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/Target/TargetAsmInfo.h"
15 #include "llvm/Target/TargetMachine.h"
16 #include "llvm/Target/TargetOptions.h"
17 #include "llvm/Support/CommandLine.h"
20 //---------------------------------------------------------------------------
21 // Command-line options that tend to be useful on more than one back-end.
25 bool PrintMachineCode;
26 bool NoFramePointerElim;
27 bool NoExcessFPPrecision;
29 bool FiniteOnlyFPMathOption;
30 bool HonorSignDependentRoundingFPMathOption;
33 bool ExceptionHandling;
34 bool UnwindTablesMandatory;
35 Reloc::Model RelocationModel;
36 CodeModel::Model CMModel;
37 bool PerformTailCallOpt;
39 unsigned StackAlignment;
42 bool DisableJumpTables;
43 bool DisableCorrectBranchFolding;
46 static cl::opt<bool, true> PrintCode("print-machineinstrs",
47 cl::desc("Print generated machine code"),
48 cl::location(PrintMachineCode), cl::init(false));
50 static cl::opt<bool, true>
51 DisableFPElim("disable-fp-elim",
52 cl::desc("Disable frame pointer elimination optimization"),
53 cl::location(NoFramePointerElim),
55 static cl::opt<bool, true>
56 DisableExcessPrecision("disable-excess-fp-precision",
57 cl::desc("Disable optimizations that may increase FP precision"),
58 cl::location(NoExcessFPPrecision),
60 static cl::opt<bool, true>
61 EnableUnsafeFPMath("enable-unsafe-fp-math",
62 cl::desc("Enable optimizations that may decrease FP precision"),
63 cl::location(UnsafeFPMath),
65 static cl::opt<bool, true>
66 EnableFiniteOnlyFPMath("enable-finite-only-fp-math",
67 cl::desc("Enable optimizations that assumes non- NaNs / +-Infs"),
68 cl::location(FiniteOnlyFPMathOption),
70 static cl::opt<bool, true>
71 EnableHonorSignDependentRoundingFPMath(cl::Hidden,
72 "enable-sign-dependent-rounding-fp-math",
73 cl::desc("Force codegen to assume rounding mode can change dynamically"),
74 cl::location(HonorSignDependentRoundingFPMathOption),
77 static cl::opt<bool, true>
78 GenerateSoftFloatCalls("soft-float",
79 cl::desc("Generate software floating point library calls"),
80 cl::location(UseSoftFloat),
82 static cl::opt<bool, true>
83 DontPlaceZerosInBSS("nozero-initialized-in-bss",
84 cl::desc("Don't place zero-initialized symbols into bss section"),
85 cl::location(NoZerosInBSS),
87 static cl::opt<bool, true>
88 EnableExceptionHandling("enable-eh",
89 cl::desc("Emit DWARF exception handling (default if target supports)"),
90 cl::location(ExceptionHandling),
92 static cl::opt<bool, true>
93 EnableUnwindTables("unwind-tables",
94 cl::desc("Generate unwinding tables for all functions"),
95 cl::location(UnwindTablesMandatory),
98 static cl::opt<llvm::Reloc::Model, true>
101 cl::desc("Choose relocation model"),
102 cl::location(RelocationModel),
103 cl::init(Reloc::Default),
105 clEnumValN(Reloc::Default, "default",
106 " Target default relocation model"),
107 clEnumValN(Reloc::Static, "static",
108 " Non-relocatable code"),
109 clEnumValN(Reloc::PIC_, "pic",
110 " Fully relocatable, position independent code"),
111 clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
112 " Relocatable external references, non-relocatable code"),
114 static cl::opt<llvm::CodeModel::Model, true>
117 cl::desc("Choose code model"),
118 cl::location(CMModel),
119 cl::init(CodeModel::Default),
121 clEnumValN(CodeModel::Default, "default",
122 " Target default code model"),
123 clEnumValN(CodeModel::Small, "small",
124 " Small code model"),
125 clEnumValN(CodeModel::Kernel, "kernel",
126 " Kernel code model"),
127 clEnumValN(CodeModel::Medium, "medium",
128 " Medium code model"),
129 clEnumValN(CodeModel::Large, "large",
130 " Large code model"),
133 static cl::opt<bool, true>
134 EnablePerformTailCallOpt("tailcallopt",
135 cl::desc("Turn on tail call optimization."),
136 cl::location(PerformTailCallOpt),
138 static cl::opt<bool, true>
139 EnableOptimizeForSize("optimize-size",
140 cl::desc("Optimize for size."),
141 cl::location(OptimizeForSize),
144 static cl::opt<unsigned, true>
145 OverrideStackAlignment("stack-alignment",
146 cl::desc("Override default stack alignment"),
147 cl::location(StackAlignment),
150 static cl::opt<bool, true>
151 EnableRealignStack("realign-stack",
152 cl::desc("Realign stack if needed"),
153 cl::location(RealignStack),
156 static cl::opt<bool, true>
157 AsmVerbose("asm-verbose", cl::desc("Add comments to directives."),
158 cl::location(VerboseAsm),
161 static cl::opt<bool, true>
162 DisableSwitchTables(cl::Hidden, "disable-jump-tables",
163 cl::desc("Do not generate jump tables."),
164 cl::location(DisableJumpTables),
167 static cl::opt<bool, true>
168 DisableCorrectISelFolding(cl::Hidden, "disable-correct-folding",
169 cl::desc("Do not perform correct branch folding in the instruction selector."),
170 cl::location(DisableCorrectBranchFolding), cl::init(false));
172 //---------------------------------------------------------------------------
173 // TargetMachine Class
176 TargetMachine::~TargetMachine() {
180 /// getRelocationModel - Returns the code generation relocation model. The
181 /// choices are static, PIC, and dynamic-no-pic, and target default.
182 Reloc::Model TargetMachine::getRelocationModel() {
183 return RelocationModel;
186 /// setRelocationModel - Sets the code generation relocation model.
187 void TargetMachine::setRelocationModel(Reloc::Model Model) {
188 RelocationModel = Model;
191 /// getCodeModel - Returns the code model. The choices are small, kernel,
192 /// medium, large, and target default.
193 CodeModel::Model TargetMachine::getCodeModel() {
197 /// setCodeModel - Sets the code model.
198 void TargetMachine::setCodeModel(CodeModel::Model Model) {
203 /// FiniteOnlyFPMath - This returns true when the -enable-finite-only-fp-math
204 /// option is specified on the command line. If this returns false (default),
205 /// the code generator is not allowed to assume that FP arithmetic arguments
206 /// and results are never NaNs or +-Infs.
207 bool FiniteOnlyFPMath() { return UnsafeFPMath || FiniteOnlyFPMathOption; }
209 /// HonorSignDependentRoundingFPMath - Return true if the codegen must assume
210 /// that the rounding mode of the FPU can change from its default.
211 bool HonorSignDependentRoundingFPMath() {
212 return !UnsafeFPMath && HonorSignDependentRoundingFPMathOption;