[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

1 files changed, 40 insertions, 0 deletions

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