aarch64 llvm 14 regression with vectors: assertion `TmpVec.size() > 1' failed #56397
Description
Does not affect LLVM 13.0.1.
Tested with LLVM 14.0.6. Have not yet confirmed whether it affects trunk.
Reduced LLVM IR:
define internal fastcc i16 @test2.doTheTest.S.doTheTest() {
Block10:
%0 = call fastcc i16 undef(<3 x i32> zeroinitializer, <3 x i32> zeroinitializer)
ret i16 0
}Reproduction:
$ ~/local/llvm14-debug/bin/clang -c reduced.ll -target aarch64-linux-unknown
warning: overriding the module target triple with aarch64-unknown-linux-unknown [-Woverride-module]
clang: /home/andy/Downloads/llvm-project-14/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp:656: llvm::MachineInstrBuilder llvm::MachineIRBuilder::buildUnmerge(llvm::ArrayRef<llvm::Register>, const llvm::SrcOp&): Assertion `TmpVec.size() > 1' failed.Downstream issue: ziglang/zig#12012
Apologies for not catching this during the RC phase.