[AMDGPU]  Return true in enableMultipleCopyHints().

Enable multiple COPY hints to eliminate more COPYs during register allocation.

Note that this is something all targets should do, see
https://reviews.llvm.org/D38128.

Review: Stanislav Mekhanoshin, Tom Stellard.
llvm-svn: 325425
diff --git a/llvm/test/CodeGen/AMDGPU/callee-special-input-sgprs.ll b/llvm/test/CodeGen/AMDGPU/callee-special-input-sgprs.ll
index 8f9fa41..de61b24 100644
--- a/llvm/test/CodeGen/AMDGPU/callee-special-input-sgprs.ll
+++ b/llvm/test/CodeGen/AMDGPU/callee-special-input-sgprs.ll
@@ -208,8 +208,8 @@
 ; GCN: enable_sgpr_workgroup_id_z = 0
 
 ; GCN: s_mov_b32 s33, s8
-; GCN: s_mov_b32 s4, s33
-; GCN: s_mov_b32 s6, s7
+; GCN-DAG: s_mov_b32 s4, s33
+; GCN-DAG: s_mov_b32 s6, s7
 ; GCN: s_mov_b32 s32, s33
 ; GCN: s_swappc_b64
 define amdgpu_kernel void @kern_indirect_use_workgroup_id_y() #1 {
@@ -223,8 +223,8 @@
 ; GCN: enable_sgpr_workgroup_id_z = 1
 
 ; GCN: s_mov_b32 s33, s8
-; GCN: s_mov_b32 s4, s33
-; GCN: s_mov_b32 s6, s7
+; GCN-DAG: s_mov_b32 s4, s33
+; GCN-DAG: s_mov_b32 s6, s7
 ; GCN: s_swappc_b64
 define amdgpu_kernel void @kern_indirect_use_workgroup_id_z() #1 {
   call void @use_workgroup_id_z()
@@ -396,7 +396,7 @@
 
 ; GCN-DAG: s_mov_b32 s33, s8
 ; GCN-DAG: v_mov_b32_e32 v0, 0x22b
-; GCN: s_mov_b32 s4, s33
+; GCN-DAG: s_mov_b32 s4, s33
 ; GCN-DAG: s_mov_b32 s6, s7
 ; GCN-DAG: s_mov_b32 s32, s33
 ; GCN: s_swappc_b64
@@ -412,7 +412,7 @@
 
 ; GCN: s_mov_b32 s33, s8
 ; GCN-DAG: v_mov_b32_e32 v0, 0x22b
-; GCN: s_mov_b32 s4, s33
+; GCN-DAG: s_mov_b32 s4, s33
 ; GCN-DAG: s_mov_b32 s6, s7
 
 ; GCN: s_mov_b32 s32, s33