llvm-project

50f9b34b - [RISCV] Prefer vmv.s.x for build_vector a, undef, ..., undef (#136164)

[RISCV] Prefer vmv.s.x for build_vector a, undef, ..., undef (#136164) If we have a build vector which could be either a splat or a scalar insert, prefer the scalar insert. At high LMUL, this reduces vector register pressure (locally, the use will likely still be aligned), and the amount of work performed for the splat.