RFR: 8309130: x86_64 AVX512 intrinsics for Arrays.sort methods (int, long, float and double arrays) [v31]

[Erik Joelsson]

On Thu, 31 Aug 2023 18:45:39 GMT, Srinivas Vamsi Parasa <duke at openjdk.org> wrote:

>> The goal is to develop faster sort routines for x86_64 CPUs by taking advantage of AVX512 instructions. This enhancement provides an order of magnitude speedup for Arrays.sort() using int, long, float and double arrays.
>> 
>> This PR shows upto ~7x improvement for 32-bit datatypes (int, float) and upto ~4.5x improvement for 64-bit datatypes (long, double) as shown in the performance data below.
>> 
>> 
>> **Arrays.sort performance data using JMH benchmarks for arrays with random data** 
>> 
>> |	Arrays.sort benchmark	|	Array Size	|	Baseline (us/op)	|	AVX512 Sort (us/op)	|	Speedup	|
>> |	---	|	---	|	---	|	---	|	---	|
>> |	ArraysSort.doubleSort	|	10	|	0.034	|	0.035	|	1.0	|
>> |	ArraysSort.doubleSort	|	25	|	0.116	|	0.089	|	1.3	|
>> |	ArraysSort.doubleSort	|	50	|	0.282	|	0.291	|	1.0	|
>> |	ArraysSort.doubleSort	|	75	|	0.474	|	0.358	|	1.3	|
>> |	ArraysSort.doubleSort	|	100	|	0.654	|	0.623	|	1.0	|
>> |	ArraysSort.doubleSort	|	1000	|	9.274	|	6.331	|	1.5	|
>> |	ArraysSort.doubleSort	|	10000	|	323.339	|	71.228	|	**4.5**	|
>> |	ArraysSort.doubleSort	|	100000	|	4471.871	|	1002.748	|	**4.5**	|
>> |	ArraysSort.doubleSort	|	1000000	|	51660.742	|	12921.295	|	**4.0**	|
>> |	ArraysSort.floatSort	|	10	|	0.045	|	0.046	|	1.0	|
>> |	ArraysSort.floatSort	|	25	|	0.103	|	0.084	|	1.2	|
>> |	ArraysSort.floatSort	|	50	|	0.285	|	0.33	|	0.9	|
>> |	ArraysSort.floatSort	|	75	|	0.492	|	0.346	|	1.4	|
>> |	ArraysSort.floatSort	|	100	|	0.597	|	0.326	|	1.8	|
>> |	ArraysSort.floatSort	|	1000	|	9.811	|	5.294	|	1.9	|
>> |	ArraysSort.floatSort	|	10000	|	323.955	|	50.547	|	**6.4**	|
>> |	ArraysSort.floatSort	|	100000	|	4326.38	|	731.152	|	**5.9**	|
>> |	ArraysSort.floatSort	|	1000000	|	52413.88	|	8409.193	|	**6.2**	|
>> |	ArraysSort.intSort	|	10	|	0.033	|	0.033	|	1.0	|
>> |	ArraysSort.intSort	|	25	|	0.086	|	0.051	|	1.7	|
>> |	ArraysSort.intSort	|	50	|	0.236	|	0.151	|	1.6	|
>> |	ArraysSort.intSort	|	75	|	0.416	|	0.332	|	1.3	|
>> |	ArraysSort.intSort	|	100	|	0.63	|	0.521	|	1.2	|
>> |	ArraysSort.intSort	|	1000	|	10.518	|	4.698	|	2.2	|
>> |	ArraysSort.intSort	|	10000	|	309.659	|	42.518	|	**7.3**	|
>> |	ArraysSort.intSort	|	100000	|	4130.917	|	573.956	|	**7.2**	|
>> |	ArraysSort.intSort	|	1000000	|	49876.307	|	6712.812	|	**7.4**	|
>> |	ArraysSort.longSort	|	10	|	0.036	|	0.037	|	1.0	|
>> |	ArraysSort.longSort	|	25	|	0.094	|	0.08	|	1.2	|
>> |	ArraysSort.longSort	|	50	|	0.218	|	0.227	|	1.0	|
>> |	ArraysSort.longSort	|	75	|	0.466	|	0.402	|	1.2	|
>> |	ArraysSort.longSort	|	100	|	0.76	|	0.58	|	1.3	|
>> |	ArraysSort.longSort	|	1000	|	10.449	|	6....
>
> Srinivas Vamsi Parasa has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 32 commits:
> 
>  - update build script
>  - Merge branch 'master' of https://git.openjdk.org/jdk into avx512sort
>  - Clean up parameters passed to arrayPartition; update the check to load library
>  - Remove unnecessary import in Arrays.java
>  - Move sort and partition intrinsics from Arrays.java to DPQS.java
>  - Fix unused assignment in DPQS.java and space in Arrays.java
>  - add parallelSort benchmarking
>  - Update copyright for DPQS.java; replace avx512 pivot calculation with scalar version
>  - Update avx512-common-qsort.h
>  - Decomposed DPQS using AVX512 partitioning and AVX512 sort (for small arrays). Works for serial and parallel sort.
>  - ... and 22 more: https://git.openjdk.org/jdk/compare/c8acab1d...1746eedd

make/modules/java.base/Lib.gmk line 255:

> 253:         TARGETS += $(BUILD_LIB_X86_64)
> 254:   endif
> 255: endif

Indentation looks off here (https://openjdk.org/groups/build/doc/code-conventions.html)
Suggestion:

ifeq ($(call isTargetOs, linux)+$(call isTargetCpu, x86_64)+$(INCLUDE_COMPILER2), true+true+true)
  ifeq ($(TOOLCHAIN_TYPE), gcc)
    $(eval $(call SetupJdkLibrary, BUILD_LIB_X86_64, \
        NAME := x86_64, \
        TOOLCHAIN := TOOLCHAIN_LINK_CXX, \
        OPTIMIZATION := HIGH, \
        CFLAGS := $(CFLAGS_JDKLIB), \
        CXXFLAGS := $(CXXFLAGS_JDKLIB), \
        LDFLAGS := $(LDFLAGS_JDKLIB) \
            $(call SET_SHARED_LIBRARY_ORIGIN), \
        LIBS := $(LIBCXX), \
        LIBS_linux := -lc -lm -ldl, \
    ))

    TARGETS += $(BUILD_LIB_X86_64)
  endif
endif


I'm also still wondering about the library name. It's very generic for something that seems to be rather specific.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/14227#discussion_r1312139279