[M680x0] Add CycleTimer implementation for M68K architecture

[myhsu]

Summary

This is a cherrypick of the upstream fix commit ffe1342 onto
llvm/utils/benchmakr and libcxx/utils/google-benchmark.
This adds CycleTimer implementation for M680x0, and simply
uses gettimeofday to implement, same as MIPS.

[lebedev.ri]

Thanks, LG, please feel free to commit this.
There's also one in test-suite, you might want to patch that too.

[myhsu]

In D88868#2313527, @lebedev.ri wrote:

Thanks, LG, please feel free to commit this.
There's also one in test-suite, you might want to patch that too.

Thanks for the swift review. I've created the test-suite part review https://reviews.llvm.org/D89011

[RKSimon]

@ldionne @mclow.lists @EricWF - can someone from the libc++ group accept this to unblock it please?

[lebedev.ri]

I don't believe this needs libc++'s signoff, it only mechanically replicates
the exact same change to the same external dependency into all the duplicate copies of said dependency.
@myhsu i still maintain that you can just commit this now.

[ldionne]

Indeed, this is fine without libc++'s signoff. Libc++ is added automatically because it touches files in libcxx/. Thanks for asking, though.

[myhsu]

In D88868#2442287, @lebedev.ri wrote:

I don't believe this needs libc++'s signoff, it only mechanically replicates
the exact same change to the same external dependency into all the duplicate copies of said dependency.
@myhsu i still maintain that you can just commit this now.

As @ldionne mentioned libcxx was added automatically and I couldn't remove it. Otherwise I've already committed this patch a while ago: https://github.com/llvm/llvm-test-suite/commit/25883edc2f615a84c4fa741e997904293474bbc0

[RKSimon]

In D88868#2443692, @myhsu wrote:

In D88868#2442287, @lebedev.ri wrote:

I don't believe this needs libc++'s signoff, it only mechanically replicates
the exact same change to the same external dependency into all the duplicate copies of said dependency.
@myhsu i still maintain that you can just commit this now.

As @ldionne mentioned libcxx was added automatically and I couldn't remove it. Otherwise I've already committed this patch a while ago: https://github.com/llvm/llvm-test-suite/commit/25883edc2f615a84c4fa741e997904293474bbc0

Isn't that just testsuite's copy of the code from D89011? It looks like at least the libcxx parts of this patch still need committing.

[myhsu]

In D88868#2445067, @RKSimon wrote:

In D88868#2443692, @myhsu wrote:

In D88868#2442287, @lebedev.ri wrote:

I don't believe this needs libc++'s signoff, it only mechanically replicates
the exact same change to the same external dependency into all the duplicate copies of said dependency.
@myhsu i still maintain that you can just commit this now.

As @ldionne mentioned libcxx was added automatically and I couldn't remove it. Otherwise I've already committed this patch a while ago: https://github.com/llvm/llvm-test-suite/commit/25883edc2f615a84c4fa741e997904293474bbc0

Isn't that just testsuite's copy of the code from D89011? It looks like at least the libcxx parts of this patch still need committing.

You’re right, this a a different one. I’ll commit this shortly

[myhsu]

It turns out I've already committed this at the same time with changes in llvm-test (after @lebedev.ri approved this) and I totally forgot about it :-P
https://github.com/llvm/llvm-project/commit/bd5fe7b010ea0d6c4b1e5e3740085f5eabf7def6