RFR: 8329077: C2 SuperWord: Add MoveD2L, MoveL2D, MoveF2I, MoveI2F [v2]

Galder Zamarreño galder at openjdk.org
Tue Aug 5 11:20:47 UTC 2025


> I've added support to vectorize `MoveD2L`, `MoveL2D`, `MoveF2I` and `MoveI2F` nodes. The implementation follows a similar pattern to what is done with conversion (`Conv*`) nodes. The tests in `TestCompatibleUseDefTypeSize` have been updated with the new expectations.
> 
> Also added a JMH benchmark which measures throughput (the higher the number the better) for methods that exercise these nodes. On darwin/aarch64 it shows:
> 
> 
> Benchmark                                (seed)  (size)   Mode  Cnt      Base      Patch   Units   Diff
> VectorBitConversion.doubleToLongBits          0    2048  thrpt    8  1168.782   1157.717  ops/ms    -1%
> VectorBitConversion.doubleToRawLongBits       0    2048  thrpt    8  3999.387   7353.936  ops/ms   +83%
> VectorBitConversion.floatToIntBits            0    2048  thrpt    8  1200.338   1188.206  ops/ms    -1%
> VectorBitConversion.floatToRawIntBits         0    2048  thrpt    8  4058.248  14792.474  ops/ms  +264%
> VectorBitConversion.intBitsToFloat            0    2048  thrpt    8  3050.313  14984.246  ops/ms  +391%
> VectorBitConversion.longBitsToDouble          0    2048  thrpt    8  3022.691   7379.360  ops/ms  +144%
> 
> 
> The improvements observed are a result of vectorization. The lack of vectorization in `doubleToLongBits` and `floatToIntBits` demonstrates that these changes do not affect their performance. These methods do not vectorize because of flow control.
> 
> I've run the tier1-3 tests on linux/aarch64 and didn't observe any regressions.

Galder Zamarreño has updated the pull request incrementally with three additional commits since the last revision:

 - Avoid VectorReinterpret::implemented
 - Refactor and add copyright header
 - Rephrase comment

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/26457/files
  - new: https://git.openjdk.org/jdk/pull/26457/files/b6ec784e..dde8699b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=26457&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=26457&range=00-01

  Stats: 307 lines in 8 files changed: 152 ins; 151 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/26457.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26457/head:pull/26457

PR: https://git.openjdk.org/jdk/pull/26457


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