1 files changed, 26 insertions, 47 deletions

diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 6631e4ab8f..5ff23d1cef 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -584,10 +584,7 @@ const char *PPCTargetLowering::getTargetNodeName(unsigned Opcode) const {
   case PPCISD::STCX:            return "PPCISD::STCX";
   case PPCISD::COND_BRANCH:     return "PPCISD::COND_BRANCH";
   case PPCISD::MFFS:            return "PPCISD::MFFS";
-  case PPCISD::MTFSB0:          return "PPCISD::MTFSB0";
-  case PPCISD::MTFSB1:          return "PPCISD::MTFSB1";
   case PPCISD::FADDRTZ:         return "PPCISD::FADDRTZ";
-  case PPCISD::MTFSF:           return "PPCISD::MTFSF";
   case PPCISD::TC_RETURN:       return "PPCISD::TC_RETURN";
   case PPCISD::CR6SET:          return "PPCISD::CR6SET";
   case PPCISD::CR6UNSET:        return "PPCISD::CR6UNSET";
@@ -5667,50 +5664,8 @@ void PPCTargetLowering::ReplaceNodeResults(SDNode *N,
                              MVT::f64, N->getOperand(0),
                              DAG.getIntPtrConstant(1));
 
-    // This sequence changes FPSCR to do round-to-zero, adds the two halves
-    // of the long double, and puts FPSCR back the way it was.  We do not
-    // actually model FPSCR.
-    std::vector<EVT> NodeTys;
-    SDValue Ops[4], Result, MFFSreg, InFlag, FPreg;
-
-    NodeTys.push_back(MVT::f64);   // Return register
-    NodeTys.push_back(MVT::Glue);    // Returns a flag for later insns
-    Result = DAG.getNode(PPCISD::MFFS, dl, NodeTys, &InFlag, 0);
-    MFFSreg = Result.getValue(0);
-    InFlag = Result.getValue(1);
-
-    NodeTys.clear();
-    NodeTys.push_back(MVT::Glue);   // Returns a flag
-    Ops[0] = DAG.getConstant(31, MVT::i32);
-    Ops[1] = InFlag;
-    Result = DAG.getNode(PPCISD::MTFSB1, dl, NodeTys, Ops, 2);
-    InFlag = Result.getValue(0);
-
-    NodeTys.clear();
-    NodeTys.push_back(MVT::Glue);   // Returns a flag
-    Ops[0] = DAG.getConstant(30, MVT::i32);
-    Ops[1] = InFlag;
-    Result = DAG.getNode(PPCISD::MTFSB0, dl, NodeTys, Ops, 2);
-    InFlag = Result.getValue(0);
-
-    NodeTys.clear();
-    NodeTys.push_back(MVT::f64);    // result of add
-    NodeTys.push_back(MVT::Glue);   // Returns a flag
-    Ops[0] = Lo;
-    Ops[1] = Hi;
-    Ops[2] = InFlag;
-    Result = DAG.getNode(PPCISD::FADDRTZ, dl, NodeTys, Ops, 3);
-    FPreg = Result.getValue(0);
-    InFlag = Result.getValue(1);
-
-    NodeTys.clear();
-    NodeTys.push_back(MVT::f64);
-    Ops[0] = DAG.getConstant(1, MVT::i32);
-    Ops[1] = MFFSreg;
-    Ops[2] = FPreg;
-    Ops[3] = InFlag;
-    Result = DAG.getNode(PPCISD::MTFSF, dl, NodeTys, Ops, 4);
-    FPreg = Result.getValue(0);
+    // Add the two halves of the long double in round-to-zero mode.
+    SDValue FPreg = DAG.getNode(PPCISD::FADDRTZ, dl, MVT::f64, Lo, Hi);
 
     // We know the low half is about to be thrown away, so just use something
     // convenient.
@@ -6523,6 +6478,30 @@ PPCTargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI,
     BB = exitMBB;
     BuildMI(*BB, BB->begin(), dl, TII->get(PPC::SRW),dest).addReg(TmpReg)
       .addReg(ShiftReg);
+  } else if (MI->getOpcode() == PPC::FADDrtz) {
+    // This pseudo performs an FADD with rounding mode temporarily forced
+    // to round-to-zero.  We emit this via custom inserter since the FPSCR
+    // is not modeled at the SelectionDAG level.
+    unsigned Dest = MI->getOperand(0).getReg();
+    unsigned Src1 = MI->getOperand(1).getReg();
+    unsigned Src2 = MI->getOperand(2).getReg();
+    DebugLoc dl   = MI->getDebugLoc();
+
+    MachineRegisterInfo &RegInfo = F->getRegInfo();
+    unsigned MFFSReg = RegInfo.createVirtualRegister(&PPC::F8RCRegClass);
+
+    // Save FPSCR value.
+    BuildMI(*BB, MI, dl, TII->get(PPC::MFFS), MFFSReg);
+
+    // Set rounding mode to round-to-zero.
+    BuildMI(*BB, MI, dl, TII->get(PPC::MTFSB1)).addImm(31);
+    BuildMI(*BB, MI, dl, TII->get(PPC::MTFSB0)).addImm(30);
+
+    // Perform addition.
+    BuildMI(*BB, MI, dl, TII->get(PPC::FADD), Dest).addReg(Src1).addReg(Src2);
+
+    // Restore FPSCR value.
+    BuildMI(*BB, MI, dl, TII->get(PPC::MTFSF)).addImm(1).addReg(MFFSReg);
   } else {
     llvm_unreachable("Unexpected instr type to insert");
   }