[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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181203 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 113 insertions, 0 deletions

diff --git a/lib/Target/SystemZ/SystemZAsmPrinter.cpp b/lib/Target/SystemZ/SystemZAsmPrinter.cpp
new file mode 100644
index 0000000000..1e15ab1413
--- /dev/null
+++ b/lib/Target/SystemZ/SystemZAsmPrinter.cpp
@@ -0,0 +1,113 @@
+//===-- SystemZAsmPrinter.cpp - SystemZ LLVM assembly printer -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Streams SystemZ assembly language and associated data, in the form of
+// MCInsts and MCExprs respectively.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SystemZAsmPrinter.h"
+#include "InstPrinter/SystemZInstPrinter.h"
+#include "SystemZConstantPoolValue.h"
+#include "SystemZMCInstLower.h"
+#include "llvm/CodeGen/MachineModuleInfoImpls.h"
+#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
+#include "llvm/MC/MCExpr.h"
+#include "llvm/MC/MCStreamer.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Target/Mangler.h"
+
+using namespace llvm;
+
+void SystemZAsmPrinter::EmitInstruction(const MachineInstr *MI) {
+  SystemZMCInstLower Lower(Mang, MF->getContext(), *this);
+  MCInst LoweredMI;
+  Lower.lower(MI, LoweredMI);
+  OutStreamer.EmitInstruction(LoweredMI);
+}
+
+// Convert a SystemZ-specific constant pool modifier into the associated
+// MCSymbolRefExpr variant kind.
+static MCSymbolRefExpr::VariantKind
+getModifierVariantKind(SystemZCP::SystemZCPModifier Modifier) {
+  switch (Modifier) {
+  case SystemZCP::NTPOFF: return MCSymbolRefExpr::VK_NTPOFF;
+  }
+  llvm_unreachable("Invalid SystemCPModifier!");
+}
+
+void SystemZAsmPrinter::
+EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
+  SystemZConstantPoolValue *ZCPV =
+    static_cast<SystemZConstantPoolValue*>(MCPV);
+
+  const MCExpr *Expr =
+    MCSymbolRefExpr::Create(Mang->getSymbol(ZCPV->getGlobalValue()),
+                            getModifierVariantKind(ZCPV->getModifier()),
+                            OutContext);
+  uint64_t Size = TM.getDataLayout()->getTypeAllocSize(ZCPV->getType());
+
+  OutStreamer.EmitValue(Expr, Size);
+}
+
+bool SystemZAsmPrinter::PrintAsmOperand(const MachineInstr *MI,
+                                        unsigned OpNo,
+                                        unsigned AsmVariant,
+                                        const char *ExtraCode,
+                                        raw_ostream &OS) {
+  if (ExtraCode && *ExtraCode == 'n') {
+    if (!MI->getOperand(OpNo).isImm())
+      return true;
+    OS << -int64_t(MI->getOperand(OpNo).getImm());
+  } else {
+    SystemZMCInstLower Lower(Mang, MF->getContext(), *this);
+    MCOperand MO(Lower.lowerOperand(MI->getOperand(OpNo)));
+    SystemZInstPrinter::printOperand(MO, OS);
+  }
+  return false;
+}
+
+bool SystemZAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
+                                              unsigned OpNo,
+                                              unsigned AsmVariant,
+                                              const char *ExtraCode,
+                                              raw_ostream &OS) {
+  SystemZInstPrinter::printAddress(MI->getOperand(OpNo).getReg(),
+                                   MI->getOperand(OpNo + 1).getImm(),
+                                   MI->getOperand(OpNo + 2).getReg(), OS);
+  return false;
+}
+
+void SystemZAsmPrinter::EmitEndOfAsmFile(Module &M) {
+  if (Subtarget->isTargetELF()) {
+    const TargetLoweringObjectFileELF &TLOFELF =
+      static_cast<const TargetLoweringObjectFileELF &>(getObjFileLowering());
+
+    MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
+
+    // Output stubs for external and common global variables.
+    MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
+    if (!Stubs.empty()) {
+      OutStreamer.SwitchSection(TLOFELF.getDataRelSection());
+      const DataLayout *TD = TM.getDataLayout();
+
+      for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
+        OutStreamer.EmitLabel(Stubs[i].first);
+        OutStreamer.EmitSymbolValue(Stubs[i].second.getPointer(),
+                                    TD->getPointerSize(0), 0);
+      }
+      Stubs.clear();
+    }
+  }
+}
+
+// Force static initialization.
+extern "C" void LLVMInitializeSystemZAsmPrinter() {
+  RegisterAsmPrinter<SystemZAsmPrinter> X(TheSystemZTarget);
+}