Convert EXTRACT_SUBREG to COPY when emitting machine instrs.
EXTRACT_SUBREG no longer appears as a machine instruction. Use COPY instead.
Add isCopy() checks in many places using isMoveInstr() and isExtractSubreg().
The isMoveInstr hook will be removed later.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107879 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/MachineCSE.cpp b/lib/CodeGen/MachineCSE.cpp
index f399c1e..833cc00 100644
--- a/lib/CodeGen/MachineCSE.cpp
+++ b/lib/CodeGen/MachineCSE.cpp
@@ -126,6 +126,28 @@
++NumCoalesces;
Changed = true;
}
+
+ if (!DefMI->isCopy())
+ continue;
+ SrcReg = DefMI->getOperand(1).getReg();
+ if (!TargetRegisterInfo::isVirtualRegister(SrcReg))
+ continue;
+ if (DefMI->getOperand(0).getSubReg() || DefMI->getOperand(1).getSubReg())
+ continue;
+ const TargetRegisterClass *SRC = MRI->getRegClass(SrcReg);
+ const TargetRegisterClass *RC = MRI->getRegClass(Reg);
+ const TargetRegisterClass *NewRC = getCommonSubClass(RC, SRC);
+ if (!NewRC)
+ continue;
+ DEBUG(dbgs() << "Coalescing: " << *DefMI);
+ DEBUG(dbgs() << "*** to: " << *MI);
+ MO.setReg(SrcReg);
+ MRI->clearKillFlags(SrcReg);
+ if (NewRC != SRC)
+ MRI->setRegClass(SrcReg, NewRC);
+ DefMI->eraseFromParent();
+ ++NumCoalesces;
+ Changed = true;
}
return Changed;