1 //===-- ARMSubtarget.cpp - ARM Subtarget Information ------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the ARM specific subclass of TargetSubtarget.
12 //===----------------------------------------------------------------------===//
14 #include "ARMSubtarget.h"
15 #include "ARMGenSubtarget.inc"
16 #include "llvm/GlobalValue.h"
17 #include "llvm/Target/TargetOptions.h"
18 #include "llvm/Support/CommandLine.h"
19 #include "llvm/ADT/SmallVector.h"
23 ReserveR9("arm-reserve-r9", cl::Hidden,
24 cl::desc("Reserve R9, making it unavailable as GPR"));
27 UseMOVT("arm-use-movt",
28 cl::init(true), cl::Hidden);
30 ARMSubtarget::ARMSubtarget(const std::string &TT, const std::string &FS,
33 , ARMProcFamily(Others)
35 , UseNEONForSinglePrecisionFP(false)
41 , PostRAScheduler(false)
42 , IsR9Reserved(ReserveR9)
45 , HasHardwareDivide(false)
46 , HasT2ExtractPack(false)
47 , HasDataBarrier(false)
48 , Pref32BitThumb(false)
51 , CPUString("generic")
52 , TargetType(isELF) // Default to ELF unless otherwise specified.
53 , TargetABI(ARM_ABI_APCS) {
54 // Default to soft float ABI
55 if (FloatABIType == FloatABI::Default)
56 FloatABIType = FloatABI::Soft;
58 // Determine default and user specified characteristics
60 // Parse features string.
61 CPUString = ParseSubtargetFeatures(FS, CPUString);
63 // When no arch is specified either by CPU or by attributes, make the default
65 if (CPUString == "generic" && (FS.empty() || FS == "generic"))
68 // Set the boolean corresponding to the current target triple, or the default
69 // if one cannot be determined, to true.
70 unsigned Len = TT.length();
73 if (Len >= 5 && TT.substr(0, 4) == "armv")
75 else if (Len >= 6 && TT.substr(0, 5) == "thumb") {
77 if (Len >= 7 && TT[5] == 'v')
81 unsigned SubVer = TT[Idx];
82 if (SubVer >= '7' && SubVer <= '9') {
84 if (Len >= Idx+2 && TT[Idx+1] == 'm')
86 } else if (SubVer == '6') {
88 if (Len >= Idx+3 && TT[Idx+1] == 't' && TT[Idx+2] == '2')
89 ARMArchVersion = V6T2;
90 } else if (SubVer == '5') {
92 if (Len >= Idx+3 && TT[Idx+1] == 't' && TT[Idx+2] == 'e')
93 ARMArchVersion = V5TE;
94 } else if (SubVer == '4') {
95 if (Len >= Idx+2 && TT[Idx+1] == 't')
102 // Thumb2 implies at least V6T2.
103 if (ARMArchVersion >= V6T2)
105 else if (ThumbMode >= Thumb2)
106 ARMArchVersion = V6T2;
109 if (TT.find("-darwin") != std::string::npos)
111 TargetType = isDarwin;
114 if (TT.find("eabi") != std::string::npos)
115 TargetABI = ARM_ABI_AAPCS;
120 if (isTargetDarwin())
121 IsR9Reserved = ReserveR9 | (ARMArchVersion < V6);
123 if (!isThumb() || hasThumb2())
124 PostRAScheduler = true;
127 /// GVIsIndirectSymbol - true if the GV will be accessed via an indirect symbol.
129 ARMSubtarget::GVIsIndirectSymbol(const GlobalValue *GV,
130 Reloc::Model RelocM) const {
131 if (RelocM == Reloc::Static)
134 // Materializable GVs (in JIT lazy compilation mode) do not require an extra
136 bool isDecl = GV->isDeclaration() && !GV->isMaterializable();
138 if (!isTargetDarwin()) {
139 // Extra load is needed for all externally visible.
140 if (GV->hasLocalLinkage() || GV->hasHiddenVisibility())
144 if (RelocM == Reloc::PIC_) {
145 // If this is a strong reference to a definition, it is definitely not
147 if (!isDecl && !GV->isWeakForLinker())
150 // Unless we have a symbol with hidden visibility, we have to go through a
151 // normal $non_lazy_ptr stub because this symbol might be resolved late.
152 if (!GV->hasHiddenVisibility()) // Non-hidden $non_lazy_ptr reference.
155 // If symbol visibility is hidden, we have a stub for common symbol
156 // references and external declarations.
157 if (isDecl || GV->hasCommonLinkage())
158 // Hidden $non_lazy_ptr reference.
163 // If this is a strong reference to a definition, it is definitely not
165 if (!isDecl && !GV->isWeakForLinker())
168 // Unless we have a symbol with hidden visibility, we have to go through a
169 // normal $non_lazy_ptr stub because this symbol might be resolved late.
170 if (!GV->hasHiddenVisibility()) // Non-hidden $non_lazy_ptr reference.
178 bool ARMSubtarget::enablePostRAScheduler(
179 CodeGenOpt::Level OptLevel,
180 TargetSubtarget::AntiDepBreakMode& Mode,
181 RegClassVector& CriticalPathRCs) const {
182 Mode = TargetSubtarget::ANTIDEP_CRITICAL;
183 CriticalPathRCs.clear();
184 CriticalPathRCs.push_back(&ARM::GPRRegClass);
185 return PostRAScheduler && OptLevel >= CodeGenOpt::Default;