From 1c450c3d7ec01d9daaf9f2651da93b01e7790ffd Mon Sep 17 00:00:00 2001
From: Kai Luo <lkail@cn.ibm.com>
Date: Tue, 15 Jun 2021 01:55:37 +0000
Subject: [PowerPC] Export 16 byte load-store instructions

Export `lq`, `stq`, `lqarx` and `stqcx.` in preparation for implementing 16-byte lock free atomic operations on AIX.
Add a new register class `g8prc` for these instructions, since these instructions require even-odd register pair.

Reviewed By: nemanjai, jsji, #powerpc

Differential Revision: https://reviews.llvm.org/D103010
---
 llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp | 61 +++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

(limited to 'llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp')

diff --git a/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp b/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp
index 260c5f3..8adef37 100644
--- a/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp
+++ b/llvm/lib/Target/PowerPC/PPCRegisterInfo.cpp
@@ -1146,6 +1146,59 @@ void PPCRegisterInfo::lowerACCRestore(MachineBasicBlock::iterator II,
   MBB.erase(II);
 }
 
+/// lowerQuadwordSpilling - Generate code to spill paired general register.
+void PPCRegisterInfo::lowerQuadwordSpilling(MachineBasicBlock::iterator II,
+                                            unsigned FrameIndex) const {
+  MachineInstr &MI = *II;
+  MachineBasicBlock &MBB = *MI.getParent();
+  MachineFunction &MF = *MBB.getParent();
+  const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
+  const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
+  DebugLoc DL = MI.getDebugLoc();
+
+  Register SrcReg = MI.getOperand(0).getReg();
+  bool IsKilled = MI.getOperand(0).isKill();
+
+  Register Reg = PPC::X0 + (SrcReg - PPC::G8p0) * 2;
+  bool IsLittleEndian = Subtarget.isLittleEndian();
+
+  addFrameReference(BuildMI(MBB, II, DL, TII.get(PPC::STD))
+                        .addReg(Reg, getKillRegState(IsKilled)),
+                    FrameIndex, IsLittleEndian ? 8 : 0);
+  addFrameReference(BuildMI(MBB, II, DL, TII.get(PPC::STD))
+                        .addReg(Reg + 1, getKillRegState(IsKilled)),
+                    FrameIndex, IsLittleEndian ? 0 : 8);
+
+  // Discard the pseudo instruction.
+  MBB.erase(II);
+}
+
+/// lowerQuadwordRestore - Generate code to restore paired general register.
+void PPCRegisterInfo::lowerQuadwordRestore(MachineBasicBlock::iterator II,
+                                           unsigned FrameIndex) const {
+  MachineInstr &MI = *II;
+  MachineBasicBlock &MBB = *MI.getParent();
+  MachineFunction &MF = *MBB.getParent();
+  const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
+  const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
+  DebugLoc DL = MI.getDebugLoc();
+
+  Register DestReg = MI.getOperand(0).getReg();
+  assert(MI.definesRegister(DestReg) &&
+         "RESTORE_QUADWORD does not define its destination");
+
+  Register Reg = PPC::X0 + (DestReg - PPC::G8p0) * 2;
+  bool IsLittleEndian = Subtarget.isLittleEndian();
+
+  addFrameReference(BuildMI(MBB, II, DL, TII.get(PPC::LD), Reg), FrameIndex,
+                    IsLittleEndian ? 8 : 0);
+  addFrameReference(BuildMI(MBB, II, DL, TII.get(PPC::LD), Reg + 1), FrameIndex,
+                    IsLittleEndian ? 0 : 8);
+
+  // Discard the pseudo instruction.
+  MBB.erase(II);
+}
+
 bool PPCRegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
                                            Register Reg, int &FrameIdx) const {
   // For the nonvolatile condition registers (CR2, CR3, CR4) return true to
@@ -1182,12 +1235,14 @@ static unsigned offsetMinAlignForOpcode(unsigned OpC) {
   case PPC::LXSSP:
   case PPC::STXSD:
   case PPC::STXSSP:
+  case PPC::STQ:
     return 4;
   case PPC::EVLDD:
   case PPC::EVSTDD:
     return 8;
   case PPC::LXV:
   case PPC::STXV:
+  case PPC::LQ:
     return 16;
   }
 }
@@ -1283,6 +1338,12 @@ PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   } else if (OpC == PPC::RESTORE_ACC || OpC == PPC::RESTORE_UACC) {
     lowerACCRestore(II, FrameIndex);
     return;
+  } else if (OpC == PPC::SPILL_QUADWORD) {
+    lowerQuadwordSpilling(II, FrameIndex);
+    return;
+  } else if (OpC == PPC::RESTORE_QUADWORD) {
+    lowerQuadwordRestore(II, FrameIndex);
+    return;
   }
 
   // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
-- 
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