[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

lib/Target/SystemZ/SystemZConstantPoolValue.cpp

@@ -0,0 +1,62 @@
+//===-- SystemZConstantPoolValue.cpp - SystemZ constant-pool value --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SystemZConstantPoolValue.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/GlobalValue.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+SystemZConstantPoolValue::
+SystemZConstantPoolValue(const GlobalValue *gv,
+                         SystemZCP::SystemZCPModifier modifier)
+  : MachineConstantPoolValue(gv->getType()), GV(gv), Modifier(modifier) {}
+
+SystemZConstantPoolValue *
+SystemZConstantPoolValue::Create(const GlobalValue *GV,
+                                 SystemZCP::SystemZCPModifier Modifier) {
+  return new SystemZConstantPoolValue(GV, Modifier);
+}
+
+unsigned SystemZConstantPoolValue::getRelocationInfo() const {
+  switch (Modifier) {
+  case SystemZCP::NTPOFF:
+    // May require a relocation, but the relocations are always resolved
+    // by the static linker.
+    return 1;
+  }
+  llvm_unreachable("Unknown modifier");
+}
+
+int SystemZConstantPoolValue::
+getExistingMachineCPValue(MachineConstantPool *CP, unsigned Alignment) {
+  unsigned AlignMask = Alignment - 1;
+  const std::vector<MachineConstantPoolEntry> Constants = CP->getConstants();
+  for (unsigned I = 0, E = Constants.size(); I != E; ++I) {
+    if (Constants[I].isMachineConstantPoolEntry() &&
+        (Constants[I].getAlignment() & AlignMask) == 0) {
+      SystemZConstantPoolValue *ZCPV =
+        static_cast<SystemZConstantPoolValue *>(Constants[I].Val.MachineCPVal);
+      if (ZCPV->GV == GV && ZCPV->Modifier == Modifier)
+        return I;
+    }
+  }
+  return -1;
+}
+
+void SystemZConstantPoolValue::addSelectionDAGCSEId(FoldingSetNodeID &ID) {
+  ID.AddPointer(GV);
+  ID.AddInteger(Modifier);
+}
+
+void SystemZConstantPoolValue::print(raw_ostream &O) const {
+  O << GV << "@" << int(Modifier);
+}