[VE] Support FRAMEADDR

[kaz7]

Summary

Implement FRAMEADDR for VE. Add a regression test also.

llvm/lib/Target/VE/VEISelLowering.cpp

SDValue VETargetLowering::lowerDYNAMIC_STACKALLOC(SDValue Op,
   //  Chain = Result.getValue(1);
   Chain = DAG.getCALLSEQ_END(Chain, DAG.getIntPtrConstant(0, DL, true),
                              DAG.getIntPtrConstant(0, DL, true), SDValue(), DL);
 
   SDValue Ops[2] = {Result, Chain};
   return DAG.getMergeValues(Ops, DL);
 }
 
+static SDValue lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG,
+                              const VETargetLowering &TLI,
+                              const VESubtarget *Subtarget) {
+  SDLoc DL(Op);
+  MachineFunction &MF = DAG.getMachineFunction();
+  EVT PtrVT = TLI.getPointerTy(MF.getDataLayout());
+
+  MachineFrameInfo &MFI = MF.getFrameInfo();
+  MFI.setFrameAddressIsTaken(true);
+
+  unsigned Depth = Op.getConstantOperandVal(0);
+  const VERegisterInfo *RegInfo = Subtarget->getRegisterInfo();
+  unsigned FrameReg = RegInfo->getFrameRegister(MF);
+  SDValue FrameAddr =
+      DAG.getCopyFromReg(DAG.getEntryNode(), DL, FrameReg, PtrVT);
+  while (Depth--)
+    FrameAddr = DAG.getLoad(Op.getValueType(), DL, DAG.getEntryNode(),
+                            FrameAddr, MachinePointerInfo());
+  return FrameAddr;
+}
+
 static SDValue getSplatValue(SDNode *N) {
   if (auto *BuildVec = dyn_cast<BuildVectorSDNode>(N)) {
     return BuildVec->getSplatValue();
   }
   return SDValue();
 }
 
 SDValue VETargetLowering::lowerBUILD_VECTOR(SDValue Op,
SDValue VETargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
   case ISD::ATOMIC_SWAP:
     return lowerATOMIC_SWAP(Op, DAG);
   case ISD::BlockAddress:
     return lowerBlockAddress(Op, DAG);
   case ISD::ConstantPool:
     return lowerConstantPool(Op, DAG);
   case ISD::DYNAMIC_STACKALLOC:
     return lowerDYNAMIC_STACKALLOC(Op, DAG);
+  case ISD::FRAMEADDR:
+    return lowerFRAMEADDR(Op, DAG, *this, Subtarget);
   case ISD::GlobalAddress:
     return lowerGlobalAddress(Op, DAG);
   case ISD::GlobalTLSAddress:
     return lowerGlobalTLSAddress(Op, DAG);
   case ISD::JumpTable:
     return lowerJumpTable(Op, DAG);
   case ISD::LOAD:
     return lowerLOAD(Op, DAG);

llvm/test/CodeGen/VE/Scalar/frameaddr.ll

+; RUN: llc < %s -mtriple=ve | FileCheck %s
+
+define i8* @test1() nounwind {
+; CHECK-LABEL: test1:
+; CHECK:       .LBB{{[0-9]+}}_2:
+; CHECK-NEXT:    or %s0, 0, %s9
+; CHECK-NEXT:    or %s11, 0, %s9
+entry:
+  %ret = tail call i8* @llvm.frameaddress(i32 0)
+  ret i8* %ret
+}
+
+define i8* @test2() nounwind {
+; CHECK-LABEL: test2:
+; CHECK:       .LBB{{[0-9]+}}_2:
+; CHECK-NEXT:    ld %s0, (, %s9)
+; CHECK-NEXT:    ld %s0, (, %s0)
+; CHECK-NEXT:    or %s11, 0, %s9
+entry:
+  %ret = tail call i8* @llvm.frameaddress(i32 2)
+  ret i8* %ret
+}
+
+declare i8* @llvm.frameaddress(i32) nounwind readnone