[CodeGen] MachineVerifier to check early-clobber constraint

llvm/lib/CodeGen/MachineVerifier.cpp

@@ -2584,6 +2584,14 @@ MachineVerifier::visitMachineOperand(const MachineOperand *MO, unsigned MONum) {
       report("Extra explicit operand on non-variadic instruction", MO, MONum);
   }
 
+  // Verify earlyClobber def operand
+  if (MCID.getOperandConstraint(MONum, MCOI::EARLY_CLOBBER) != -1) {
+    if (!MO->isReg())
+      report("Early clobber must be a register", MI);
+    if (!MO->isEarlyClobber())
+      report("Missing earlyClobber flag", MI);
+  }
+
   switch (MO->getType()) {
   case MachineOperand::MO_Register: {
     // Verify debug flag on debug instructions. Check this first because reg0

llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp

@@ -116,8 +116,14 @@ bool AMDGPUInstructionSelector::constrainCopyLikeIntrin(MachineInstr &MI,
   if (!DstRC || DstRC != SrcRC)
     return false;
 
-  return RBI.constrainGenericRegister(Dst.getReg(), *DstRC, *MRI) &&
-         RBI.constrainGenericRegister(Src.getReg(), *SrcRC, *MRI);
+  if (!RBI.constrainGenericRegister(Dst.getReg(), *DstRC, *MRI) ||
+      !RBI.constrainGenericRegister(Src.getReg(), *SrcRC, *MRI))
+    return false;
+  const MCInstrDesc &MCID = MI.getDesc();
+  if (MCID.getOperandConstraint(0, MCOI::EARLY_CLOBBER) != -1) {
+    MI.getOperand(0).setIsEarlyClobber(true);
+  }
+  return true;
 }
 
 bool AMDGPUInstructionSelector::selectCOPY(MachineInstr &I) const {
@@ -602,6 +608,7 @@ bool AMDGPUInstructionSelector::selectG_AMDGPU_MAD_64_32(
   I.setDesc(TII.get(Opc));
   I.addOperand(*MF, MachineOperand::CreateImm(0));
   I.addImplicitDefUseOperands(*MF);
+  I.getOperand(0).setIsEarlyClobber(true);
   return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
 }
 
@@ -3787,6 +3794,10 @@ bool AMDGPUInstructionSelector::selectSMFMACIntrin(MachineInstr &MI) const {
   MI.removeOperand(1); // Intrinsic ID
   MI.addOperand(VDst_In); // Readd VDst_In to the end
   MI.addImplicitDefUseOperands(*MI.getParent()->getParent());
+  const MCInstrDesc &MCID = MI.getDesc();
+  if (MCID.getOperandConstraint(0, MCOI::EARLY_CLOBBER) != -1) {
+    MI.getOperand(0).setIsEarlyClobber(true);
+  }
   return true;
 }
 

llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.amdgcn.set.inactive.ll

@@ -27,11 +27,11 @@ define amdgpu_kernel void @set_inactive_imm_poison(ptr addrspace(1) %out) {
 ; GCN:       ; %bb.0:
 ; GCN-NEXT:    s_load_dwordx2 s[0:1], s[4:5], 0x24
 ; GCN-NEXT:    v_mov_b32_e32 v0, 1
-; GCN-NEXT:    v_mov_b32_e32 v0, v0
+; GCN-NEXT:    v_mov_b32_e32 v1, v0
 ; GCN-NEXT:    s_mov_b32 s2, -1
 ; GCN-NEXT:    s_mov_b32 s3, 0xf000
 ; GCN-NEXT:    s_waitcnt lgkmcnt(0)
-; GCN-NEXT:    buffer_store_dword v0, off, s[0:3], 0
+; GCN-NEXT:    buffer_store_dword v1, off, s[0:3], 0
 ; GCN-NEXT:    s_endpgm
   %tmp.0 = call i32 @llvm.amdgcn.set.inactive.i32(i32 1, i32 poison) #0
   %tmp = call i32 @llvm.amdgcn.strict.wwm.i32(i32 %tmp.0)
@@ -68,12 +68,12 @@ define amdgpu_kernel void @set_inactive_imm_poison_64(ptr addrspace(1) %out) {
 ; GCN-NEXT:    s_load_dwordx2 s[0:1], s[4:5], 0x24
 ; GCN-NEXT:    v_mov_b32_e32 v0, 1
 ; GCN-NEXT:    v_mov_b32_e32 v1, 0
-; GCN-NEXT:    v_mov_b32_e32 v0, v0
-; GCN-NEXT:    v_mov_b32_e32 v1, v1
+; GCN-NEXT:    v_mov_b32_e32 v2, v0
+; GCN-NEXT:    v_mov_b32_e32 v3, v1
 ; GCN-NEXT:    s_mov_b32 s2, -1
 ; GCN-NEXT:    s_mov_b32 s3, 0xf000
 ; GCN-NEXT:    s_waitcnt lgkmcnt(0)
-; GCN-NEXT:    buffer_store_dwordx2 v[0:1], off, s[0:3], 0
+; GCN-NEXT:    buffer_store_dwordx2 v[2:3], off, s[0:3], 0
 ; GCN-NEXT:    s_endpgm
   %tmp.0 = call i64 @llvm.amdgcn.set.inactive.i64(i64 1, i64 poison) #0
   %tmp = call i64 @llvm.amdgcn.strict.wwm.i64(i64 %tmp.0)

llvm/test/CodeGen/AMDGPU/GlobalISel/mul-known-bits.i64.ll

@@ -165,10 +165,10 @@ define amdgpu_kernel void @v_mul_i64_zext_src0_src1(ptr addrspace(1) %out, ptr a
 ; GFX10-NEXT:    v_lshlrev_b32_e32 v0, 2, v0
 ; GFX10-NEXT:    s_waitcnt lgkmcnt(0)
 ; GFX10-NEXT:    s_clause 0x1
-; GFX10-NEXT:    global_load_dword v1, v0, s[2:3]
-; GFX10-NEXT:    global_load_dword v2, v0, s[6:7]
+; GFX10-NEXT:    global_load_dword v2, v0, s[2:3]
+; GFX10-NEXT:    global_load_dword v3, v0, s[6:7]
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
-; GFX10-NEXT:    v_mad_u64_u32 v[0:1], s2, v1, v2, 0
+; GFX10-NEXT:    v_mad_u64_u32 v[0:1], s2, v2, v3, 0
 ; GFX10-NEXT:    v_mov_b32_e32 v2, 0
 ; GFX10-NEXT:    global_store_dwordx2 v2, v[0:1], s[0:1]
 ; GFX10-NEXT:    s_endpgm
@@ -179,15 +179,15 @@ define amdgpu_kernel void @v_mul_i64_zext_src0_src1(ptr addrspace(1) %out, ptr a
 ; GFX11-NEXT:    s_load_b128 s[0:3], s[4:5], 0x24
 ; GFX11-NEXT:    s_load_b64 s[4:5], s[4:5], 0x34
 ; GFX11-NEXT:    v_and_b32_e32 v0, 0x3ff, v0
-; GFX11-NEXT:    v_mov_b32_e32 v2, 0
-; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_2)
+; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
 ; GFX11-NEXT:    v_lshlrev_b32_e32 v0, 2, v0
 ; GFX11-NEXT:    s_waitcnt lgkmcnt(0)
 ; GFX11-NEXT:    s_clause 0x1
-; GFX11-NEXT:    global_load_b32 v1, v0, s[2:3]
-; GFX11-NEXT:    global_load_b32 v0, v0, s[4:5]
+; GFX11-NEXT:    global_load_b32 v2, v0, s[2:3]
+; GFX11-NEXT:    global_load_b32 v3, v0, s[4:5]
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
-; GFX11-NEXT:    v_mad_u64_u32 v[0:1], null, v1, v0, 0
+; GFX11-NEXT:    v_mad_u64_u32 v[0:1], null, v2, v3, 0
+; GFX11-NEXT:    v_mov_b32_e32 v2, 0
 ; GFX11-NEXT:    global_store_b64 v2, v[0:1], s[0:1]
 ; GFX11-NEXT:    s_endpgm
   %tid = call i32 @llvm.amdgcn.workitem.id.x()