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 using 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.
anchor()24 void SystemZSubtarget::anchor() {}
25
26 SystemZSubtarget &
initializeSubtargetDependencies(StringRef CPU,StringRef FS)27 SystemZSubtarget::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
SystemZSubtarget(const std::string & TT,const std::string & CPU,const std::string & FS,const TargetMachine & TM)40 SystemZSubtarget::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.
bindsLocally(const GlobalValue * GV,Reloc::Model RM)56 static 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
isPC32DBLSymbol(const GlobalValue * GV,Reloc::Model RM,CodeModel::Model CM) const64 bool 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