[WIP] Spill to register instead of stack

Author: niwinanto

llvm/lib/Target/AIE/aie2p/AIE2PInstrInfo.cpp

@@ -913,6 +913,18 @@ void AIE2PInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
     Opcode = AIE2P::VST_E_SPILL;
   } else if (regClassMatches(AIE2P::VEC576RegClass, RC, SrcReg)) {
     Opcode = AIE2P::VST_EX_SPILL;
+  } else if (regClassMatches(AIE2P::spill_acc1024_to_compositeRegClass, RC,
+                             SrcReg)) {
+    Opcode = AIE2P::VST_CM_SPILL;
+  } else if (regClassMatches(AIE2P::spill_acc512_to_compositeRegClass, RC,
+                             SrcReg)) {
+    Opcode = AIE2P::VST_dmx_sts_bm_spill;
+  } else if (regClassMatches(AIE2P::spill_vec1024_to_compositeRegClass, RC,
+                             SrcReg)) {
+    Opcode = AIE2P::VST_Y_SPILL;
+  } else if (regClassMatches(AIE2P::spill_vec512_to_compositeRegClass, RC,
+                             SrcReg)) {
+    Opcode = AIE2P::VST_dmx_sts_x_spill;
   } else if (regClassMatches(AIE2P::eSRegClass, RC, SrcReg) ||
              regClassMatches(AIE2P::spill_eS_to_eRRegClass, RC, SrcReg)) {
     // Can't spill these directly.  Need to bounce through a GPR.
@@ -982,6 +994,7 @@ void AIE2PInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
   } else if (regClassMatches(AIE2P::ACC2048RegClass, RC, DstReg)) {
     Opcode = AIE2P::VLDA_DM_SPILL;
   } else if (regClassMatches(AIE2P::ACC1024RegClass, RC, DstReg)) {
+    I->dump();
     Opcode = AIE2P::VLDA_CM_SPILL;
   } else if (regClassMatches(AIE2P::FIFO1024RegClass, RC, DstReg)) {
     Opcode = AIE2P::VLDA_FIFO_SPILL;
@@ -999,6 +1012,18 @@ void AIE2PInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
     Opcode = AIE2P::VLDA_E_SPILL;
   } else if (regClassMatches(AIE2P::VEC576RegClass, RC, DstReg)) {
     Opcode = AIE2P::VLDA_EX_SPILL;
+  } else if (regClassMatches(AIE2P::spill_acc1024_to_compositeRegClass, RC,
+                             DstReg)) {
+    Opcode = AIE2P::VLDA_CM_SPILL;
+  } else if (regClassMatches(AIE2P::spill_acc512_to_compositeRegClass, RC,
+                             DstReg)) {
+    Opcode = AIE2P::VLDA_dmx_lda_bm_spill;
+  } else if (regClassMatches(AIE2P::spill_vec1024_to_compositeRegClass, RC,
+                             DstReg)) {
+    Opcode = AIE2P::VLDA_Y_SPILL;
+  } else if (regClassMatches(AIE2P::spill_vec512_to_compositeRegClass, RC,
+                             DstReg)) {
+    Opcode = AIE2P::VLDA_dmx_lda_x_spill;
   } else if (regClassMatches(AIE2P::eSRegClass, RC, DstReg) ||
              regClassMatches(AIE2P::spill_eS_to_eRRegClass, RC, DstReg)) {
     // Can't spill these directly.  Need to bounce through a GPR.
@@ -1011,6 +1036,7 @@ void AIE2PInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
         .addReg(Reg, getKillRegState(true));
     return;
   } else {
+    I->dump();
     llvm_unreachable(
         "Can't load this register from stack slot: is it virtual?");
   }

llvm/lib/Target/AIE/aie2p/AIE2PRegisterInfo.cpp

@@ -43,6 +43,12 @@ cl::opt<bool> EnableCoalescingForWideCopy(
 
 extern llvm::cl::opt<unsigned> ReservedGPRs;
 
+static llvm::cl::opt<bool>
+    SpillAccToVecOrAcc("aie2p-spill-accumulator-to-vec-or-acc", cl::Hidden,
+                       cl::init(true),
+                       cl::desc("Allow spilling accumulator registers to "
+                                "vector or accumulator registers"));
+
 AIE2PRegisterInfo::AIE2PRegisterInfo(unsigned HwMode)
     : AIE2PGenRegisterInfo(AIE2P::sp, /*DwarfFlavour*/ 0, /*EHFlavor*/ 0,
                            /*PC*/ 0, HwMode) {}
@@ -482,6 +488,14 @@ AIE2PRegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
 
   if (AIE2P::eSRegClass.hasSubClassEq(RC))
     return &AIE2P::spill_eS_to_eRRegClass;
+  if (SpillAccToVecOrAcc && RC == &AIE2P::ACC1024RegClass)
+    return &AIE2P::spill_acc1024_to_compositeRegClass;
+  if (SpillAccToVecOrAcc && RC == &AIE2P::ACC512RegClass)
+    return &AIE2P::spill_acc512_to_compositeRegClass;
+  if (SpillAccToVecOrAcc && RC == &AIE2P::VEC1024RegClass)
+    return &AIE2P::spill_vec1024_to_compositeRegClass;
+  if (SpillAccToVecOrAcc && RC == &AIE2P::VEC512RegClass)
+    return &AIE2P::spill_vec512_to_compositeRegClass;
   return RC;
 }
 

llvm/lib/Target/AIE/aie2p/AIE2PRegisterInfo.td

@@ -1003,4 +1003,9 @@ def spill_eDN_to_eR : AIE2PScalarRegisterClass<(add eDN, eR)>;
 def spill_eDJ_to_eR : AIE2PScalarRegisterClass<(add eDJ, eR, eDN)>;
 def spill_eDC_to_eR : AIE2PScalarRegisterClass<(add eDC, eR)>;
 
+def spill_vec512_to_composite : AIE2PVector512RegisterClass<(add mXm, mBMm)>;
+def spill_vec1024_to_composite : AIE2PVector1024RegisterClass<(add eY, mCMm)>;
+def spill_acc512_to_composite : AIE2PVector512RegisterClass<(add mBMm, mXm)>;
+def spill_acc1024_to_composite : AIE2PVector1024RegisterClass<(add mCMm, eY)>;
+
 } // End AIE2P Namespace