+
+static bool combineRestoreADD(MachineBasicBlock::iterator RestoreMI,
+ MachineBasicBlock::iterator AddMI,
+ const TargetInstrInfo *TII)
+{
+ //Before: add <op0>, <op1>, %i[0-7]
+ // restore %g0, %g0, %i[0-7]
+ //
+ //After : restore <op0>, <op1>, %o[0-7]
+
+ unsigned reg = AddMI->getOperand(0).getReg();
+ if (reg < SP::I0 || reg > SP::I7)
+ return false;
+
+ //Erase RESTORE
+ RestoreMI->eraseFromParent();
+
+ //Change ADD to RESTORE
+ AddMI->setDesc(TII->get((AddMI->getOpcode() == SP::ADDrr)
+ ? SP::RESTORErr
+ : SP::RESTOREri));
+
+ //map the destination register
+ AddMI->getOperand(0).setReg(reg - SP::I0 + SP::O0);
+
+ return true;
+}
+
+static bool combineRestoreOR(MachineBasicBlock::iterator RestoreMI,
+ MachineBasicBlock::iterator OrMI,
+ const TargetInstrInfo *TII)
+{
+ //Before: or <op0>, <op1>, %i[0-7]
+ // restore %g0, %g0, %i[0-7]
+ // and <op0> or <op1> is zero,
+ //
+ //After : restore <op0>, <op1>, %o[0-7]
+
+ unsigned reg = OrMI->getOperand(0).getReg();
+ if (reg < SP::I0 || reg > SP::I7)
+ return false;
+
+ //check whether it is a copy
+ if (OrMI->getOpcode() == SP::ORrr
+ && OrMI->getOperand(1).getReg() != SP::G0
+ && OrMI->getOperand(2).getReg() != SP::G0)
+ return false;
+
+ if (OrMI->getOpcode() == SP::ORri
+ && OrMI->getOperand(1).getReg() != SP::G0
+ && (!OrMI->getOperand(2).isImm() || OrMI->getOperand(2).getImm() != 0))
+ return false;
+
+ //Erase RESTORE
+ RestoreMI->eraseFromParent();
+
+ //Change OR to RESTORE
+ OrMI->setDesc(TII->get((OrMI->getOpcode() == SP::ORrr)
+ ? SP::RESTORErr
+ : SP::RESTOREri));
+
+ //map the destination register
+ OrMI->getOperand(0).setReg(reg - SP::I0 + SP::O0);
+
+ return true;
+}
+
+static bool combineRestoreSETHIi(MachineBasicBlock::iterator RestoreMI,
+ MachineBasicBlock::iterator SetHiMI,
+ const TargetInstrInfo *TII)
+{
+ //Before: sethi imm3, %i[0-7]
+ // restore %g0, %g0, %g0
+ //
+ //After : restore %g0, (imm3<<10), %o[0-7]
+
+ unsigned reg = SetHiMI->getOperand(0).getReg();
+ if (reg < SP::I0 || reg > SP::I7)
+ return false;
+
+ if (!SetHiMI->getOperand(1).isImm())
+ return false;
+
+ int64_t imm = SetHiMI->getOperand(1).getImm();
+
+ //is it a 3 bit immediate?
+ if (!isInt<3>(imm))
+ return false;
+
+ //make it a 13 bit immediate
+ imm = (imm << 10) & 0x1FFF;
+
+ assert(RestoreMI->getOpcode() == SP::RESTORErr);
+
+ RestoreMI->setDesc(TII->get(SP::RESTOREri));
+
+ RestoreMI->getOperand(0).setReg(reg - SP::I0 + SP::O0);
+ RestoreMI->getOperand(1).setReg(SP::G0);
+ RestoreMI->getOperand(2).ChangeToImmediate(imm);
+
+
+ //Erase the original SETHI
+ SetHiMI->eraseFromParent();
+
+ return true;
+}
+
+bool Filler::tryCombineRestoreWithPrevInst(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI)
+{
+ //No previous instruction
+ if (MBBI == MBB.begin())
+ return false;
+
+ //asssert that MBBI is "restore %g0, %g0, %g0"
+ assert(MBBI->getOpcode() == SP::RESTORErr
+ && MBBI->getOperand(0).getReg() == SP::G0
+ && MBBI->getOperand(1).getReg() == SP::G0
+ && MBBI->getOperand(2).getReg() == SP::G0);
+
+ MachineBasicBlock::iterator PrevInst = MBBI; --PrevInst;
+
+ //Cannot combine with a delay filler
+ if (isDelayFiller(MBB, PrevInst))
+ return false;
+
+ switch (PrevInst->getOpcode()) {
+ default: break;
+ case SP::ADDrr:
+ case SP::ADDri: return combineRestoreADD(MBBI, PrevInst, TII); break;
+ case SP::ORrr:
+ case SP::ORri: return combineRestoreOR(MBBI, PrevInst, TII); break;
+ case SP::SETHIi: return combineRestoreSETHIi(MBBI, PrevInst, TII); break;
+ }
+ //Cannot combine with the previous instruction
+ return false;
+}