[SystemZ] Add back end

This adds the actual lib/Target/SystemZ target files necessary to
implement the SystemZ target.  Note that at this point, the target
cannot yet be built since the configure bits are missing.  Those
will be provided shortly by a follow-on patch.

This version of the patch incorporates feedback from reviews by
Chris Lattner and Anton Korobeynikov.  Thanks to all reviewers!

Patch by Richard Sandiford.

llvm-svn: 181203
diff --git a/llvm/lib/Target/SystemZ/InstPrinter/SystemZInstPrinter.cpp b/llvm/lib/Target/SystemZ/InstPrinter/SystemZInstPrinter.cpp
new file mode 100644
index 0000000..d73cf49
--- /dev/null
+++ b/llvm/lib/Target/SystemZ/InstPrinter/SystemZInstPrinter.cpp
@@ -0,0 +1,150 @@
+//===-- SystemZInstPrinter.cpp - Convert SystemZ 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.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "asm-printer"
+
+#include "SystemZInstPrinter.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+#include "SystemZGenAsmWriter.inc"
+
+void SystemZInstPrinter::printAddress(unsigned Base, int64_t Disp,
+                                      unsigned Index, raw_ostream &O) {
+  O << Disp;
+  if (Base) {
+    O << '(';
+    if (Index)
+      O << '%' << getRegisterName(Index) << ',';
+    O << '%' << getRegisterName(Base) << ')';
+  } else
+    assert(!Index && "Shouldn't have an index without a base");
+}
+
+void SystemZInstPrinter::printOperand(const MCOperand &MO, raw_ostream &O) {
+  if (MO.isReg())
+    O << '%' << getRegisterName(MO.getReg());
+  else if (MO.isImm())
+    O << MO.getImm();
+  else if (MO.isExpr())
+    O << *MO.getExpr();
+  else
+    llvm_unreachable("Invalid operand");
+}
+
+void SystemZInstPrinter::printInst(const MCInst *MI, raw_ostream &O,
+                                   StringRef Annot) {
+  printInstruction(MI, O);
+  printAnnotation(O, Annot);
+}
+
+void SystemZInstPrinter::printRegName(raw_ostream &O, unsigned RegNo) const {
+  O << '%' << getRegisterName(RegNo);
+}
+
+void SystemZInstPrinter::printU4ImmOperand(const MCInst *MI, int OpNum,
+                                           raw_ostream &O) {
+  int64_t Value = MI->getOperand(OpNum).getImm();
+  assert(isUInt<4>(Value) && "Invalid u4imm argument");
+  O << Value;
+}
+
+void SystemZInstPrinter::printU6ImmOperand(const MCInst *MI, int OpNum,
+                                           raw_ostream &O) {
+  int64_t Value = MI->getOperand(OpNum).getImm();
+  assert(isUInt<6>(Value) && "Invalid u6imm argument");
+  O << Value;
+}
+
+void SystemZInstPrinter::printS8ImmOperand(const MCInst *MI, int OpNum,
+                                           raw_ostream &O) {
+  int64_t Value = MI->getOperand(OpNum).getImm();
+  assert(isInt<8>(Value) && "Invalid s8imm argument");
+  O << Value;
+}
+
+void SystemZInstPrinter::printU8ImmOperand(const MCInst *MI, int OpNum,
+                                           raw_ostream &O) {
+  int64_t Value = MI->getOperand(OpNum).getImm();
+  assert(isUInt<8>(Value) && "Invalid u8imm argument");
+  O << Value;
+}
+
+void SystemZInstPrinter::printS16ImmOperand(const MCInst *MI, int OpNum,
+                                            raw_ostream &O) {
+  int64_t Value = MI->getOperand(OpNum).getImm();
+  assert(isInt<16>(Value) && "Invalid s16imm argument");
+  O << Value;
+}
+
+void SystemZInstPrinter::printU16ImmOperand(const MCInst *MI, int OpNum,
+                                            raw_ostream &O) {
+  int64_t Value = MI->getOperand(OpNum).getImm();
+  assert(isUInt<16>(Value) && "Invalid u16imm argument");
+  O << Value;
+}
+
+void SystemZInstPrinter::printS32ImmOperand(const MCInst *MI, int OpNum,
+                                            raw_ostream &O) {
+  int64_t Value = MI->getOperand(OpNum).getImm();
+  assert(isInt<32>(Value) && "Invalid s32imm argument");
+  O << Value;
+}
+
+void SystemZInstPrinter::printU32ImmOperand(const MCInst *MI, int OpNum,
+                                            raw_ostream &O) {
+  int64_t Value = MI->getOperand(OpNum).getImm();
+  assert(isUInt<32>(Value) && "Invalid u32imm argument");
+  O << Value;
+}
+
+void SystemZInstPrinter::printAccessRegOperand(const MCInst *MI, int OpNum,
+                                               raw_ostream &O) {
+  uint64_t Value = MI->getOperand(OpNum).getImm();
+  assert(Value < 16 && "Invalid access register number");
+  O << "%a" << (unsigned int)Value;
+}
+
+void SystemZInstPrinter::printCallOperand(const MCInst *MI, int OpNum,
+                                          raw_ostream &O) {
+  printOperand(MI, OpNum, O);
+  O << "@PLT";
+}
+
+void SystemZInstPrinter::printOperand(const MCInst *MI, int OpNum,
+                                      raw_ostream &O) {
+  printOperand(MI->getOperand(OpNum), O);
+}
+
+void SystemZInstPrinter::printBDAddrOperand(const MCInst *MI, int OpNum,
+                                            raw_ostream &O) {
+  printAddress(MI->getOperand(OpNum).getReg(),
+               MI->getOperand(OpNum + 1).getImm(), 0, O);
+}
+
+void SystemZInstPrinter::printBDXAddrOperand(const MCInst *MI, int OpNum,
+                                             raw_ostream &O) {
+  printAddress(MI->getOperand(OpNum).getReg(),
+               MI->getOperand(OpNum + 1).getImm(),
+               MI->getOperand(OpNum + 2).getReg(), O);
+}
+
+void SystemZInstPrinter::printCond4Operand(const MCInst *MI, int OpNum,
+                                           raw_ostream &O) {
+  static const char *const CondNames[] = {
+    "o", "h", "nle", "l", "nhe", "lh", "ne",
+    "e", "nlh", "he", "nl", "le", "nh", "no"
+  };
+  uint64_t Imm = MI->getOperand(OpNum).getImm();
+  assert(Imm > 0 && Imm < 15 && "Invalid condition");
+  O << CondNames[Imm - 1];
+}