[PATCH] D150107: [X86] Remove patterns for shift/rotate with immediate 1 and optimize during MC lowering

Fri May 19 07:32:52 PDT 2023

skan added a comment.

In D150107#4356140 <https://reviews.llvm.org/D150107#4356140>, @hans wrote:

> In D150107#4356102 <https://reviews.llvm.org/D150107#4356102>, @hans wrote:
>
>>> skan mentioned this in rG2ef8ae134828 <https://reviews.llvm.org/rG2ef8ae134828876ab3ebda4a81bb2df7b095d030>: [X86] Remove patterns for ADC/SBB with immediate 8 and optimize during MC…
>>
>> That caused assert in Chromium builds. See https://bugs.chromium.org/p/chromium/issues/detail?id=1446973#c2 for a reproducer.
>
> I'll revert while that's investigated.

If you retested the reproducer before the revert, you would find it already passed after 5586bc539acb26cb94e461438de01a5080513401 <https://reviews.llvm.org/rG5586bc539acb26cb94e461438de01a5080513401>. So I reapplied the patch.

It failed before b/c the last operand of `MCInst` ADC/SBBri could be an expression instead of an immediate.

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D150107/new/

https://reviews.llvm.org/D150107