[llvm] r174402 - Move MRI liveouts to X86 return instructions.

Jakob Stoklund Olesen stoklund at 2pi.dk
Tue Feb 5 09:59:48 PST 2013


Author: stoklund
Date: Tue Feb  5 11:59:48 2013
New Revision: 174402

URL: http://llvm.org/viewvc/llvm-project?rev=174402&view=rev
Log:
Move MRI liveouts to X86 return instructions.

Modified:
    llvm/trunk/lib/Target/X86/X86FastISel.cpp
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86FastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FastISel.cpp?rev=174402&r1=174401&r2=174402&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86FastISel.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86FastISel.cpp Tue Feb  5 11:59:48 2013
@@ -738,6 +738,9 @@ bool X86FastISel::X86SelectRet(const Ins
   if (F.isVarArg())
     return false;
 
+  // Build a list of return value registers.
+  SmallVector<unsigned, 4> RetRegs;
+
   if (Ret->getNumOperands() > 0) {
     SmallVector<ISD::OutputArg, 4> Outs;
     GetReturnInfo(F.getReturnType(), F.getAttributes(), Outs, TLI);
@@ -805,8 +808,8 @@ bool X86FastISel::X86SelectRet(const Ins
     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
             DstReg).addReg(SrcReg);
 
-    // Mark the register as live out of the function.
-    MRI.addLiveOut(VA.getLocReg());
+    // Add register to return instruction.
+    RetRegs.push_back(VA.getLocReg());
   }
 
   // The x86-64 ABI for returning structs by value requires that we copy
@@ -819,11 +822,14 @@ bool X86FastISel::X86SelectRet(const Ins
            "SRetReturnReg should have been set in LowerFormalArguments()!");
     BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
             X86::RAX).addReg(Reg);
-    MRI.addLiveOut(X86::RAX);
+    RetRegs.push_back(X86::RAX);
   }
 
   // Now emit the RET.
-  BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::RET));
+  MachineInstrBuilder MIB =
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(X86::RET));
+  for (unsigned i = 0, e = RetRegs.size(); i != e; ++i)
+    MIB.addReg(RetRegs[i], RegState::Implicit);
   return true;
 }
 

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=174402&r1=174401&r2=174402&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Tue Feb  5 11:59:48 2013
@@ -1590,14 +1590,7 @@ X86TargetLowering::LowerReturn(SDValue C
                  RVLocs, *DAG.getContext());
   CCInfo.AnalyzeReturn(Outs, RetCC_X86);
 
-  // Add the regs to the liveout set for the function.
-  MachineRegisterInfo &MRI = DAG.getMachineFunction().getRegInfo();
-  for (unsigned i = 0; i != RVLocs.size(); ++i)
-    if (RVLocs[i].isRegLoc() && !MRI.isLiveOut(RVLocs[i].getLocReg()))
-      MRI.addLiveOut(RVLocs[i].getLocReg());
-
   SDValue Flag;
-
   SmallVector<SDValue, 6> RetOps;
   RetOps.push_back(Chain); // Operand #0 = Chain (updated below)
   // Operand #1 = Bytes To Pop
@@ -1666,6 +1659,7 @@ X86TargetLowering::LowerReturn(SDValue C
 
     Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(), ValToCopy, Flag);
     Flag = Chain.getValue(1);
+    RetOps.push_back(DAG.getRegister(VA.getLocReg(), VA.getLocVT()));
   }
 
   // The x86-64 ABIs require that for returning structs by value we copy
@@ -1686,7 +1680,7 @@ X86TargetLowering::LowerReturn(SDValue C
     Flag = Chain.getValue(1);
 
     // RAX/EAX now acts like a return value.
-    MRI.addLiveOut(RetValReg);
+    RetOps.push_back(DAG.getRegister(RetValReg, MVT::i64));
   }
 
   RetOps[0] = Chain;  // Update chain.





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