benchmark (iterations) unpatched patched CntL.Cr.cr3 N/A 16039.108 15821.583 CntL.Cr.cr4 N/A 15621.959 15869.730 CntL.Inv.bl3 0 2.858 2.835 CntL.Inv.bl3 1 5.125 5.179 CntL.Inv.bl3 10 11.887 12.005 CntL.Inv.bl3 100 67.441 67.279 CntL.Inv.bl4 0 2.855 2.858 CntL.Inv.bl4 1 5.120 5.210 CntL.Inv.bl4 10 11.875 12.012 CntL.Inv.bl4 100 67.607 67.296 CntL.Inv.blMH3 0 9.734 9.722 CntL.Inv.blMH3 1 15.689 15.865 CntL.Inv.blMH3 10 68.912 69.098 CntL.Inv.blMH3 100 605.666 605.526 CntL.Inv.blMH4 0 14.561 13.274 CntL.Inv.blMH4 1 19.543 19.709 CntL.Inv.blMH4 10 71.977 72.446 CntL.Inv.blMH4 100 596.842 598.271 CntL.Inv.cntL3 0 49.339 6.311 CntL.Inv.cntL3 1 95.444 7.333 CntL.Inv.cntL3 10 508.746 20.930 CntL.Inv.cntL3 100 4701.808 147.383 CntL.Inv.cntL4 0 49.443 5.780 CntL.Inv.cntL4 1 98.721 7.465 CntL.Inv.cntL4 10 503.825 20.932 CntL.Inv.cntL4 100 4681.803 147.278 DoWhL.Cr.cr N/A 7628.312 7803.187 DoWhL.Inv.bl 1 3.868 3.869 DoWhL.Inv.bl 10 16.480 16.528 DoWhL.Inv.bl 100 144.260 144.290 DoWhL.Inv.blMH 1 14.434 14.430 DoWhL.Inv.blMH 10 92.542 92.733 DoWhL.Inv.blMH 100 877.480 876.735 DoWhL.Inv.doWhL 1 26.791 7.134 DoWhL.Inv.doWhL 10 158.985 17.004 DoWhL.Inv.doWhL 100 1391.746 133.253 ItrL.Cr.cr N/A 13547.499 13248.913 ItrL.Inv.bl 0 2.973 2.983 ItrL.Inv.bl 1 6.771 6.705 ItrL.Inv.bl 10 14.955 14.952 ItrL.Inv.bl 100 81.842 82.152 ItrL.Inv.blMH 0 14.893 15.014 ItrL.Inv.blMH 1 20.998 21.459 ItrL.Inv.blMH 10 73.677 73.888 ItrL.Inv.blMH 100 613.913 615.208 ItrL.Inv.itrL 0 33.583 10.842 ItrL.Inv.itrL 1 82.239 13.573 ItrL.Inv.itrL 10 448.356 38.773 ItrL.Inv.itrL 100 4189.034 279.918 L.Cr.cr N/A 15505.970 15640.994 L.Inv0.bl 1 3.179 3.186 L.Inv0.bl 10 5.952 5.912 L.Inv0.bl 100 50.942 50.964 L.Inv0.lo 1 46.454 5.290 L.Inv0.lo 10 514.230 8.492 L.Inv0.lo 100 5166.251 52.187 L.Inv1.lo 1 34.321 5.291 L.Inv1.lo 10 430.839 8.474 L.Inv1.lo 100 4095.302 52.173 TF.blEx N/A 3.005 2.986 TF.blMHEx N/A 166.316 165.856 TF.blMHNor N/A 9.337 9.290 TF.blNor N/A 2.696 2.682 TF.cr N/A 406.255 415.090 TF.invTFEx N/A 154.121 154.826 TF.invTFNor N/A 5.350 5.328 WhL.Cr.cr N/A 12214.383 12112.535 WhL.Inv.bl 0 3.886 3.931 WhL.Inv.bl 1 5.379 5.411 WhL.Inv.bl 10 16.000 16.203 WhL.Inv.bl 100 142.066 142.127 WhL.Inv.blMH 0 11.028 10.915 WhL.Inv.blMH 1 21.269 21.419 WhL.Inv.blMH 10 97.493 98.373 WhL.Inv.blMH 100 887.579 892.955 WhL.Inv.whL 0 24.829 7.082 WhL.Inv.whL 1 46.039 8.598 WhL.Inv.whL 10 240.963 21.108 WhL.Inv.whL 100 2092.671 167.619 > Am 20.09.2016 um 21:54 schrieb John Rose <john.r.r...@oracle.com>: > > There should also be an assert in the new LF constructor, which ensures that > the two > arguments are congruent. Better yet, just supply one argument (the > speciesData), > and derive the MT. These new LFs are pretty confusing, and it's best to nail > down > unused degrees of freedom. > > — John > > P.S. I would have expected this problem to be solved by having the > MHI.toArray function > return a box object with a single @Stable array field. Did that approach > fail? > > I.e., this wrapper emulates a frozen array (until that happy day when we have > real > frozen arrays): > > class ArrayConstant<T> { > private final @Stable T[] values; > public ArrayConstant(T[] values) { > for (T v : values) Objects.requireNonNull(v); > this.values = values.clone(); > } > public T get(int i) { return values[i]; } > //public int length() { return values.length; } > } > > The JIT should be able to constant fold through ac.get(i) whenever ac and i > are constants. > > On Sep 20, 2016, at 8:17 AM, Vladimir Ivanov <vladimir.x.iva...@oracle.com> > wrote: >> >> Looks good. >> >> src/java.base/share/classes/java/lang/invoke/LambdaFormEditor.java: >> + LambdaForm bmhArrayForm(MethodType type, BoundMethodHandle.SpeciesData >> speciesData) { >> + int size = type.parameterCount(); >> + Transform key = Transform.of(Transform.BMH_AS_ARRAY, size); >> + LambdaForm form = getInCache(key); >> + if (form != null) { >> + return form; >> + } >> >> Please, add an assert to ensure the cached LF has the same constraint as >> requested (speciesData). >> >> Best regards, >> Vladimir Ivanov >> >> On 9/20/16 3:53 PM, Michael Haupt wrote: >>> Dear all, >>> >>> please review this change. >>> Bug: https://bugs.openjdk.java.net/browse/JDK-8161211 >>> Webrev: http://cr.openjdk.java.net/~mhaupt/8161211/webrev.00/ >>> >>> The method handle loop combinators introduced with JEP 274 were originally >>> not intrinsified, leading to poor performance as compared to a pure-Java >>> baseline, but also to handwired method handle combinations. The intrinsics >>> introduced with 8143211 [1] improved on the situation somewhat, but still >>> did not provide good inlining opportunities for the JIT compiler. This >>> change introduces a usage of BoundMethodHandles as arrays to carry the >>> various handles involved in loop execution. >>> >>> Extra credits to Vladimir Ivanov, who suggested the BMH-as-arrays approach >>> in the first place, and Claes Redestad, who suggested to use LambdaForm >>> editing to neatly enable caching. Thanks! >>> >>> Performance improves considerably. The table below reports scores in ns/op. >>> The "unpatched" column contains results from before applying the patch for >>> 8161211; the "patched" column, from thereafter. >>> >>> The create benchmarks measure the cost of loop handle creation. The >>> baseline and baselineMH benchmarks measure the cost of running a pure Java >>> and handwired method handle construct. >>> >>> Relevant comparisons include loop combinator results versus baselines, and >>> versus unpatched loop combinator results. For the latter, there are >>> significant improvements, except for the creation benchmarks (creation has >>> a more complex workflow now). For the former, it can be seen that the >>> BMH-array intrinsics generally perform better than handwired handle >>> constructs, and have moved much closer to. >>> >>> Thanks, >>> >>> Michael >>> >>> >>> >>> [1] https://bugs.openjdk.java.net/browse/JDK-8143211 >>> >>> >>> >>> Benchmark (iterations) >>> unpatched patched >>> MethodHandlesCountedLoop.Create.create3 N/A >>> 16039.108 18400.405 >>> MethodHandlesCountedLoop.Create.create4 N/A >>> 15621.959 17924.696 >>> MethodHandlesCountedLoop.Invoke.baseline3 0 2.858 >>> 2.839 >>> MethodHandlesCountedLoop.Invoke.baseline3 1 5.125 >>> 5.164 >>> MethodHandlesCountedLoop.Invoke.baseline3 10 11.887 >>> 11.924 >>> MethodHandlesCountedLoop.Invoke.baseline3 100 67.441 >>> 67.281 >>> MethodHandlesCountedLoop.Invoke.baseline4 0 2.855 >>> 2.838 >>> MethodHandlesCountedLoop.Invoke.baseline4 1 5.120 >>> 5.179 >>> MethodHandlesCountedLoop.Invoke.baseline4 10 11.875 >>> 11.906 >>> MethodHandlesCountedLoop.Invoke.baseline4 100 67.607 >>> 67.374 >>> MethodHandlesCountedLoop.Invoke.baselineMH3 0 9.734 >>> 9.606 >>> MethodHandlesCountedLoop.Invoke.baselineMH3 1 15.689 >>> 15.674 >>> MethodHandlesCountedLoop.Invoke.baselineMH3 10 68.912 >>> 69.303 >>> MethodHandlesCountedLoop.Invoke.baselineMH3 100 >>> 605.666 606.432 >>> MethodHandlesCountedLoop.Invoke.baselineMH4 0 14.561 >>> 13.234 >>> MethodHandlesCountedLoop.Invoke.baselineMH4 1 19.543 >>> 19.773 >>> MethodHandlesCountedLoop.Invoke.baselineMH4 10 71.977 >>> 72.466 >>> MethodHandlesCountedLoop.Invoke.baselineMH4 100 >>> 596.842 602.469 >>> MethodHandlesCountedLoop.Invoke.countedLoop3 0 49.339 >>> 5.810 >>> MethodHandlesCountedLoop.Invoke.countedLoop3 1 95.444 >>> 7.441 >>> MethodHandlesCountedLoop.Invoke.countedLoop3 10 >>> 508.746 21.002 >>> MethodHandlesCountedLoop.Invoke.countedLoop3 100 >>> 4701.808 145.996 >>> MethodHandlesCountedLoop.Invoke.countedLoop4 0 49.443 >>> 5.798 >>> MethodHandlesCountedLoop.Invoke.countedLoop4 1 98.721 >>> 7.438 >>> MethodHandlesCountedLoop.Invoke.countedLoop4 10 >>> 503.825 21.049 >>> MethodHandlesCountedLoop.Invoke.countedLoop4 100 >>> 4681.803 147.020 >>> MethodHandlesDoWhileLoop.Create.create N/A >>> 7628.312 9100.332 >>> MethodHandlesDoWhileLoop.Invoke.baseline 1 3.868 >>> 3.909 >>> MethodHandlesDoWhileLoop.Invoke.baseline 10 16.480 >>> 16.461 >>> MethodHandlesDoWhileLoop.Invoke.baseline 100 >>> 144.260 144.232 >>> MethodHandlesDoWhileLoop.Invoke.baselineMH 1 14.434 >>> 14.494 >>> MethodHandlesDoWhileLoop.Invoke.baselineMH 10 92.542 >>> 93.454 >>> MethodHandlesDoWhileLoop.Invoke.baselineMH 100 >>> 877.480 880.496 >>> MethodHandlesDoWhileLoop.Invoke.doWhileLoop 1 26.791 >>> 7.153 >>> MethodHandlesDoWhileLoop.Invoke.doWhileLoop 10 >>> 158.985 16.990 >>> MethodHandlesDoWhileLoop.Invoke.doWhileLoop 100 >>> 1391.746 130.946 >>> MethodHandlesIteratedLoop.Create.create N/A >>> 13547.499 15478.542 >>> MethodHandlesIteratedLoop.Invoke.baseline 0 2.973 >>> 2.980 >>> MethodHandlesIteratedLoop.Invoke.baseline 1 6.771 >>> 6.658 >>> MethodHandlesIteratedLoop.Invoke.baseline 10 14.955 >>> 14.955 >>> MethodHandlesIteratedLoop.Invoke.baseline 100 81.842 >>> 82.582 >>> MethodHandlesIteratedLoop.Invoke.baselineMH 0 14.893 >>> 14.668 >>> MethodHandlesIteratedLoop.Invoke.baselineMH 1 20.998 >>> 21.304 >>> MethodHandlesIteratedLoop.Invoke.baselineMH 10 73.677 >>> 72.703 >>> MethodHandlesIteratedLoop.Invoke.baselineMH 100 >>> 613.913 614.475 >>> MethodHandlesIteratedLoop.Invoke.iteratedLoop 0 33.583 >>> 9.603 >>> MethodHandlesIteratedLoop.Invoke.iteratedLoop 1 82.239 >>> 14.433 >>> MethodHandlesIteratedLoop.Invoke.iteratedLoop 10 >>> 448.356 38.650 >>> MethodHandlesIteratedLoop.Invoke.iteratedLoop 100 >>> 4189.034 279.779 >>> MethodHandlesLoop.Create.create N/A >>> 15505.970 17559.399 >>> MethodHandlesLoop.Invoke0.baseline 1 3.179 >>> 3.181 >>> MethodHandlesLoop.Invoke0.baseline 10 5.952 >>> 6.115 >>> MethodHandlesLoop.Invoke0.baseline 100 50.942 >>> 50.943 >>> MethodHandlesLoop.Invoke0.loop 1 46.454 >>> 5.353 >>> MethodHandlesLoop.Invoke0.loop 10 >>> 514.230 8.487 >>> MethodHandlesLoop.Invoke0.loop 100 >>> 5166.251 52.188 >>> MethodHandlesLoop.Invoke1.loop 1 34.321 >>> 5.277 >>> MethodHandlesLoop.Invoke1.loop 10 >>> 430.839 8.481 >>> MethodHandlesLoop.Invoke1.loop 100 >>> 4095.302 52.206 >>> MethodHandlesTryFinally.baselineExceptional N/A 3.005 >>> 3.002 >>> MethodHandlesTryFinally.baselineMHExceptional N/A >>> 166.316 166.087 >>> MethodHandlesTryFinally.baselineMHNormal N/A 9.337 >>> 9.276 >>> MethodHandlesTryFinally.baselineNormal N/A 2.696 >>> 2.683 >>> MethodHandlesTryFinally.create N/A >>> 406.255 406.594 >>> MethodHandlesTryFinally.invokeTryFinallyExceptional N/A >>> 154.121 154.692 >>> MethodHandlesTryFinally.invokeTryFinallyNormal N/A 5.350 >>> 5.334 >>> MethodHandlesWhileLoop.Create.create N/A >>> 12214.383 14503.515 >>> MethodHandlesWhileLoop.Invoke.baseline 0 3.886 >>> 3.888 >>> MethodHandlesWhileLoop.Invoke.baseline 1 5.379 >>> 5.377 >>> MethodHandlesWhileLoop.Invoke.baseline 10 16.000 >>> 16.201 >>> MethodHandlesWhileLoop.Invoke.baseline 100 >>> 142.066 143.338 >>> MethodHandlesWhileLoop.Invoke.baselineMH 0 11.028 >>> 11.012 >>> MethodHandlesWhileLoop.Invoke.baselineMH 1 21.269 >>> 21.159 >>> MethodHandlesWhileLoop.Invoke.baselineMH 10 97.493 >>> 97.656 >>> MethodHandlesWhileLoop.Invoke.baselineMH 100 >>> 887.579 886.532 >>> MethodHandlesWhileLoop.Invoke.whileLoop 0 24.829 >>> 7.108 >>> MethodHandlesWhileLoop.Invoke.whileLoop 1 46.039 >>> 8.573 >>> MethodHandlesWhileLoop.Invoke.whileLoop 10 >>> 240.963 21.088 >>> MethodHandlesWhileLoop.Invoke.whileLoop 100 >>> 2092.671 159.016 >>> >>> >>> > -- <http://www.oracle.com/> Dr. Michael Haupt | Principal Member of Technical Staff Phone: +49 331 200 7277 | Fax: +49 331 200 7561 Oracle Java Platform Group | LangTools Team | Nashorn Oracle Deutschland B.V. & Co. 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