Implement carry for subtract/add for mips16

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166755 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 29 insertions, 4 deletions

diff --git a/lib/Target/Mips/Mips16InstrInfo.td b/lib/Target/Mips/Mips16InstrInfo.td
index 74ddc99e13..3721cc7ba0 100644
--- a/lib/Target/Mips/Mips16InstrInfo.td
+++ b/lib/Target/Mips/Mips16InstrInfo.td
@@ -194,6 +194,10 @@ class FRR16_ins<bits<5> f, string asmstr, InstrItinClass itin> :
         !strconcat(asmstr, "\t$rx, $ry"), [], itin> {
 }
 
+class FRRTR16_ins<bits<5> f, string asmstr, InstrItinClass itin> :
+  FRR16<f, (outs CPU16Regs:$rz), (ins CPU16Regs:$rx, CPU16Regs:$ry),
+        !strconcat(asmstr, "\t$rx, $ry\n\tmove\t$rz, $$t8"), [], itin> ;
+
 //
 // maybe refactor but need a $zero as a dummy first parameter
 //
@@ -816,6 +820,9 @@ def SltCCRxRy16: FCCRR16_ins<0b00010, "slt", IIAlu>;
 // Purpose: Set on Less Than Unsigned
 // To record the result of an unsigned less-than comparison.
 //
+def SltuRxRyRz16: FRRTR16_ins<0b00011, "sltu", IIAlu> {
+  let isCodeGenOnly=1;
+}
 
 
 def SltuCCRxRy16: FCCRR16_ins<0b00011, "sltu", IIAlu>;
@@ -976,6 +983,14 @@ def : Mips16Pat<(i32 imm:$imm),
                 (OrRxRxRy16 (SllX16 (LiRxImmX16 (HI16 imm:$imm)), 16),
                 (LiRxImmX16 (LO16 imm:$imm)))>;
 
+// Carry MipsPatterns
+def : Mips16Pat<(subc CPU16Regs:$lhs, CPU16Regs:$rhs),
+                (SubuRxRyRz16 CPU16Regs:$lhs, CPU16Regs:$rhs)>;
+def : Mips16Pat<(addc CPU16Regs:$lhs, CPU16Regs:$rhs),
+                (AdduRxRyRz16 CPU16Regs:$lhs, CPU16Regs:$rhs)>;
+def : Mips16Pat<(addc  CPU16Regs:$src, immSExt16:$imm),
+                (AddiuRxRxImmX16 CPU16Regs:$src, imm:$imm)>;
+
 //
 // Some branch conditional patterns are not generated by llvm at this time.
 // Some are for seemingly arbitrary reasons not used: i.e. with signed number
diff --git a/lib/Target/Mips/MipsISelDAGToDAG.cpp b/lib/Target/Mips/MipsISelDAGToDAG.cpp
index fceb63a1bc..9a5a712ee7 100644
--- a/lib/Target/Mips/MipsISelDAGToDAG.cpp
+++ b/lib/Target/Mips/MipsISelDAGToDAG.cpp
@@ -413,6 +413,7 @@ SDNode* MipsDAGToDAGISel::Select(SDNode *Node) {
 
   case ISD::SUBE:
   case ISD::ADDE: {
+    bool inMips16Mode = Subtarget.inMips16Mode();
     SDValue InFlag = Node->getOperand(2), CmpLHS;
     unsigned Opc = InFlag.getOpcode(); (void)Opc;
     assert(((Opc == ISD::ADDC || Opc == ISD::ADDE) ||
@@ -422,10 +423,16 @@ SDNode* MipsDAGToDAGISel::Select(SDNode *Node) {
     unsigned MOp;
     if (Opcode == ISD::ADDE) {
       CmpLHS = InFlag.getValue(0);
-      MOp = Mips::ADDu;
+      if (inMips16Mode)
+        MOp = Mips::AdduRxRyRz16;
+      else
+        MOp = Mips::ADDu;
     } else {
       CmpLHS = InFlag.getOperand(0);
-      MOp = Mips::SUBu;
+      if (inMips16Mode)
+        MOp = Mips::SubuRxRyRz16;
+      else
+        MOp = Mips::SUBu;
     }
 
     SDValue Ops[] = { CmpLHS, InFlag.getOperand(1) };
@@ -434,8 +441,11 @@ SDNode* MipsDAGToDAGISel::Select(SDNode *Node) {
     SDValue RHS = Node->getOperand(1);
 
     EVT VT = LHS.getValueType();
-    SDNode *Carry = CurDAG->getMachineNode(Mips::SLTu, dl, VT, Ops, 2);
-    SDNode *AddCarry = CurDAG->getMachineNode(Mips::ADDu, dl, VT,
+
+    unsigned Sltu_op = inMips16Mode? Mips::SltuRxRyRz16: Mips::SLTu;
+    SDNode *Carry = CurDAG->getMachineNode(Sltu_op, dl, VT, Ops, 2);
+    unsigned Addu_op = inMips16Mode? Mips::AdduRxRyRz16 : Mips::ADDu;
+    SDNode *AddCarry = CurDAG->getMachineNode(Addu_op, dl, VT,
                                               SDValue(Carry,0), RHS);
 
     return CurDAG->SelectNodeTo(Node, MOp, VT, MVT::Glue,