1//===-- SystemZSubtarget.cpp - SystemZ subtarget information --------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "SystemZSubtarget.h"
11#include "MCTargetDesc/SystemZMCTargetDesc.h"
12#include "llvm/IR/GlobalValue.h"
13#include "llvm/Support/Host.h"
14
15using namespace llvm;
16
17#define DEBUG_TYPE "systemz-subtarget"
18
19#define GET_SUBTARGETINFO_TARGET_DESC
20#define GET_SUBTARGETINFO_CTOR
21#include "SystemZGenSubtargetInfo.inc"
22
23// Pin the vtable to this file.
24void SystemZSubtarget::anchor() {}
25
26SystemZSubtarget &
27SystemZSubtarget::initializeSubtargetDependencies(StringRef CPU, StringRef FS) {
28  std::string CPUName = CPU;
29  if (CPUName.empty())
30    CPUName = "generic";
31#if defined(__linux__) && defined(__s390x__)
32  if (CPUName == "generic")
33    CPUName = sys::getHostCPUName();
34#endif
35  // Parse features string.
36  ParseSubtargetFeatures(CPUName, FS);
37  return *this;
38}
39
40SystemZSubtarget::SystemZSubtarget(const std::string &TT,
41                                   const std::string &CPU,
42                                   const std::string &FS,
43                                   const TargetMachine &TM)
44    : SystemZGenSubtargetInfo(TT, CPU, FS), HasDistinctOps(false),
45      HasLoadStoreOnCond(false), HasHighWord(false), HasFPExtension(false),
46      HasFastSerialization(false), HasInterlockedAccess1(false),
47      TargetTriple(TT),
48      // Make sure that global data has at least 16 bits of alignment by
49      // default, so that we can refer to it using LARL.  We don't have any
50      // special requirements for stack variables though.
51      DL("E-m:e-i1:8:16-i8:8:16-i64:64-f128:64-a:8:16-n32:64"),
52      InstrInfo(initializeSubtargetDependencies(CPU, FS)), TLInfo(TM),
53      TSInfo(DL), FrameLowering() {}
54
55// Return true if GV binds locally under reloc model RM.
56static bool bindsLocally(const GlobalValue *GV, Reloc::Model RM) {
57  // For non-PIC, all symbols bind locally.
58  if (RM == Reloc::Static)
59    return true;
60
61  return GV->hasLocalLinkage() || !GV->hasDefaultVisibility();
62}
63
64bool SystemZSubtarget::isPC32DBLSymbol(const GlobalValue *GV,
65                                       Reloc::Model RM,
66                                       CodeModel::Model CM) const {
67  // PC32DBL accesses require the low bit to be clear.  Note that a zero
68  // value selects the default alignment and is therefore OK.
69  if (GV->getAlignment() == 1)
70    return false;
71
72  // For the small model, all locally-binding symbols are in range.
73  if (CM == CodeModel::Small)
74    return bindsLocally(GV, RM);
75
76  // For Medium and above, assume that the symbol is not within the 4GB range.
77  // Taking the address of locally-defined text would be OK, but that
78  // case isn't easy to detect.
79  return false;
80}
81