ARM: 'add Rd, pc, #imm' is an alias for 'adr Rd, #imm'.

rdar://9795790

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164577 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index a7997d5..aa5ba46 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5666,6 +5666,20 @@
 processInstruction(MCInst &Inst,
                    const SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
   switch (Inst.getOpcode()) {
+  // Alias for alternate form of 'ADR Rd, #imm' instruction.
+  case ARM::ADDri: {
+    if (Inst.getOperand(1).getReg() != ARM::PC ||
+        Inst.getOperand(5).getReg() != 0)
+      return false;
+    MCInst TmpInst;
+    TmpInst.setOpcode(ARM::ADR);
+    TmpInst.addOperand(Inst.getOperand(0));
+    TmpInst.addOperand(Inst.getOperand(2));
+    TmpInst.addOperand(Inst.getOperand(3));
+    TmpInst.addOperand(Inst.getOperand(4));
+    Inst = TmpInst;
+    return true;
+  }
   // Aliases for alternate PC+imm syntax of LDR instructions.
   case ARM::t2LDRpcrel:
     Inst.setOpcode(ARM::t2LDRpci);