Thanks!

In D96946#2571506, @ldionne wrote:

First of all, thanks for writing a design document and explaining the purpose of your patch. Let me try to understand the use case a bit better.

So basically, let's say you're trying to adopt a new implementation of std::sort internally. You change that, but then you realize that a bunch of tests break because they were relying on the exact order of equal elements after std::sort, which is really unspecified. But since those tests are failing, you can't use the new std::sort implementation until all the tests have been fixed. So, in order to make that transition easier and allow fixing tests one by one, you add this feature. You then turn it on locally for some projects/tests inside your organization, and you fix them one by one. Once you're done, you can switch the algorithm implementation, and turn off the randomization. Is that the idea?

Address comments

Fix unused parameters

Correctness

I need to double check the cold cache performance, it may happen that it is slower in that case

Provide better names than in paper

In D83547#2143840, @courbet wrote:

I have no idea what the policy is WRT size for compiler-rt. How big is the diff if you take code size into consideration ?

Fix clang format

Fix comments

Please, take a look

Update the real reference

879f4962e83f98863c83e385e956d579e131791f

Fix comments

Fix

Fix comments

Could you submit it for me? I don't have commit rights for now. danilak@google.com

Fix clang-tidy readability warnings more

clang-format

Fix non x86-mode

Fix clang-tidy warnings

Ping

Fix comments

Remove unnecessary header

In D81809#2092173, @courbet wrote:

Nice. I have not looked at the code yet, but I think it would make sense to add your benchmark to the compiler-rt unit tests.

CHAR_BIT instead of 8

Style

Ping and maybe I need some help in introducing benchmarks (if we really need to) for this because I don't quite understand how and where it should be best located.

Style

Clang format

Use native division when high is zero.

@spatel @lebedev.ri Ping

@lebedev.ri Friendly ping and see message from spatel@ above :)

In D71568#1812463, @danlark wrote:

In D71568#1812426, @spatel wrote:

In D71568#1812355, @spatel wrote:

There's a lot going on here, and the patch doesn't apply cleanly to current source. Can you pre-commit any NFC changes/tests to make this patch smaller? For example, the udiv change/tests are not affected by the mul code?

Sorry - I didn't see earlier that this patch is part of a sequence.
I'm a bit skeptical about the need to extend the "udiv action" machine. Are the motivating cases really that complicated or could we get away with a simpler pattern match of mul(select...)?

I am not sure but I just reused the code for both division and multiplication -- from my perspective the idea is the same.

Also, I rebased a bit and made the patch smaller as you asked.

In D71568#1812426, @spatel wrote:

In D71568#1812355, @spatel wrote:

There's a lot going on here, and the patch doesn't apply cleanly to current source. Can you pre-commit any NFC changes/tests to make this patch smaller? For example, the udiv change/tests are not affected by the mul code?

Sorry - I didn't see earlier that this patch is part of a sequence.
I'm a bit skeptical about the need to extend the "udiv action" machine. Are the motivating cases really that complicated or could we get away with a simpler pattern match of mul(select...)?

Rebase and make tests committed before

Rebase

Update tests

Removing div tests, we don't need them

@spatel You are doing a lot of stuff around this code, PTAL.

Applying m_ZExtOrSelf

@lebedev.ri Can you please take a look and possibly submit?

Ping

Replace finally everything with asserts

Remove nullptr assignment

Fix asserts

Another hopeless ping before NY

Ping

Ping.

Ping

Don't add zero

Also add NUW

In D71568#1788655, @lebedev.ri wrote:

Thank you for working on this.

Fix overflow in shifting and further propagation

Now I think review is in a good shape

Rebase and style

Update vector test

undef should return zero in select+shl

Correct INT_MIN test

Correct INT_MIN test

Rebase

More robust zext tests

Even more robust tests

More robust zext tests

Add zext test

Add simple min integer test