AMDGPU/GlobalISel: Implement select for G_INSERT

Re-commit r344310.

Reviewers: arsenm

Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, rovka, kristof.beyls, dstuttard, tpr, t-tye, llvm-commits

Differential Revision: https://reviews.llvm.org/D53116

llvm-svn: 355159

1 files changed, 30 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
index 0619f1fc3db..f35c2a1a259 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUInstructionSelector.cpp
@@ -199,6 +199,34 @@ bool AMDGPUInstructionSelector::selectG_IMPLICIT_DEF(MachineInstr &I) const {
   return true;
 }
 
+bool AMDGPUInstructionSelector::selectG_INSERT(MachineInstr &I) const {
+  MachineBasicBlock *BB = I.getParent();
+  MachineFunction *MF = BB->getParent();
+  MachineRegisterInfo &MRI = MF->getRegInfo();
+  unsigned SubReg = TRI.getSubRegFromChannel(I.getOperand(3).getImm() / 32);
+  DebugLoc DL = I.getDebugLoc();
+  MachineInstr *Ins = BuildMI(*BB, &I, DL, TII.get(TargetOpcode::INSERT_SUBREG))
+                               .addDef(I.getOperand(0).getReg())
+                               .addReg(I.getOperand(1).getReg())
+                               .addReg(I.getOperand(2).getReg())
+                               .addImm(SubReg);
+
+  for (const MachineOperand &MO : Ins->operands()) {
+    if (!MO.isReg())
+      continue;
+    if (TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
+      continue;
+
+    const TargetRegisterClass *RC =
+            TRI.getConstrainedRegClassForOperand(MO, MRI);
+    if (!RC)
+      continue;
+    RBI.constrainGenericRegister(MO.getReg(), *RC, MRI);
+  }
+  I.eraseFromParent();
+  return true;
+}
+
 bool AMDGPUInstructionSelector::selectG_INTRINSIC(MachineInstr &I,
                                           CodeGenCoverage &CoverageInfo) const {
   unsigned IntrinsicID =  I.getOperand(1).getIntrinsicID();
@@ -537,6 +565,8 @@ bool AMDGPUInstructionSelector::select(MachineInstr &I,
     return selectG_GEP(I);
   case TargetOpcode::G_IMPLICIT_DEF:
     return selectG_IMPLICIT_DEF(I);
+  case TargetOpcode::G_INSERT:
+    return selectG_INSERT(I);
   case TargetOpcode::G_INTRINSIC:
     return selectG_INTRINSIC(I, CoverageInfo);
   case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS: