Trivial MC code emitter shell. No instruction forms actually handled yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115993 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMMCCodeEmitter.cpp b/lib/Target/ARM/ARMMCCodeEmitter.cpp
index cfebe97..35319a4 100644
--- a/lib/Target/ARM/ARMMCCodeEmitter.cpp
+++ b/lib/Target/ARM/ARMMCCodeEmitter.cpp
@@ -13,13 +13,16 @@
 
 #define DEBUG_TYPE "arm-emitter"
 #include "ARM.h"
-#include "ARMBaseInfo.h"
+#include "ARMInstrInfo.h"
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCInst.h"
+#include "llvm/ADT/Statistic.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
+STATISTIC(MCNumEmitted, "Number of MC instructions emitted");
+
 namespace {
 class ARMMCCodeEmitter : public MCCodeEmitter {
   ARMMCCodeEmitter(const ARMMCCodeEmitter &); // DO NOT IMPLEMENT
@@ -31,7 +34,6 @@
 public:
   ARMMCCodeEmitter(TargetMachine &tm, MCContext &ctx)
     : TM(tm), TII(*TM.getInstrInfo()), Ctx(ctx) {
-    assert(0 && "ARMMCCodeEmitter::ARMMCCodeEmitter() not yet implemented.");
   }
 
   ~ARMMCCodeEmitter() {}
@@ -107,7 +109,21 @@
 void ARMMCCodeEmitter::
 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
                   SmallVectorImpl<MCFixup> &Fixups) const {
-  assert(0 && "ARMMCCodeEmitter::EncodeInstruction() not yet implemented.");
+  unsigned Opcode = MI.getOpcode();
+  const TargetInstrDesc &Desc = TII.get(Opcode);
+  uint64_t TSFlags = Desc.TSFlags;
+
+  // Pseudo instructions don't get encoded.
+  if ((TSFlags & ARMII::FormMask) == ARMII::Pseudo)
+    return;
+
+  ++MCNumEmitted;  // Keep track of the # of mi's emitted
+  switch (TSFlags & ARMII::FormMask) {
+  default: {
+    llvm_unreachable("Unhandled instruction encoding format!");
+    break;
+  }
+  }
 }
 
 // FIXME: These #defines shouldn't be necessary. Instead, tblgen should