AMDGPU: Use getTargetConstant

[arsenm]

Summary

Avoids creating an extra intermediate mov.

[rampitec]

LGTM

[arsenm]

r366340

lib/Target/AMDGPU/AMDGPUISelDAGToDAG.cpp

SDNode *AMDGPUDAGToDAGISel::glueCopyToM0LDSInit(SDNode *N) const {
   }
   return N;
 }
 
 MachineSDNode *AMDGPUDAGToDAGISel::buildSMovImm64(SDLoc &DL, uint64_t Imm,
                                                   EVT VT) const {
   SDNode *Lo = CurDAG->getMachineNode(
       AMDGPU::S_MOV_B32, DL, MVT::i32,
-      CurDAG->getConstant(Imm & 0xFFFFFFFF, DL, MVT::i32));
+      CurDAG->getTargetConstant(Imm & 0xFFFFFFFF, DL, MVT::i32));
   SDNode *Hi =
       CurDAG->getMachineNode(AMDGPU::S_MOV_B32, DL, MVT::i32,
-                             CurDAG->getConstant(Imm >> 32, DL, MVT::i32));
+                             CurDAG->getTargetConstant(Imm >> 32, DL, MVT::i32));
   const SDValue Ops[] = {
       CurDAG->getTargetConstant(AMDGPU::SReg_64RegClassID, DL, MVT::i32),
       SDValue(Lo, 0), CurDAG->getTargetConstant(AMDGPU::sub0, DL, MVT::i32),
       SDValue(Hi, 0), CurDAG->getTargetConstant(AMDGPU::sub1, DL, MVT::i32)};
 
   return CurDAG->getMachineNode(TargetOpcode::REG_SEQUENCE, DL, VT, Ops);
 }
 

test/CodeGen/AMDGPU/shift-i128.ll

; GCN-NEXT:    s_setpc_b64 s[30:31]
   %shl = shl i128 17, %rhs
   ret i128 %shl
 }
 
 define i128 @v_lshr_i128_kv(i128 %rhs) {
 ; GCN-LABEL: v_lshr_i128_kv:
 ; GCN:       ; %bb.0:
 ; GCN-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GCN-NEXT:    s_mov_b32 s5, 0
 ; GCN-NEXT:    s_movk_i32 s4, 0x41
+; GCN-NEXT:    s_mov_b32 s5, 0
 ; GCN-NEXT:    v_lshr_b64 v[1:2], s[4:5], v0
 ; GCN-NEXT:    v_cmp_gt_u32_e32 vcc, 64, v0
+; GCN-NEXT:    v_mov_b32_e32 v3, s4
 ; GCN-NEXT:    v_cmp_ne_u32_e64 s[4:5], 0, v0
 ; GCN-NEXT:    v_cndmask_b32_e32 v1, 0, v1, vcc
-; GCN-NEXT:    v_mov_b32_e32 v3, 0x41
 ; GCN-NEXT:    s_and_b64 vcc, s[4:5], vcc
 ; GCN-NEXT:    v_cndmask_b32_e64 v0, v3, v1, s[4:5]
 ; GCN-NEXT:    v_cndmask_b32_e32 v1, 0, v2, vcc
 ; GCN-NEXT:    v_mov_b32_e32 v2, 0
 ; GCN-NEXT:    v_mov_b32_e32 v3, 0
 ; GCN-NEXT:    s_setpc_b64 s[30:31]
   %shl = lshr i128 65, %rhs
   ret i128 %shl