[mips] Handle reading, writing or copying of ccond field of DSP control

register.

- Define pseudo instructions which store or load ccond field of the DSP
  control register.
- Emit the pseudos in MipsSEInstrInfo::storeRegToStack and loadRegFromStack.
- Expand the pseudos before callee-scan save.
- Emit instructions RDDSP or WRDSP to copy between ccond field and GPRs. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180969 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 60 insertions, 1 deletions

diff --git a/lib/Target/Mips/MipsDSPInstrInfo.td b/lib/Target/Mips/MipsDSPInstrInfo.td
index 710b40d68e..2a5f138c0f 100644
--- a/lib/Target/Mips/MipsDSPInstrInfo.td
+++ b/lib/Target/Mips/MipsDSPInstrInfo.td
@@ -1231,10 +1231,14 @@ def PREPEND : PREPEND_ENC, PREPEND_DESC;
 }
 
 // Pseudos.
-/// Pseudo instructions for loading and storing accumulator registers.
 let isPseudo = 1 in {
+  // Pseudo instructions for loading and storing accumulator registers.
   defm LOAD_AC_DSP  : LoadM<"load_ac_dsp", ACRegsDSP>;
   defm STORE_AC_DSP : StoreM<"store_ac_dsp", ACRegsDSP>;
+
+  // Pseudos for loading and storing ccond field of DSP control register.
+  defm LOAD_CCOND_DSP  : LoadM<"load_ccond_dsp", DSPCC>;
+  defm STORE_CCOND_DSP : StoreM<"store_ccond_dsp", DSPCC>;
 }
 
 // Pseudo CMP and PICK instructions.
diff --git a/lib/Target/Mips/MipsSEFrameLowering.cpp b/lib/Target/Mips/MipsSEFrameLowering.cpp
index 2b7670497b..b295e911bd 100644
--- a/lib/Target/Mips/MipsSEFrameLowering.cpp
+++ b/lib/Target/Mips/MipsSEFrameLowering.cpp
@@ -40,6 +40,8 @@ public:
 
 private:
   bool expandInstr(MachineBasicBlock &MBB, Iter I);
+  void expandLoadCCond(MachineBasicBlock &MBB, Iter I);
+  void expandStoreCCond(MachineBasicBlock &MBB, Iter I);
   void expandLoadACC(MachineBasicBlock &MBB, Iter I, unsigned RegSize);
   void expandStoreACC(MachineBasicBlock &MBB, Iter I, unsigned RegSize);
   bool expandCopy(MachineBasicBlock &MBB, Iter I);
@@ -71,6 +73,14 @@ bool ExpandPseudo::expand() {
 
 bool ExpandPseudo::expandInstr(MachineBasicBlock &MBB, Iter I) {
   switch(I->getOpcode()) {
+  case Mips::LOAD_CCOND_DSP:
+  case Mips::LOAD_CCOND_DSP_P8:
+    expandLoadCCond(MBB, I);
+    break;
+  case Mips::STORE_CCOND_DSP:
+  case Mips::STORE_CCOND_DSP_P8:
+    expandStoreCCond(MBB, I);
+    break;
   case Mips::LOAD_AC64:
   case Mips::LOAD_AC64_P8:
   case Mips::LOAD_AC_DSP:
@@ -103,6 +113,36 @@ bool ExpandPseudo::expandInstr(MachineBasicBlock &MBB, Iter I) {
   return true;
 }
 
+void ExpandPseudo::expandLoadCCond(MachineBasicBlock &MBB, Iter I) {
+  //  load $vr, FI
+  //  copy ccond, $vr
+
+  assert(I->getOperand(0).isReg() && I->getOperand(1).isFI());
+
+  const TargetRegisterClass *RC = RegInfo.intRegClass(4);
+  unsigned VR = MRI.createVirtualRegister(RC);
+  unsigned Dst = I->getOperand(0).getReg(), FI = I->getOperand(1).getIndex();
+
+  TII.loadRegFromStack(MBB, I, VR, FI, RC, &RegInfo, 0);
+  BuildMI(MBB, I, I->getDebugLoc(), TII.get(TargetOpcode::COPY), Dst)
+    .addReg(VR, RegState::Kill);
+}
+
+void ExpandPseudo::expandStoreCCond(MachineBasicBlock &MBB, Iter I) {
+  //  copy $vr, ccond
+  //  store $vr, FI
+
+  assert(I->getOperand(0).isReg() && I->getOperand(1).isFI());
+
+  const TargetRegisterClass *RC = RegInfo.intRegClass(4);
+  unsigned VR = MRI.createVirtualRegister(RC);
+  unsigned Src = I->getOperand(0).getReg(), FI = I->getOperand(1).getIndex();
+
+  BuildMI(MBB, I, I->getDebugLoc(), TII.get(TargetOpcode::COPY), VR)
+    .addReg(Src, getKillRegState(I->getOperand(0).isKill()));
+  TII.storeRegToStack(MBB, I, VR, true, FI, RC, &RegInfo, 0);
+}
+
 void ExpandPseudo::expandLoadACC(MachineBasicBlock &MBB, Iter I,
                                  unsigned RegSize) {
   //  load $vr0, FI
diff --git a/lib/Target/Mips/MipsSEInstrInfo.cpp b/lib/Target/Mips/MipsSEInstrInfo.cpp
index 2e7048d26e..a0768e51c0 100644
--- a/lib/Target/Mips/MipsSEInstrInfo.cpp
+++ b/lib/Target/Mips/MipsSEInstrInfo.cpp
@@ -103,6 +103,11 @@ void MipsSEInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
       Opc = Mips::MFHI_DSP;
     else if (Mips::LORegsDSPRegClass.contains(SrcReg))
       Opc = Mips::MFLO_DSP;
+    else if (Mips::DSPCCRegClass.contains(SrcReg)) {
+      BuildMI(MBB, I, DL, get(Mips::RDDSP), DestReg).addImm(1 << 4)
+        .addReg(SrcReg, RegState::Implicit | getKillRegState(KillSrc));
+      return;
+    }
   }
   else if (Mips::CPURegsRegClass.contains(SrcReg)) { // Copy from CPU Reg.
     if (Mips::CCRRegClass.contains(DestReg))
@@ -117,6 +122,12 @@ void MipsSEInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
       Opc = Mips::MTHI_DSP;
     else if (Mips::LORegsDSPRegClass.contains(DestReg))
       Opc = Mips::MTLO_DSP;
+    else if (Mips::DSPCCRegClass.contains(DestReg)) {
+      BuildMI(MBB, I, DL, get(Mips::WRDSP))
+        .addReg(SrcReg, getKillRegState(KillSrc)).addImm(1 << 4)
+        .addReg(DestReg, RegState::ImplicitDefine);
+      return;
+    }
   }
   else if (Mips::FGR32RegClass.contains(DestReg, SrcReg))
     Opc = Mips::FMOV_S;
@@ -180,6 +191,8 @@ storeRegToStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
     Opc = IsN64 ? Mips::STORE_AC_DSP_P8 : Mips::STORE_AC_DSP;
   else if (Mips::ACRegs128RegClass.hasSubClassEq(RC))
     Opc = IsN64 ? Mips::STORE_AC128_P8 : Mips::STORE_AC128;
+  else if (Mips::DSPCCRegClass.hasSubClassEq(RC))
+    Opc = IsN64 ? Mips::STORE_CCOND_DSP_P8 : Mips::STORE_CCOND_DSP;
   else if (Mips::FGR32RegClass.hasSubClassEq(RC))
     Opc = IsN64 ? Mips::SWC1_P8 : Mips::SWC1;
   else if (Mips::AFGR64RegClass.hasSubClassEq(RC))
@@ -211,6 +224,8 @@ loadRegFromStack(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
     Opc = IsN64 ? Mips::LOAD_AC_DSP_P8 : Mips::LOAD_AC_DSP;
   else if (Mips::ACRegs128RegClass.hasSubClassEq(RC))
     Opc = IsN64 ? Mips::LOAD_AC128_P8 : Mips::LOAD_AC128;
+  else if (Mips::DSPCCRegClass.hasSubClassEq(RC))
+    Opc = IsN64 ? Mips::LOAD_CCOND_DSP_P8 : Mips::LOAD_CCOND_DSP;
   else if (Mips::FGR32RegClass.hasSubClassEq(RC))
     Opc = IsN64 ? Mips::LWC1_P8 : Mips::LWC1;
   else if (Mips::AFGR64RegClass.hasSubClassEq(RC))