[PowerPC] Add extended subtract mnemonics

This adds support for the extended subtract mnemonics to the asm parser:
   subi
   subis
   subic
   subic.
   sub
   sub.
   subc
   subc.
 

llvm-svn: 184832
diff --git a/llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp b/llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
index 2aed324..d426ba0 100644
--- a/llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
+++ b/llvm/lib/Target/PowerPC/AsmParser/PPCAsmParser.cpp
@@ -432,6 +432,46 @@
     Inst = TmpInst;
     break;
   }
+  case PPC::SUBI: {
+    MCInst TmpInst;
+    int64_t N = Inst.getOperand(2).getImm();
+    TmpInst.setOpcode(PPC::ADDI);
+    TmpInst.addOperand(Inst.getOperand(0));
+    TmpInst.addOperand(Inst.getOperand(1));
+    TmpInst.addOperand(MCOperand::CreateImm(-N));
+    Inst = TmpInst;
+    break;
+  }
+  case PPC::SUBIS: {
+    MCInst TmpInst;
+    int64_t N = Inst.getOperand(2).getImm();
+    TmpInst.setOpcode(PPC::ADDIS);
+    TmpInst.addOperand(Inst.getOperand(0));
+    TmpInst.addOperand(Inst.getOperand(1));
+    TmpInst.addOperand(MCOperand::CreateImm(-N));
+    Inst = TmpInst;
+    break;
+  }
+  case PPC::SUBIC: {
+    MCInst TmpInst;
+    int64_t N = Inst.getOperand(2).getImm();
+    TmpInst.setOpcode(PPC::ADDIC);
+    TmpInst.addOperand(Inst.getOperand(0));
+    TmpInst.addOperand(Inst.getOperand(1));
+    TmpInst.addOperand(MCOperand::CreateImm(-N));
+    Inst = TmpInst;
+    break;
+  }
+  case PPC::SUBICo: {
+    MCInst TmpInst;
+    int64_t N = Inst.getOperand(2).getImm();
+    TmpInst.setOpcode(PPC::ADDICo);
+    TmpInst.addOperand(Inst.getOperand(0));
+    TmpInst.addOperand(Inst.getOperand(1));
+    TmpInst.addOperand(MCOperand::CreateImm(-N));
+    Inst = TmpInst;
+    break;
+  }
   case PPC::SLWI: {
     MCInst TmpInst;
     int64_t N = Inst.getOperand(2).getImm();