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 
15 #define GET_SUBTARGETINFO_TARGET_DESC
16 #define GET_SUBTARGETINFO_CTOR
17 #include "SystemZGenSubtargetInfo.inc"
18 
19 using namespace llvm;
20 
21 // Pin the vtabel to this file.
22 void SystemZSubtarget::anchor() {}
23 
24 SystemZSubtarget::SystemZSubtarget(const std::string &TT,
25                                    const std::string &CPU,
26                                    const std::string &FS)
27   : SystemZGenSubtargetInfo(TT, CPU, FS), HasDistinctOps(false),
28     HasLoadStoreOnCond(false), HasHighWord(false), HasFPExtension(false),
29     HasFastSerialization(false), HasInterlockedAccess1(false),
30     TargetTriple(TT) {
31   std::string CPUName = CPU;
32   if (CPUName.empty())
33     CPUName = "generic";
34 #if defined(__linux__) && defined(__s390x__)
35   if (CPUName == "generic")
36     CPUName = sys::getHostCPUName();
37 #endif
38 
39   // Parse features string.
40   ParseSubtargetFeatures(CPUName, FS);
41 }
42 
43 // Return true if GV binds locally under reloc model RM.
44 static bool bindsLocally(const GlobalValue *GV, Reloc::Model RM) {
45   // For non-PIC, all symbols bind locally.
46   if (RM == Reloc::Static)
47     return true;
48 
49   return GV->hasLocalLinkage() || !GV->hasDefaultVisibility();
50 }
51 
52 bool SystemZSubtarget::isPC32DBLSymbol(const GlobalValue *GV,
53                                        Reloc::Model RM,
54                                        CodeModel::Model CM) const {
55   // PC32DBL accesses require the low bit to be clear.  Note that a zero
56   // value selects the default alignment and is therefore OK.
57   if (GV->getAlignment() == 1)
58     return false;
59 
60   // For the small model, all locally-binding symbols are in range.
61   if (CM == CodeModel::Small)
62     return bindsLocally(GV, RM);
63 
64   // For Medium and above, assume that the symbol is not within the 4GB range.
65   // Taking the address of locally-defined text would be OK, but that
66   // case isn't easy to detect.
67   return false;
68 }
69