[PATCH] D70237: [X86] Add more addcarry tests

Fri Nov 15 02:59:06 PST 2019

chfast added a comment.

In D70237#1747220 <https://reviews.llvm.org/D70237#1747220>, @davezarzycki wrote:

> Yes, please update subcarry.ll too.

I will.

> And thanks, I was trying to see why the AND instruction was used by "add_U256_without_i128_or_recursive". It's not wrong but it is more complicated than it needs to be. If you are somebody else wants to add more pattern matching as a refinement, let's handle that in a subsequent patch.

Yes, that's reasonable. This implementation comes from my small library for 256-bit arithmetic. The 255-bit addition is defined in terms of uint128 type (custom, not __int128). I just inlined all the functions manually. Maybe there is a way to change my implementation in a way it will benefit from this PR.
Anyway, the only question for is if I should keep this test.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D70237/new/

https://reviews.llvm.org/D70237