On Fri, 1 Aug 2025 12:17:03 GMT, Bhavana Kilambi <[email protected]> wrote:
>> 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.
>
> src/hotspot/share/opto/vectornode.cpp line 1830:
>
>> 1828: }
>> 1829:
>> 1830: bool VectorReinterpretNode::implemented(int opc, uint vlen, BasicType
>> src_type, BasicType dst_type) {
>
> `opc` is not used in this method. Do we need this parameter here?
Yup not needed
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/26457#discussion_r2251882431
