1 //===-- TargetMachine.cpp - General Target Information ---------------------==//
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 describes the general parts of a Target machine.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/CodeGen/MachineFunction.h"
15 #include "llvm/CodeGen/MachineFrameInfo.h"
16 #include "llvm/MC/MCAsmInfo.h"
17 #include "llvm/Target/TargetMachine.h"
18 #include "llvm/Target/TargetOptions.h"
19 #include "llvm/Support/CommandLine.h"
22 //---------------------------------------------------------------------------
23 // Command-line options that tend to be useful on more than one back-end.
27 bool LessPreciseFPMADOption;
28 bool PrintMachineCode;
29 bool NoFramePointerElim;
30 bool NoFramePointerElimNonLeaf;
31 bool NoExcessFPPrecision;
35 bool HonorSignDependentRoundingFPMathOption;
37 FloatABI::ABIType FloatABIType;
40 bool JITExceptionHandling;
41 bool JITEmitDebugInfo;
42 bool JITEmitDebugInfoToDisk;
43 Reloc::Model RelocationModel;
44 CodeModel::Model CMModel;
45 bool GuaranteedTailCallOpt;
46 unsigned StackAlignment;
48 bool DisableJumpTables;
50 bool HasDivModLibcall;
51 bool AsmVerbosityDefault(false);
54 static cl::opt<bool, true>
55 PrintCode("print-machineinstrs",
56 cl::desc("Print generated machine code"),
57 cl::location(PrintMachineCode), cl::init(false));
58 static cl::opt<bool, true>
59 DisableFPElim("disable-fp-elim",
60 cl::desc("Disable frame pointer elimination optimization"),
61 cl::location(NoFramePointerElim),
63 static cl::opt<bool, true>
64 DisableFPElimNonLeaf("disable-non-leaf-fp-elim",
65 cl::desc("Disable frame pointer elimination optimization for non-leaf funcs"),
66 cl::location(NoFramePointerElimNonLeaf),
68 static cl::opt<bool, true>
69 DisableExcessPrecision("disable-excess-fp-precision",
70 cl::desc("Disable optimizations that may increase FP precision"),
71 cl::location(NoExcessFPPrecision),
73 static cl::opt<bool, true>
74 EnableFPMAD("enable-fp-mad",
75 cl::desc("Enable less precise MAD instructions to be generated"),
76 cl::location(LessPreciseFPMADOption),
78 static cl::opt<bool, true>
79 EnableUnsafeFPMath("enable-unsafe-fp-math",
80 cl::desc("Enable optimizations that may decrease FP precision"),
81 cl::location(UnsafeFPMath),
83 static cl::opt<bool, true>
84 EnableNoInfsFPMath("enable-no-infs-fp-math",
85 cl::desc("Enable FP math optimizations that assume no +-Infs"),
86 cl::location(NoInfsFPMath),
88 static cl::opt<bool, true>
89 EnableNoNaNsFPMath("enable-no-nans-fp-math",
90 cl::desc("Enable FP math optimizations that assume no NaNs"),
91 cl::location(NoNaNsFPMath),
93 static cl::opt<bool, true>
94 EnableHonorSignDependentRoundingFPMath("enable-sign-dependent-rounding-fp-math",
96 cl::desc("Force codegen to assume rounding mode can change dynamically"),
97 cl::location(HonorSignDependentRoundingFPMathOption),
99 static cl::opt<bool, true>
100 GenerateSoftFloatCalls("soft-float",
101 cl::desc("Generate software floating point library calls"),
102 cl::location(UseSoftFloat),
104 static cl::opt<llvm::FloatABI::ABIType, true>
105 FloatABIForCalls("float-abi",
106 cl::desc("Choose float ABI type"),
107 cl::location(FloatABIType),
108 cl::init(FloatABI::Default),
110 clEnumValN(FloatABI::Default, "default",
111 "Target default float ABI type"),
112 clEnumValN(FloatABI::Soft, "soft",
113 "Soft float ABI (implied by -soft-float)"),
114 clEnumValN(FloatABI::Hard, "hard",
115 "Hard float ABI (uses FP registers)"),
117 static cl::opt<bool, true>
118 DontPlaceZerosInBSS("nozero-initialized-in-bss",
119 cl::desc("Don't place zero-initialized symbols into bss section"),
120 cl::location(NoZerosInBSS),
122 static cl::opt<bool, true>
123 EnableJITExceptionHandling("jit-enable-eh",
124 cl::desc("Emit exception handling information"),
125 cl::location(JITExceptionHandling),
127 // In debug builds, make this default to true.
129 #define EMIT_DEBUG false
131 #define EMIT_DEBUG true
133 static cl::opt<bool, true>
134 EmitJitDebugInfo("jit-emit-debug",
135 cl::desc("Emit debug information to debugger"),
136 cl::location(JITEmitDebugInfo),
137 cl::init(EMIT_DEBUG));
139 static cl::opt<bool, true>
140 EmitJitDebugInfoToDisk("jit-emit-debug-to-disk",
142 cl::desc("Emit debug info objfiles to disk"),
143 cl::location(JITEmitDebugInfoToDisk),
146 static cl::opt<llvm::Reloc::Model, true>
147 DefRelocationModel("relocation-model",
148 cl::desc("Choose relocation model"),
149 cl::location(RelocationModel),
150 cl::init(Reloc::Default),
152 clEnumValN(Reloc::Default, "default",
153 "Target default relocation model"),
154 clEnumValN(Reloc::Static, "static",
155 "Non-relocatable code"),
156 clEnumValN(Reloc::PIC_, "pic",
157 "Fully relocatable, position independent code"),
158 clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
159 "Relocatable external references, non-relocatable code"),
161 static cl::opt<llvm::CodeModel::Model, true>
162 DefCodeModel("code-model",
163 cl::desc("Choose code model"),
164 cl::location(CMModel),
165 cl::init(CodeModel::Default),
167 clEnumValN(CodeModel::Default, "default",
168 "Target default code model"),
169 clEnumValN(CodeModel::Small, "small",
171 clEnumValN(CodeModel::Kernel, "kernel",
172 "Kernel code model"),
173 clEnumValN(CodeModel::Medium, "medium",
174 "Medium code model"),
175 clEnumValN(CodeModel::Large, "large",
178 static cl::opt<bool, true>
179 EnableGuaranteedTailCallOpt("tailcallopt",
180 cl::desc("Turn fastcc calls into tail calls by (potentially) changing ABI."),
181 cl::location(GuaranteedTailCallOpt),
183 static cl::opt<unsigned, true>
184 OverrideStackAlignment("stack-alignment",
185 cl::desc("Override default stack alignment"),
186 cl::location(StackAlignment),
188 static cl::opt<bool, true>
189 EnableRealignStack("realign-stack",
190 cl::desc("Realign stack if needed"),
191 cl::location(RealignStack),
193 static cl::opt<bool, true>
194 DisableSwitchTables(cl::Hidden, "disable-jump-tables",
195 cl::desc("Do not generate jump tables."),
196 cl::location(DisableJumpTables),
198 static cl::opt<bool, true>
199 EnableStrongPHIElim(cl::Hidden, "strong-phi-elim",
200 cl::desc("Use strong PHI elimination."),
201 cl::location(StrongPHIElim),
203 static cl::opt<std::string>
204 TrapFuncName("trap-func", cl::Hidden,
205 cl::desc("Emit a call to trap function rather than a trap instruction"),
208 DataSections("fdata-sections",
209 cl::desc("Emit data into separate sections"),
212 FunctionSections("ffunction-sections",
213 cl::desc("Emit functions into separate sections"),
215 //---------------------------------------------------------------------------
216 // TargetMachine Class
219 TargetMachine::TargetMachine(const Target &T)
220 : TheTarget(T), AsmInfo(0),
222 MCNoExecStack(false),
223 MCSaveTempLabels(false),
226 // Typically it will be subtargets that will adjust FloatABIType from Default
229 FloatABIType = FloatABI::Soft;
232 TargetMachine::~TargetMachine() {
236 /// getRelocationModel - Returns the code generation relocation model. The
237 /// choices are static, PIC, and dynamic-no-pic, and target default.
238 Reloc::Model TargetMachine::getRelocationModel() {
239 return RelocationModel;
242 /// setRelocationModel - Sets the code generation relocation model.
243 void TargetMachine::setRelocationModel(Reloc::Model Model) {
244 RelocationModel = Model;
247 /// getCodeModel - Returns the code model. The choices are small, kernel,
248 /// medium, large, and target default.
249 CodeModel::Model TargetMachine::getCodeModel() {
253 /// setCodeModel - Sets the code model.
254 void TargetMachine::setCodeModel(CodeModel::Model Model) {
258 bool TargetMachine::getAsmVerbosityDefault() {
259 return AsmVerbosityDefault;
262 void TargetMachine::setAsmVerbosityDefault(bool V) {
263 AsmVerbosityDefault = V;
266 bool TargetMachine::getFunctionSections() {
267 return FunctionSections;
270 bool TargetMachine::getDataSections() {
274 void TargetMachine::setFunctionSections(bool V) {
275 FunctionSections = V;
278 void TargetMachine::setDataSections(bool V) {
283 /// DisableFramePointerElim - This returns true if frame pointer elimination
284 /// optimization should be disabled for the given machine function.
285 bool DisableFramePointerElim(const MachineFunction &MF) {
286 // Check to see if we should eliminate non-leaf frame pointers and then
287 // check to see if we should eliminate all frame pointers.
288 if (NoFramePointerElimNonLeaf && !NoFramePointerElim) {
289 const MachineFrameInfo *MFI = MF.getFrameInfo();
290 return MFI->hasCalls();
293 return NoFramePointerElim;
296 /// LessPreciseFPMAD - This flag return true when -enable-fp-mad option
297 /// is specified on the command line. When this flag is off(default), the
298 /// code generator is not allowed to generate mad (multiply add) if the
299 /// result is "less precise" than doing those operations individually.
300 bool LessPreciseFPMAD() { return UnsafeFPMath || LessPreciseFPMADOption; }
302 /// HonorSignDependentRoundingFPMath - Return true if the codegen must assume
303 /// that the rounding mode of the FPU can change from its default.
304 bool HonorSignDependentRoundingFPMath() {
305 return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption;
308 /// getTrapFunctionName - If this returns a non-empty string, this means isel
309 /// should lower Intrinsic::trap to a call to the specified function name
310 /// instead of an ISD::TRAP node.
311 StringRef getTrapFunctionName() {