llvm-project

45ccbd4e - AMDGPU: Don't pack a build_vector with an undef/poison lane (#211871)

AMDGPU: Don't pack a build_vector with an undef/poison lane (#211871) Once ISD::POISON is legal it reaches isel and is treated as canonical, so is_canonicalized_2<build_vector> matched build_vector<x, poison> and selected a v_pack for a don't-care high lane. Avoids regressions in future patches. Co-authored-by: Claude (Claude-Opus-4.8)