AMDGPU: Add VI i16 support

Patch By: Wei Ding

Differential Revision: https://reviews.llvm.org/D18049

llvm-svn: 286464
diff --git a/llvm/test/CodeGen/AMDGPU/load-local-i8.ll b/llvm/test/CodeGen/AMDGPU/load-local-i8.ll
index 6b5b1cf..02b59e8 100644
--- a/llvm/test/CodeGen/AMDGPU/load-local-i8.ll
+++ b/llvm/test/CodeGen/AMDGPU/load-local-i8.ll
@@ -1,5 +1,5 @@
-; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=FUNC %s
-; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs < %s | FileCheck -check-prefix=GCN -check-prefix=FUNC %s
+; RUN: llc -march=amdgcn -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,SI,FUNC %s
+; RUN: llc -march=amdgcn -mcpu=tonga -verify-machineinstrs < %s | FileCheck -check-prefixes=GCN,VI,FUNC %s
 ; RUN: llc -march=r600 -mcpu=redwood < %s | FileCheck -check-prefix=EG -check-prefix=FUNC %s
 
 
@@ -141,8 +141,17 @@
 ; GCN-NOT: s_wqm_b64
 ; GCN: s_mov_b32 m0
 ; GCN: ds_read_u16
-; GCN-DAG: v_bfe_i32 v{{[0-9]+}}, v{{[0-9]+}}, 8, 8
-; GCN-DAG: v_bfe_i32 v{{[0-9]+}}, v{{[0-9]+}}, 0, 8
+; FIXME: Need to optimize this sequence to avoid extra shift on VI.
+;         t23: i16 = srl t39, Constant:i32<8> 
+;          t31: i32 = any_extend t23
+;        t33: i32 = sign_extend_inreg t31, ValueType:ch:i8
+
+; SI-DAG: v_bfe_i32 v{{[0-9]+}}, v{{[0-9]+}}, 8, 8
+; SI-DAG: v_bfe_i32 v{{[0-9]+}}, v{{[0-9]+}}, 0, 8
+
+; VI-DAG: v_lshrrev_b16_e32 [[SHIFT:v[0-9]+]], 8, v{{[0-9]+}}
+; VI-DAG: v_bfe_i32 v{{[0-9]+}}, v{{[0-9]+}}, 0, 8
+; VI-DAG: v_bfe_i32 v{{[0-9]+}}, [[SHIFT]], 0, 8
 
 ; EG: LDS_USHORT_READ_RET
 ; EG-DAG: BFE_INT
@@ -157,7 +166,8 @@
 ; FUNC-LABEL: {{^}}local_zextload_v3i8_to_v3i32:
 ; GCN: ds_read_b32
 
-; GCN-DAG: v_bfe_u32 v{{[0-9]+}}, v{{[0-9]+}}, 8, 8
+; SI-DAG: v_bfe_u32 v{{[0-9]+}}, v{{[0-9]+}}, 8, 8
+; VI-DAG: v_lshrrev_b16_e32 v{{[0-9]+}}, 8, {{v[0-9]+}}
 ; GCN-DAG: v_bfe_u32 v{{[0-9]+}}, v{{[0-9]+}}, 16, 8
 ; GCN-DAG: v_and_b32_e32 v{{[0-9]+}}, 0xff,