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;
25 // Possible float ABI settings. Used with FloatABIType in TargetOptions.h.
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 LessPreciseFPMADOption(false), UnsafeFPMath(false),
65 NoInfsFPMath(false), NoNaNsFPMath(false),
66 HonorSignDependentRoundingFPMathOption(false), UseSoftFloat(false),
67 NoZerosInBSS(false), JITEmitDebugInfo(false),
68 JITEmitDebugInfoToDisk(false), GuaranteedTailCallOpt(false),
69 DisableTailCalls(false), StackAlignmentOverride(0),
70 EnableFastISel(false), PositionIndependentExecutable(false),
71 UseInitArray(false), DisableIntegratedAS(false),
72 CompressDebugSections(false), FunctionSections(false),
73 DataSections(false), TrapUnreachable(false), TrapFuncName(""),
74 FloatABIType(FloatABI::Default),
75 AllowFPOpFusion(FPOpFusion::Standard), JTType(JumpTable::Single) {}
77 /// PrintMachineCode - This flag is enabled when the -print-machineinstrs
78 /// option is specified on the command line, and should enable debugging
79 /// output from the code generator.
80 unsigned PrintMachineCode : 1;
82 /// NoFramePointerElim - This flag is enabled when the -disable-fp-elim is
83 /// specified on the command line. If the target supports the frame pointer
84 /// elimination optimization, this option should disable it.
85 unsigned NoFramePointerElim : 1;
87 /// DisableFramePointerElim - This returns true if frame pointer elimination
88 /// optimization should be disabled for the given machine function.
89 bool DisableFramePointerElim(const MachineFunction &MF) const;
91 /// LessPreciseFPMAD - This flag is enabled when the
92 /// -enable-fp-mad is specified on the command line. When this flag is off
93 /// (the default), the code generator is not allowed to generate mad
94 /// (multiply add) if the result is "less precise" than doing those
95 /// operations individually.
96 unsigned LessPreciseFPMADOption : 1;
97 bool LessPreciseFPMAD() const;
99 /// UnsafeFPMath - This flag is enabled when the
100 /// -enable-unsafe-fp-math flag is specified on the command line. When
101 /// this flag is off (the default), the code generator is not allowed to
102 /// produce results that are "less precise" than IEEE allows. This includes
103 /// use of X86 instructions like FSIN and FCOS instead of libcalls.
104 /// UnsafeFPMath implies LessPreciseFPMAD.
105 unsigned UnsafeFPMath : 1;
107 /// NoInfsFPMath - This flag is enabled when the
108 /// -enable-no-infs-fp-math flag is specified on the command line. When
109 /// this flag is off (the default), the code generator is not allowed to
110 /// assume the FP arithmetic arguments and results are never +-Infs.
111 unsigned NoInfsFPMath : 1;
113 /// NoNaNsFPMath - This flag is enabled when the
114 /// -enable-no-nans-fp-math flag is specified on the command line. When
115 /// this flag is off (the default), the code generator is not allowed to
116 /// assume the FP arithmetic arguments and results are never NaNs.
117 unsigned NoNaNsFPMath : 1;
119 /// HonorSignDependentRoundingFPMath - This returns true when the
120 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns
121 /// false (the default), the code generator is allowed to assume that the
122 /// rounding behavior is the default (round-to-zero for all floating point
123 /// to integer conversions, and round-to-nearest for all other arithmetic
124 /// truncations). If this is enabled (set to true), the code generator must
125 /// assume that the rounding mode may dynamically change.
126 unsigned HonorSignDependentRoundingFPMathOption : 1;
127 bool HonorSignDependentRoundingFPMath() const;
129 /// UseSoftFloat - This flag is enabled when the -soft-float flag is
130 /// specified on the command line. When this flag is on, the code generator
131 /// will generate libcalls to the software floating point library instead of
132 /// target FP instructions.
133 unsigned UseSoftFloat : 1;
135 /// NoZerosInBSS - By default some codegens place zero-initialized data to
136 /// .bss section. This flag disables such behaviour (necessary, e.g. for
137 /// crt*.o compiling).
138 unsigned NoZerosInBSS : 1;
140 /// JITEmitDebugInfo - This flag indicates that the JIT should try to emit
141 /// debug information and notify a debugger about it.
142 unsigned JITEmitDebugInfo : 1;
144 /// JITEmitDebugInfoToDisk - This flag indicates that the JIT should write
145 /// the object files generated by the JITEmitDebugInfo flag to disk. This
146 /// flag is hidden and is only for debugging the debug info.
147 unsigned JITEmitDebugInfoToDisk : 1;
149 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is
150 /// specified on the commandline. When the flag is on, participating targets
151 /// will perform tail call optimization on all calls which use the fastcc
152 /// calling convention and which satisfy certain target-independent
153 /// criteria (being at the end of a function, having the same return type
154 /// as their parent function, etc.), using an alternate ABI if necessary.
155 unsigned GuaranteedTailCallOpt : 1;
157 /// DisableTailCalls - This flag controls whether we will use tail calls.
158 /// Disabling them may be useful to maintain a correct call stack.
159 unsigned DisableTailCalls : 1;
161 /// StackAlignmentOverride - Override default stack alignment for target.
162 unsigned StackAlignmentOverride;
164 /// EnableFastISel - This flag enables fast-path instruction selection
165 /// which trades away generated code quality in favor of reducing
167 unsigned EnableFastISel : 1;
169 /// PositionIndependentExecutable - This flag indicates whether the code
170 /// will eventually be linked into a single executable, despite the PIC
171 /// relocation model being in use. It's value is undefined (and irrelevant)
172 /// if the relocation model is anything other than PIC.
173 unsigned PositionIndependentExecutable : 1;
175 /// UseInitArray - Use .init_array instead of .ctors for static
177 unsigned UseInitArray : 1;
179 /// Disable the integrated assembler.
180 unsigned DisableIntegratedAS : 1;
182 /// Compress DWARF debug sections.
183 unsigned CompressDebugSections : 1;
185 /// Emit functions into separate sections.
186 unsigned FunctionSections : 1;
188 /// Emit data into separate sections.
189 unsigned DataSections : 1;
191 /// Emit target-specific trap instruction for 'unreachable' IR instructions.
192 unsigned TrapUnreachable : 1;
194 /// getTrapFunctionName - If this returns a non-empty string, this means
195 /// isel should lower Intrinsic::trap to a call to the specified function
196 /// name instead of an ISD::TRAP node.
197 std::string TrapFuncName;
198 StringRef getTrapFunctionName() const;
200 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
201 /// on the command line. This setting may either be Default, Soft, or Hard.
202 /// Default selects the target's default behavior. Soft selects the ABI for
203 /// UseSoftFloat, but does not indicate that FP hardware may not be used.
204 /// Such a combination is unfortunately popular (e.g. arm-apple-darwin).
205 /// Hard presumes that the normal FP ABI is used.
206 FloatABI::ABIType FloatABIType;
208 /// AllowFPOpFusion - This flag is set by the -fuse-fp-ops=xxx option.
209 /// This controls the creation of fused FP ops that store intermediate
210 /// results in higher precision than IEEE allows (E.g. FMAs).
212 /// Fast mode - allows formation of fused FP ops whenever they're
214 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the
215 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops
217 /// Strict mode - allow fusion only if/when it can be proven that the excess
218 /// precision won't effect the result.
220 /// Note: This option only controls formation of fused ops by the
221 /// optimizers. Fused operations that are explicitly specified (e.g. FMA
222 /// via the llvm.fma.* intrinsic) will always be honored, regardless of
223 /// the value of this option.
224 FPOpFusion::FPOpFusionMode AllowFPOpFusion;
226 /// JTType - This flag specifies the type of jump-instruction table to
227 /// create for functions that have the jumptable attribute.
228 JumpTable::JumpTableType JTType;
230 /// ThreadModel - This flag specifies the type of threading model to assume
231 /// for things like atomics
232 ThreadModel::Model ThreadModel;
234 /// Machine level options.
235 MCTargetOptions MCOptions;
238 // Comparison operators:
241 inline bool operator==(const TargetOptions &LHS,
242 const TargetOptions &RHS) {
243 #define ARE_EQUAL(X) LHS.X == RHS.X
245 ARE_EQUAL(UnsafeFPMath) &&
246 ARE_EQUAL(NoInfsFPMath) &&
247 ARE_EQUAL(NoNaNsFPMath) &&
248 ARE_EQUAL(HonorSignDependentRoundingFPMathOption) &&
249 ARE_EQUAL(UseSoftFloat) &&
250 ARE_EQUAL(NoZerosInBSS) &&
251 ARE_EQUAL(JITEmitDebugInfo) &&
252 ARE_EQUAL(JITEmitDebugInfoToDisk) &&
253 ARE_EQUAL(GuaranteedTailCallOpt) &&
254 ARE_EQUAL(DisableTailCalls) &&
255 ARE_EQUAL(StackAlignmentOverride) &&
256 ARE_EQUAL(EnableFastISel) &&
257 ARE_EQUAL(PositionIndependentExecutable) &&
258 ARE_EQUAL(UseInitArray) &&
259 ARE_EQUAL(TrapUnreachable) &&
260 ARE_EQUAL(TrapFuncName) &&
261 ARE_EQUAL(FloatABIType) &&
262 ARE_EQUAL(AllowFPOpFusion) &&
263 ARE_EQUAL(MCOptions);
267 inline bool operator!=(const TargetOptions &LHS,
268 const TargetOptions &RHS) {
269 return !(LHS == RHS);
272 } // End llvm namespace