1 //===-- llvm/Target/TargetOptions.h - Target Options ------------*- 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 defines command line option flags that are shared across various
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_TARGET_TARGETOPTIONS_H
16 #define LLVM_TARGET_TARGETOPTIONS_H
18 #include "llvm/MC/MCTargetOptions.h"
22 class MachineFunction;
28 Default, // Target-specific (either soft or hard depending on triple, etc).
34 namespace FPOpFusion {
36 Fast, // Enable fusion of FP ops wherever it's profitable.
37 Standard, // Only allow fusion of 'blessed' ops (currently just fmuladd).
38 Strict // Never fuse FP-ops.
44 Single, // Use a single table for all indirect jumptable calls.
45 Arity, // Use one table per number of function parameters.
46 Simplified, // Use one table per function type, with types projected
47 // into 4 types: pointer to non-function, struct,
48 // primitive, and function pointer.
49 Full // Use one table per unique function type
53 namespace ThreadModel {
55 POSIX, // POSIX Threads
56 Single // Single Threaded Environment
63 : PrintMachineCode(false), NoFramePointerElim(false),
64 NoFramePointerElimOverride(false),
65 LessPreciseFPMADOption(false), UnsafeFPMath(false),
66 NoInfsFPMath(false), NoNaNsFPMath(false),
67 HonorSignDependentRoundingFPMathOption(false),
69 GuaranteedTailCallOpt(false),
70 DisableTailCalls(false), StackAlignmentOverride(0),
71 EnableFastISel(false), PositionIndependentExecutable(false),
72 UseInitArray(false), DisableIntegratedAS(false),
73 CompressDebugSections(false), FunctionSections(false),
74 DataSections(false), UniqueSectionNames(true), TrapUnreachable(false),
75 TrapFuncName(), FloatABIType(FloatABI::Default),
76 AllowFPOpFusion(FPOpFusion::Standard), JTType(JumpTable::Single),
77 ThreadModel(ThreadModel::POSIX) {}
79 /// PrintMachineCode - This flag is enabled when the -print-machineinstrs
80 /// option is specified on the command line, and should enable debugging
81 /// output from the code generator.
82 unsigned PrintMachineCode : 1;
84 /// NoFramePointerElim - This flag is enabled when the -disable-fp-elim is
85 /// specified on the command line. If the target supports the frame pointer
86 /// elimination optimization, this option should disable it.
87 unsigned NoFramePointerElim : 1;
89 /// This flag is true when "disable-fp-elim" appeared on the command line.
90 unsigned NoFramePointerElimOverride : 1;
92 /// DisableFramePointerElim - This returns true if frame pointer elimination
93 /// optimization should be disabled for the given machine function.
94 bool DisableFramePointerElim(const MachineFunction &MF) const;
96 /// LessPreciseFPMAD - This flag is enabled when the
97 /// -enable-fp-mad is specified on the command line. When this flag is off
98 /// (the default), the code generator is not allowed to generate mad
99 /// (multiply add) if the result is "less precise" than doing those
100 /// operations individually.
101 unsigned LessPreciseFPMADOption : 1;
102 bool LessPreciseFPMAD() const;
104 /// UnsafeFPMath - This flag is enabled when the
105 /// -enable-unsafe-fp-math flag is specified on the command line. When
106 /// this flag is off (the default), the code generator is not allowed to
107 /// produce results that are "less precise" than IEEE allows. This includes
108 /// use of X86 instructions like FSIN and FCOS instead of libcalls.
109 /// UnsafeFPMath implies LessPreciseFPMAD.
110 unsigned UnsafeFPMath : 1;
112 /// NoInfsFPMath - This flag is enabled when the
113 /// -enable-no-infs-fp-math flag is specified on the command line. When
114 /// this flag is off (the default), the code generator is not allowed to
115 /// assume the FP arithmetic arguments and results are never +-Infs.
116 unsigned NoInfsFPMath : 1;
118 /// NoNaNsFPMath - This flag is enabled when the
119 /// -enable-no-nans-fp-math flag is specified on the command line. When
120 /// this flag is off (the default), the code generator is not allowed to
121 /// assume the FP arithmetic arguments and results are never NaNs.
122 unsigned NoNaNsFPMath : 1;
124 /// HonorSignDependentRoundingFPMath - This returns true when the
125 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns
126 /// false (the default), the code generator is allowed to assume that the
127 /// rounding behavior is the default (round-to-zero for all floating point
128 /// to integer conversions, and round-to-nearest for all other arithmetic
129 /// truncations). If this is enabled (set to true), the code generator must
130 /// assume that the rounding mode may dynamically change.
131 unsigned HonorSignDependentRoundingFPMathOption : 1;
132 bool HonorSignDependentRoundingFPMath() const;
134 /// NoZerosInBSS - By default some codegens place zero-initialized data to
135 /// .bss section. This flag disables such behaviour (necessary, e.g. for
136 /// crt*.o compiling).
137 unsigned NoZerosInBSS : 1;
139 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is
140 /// specified on the commandline. When the flag is on, participating targets
141 /// will perform tail call optimization on all calls which use the fastcc
142 /// calling convention and which satisfy certain target-independent
143 /// criteria (being at the end of a function, having the same return type
144 /// as their parent function, etc.), using an alternate ABI if necessary.
145 unsigned GuaranteedTailCallOpt : 1;
147 /// DisableTailCalls - This flag controls whether we will use tail calls.
148 /// Disabling them may be useful to maintain a correct call stack.
149 unsigned DisableTailCalls : 1;
151 /// StackAlignmentOverride - Override default stack alignment for target.
152 unsigned StackAlignmentOverride;
154 /// EnableFastISel - This flag enables fast-path instruction selection
155 /// which trades away generated code quality in favor of reducing
157 unsigned EnableFastISel : 1;
159 /// PositionIndependentExecutable - This flag indicates whether the code
160 /// will eventually be linked into a single executable, despite the PIC
161 /// relocation model being in use. It's value is undefined (and irrelevant)
162 /// if the relocation model is anything other than PIC.
163 unsigned PositionIndependentExecutable : 1;
165 /// UseInitArray - Use .init_array instead of .ctors for static
167 unsigned UseInitArray : 1;
169 /// Disable the integrated assembler.
170 unsigned DisableIntegratedAS : 1;
172 /// Compress DWARF debug sections.
173 unsigned CompressDebugSections : 1;
175 /// Emit functions into separate sections.
176 unsigned FunctionSections : 1;
178 /// Emit data into separate sections.
179 unsigned DataSections : 1;
181 unsigned UniqueSectionNames : 1;
183 /// Emit target-specific trap instruction for 'unreachable' IR instructions.
184 unsigned TrapUnreachable : 1;
186 /// getTrapFunctionName - If this returns a non-empty string, this means
187 /// isel should lower Intrinsic::trap to a call to the specified function
188 /// name instead of an ISD::TRAP node.
189 std::string TrapFuncName;
190 StringRef getTrapFunctionName() const;
192 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
193 /// on the command line. This setting may either be Default, Soft, or Hard.
194 /// Default selects the target's default behavior. Soft selects the ABI for
195 /// software floating point, but does not indicate that FP hardware may not
196 /// be used. Such a combination is unfortunately popular (e.g.
197 /// arm-apple-darwin). Hard presumes that the normal FP ABI is used.
198 FloatABI::ABIType FloatABIType;
200 /// AllowFPOpFusion - This flag is set by the -fuse-fp-ops=xxx option.
201 /// This controls the creation of fused FP ops that store intermediate
202 /// results in higher precision than IEEE allows (E.g. FMAs).
204 /// Fast mode - allows formation of fused FP ops whenever they're
206 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the
207 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops
209 /// Strict mode - allow fusion only if/when it can be proven that the excess
210 /// precision won't effect the result.
212 /// Note: This option only controls formation of fused ops by the
213 /// optimizers. Fused operations that are explicitly specified (e.g. FMA
214 /// via the llvm.fma.* intrinsic) will always be honored, regardless of
215 /// the value of this option.
216 FPOpFusion::FPOpFusionMode AllowFPOpFusion;
218 /// JTType - This flag specifies the type of jump-instruction table to
219 /// create for functions that have the jumptable attribute.
220 JumpTable::JumpTableType JTType;
222 /// ThreadModel - This flag specifies the type of threading model to assume
223 /// for things like atomics
224 ThreadModel::Model ThreadModel;
226 /// Machine level options.
227 MCTargetOptions MCOptions;
230 /// \brief Set function attributes of functions in Module M based on CPU,
231 /// Features, and Options.
232 /// If AlwaysRecordAttrs is true, it will always record the function attributes
233 /// in Options regardless of whether those attributes were specified on the
234 /// tool's command line.
235 void setFunctionAttributes(StringRef CPU, StringRef Features,
236 const TargetOptions &Options, Module &M,
237 bool AlwaysRecordAttrs);
239 // Comparison operators:
242 inline bool operator==(const TargetOptions &LHS,
243 const TargetOptions &RHS) {
244 #define ARE_EQUAL(X) LHS.X == RHS.X
246 ARE_EQUAL(UnsafeFPMath) &&
247 ARE_EQUAL(NoInfsFPMath) &&
248 ARE_EQUAL(NoNaNsFPMath) &&
249 ARE_EQUAL(HonorSignDependentRoundingFPMathOption) &&
250 ARE_EQUAL(NoZerosInBSS) &&
251 ARE_EQUAL(GuaranteedTailCallOpt) &&
252 ARE_EQUAL(DisableTailCalls) &&
253 ARE_EQUAL(StackAlignmentOverride) &&
254 ARE_EQUAL(EnableFastISel) &&
255 ARE_EQUAL(PositionIndependentExecutable) &&
256 ARE_EQUAL(UseInitArray) &&
257 ARE_EQUAL(TrapUnreachable) &&
258 ARE_EQUAL(TrapFuncName) &&
259 ARE_EQUAL(FloatABIType) &&
260 ARE_EQUAL(AllowFPOpFusion) &&
262 ARE_EQUAL(ThreadModel) &&
263 ARE_EQUAL(MCOptions);
267 inline bool operator!=(const TargetOptions &LHS,
268 const TargetOptions &RHS) {
269 return !(LHS == RHS);
272 } // End llvm namespace