1 ; RUN: llc < %s -mtriple=aarch64--linux-gnu | FileCheck %s 2 3 ; PR23065: SCALAR_TO_VECTOR implies the top elements 1 to N-1 of the N-element vector are undefined. 4 5 define <4 x i16> @foo1(<2 x i32> %a) { 6 ; CHECK-LABEL: foo1: 7 ; CHECK: movi d0, #0000000000000000 8 ; CHECK-NEXT: ret 9 10 %1 = shufflevector <2 x i32> <i32 58712, i32 undef>, <2 x i32> %a, <2 x i32> <i32 0, i32 2> 11 ; Can't optimize the following bitcast to scalar_to_vector. 12 %2 = bitcast <2 x i32> %1 to <4 x i16> 13 %3 = shufflevector <4 x i16> %2, <4 x i16> undef, <4 x i32> <i32 1, i32 undef, i32 undef, i32 undef> 14 ret <4 x i16> %3 15 } 16 17 define <4 x i16> @foo2(<2 x i32> %a) { 18 ; CHECK-LABEL: foo2: 19 ; CHECK: movi d0, #0000000000000000 20 ; CHECK-NEXT: ret 21 22 %1 = shufflevector <2 x i32> <i32 712, i32 undef>, <2 x i32> %a, <2 x i32> <i32 0, i32 2> 23 ; Can't optimize the following bitcast to scalar_to_vector. 24 %2 = bitcast <2 x i32> %1 to <4 x i16> 25 %3 = shufflevector <4 x i16> %2, <4 x i16> undef, <4 x i32> <i32 1, i32 undef, i32 undef, i32 undef> 26 ret <4 x i16> %3 27 } 28