Add ComplexDotProduct to SVE microbenchmark

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Performance Results

Run on Neoverse-V2

Method	Size	Mean	Error	StdDev	Median	Min	Max	Allocated
Scalar	15	31.642 ns	0.0282 ns	0.0264 ns	31.650 ns	31.604 ns	31.678 ns	-
Vector128ComplexDotProduct	15	33.523 ns	0.0144 ns	0.0128 ns	33.523 ns	33.500 ns	33.545 ns	-
SveComplexDotProduct	15	8.784 ns	0.0024 ns	0.0018 ns	8.785 ns	8.781 ns	8.786 ns	-
Sve2ComplexDotProduct	15	4.578 ns	0.0275 ns	0.0257 ns	4.570 ns	4.537 ns	4.632 ns	-
Scalar	127	254.706 ns	0.1650 ns	0.1463 ns	254.740 ns	254.471 ns	254.904 ns	-
Vector128ComplexDotProduct	127	144.932 ns	0.0580 ns	0.0484 ns	144.919 ns	144.828 ns	145.040 ns	-
SveComplexDotProduct	127	58.618 ns	0.0696 ns	0.0651 ns	58.594 ns	58.521 ns	58.731 ns	-
Sve2ComplexDotProduct	127	29.771 ns	0.3099 ns	0.2899 ns	29.924 ns	29.211 ns	29.941 ns	-
Scalar	527	1,038.988 ns	9.4551 ns	8.3817 ns	1,034.788 ns	1,032.676 ns	1,056.532 ns	-
Vector128ComplexDotProduct	527	561.940 ns	0.1210 ns	0.1073 ns	561.913 ns	561.773 ns	562.091 ns	-
SveComplexDotProduct	527	243.188 ns	0.6070 ns	0.5381 ns	243.338 ns	242.279 ns	243.973 ns	-
Sve2ComplexDotProduct	527	131.501 ns	0.0279 ns	0.0218 ns	131.498 ns	131.473 ns	131.550 ns	-
Scalar	10015	19,521.519 ns	15.6588 ns	14.6473 ns	19,512.407 ns	19,507.914 ns	19,546.593 ns	-
Vector128ComplexDotProduct	10015	10,432.399 ns	1.9337 ns	1.6147 ns	10,432.093 ns	10,429.260 ns	10,434.932 ns	-
SveComplexDotProduct	10015	4,589.976 ns	3.3737 ns	3.1558 ns	4,590.562 ns	4,584.570 ns	4,594.806 ns	-
Sve2ComplexDotProduct	10015	2,504.080 ns	85.1232 ns	94.6142 ns	2,544.328 ns	2,290.715 ns	2,545.745 ns	-

cc @dotnet/arm64-contrib @SwapnilGaikwad @LoopedBard3

[Copilot]

Pull request overview

Adds a new Arm64 SVE microbenchmark to measure complex dot-product implementations across scalar, AdvSimd (Vector128), SVE, and SVE2 paths, and wires it into the microbenchmark project with TFM gating for newer intrinsics.

Changes:

• Introduce ComplexDotProduct SVE microbenchmark with Scalar, Vector128, SVE, and SVE2 implementations.
• Add MSBuild conditional to exclude this benchmark for target frameworks older than net10.0 (due to SVE2 API usage).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
src/benchmarks/micro/sve/ComplexDotProduct.cs	New benchmark implementing and verifying multiple complex dot-product variants (Scalar/AdvSimd/SVE/SVE2).
src/benchmarks/micro/MicroBenchmarks.csproj	Excludes the new benchmark when building for TFMs < net10.0.

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