On Thu, 24 Jul 2025 10:29:15 GMT, Galder Zamarreño <gal...@openjdk.org> 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 1831:
> 1829:
> 1830: bool VectorReinterpretNode::implemented(int opc, uint vlen, BasicType
> src_type, BasicType dst_type) {
> 1831: if ((src_type == T_FLOAT && dst_type == T_INT) ||
Just a suggestion, do you feel a `switch-case` could be more readable/clear in
this case? Something like this -
bool VectorReinterpretNode::implemented(uint vlen, BasicType src_type,
BasicType dst_type) {
switch (src_type) {
case T_FLOAT:
if (dst_type != T_INT) return false;
break;
case T_INT:
if (dst_type != T_FLOAT) return false;
break;
case T_DOUBLE:
if (dst_type != T_LONG) return false;
break;
case T_LONG:
if (dst_type != T_DOUBLE) return false;
break;
default:
return false;
}
return Matcher::match_rule_supported_auto_vectorization(Op_VectorReinterpret,
vlen, dst_type);
}
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/26457#discussion_r2247906630
