llvm-project

bb315b7e - [X86] Update (p)haddsub undef element tests to match the output IR from the middle-end (#207244)

[X86] Update (p)haddsub undef element tests to match the output IR from the middle-end (#207244) Use the vectorised output from the PhaseOrdering/X86 hadd.ll tests - I've added test coverage for multiple SSE/AVX levels for cases where the middle-end output is different for any level. This exposes a number of regressions that have been there for some time but we'd missed as we'd assumed the backend would still be receiving non-vectorised IR, but there's been plenty of changes to SLP, InstCombine and VectorCombine since then - end2end tests would have been very useful here :( Looking at fixes next before finally removing the (dead) scalar hadd matching code for #143000