RFR: 8297092: [macos_aarch64] Add support for SHA feature detection

[Hao Sun]

On Mon, 28 Nov 2022 02:19:47 GMT, Hao Sun <haosun at openjdk.org> wrote:

> The detection of SHA features including SHA1, SHA2, SHA512 and SHA3, is missing in macOS on Apple silicon. In this patch, we add the support.
> 
> * SHA1 and SHA2 are set uncoditionally to true on darwin. See [1].
> 
> * SHA512 and SHA3 will be set depending on the existing `hw.optional` flags
> 
> * Some old links are updated in this patch as well.
> 
> With the detection, the corresponding SHA related intrinsics flags are enabled. See the test result on my local environment, i.e. M1.
> 
> 
> $ ./jdk/bin/java -XX:+PrintFlagsFinal --version | grep SHA
>      bool UseSHA                = true       {product} {default}
>      bool UseSHA1Intrinsics     = true    {diagnostic} {default}
>      bool UseSHA256Intrinsics   = true    {diagnostic} {default}
>      bool UseSHA3Intrinsics     = false   {diagnostic} {default}
>      bool UseSHA512Intrinsics   = true    {diagnostic} {default}
> 
> $ ./jdk/bin/java -XX:+PrintFlagsFinal -XX:+UseSHA3Intrinsics  --version | grep SHA3
>      bool UseSHA3Intrinsics     = true    {diagnostic} {command line}
> 
> 
> Note that UseSHA3Intrinsics are NOT enabled by default on supported hardware because there is performance regression one some hardware. See JDK-8292894. Hence we have to enable it explicitly.
> 
> Jtreg testing:
> 
> We ran tier1~3 on M1 and found the following two new failures. They can be fixed once JDK-8292894 are resolved.
> 
> 
> compiler/intrinsics/sha/cli/TestUseSHA3IntrinsicsOptionOnSupportedCPU.java
> 
> 
> Performance testing:
> 
> JMH test case MessageDigests.java is used to evaluate the performance uplifts of UseSHA*Intrinsics. Here shows the data on M1.
> 
> 
> Benchmark                    (digesterName)  (length)   Mode  Cnt    Before      After   Units
> MessageDigests.digest                 SHA-1        64  thrpt   15  2670.195  14767.116  ops/ms
> MessageDigests.digest                 SHA-1     16384  thrpt   15    21.756    147.816  ops/ms
> MessageDigests.digest               SHA-224        64  thrpt   15  1729.686  17366.833  ops/ms
> MessageDigests.digest               SHA-224     16384  thrpt   15    14.044    149.707  ops/ms
> MessageDigests.digest               SHA-256        64  thrpt   15  1729.529  16915.554  ops/ms
> MessageDigests.digest               SHA-256     16384  thrpt   15    14.040    149.720  ops/ms
> MessageDigests.digest               SHA-384        64  thrpt   15  2551.285   8996.372  ops/ms
> MessageDigests.digest               SHA-384     16384  thrpt   15    21.338     86.996  ops/ms
> MessageDigests.digest               SHA-512        64  thrpt   15  2528.185   8886.926  ops/ms
> MessageDigests.digest               SHA-512     16384  thrpt   15    21.298     86.840  ops/ms
> MessageDigests.digest              SHA3-256        64  thrpt   15  3595.392   5628.810  ops/ms
> MessageDigests.digest              SHA3-256     16384  thrpt   15    29.208     52.917  ops/ms
> MessageDigests.digest              SHA3-512        64  thrpt   15  3604.652   5563.199  ops/ms
> MessageDigests.digest              SHA3-512     16384  thrpt   15    16.545     28.182  ops/ms
> MessageDigests.getAndDigest           SHA-1        64  thrpt   15  2467.470  11878.581  ops/ms
> MessageDigests.getAndDigest           SHA-1     16384  thrpt   15    21.179    146.849  ops/ms
> MessageDigests.getAndDigest         SHA-224        64  thrpt   15  1635.583   5864.632  ops/ms
> MessageDigests.getAndDigest         SHA-224     16384  thrpt   15    14.023    148.556  ops/ms
> MessageDigests.getAndDigest         SHA-256        64  thrpt   15  1633.913   5741.416  ops/ms
> MessageDigests.getAndDigest         SHA-256     16384  thrpt   15    14.029    148.518  ops/ms
> MessageDigests.getAndDigest         SHA-384        64  thrpt   15  2373.041   7634.589  ops/ms
> MessageDigests.getAndDigest         SHA-384     16384  thrpt   15    21.335     86.452  ops/ms
> MessageDigests.getAndDigest         SHA-512        64  thrpt   15  2366.305   7781.053  ops/ms
> MessageDigests.getAndDigest         SHA-512     16384  thrpt   15    21.324     86.352  ops/ms
> MessageDigests.getAndDigest        SHA3-256        64  thrpt   15  3154.196   4770.368  ops/ms
> MessageDigests.getAndDigest        SHA3-256     16384  thrpt   15    29.028     52.621  ops/ms
> MessageDigests.getAndDigest        SHA3-512        64  thrpt   15  3345.374   4828.986  ops/ms
> MessageDigests.getAndDigest        SHA3-512     16384  thrpt   15    16.443     28.063  ops/ms
> 
> 
> [1] https://github.com/golang/go/blob/master/src/internal/cpu/cpu_arm64_darwin.go#L14

It's a follow-up patch for JDK-8295698 (See the discussion in https://github.com/openjdk/jdk/pull/10939#issuecomment-1316429451). Could you help take a look at it when you got a chance? @theRealAph and @dgbo Thanks.

Besides, I was wondering if I can have your opinion on `UseSHA3Intrinsics`?
* as discussed in JDK-8295698, `UseSHA3INtrinsics` may introduce performance regress on some CPUs
* as evaluated in this patch, `UseSHA3Intrinsics` can introduce performance uplift in M1.

My question is 
1) should we enable `UseSHA3Intrinsics` by default on M1?
2) if so, should we do this in current patch, or one separate one, e.g., JDK-8292894?

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

PR: https://git.openjdk.org/jdk/pull/11382