[llvm] [X86] Remove single use assumption in combineVectorSizedSetCCEquality (PR #182200)

Fri Apr 3 00:10:02 PDT 2026

ilovepi wrote:

Sorry for the late response. It took me some time to figure this  out. Turns out some feature the existing test got enabled by another part of the system. The bug was already there in the source and didn’t have coverage on x86. What it ended up being was some UB due to an out of bounds write. This only showed up on asserts enabled builds of the Toolchain due (I think) to some different behavior in frame lowering in asserts builds. 

Long story short: your patch is good and we misattributed the failure to something in the Toolchain. Sorry for the noise. 

https://github.com/llvm/llvm-project/pull/182200