Change XCoreAsmPrinter to lower MachineInstrs to MCInsts before emission.

This change adds XCoreMCInstLower to do the lowering to MCInst and
XCoreInstPrinter to print the MCInsts.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170288 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/XCore/InstPrinter/XCoreInstPrinter.cpp

@@ -0,0 +1,96 @@
+//===-- XCoreInstPrinter.cpp - Convert XCore MCInst to assembly syntax ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class prints an XCore MCInst to a .s file.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "asm-printer"
+#include "XCoreInstPrinter.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+#include "XCoreGenAsmWriter.inc"
+
+void XCoreInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const {
+  OS << StringRef(getRegisterName(RegNo)).lower();
+}
+
+void XCoreInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
+                                 StringRef Annot) {
+  printInstruction(MI, O);
+  printAnnotation(O, Annot);
+}
+
+void XCoreInstPrinter::
+printInlineJT(const MCInst *MI, int opNum, raw_ostream &O) {
+  report_fatal_error("can't handle InlineJT");
+}
+
+void XCoreInstPrinter::
+printInlineJT32(const MCInst *MI, int opNum, raw_ostream &O) {
+  report_fatal_error("can't handle InlineJT32");
+}
+
+static void printExpr(const MCExpr *Expr, raw_ostream &OS) {
+  int Offset = 0;
+  const MCSymbolRefExpr *SRE;
+
+  if (const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr)) {
+    SRE = dyn_cast<MCSymbolRefExpr>(BE->getLHS());
+    const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(BE->getRHS());
+    assert(SRE && CE && "Binary expression must be sym+const.");
+    Offset = CE->getValue();
+  } else if (!(SRE = dyn_cast<MCSymbolRefExpr>(Expr))) {
+    assert(false && "Unexpected MCExpr type.");
+  }
+  assert(SRE->getKind() == MCSymbolRefExpr::VK_None);
+
+  OS << SRE->getSymbol();
+
+  if (Offset) {
+    if (Offset > 0)
+      OS << '+';
+    OS << Offset;
+  }
+}
+
+void XCoreInstPrinter::
+printOperand(const MCInst *MI, unsigned OpNo, raw_ostream &O) {
+  const MCOperand &Op = MI->getOperand(OpNo);
+  if (Op.isReg()) {
+    printRegName(O, Op.getReg());
+    return;
+  }
+
+  if (Op.isImm()) {
+    O << Op.getImm();
+    return;
+  }
+
+  assert(Op.isExpr() && "unknown operand kind in printOperand");
+  printExpr(Op.getExpr(), O);
+}
+
+void XCoreInstPrinter::
+printMemOperand(const MCInst *MI, int opNum, raw_ostream &O) {
+  printOperand(MI, opNum, O);
+
+  if (MI->getOperand(opNum+1).isImm() && MI->getOperand(opNum+1).getImm() == 0)
+    return;
+
+  O << "+";
+  printOperand(MI, opNum+1, O);
+}