[AArch64][SVE] Add +fullfp16 to sve-vector-splat.ll

[cameron.mcinally]

Summary

Add +fullfp16 to sve-vector-splat.ll so we can test folding of immediates into moves.

This attribute can go away later when SVE has a full set of fp16 patterns in place.

[efriedma]

LGTM

llvm/test/CodeGen/AArch64/sve-vector-splat.ll

-; RUN: llc -mtriple=aarch64-linux-gnu -mattr=+sve < %s | FileCheck %s
+; RUN: llc -mtriple=aarch64-linux-gnu -mattr=+sve,+fullfp16  < %s | FileCheck %s
 
 ;; Splats of legal integer vector types
 
 define <vscale x 16 x i8> @sve_splat_16xi8(i8 %val) {
 ; CHECK-LABEL: @sve_splat_16xi8
 ; CHECK: mov z0.b, w0
 ; CHECK-NEXT: ret
   %ins = insertelement <vscale x 16 x i8> undef, i8 %val, i32 0

 ; CHECK-LABEL: splat_nxv2f64:
 ; CHECK: mov z0.d, d0
 ; CHECK-NEXT: ret
   %1 = insertelement <vscale x 2 x double> undef, double %val, i32 0
   %2 = shufflevector <vscale x 2 x double> %1, <vscale x 2 x double> undef, <vscale x 2 x i32> zeroinitializer
   ret <vscale x 2 x double> %2
 }
 
-; TODO: The f16 constant should be folded into the move.
 define <vscale x 8 x half> @splat_nxv8f16_zero() {
 ; CHECK-LABEL: splat_nxv8f16_zero:
-; CHECK: mov z0.h, h0
+; CHECK: mov z0.h, #0
 ; CHECK-NEXT: ret
   ret <vscale x 8 x half> zeroinitializer
 }
 
-; TODO: The f16 constant should be folded into the move.
 define <vscale x 4 x half> @splat_nxv4f16_zero() {
 ; CHECK-LABEL: splat_nxv4f16_zero:
-; CHECK: mov z0.h, h0
+; CHECK: mov z0.h, #0
 ; CHECK-NEXT: ret
   ret <vscale x 4 x half> zeroinitializer
 }
 
-; TODO: The f16 constant should be folded into the move.
 define <vscale x 2 x half> @splat_nxv2f16_zero() {
 ; CHECK-LABEL: splat_nxv2f16_zero:
-; CHECK: mov z0.h, h0
+; CHECK: mov z0.h, #0
 ; CHECK-NEXT: ret
   ret <vscale x 2 x half> zeroinitializer
 }
 
 define <vscale x 4 x float> @splat_nxv4f32_zero() {
 ; CHECK-LABEL: splat_nxv4f32_zero:
 ; CHECK: mov z0.s, #0
 ; CHECK-NEXT: ret