[PowerPC] Add DMR and WACC COPY support (llvm#149129)

This patch updates PPCInstrInfo::copyPhysReg to support DMR and WACC
register classes and extends the PPCVSXCopy pass to handle specific WACC
copy patterns.

Author: maryammo

llvm/lib/Target/PowerPC/CMakeLists.txt

@@ -49,7 +49,7 @@ add_llvm_target(PowerPCCodeGen
   PPCTargetTransformInfo.cpp
   PPCTOCRegDeps.cpp
   PPCTLSDynamicCall.cpp
-  PPCVSXCopy.cpp
+  PPCVSXWACCCopy.cpp
   PPCReduceCRLogicals.cpp
   PPCVSXFMAMutate.cpp
   PPCVSXSwapRemoval.cpp

llvm/lib/Target/PowerPC/PPC.h

@@ -39,7 +39,7 @@ class ModulePass;
   FunctionPass *createPPCLoopInstrFormPrepPass(PPCTargetMachine &TM);
   FunctionPass *createPPCTOCRegDepsPass();
   FunctionPass *createPPCEarlyReturnPass();
-  FunctionPass *createPPCVSXCopyPass();
+  FunctionPass *createPPCVSXWACCCopyPass();
   FunctionPass *createPPCVSXFMAMutatePass();
   FunctionPass *createPPCVSXSwapRemovalPass();
   FunctionPass *createPPCReduceCRLogicalsPass();
@@ -64,7 +64,7 @@ class ModulePass;
   void initializePPCLoopInstrFormPrepPass(PassRegistry&);
   void initializePPCTOCRegDepsPass(PassRegistry&);
   void initializePPCEarlyReturnPass(PassRegistry&);
-  void initializePPCVSXCopyPass(PassRegistry&);
+  void initializePPCVSXWACCCopyPass(PassRegistry &);
   void initializePPCVSXFMAMutatePass(PassRegistry&);
   void initializePPCVSXSwapRemovalPass(PassRegistry&);
   void initializePPCReduceCRLogicalsPass(PassRegistry&);

llvm/lib/Target/PowerPC/PPCInstrInfo.cpp

@@ -30,6 +30,7 @@
 #include "llvm/CodeGen/PseudoSourceValue.h"
 #include "llvm/CodeGen/RegisterClassInfo.h"
 #include "llvm/CodeGen/RegisterPressure.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
 #include "llvm/CodeGen/ScheduleDAG.h"
 #include "llvm/CodeGen/SlotIndexes.h"
 #include "llvm/CodeGen/StackMaps.h"
@@ -1863,6 +1864,48 @@ void PPCInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
         .addReg(SrcRegSub1)
         .addReg(SrcRegSub1, getKillRegState(KillSrc));
     return;
+  } else if ((PPC::WACCRCRegClass.contains(DestReg) ||
+              PPC::WACC_HIRCRegClass.contains(DestReg)) &&
+             (PPC::WACCRCRegClass.contains(SrcReg) ||
+              PPC::WACC_HIRCRegClass.contains(SrcReg))) {
+
+    Opc = PPC::WACCRCRegClass.contains(SrcReg) ? PPC::DMXXEXTFDMR512
+                                               : PPC::DMXXEXTFDMR512_HI;
+
+    RegScavenger RS;
+    RS.enterBasicBlockEnd(MBB);
+    RS.backward(std::next(I));
+
+    Register TmpReg1 = RS.scavengeRegisterBackwards(PPC::VSRpRCRegClass, I,
+                                                    /* RestoreAfter */ false, 0,
+                                                    /* AllowSpill */ false);
+
+    RS.setRegUsed(TmpReg1);
+    Register TmpReg2 = RS.scavengeRegisterBackwards(PPC::VSRpRCRegClass, I,
+                                                    /* RestoreAfter */ false, 0,
+                                                    /* AllowSpill */ false);
+
+    BuildMI(MBB, I, DL, get(Opc))
+        .addReg(TmpReg1, RegState::Define)
+        .addReg(TmpReg2, RegState::Define)
+        .addReg(SrcReg, getKillRegState(KillSrc));
+
+    Opc = PPC::WACCRCRegClass.contains(DestReg) ? PPC::DMXXINSTDMR512
+                                                : PPC::DMXXINSTDMR512_HI;
+
+    BuildMI(MBB, I, DL, get(Opc), DestReg)
+        .addReg(TmpReg1, RegState::Kill)
+        .addReg(TmpReg2, RegState::Kill);
+
+    return;
+  } else if (PPC::DMRRCRegClass.contains(DestReg) &&
+             PPC::DMRRCRegClass.contains(SrcReg)) {
+
+    BuildMI(MBB, I, DL, get(PPC::DMMR), DestReg)
+        .addReg(SrcReg, getKillRegState(KillSrc));
+
+    return;
+
   } else
     llvm_unreachable("Impossible reg-to-reg copy");
 

llvm/lib/Target/PowerPC/PPCTargetMachine.cpp

@@ -129,7 +129,7 @@ LLVMInitializePowerPCTarget() {
   initializePPCLoopInstrFormPrepPass(PR);
   initializePPCTOCRegDepsPass(PR);
   initializePPCEarlyReturnPass(PR);
-  initializePPCVSXCopyPass(PR);
+  initializePPCVSXWACCCopyPass(PR);
   initializePPCVSXFMAMutatePass(PR);
   initializePPCVSXSwapRemovalPass(PR);
   initializePPCReduceCRLogicalsPass(PR);
@@ -528,7 +528,7 @@ bool PPCPassConfig::addInstSelector() {
     addPass(createPPCCTRLoopsVerify());
 #endif
 
-  addPass(createPPCVSXCopyPass());
+  addPass(createPPCVSXWACCCopyPass());
   return false;
 }