Integrated: 8295023: Interpreter(AArch64): Implement -XX:+PrintBytecodeHistogram and -XX:+PrintBytecodePairHistogram options

[Hao Sun]

On Tue, 11 Oct 2022 01:27:23 GMT, Hao Sun <haosun at openjdk.org> wrote:

> In this patch, we implement functions histogram_bytecode() and histogram_bytecode_pair() for interpreter AArch64 part. Similar to count_bytecode(), we use atomic operations to update the counters as well.
> 
> Here shows part of the message produced with -XX:+PrintBytecodeHistogram and -XX:+PrintBytecodePairHistogram options after this patch.
> 
> 
> $ java -XX:+PrintBytecodeHistogram --version | head -20
> openjdk 20-internal 2023-03-21
> OpenJDK Runtime Environment (fastdebug build 20-internal-adhoc.haosun.jdk-src-dev)
> OpenJDK 64-Bit Server VM (fastdebug build 20-internal-adhoc.haosun.jdk-src-dev, mixed mode)
> 
> Histogram of 5004099 executed bytecodes:
> 
>   absolute  relative  code    name
> ----------------------------------------------------------------------
>     319124     6.38%    dc    fast_aload_0
>     313397     6.26%    e0    fast_iload
>     251436     5.02%    b6    invokevirtual
>     227428     4.54%    19    aload
>     166054     3.32%    a7    goto
>     159167     3.18%    2b    aload_1
>     151803     3.03%    de    fast_aaccess_0
>     136787     2.73%    1b    iload_1
>     124037     2.48%    36    istore
>     118791     2.37%    84    iinc
>     118121     2.36%    1c    iload_2
>     110484     2.21%    a2    if_icmpge
> 
> $ java -XX:+PrintBytecodePairHistogram --version | head -20
> openjdk 20-internal 2023-03-21
> OpenJDK Runtime Environment (fastdebug build 20-internal-adhoc.haosun.jdk-src-dev)
> OpenJDK 64-Bit Server VM (fastdebug build 20-internal-adhoc.haosun.jdk-src-dev, mixed mode)
> 
> Histogram of 4804441 executed bytecode pairs:
> 
>   absolute  relative    codes    1st bytecode        2nd bytecode
> ----------------------------------------------------------------------
>      77602    1.615%    84 a7    iinc                goto
>      49749    1.035%    36 e0    istore              fast_iload
>      48931    1.018%    e0 10    fast_iload          bipush
>      46294    0.964%    e0 b6    fast_iload          invokevirtual
>      42661    0.888%    a7 e0    goto                fast_iload
>      42243    0.879%    3a 19    astore              aload
>      40138    0.835%    19 b9    aload               invokeinterface
>      36617    0.762%    dc 2b    fast_aload_0        aload_1
>      35745    0.744%    b7 dc    invokespecial       fast_aload_0
>      35384    0.736%    19 b6    aload               invokevirtual
>      35035    0.729%    b6 de    invokevirtual       fast_aaccess_0
>      34667    0.722%    dc b6    fast_aload_0        invokevirtual
> 
> 
> In order to verfiy the correctness, I took the trace information produced by -XX:+TraceBytecodes as a cross reference. The hit times for some bytecodes/bytecode pairs can be obtained via parsing the trace. Then I compared the hit times with the corresponding "absolute" columns. I randomly selected several bytecodes/bytecode pairs, and the manual comparion results showed that "absolute" columns are correct.
> 
> Note-1: count_bytecode() is updated. 1) caller-saved registers are used as temporary registers and there is no need to save/restore them. 2) atomic_addw() should be used since the counter is of int type.
> 
> Note-2: As shown by the update in file templateInterpreterGenerator.cpp, function histogram_bytecode() should be invoked only inside !PRODUCT scope.

This pull request has now been integrated.

Changeset: ae60599e
Author:    Hao Sun <haosun at openjdk.org>
Committer: Nick Gasson <ngasson at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/ae60599e2ba75d80c3b4279903137b2c549f8066
Stats:     61 lines in 4 files changed: 23 ins; 33 del; 5 mod

8295023: Interpreter(AArch64): Implement -XX:+PrintBytecodeHistogram and -XX:+PrintBytecodePairHistogram options

Reviewed-by: aph, ngasson

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PR: https://git.openjdk.org/jdk/pull/10642