PR8918 - When used with MinGW64, LLVM generates a "calll __main" at the
beginning of the "main" function. The assembler complains about the invalid
suffix for the 'call' instruction. The right instruction is "callq __main".
Patch by KS Sreeram!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122933 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 7fe4e82..dd751fa 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -530,9 +530,12 @@
 void X86DAGToDAGISel::EmitSpecialCodeForMain(MachineBasicBlock *BB,
                                              MachineFrameInfo *MFI) {
   const TargetInstrInfo *TII = TM.getInstrInfo();
-  if (Subtarget->isTargetCygMing())
+  if (Subtarget->isTargetCygMing()) {
+    unsigned CallOp =
+      Subtarget->is64Bit() ? X86::CALL64pcrel32 : X86::CALLpcrel32;
     BuildMI(BB, DebugLoc(),
-            TII->get(X86::CALLpcrel32)).addExternalSymbol("__main");
+            TII->get(CallOp)).addExternalSymbol("__main");
+  }
 }
 
 void X86DAGToDAGISel::EmitFunctionEntryCode() {