Better codegen / perf form Math.Max and Math.Min

[gfoidl]

Based on #33057 (comment) I picked the variant MinReorder as it has best overall performance on average.
With #33476 there will be "another boost" for this method.

Added more testcases for Max / Min.

Fixes #33057

/cc: @tannergooding

[tannergooding]

LGTM. Thanks for doing this and increasing the test coverage.

It might be worth looking at a similar optimization for MaxMagnitude and MinMagnitude which are functionally similar but which don't propagate NaN

[tannergooding]

CC. @pgovind

[gfoidl]

It might be worth looking at a similar optimization for MaxMagnitude and MinMagnitude which are functionally similar but which don't propagate NaN

I will have a look over the weekend / next week.

[jkotas]

Any performance numbers?

How much of the improvement is due to AggressiveInlining vs. the other changes? Also, what is the code side growth due to AggressiveInlining?

[tannergooding]

Various perf numbers listed starting here: #33057 (comment), with additional analysis and graphs shown below that in the additional conversation.

It is a 2-3x perf increase from aggressive inlining alone. The code reorder increases perf an additional 10% or so from the instruction reordering (depending on inputs).

Assuming nothing gets dropped from inlining (both inputs are non-constant) the bloat isn't trivial: https://gist.github.com/tannergooding/d81a6cd7530ec1cdc27e08530922f02a, it would be ~67 bytes for just aggressive inlining and ~66 bytes for the branch reorder. The SIMD version is almost half that (~35 bytes), but doesn't perform as well on Intel CPUs (we get less than a 2x perf increase).

[tannergooding]

@jkotas, do you have any concerns with the change based on the numbers and code size growth?

[jkotas]

Math.Max/Min is not used that often. I can live with this.

[tannergooding]

Closing and reopening to retrigger tests.

[tannergooding]

Thanks for the improvement @gfoidl!