; RUN: llc < %s -mtriple=aarch64--linux-gnu | FileCheck %s ; PR23065: SCALAR_TO_VECTOR implies the top elements 1 to N-1 of the N-element vector are undefined. define <4 x i16> @foo1(<2 x i32> %a) { ; CHECK-LABEL: foo1: ; CHECK: movi d0, #0000000000000000 ; CHECK-NEXT: ret %1 = shufflevector <2 x i32> , <2 x i32> %a, <2 x i32> ; Can't optimize the following bitcast to scalar_to_vector. %2 = bitcast <2 x i32> %1 to <4 x i16> %3 = shufflevector <4 x i16> %2, <4 x i16> undef, <4 x i32> ret <4 x i16> %3 } define <4 x i16> @foo2(<2 x i32> %a) { ; CHECK-LABEL: foo2: ; CHECK: movi d0, #0000000000000000 ; CHECK-NEXT: ret %1 = shufflevector <2 x i32> , <2 x i32> %a, <2 x i32> ; Can't optimize the following bitcast to scalar_to_vector. %2 = bitcast <2 x i32> %1 to <4 x i16> %3 = shufflevector <4 x i16> %2, <4 x i16> undef, <4 x i32> ret <4 x i16> %3 }