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/Target/TargetRecip.h"
19 #include "llvm/MC/MCTargetOptions.h"
23 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 LessPreciseFPMADOption(false), UnsafeFPMath(false),
65 NoInfsFPMath(false), NoNaNsFPMath(false),
66 HonorSignDependentRoundingFPMathOption(false),
68 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), UniqueSectionNames(true), TrapUnreachable(false),
74 TrapFuncName(), FloatABIType(FloatABI::Default),
75 AllowFPOpFusion(FPOpFusion::Standard), Reciprocals(),
76 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 /// DisableFramePointerElim - This returns true if frame pointer elimination
90 /// optimization should be disabled for the given machine function.
91 bool DisableFramePointerElim(const MachineFunction &MF) const;
93 /// LessPreciseFPMAD - This flag is enabled when the
94 /// -enable-fp-mad is specified on the command line. When this flag is off
95 /// (the default), the code generator is not allowed to generate mad
96 /// (multiply add) if the result is "less precise" than doing those
97 /// operations individually.
98 unsigned LessPreciseFPMADOption : 1;
99 bool LessPreciseFPMAD() const;
101 /// UnsafeFPMath - This flag is enabled when the
102 /// -enable-unsafe-fp-math flag is specified on the command line. When
103 /// this flag is off (the default), the code generator is not allowed to
104 /// produce results that are "less precise" than IEEE allows. This includes
105 /// use of X86 instructions like FSIN and FCOS instead of libcalls.
106 /// UnsafeFPMath implies LessPreciseFPMAD.
107 unsigned UnsafeFPMath : 1;
109 /// NoInfsFPMath - This flag is enabled when the
110 /// -enable-no-infs-fp-math flag is specified on the command line. When
111 /// this flag is off (the default), the code generator is not allowed to
112 /// assume the FP arithmetic arguments and results are never +-Infs.
113 unsigned NoInfsFPMath : 1;
115 /// NoNaNsFPMath - This flag is enabled when the
116 /// -enable-no-nans-fp-math flag is specified on the command line. When
117 /// this flag is off (the default), the code generator is not allowed to
118 /// assume the FP arithmetic arguments and results are never NaNs.
119 unsigned NoNaNsFPMath : 1;
121 /// HonorSignDependentRoundingFPMath - This returns true when the
122 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns
123 /// false (the default), the code generator is allowed to assume that the
124 /// rounding behavior is the default (round-to-zero for all floating point
125 /// to integer conversions, and round-to-nearest for all other arithmetic
126 /// truncations). If this is enabled (set to true), the code generator must
127 /// assume that the rounding mode may dynamically change.
128 unsigned HonorSignDependentRoundingFPMathOption : 1;
129 bool HonorSignDependentRoundingFPMath() const;
131 /// NoZerosInBSS - By default some codegens place zero-initialized data to
132 /// .bss section. This flag disables such behaviour (necessary, e.g. for
133 /// crt*.o compiling).
134 unsigned NoZerosInBSS : 1;
136 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is
137 /// specified on the commandline. When the flag is on, participating targets
138 /// will perform tail call optimization on all calls which use the fastcc
139 /// calling convention and which satisfy certain target-independent
140 /// criteria (being at the end of a function, having the same return type
141 /// as their parent function, etc.), using an alternate ABI if necessary.
142 unsigned GuaranteedTailCallOpt : 1;
144 /// DisableTailCalls - This flag controls whether we will use tail calls.
145 /// Disabling them may be useful to maintain a correct call stack.
146 unsigned DisableTailCalls : 1;
148 /// StackAlignmentOverride - Override default stack alignment for target.
149 unsigned StackAlignmentOverride;
151 /// EnableFastISel - This flag enables fast-path instruction selection
152 /// which trades away generated code quality in favor of reducing
154 unsigned EnableFastISel : 1;
156 /// PositionIndependentExecutable - This flag indicates whether the code
157 /// will eventually be linked into a single executable, despite the PIC
158 /// relocation model being in use. It's value is undefined (and irrelevant)
159 /// if the relocation model is anything other than PIC.
160 unsigned PositionIndependentExecutable : 1;
162 /// UseInitArray - Use .init_array instead of .ctors for static
164 unsigned UseInitArray : 1;
166 /// Disable the integrated assembler.
167 unsigned DisableIntegratedAS : 1;
169 /// Compress DWARF debug sections.
170 unsigned CompressDebugSections : 1;
172 /// Emit functions into separate sections.
173 unsigned FunctionSections : 1;
175 /// Emit data into separate sections.
176 unsigned DataSections : 1;
178 unsigned UniqueSectionNames : 1;
180 /// Emit target-specific trap instruction for 'unreachable' IR instructions.
181 unsigned TrapUnreachable : 1;
183 /// getTrapFunctionName - If this returns a non-empty string, this means
184 /// isel should lower Intrinsic::trap to a call to the specified function
185 /// name instead of an ISD::TRAP node.
186 std::string TrapFuncName;
187 StringRef getTrapFunctionName() const;
189 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
190 /// on the command line. This setting may either be Default, Soft, or Hard.
191 /// Default selects the target's default behavior. Soft selects the ABI for
192 /// software floating point, but does not indicate that FP hardware may not
193 /// be used. Such a combination is unfortunately popular (e.g.
194 /// arm-apple-darwin). Hard presumes that the normal FP ABI is used.
195 FloatABI::ABIType FloatABIType;
197 /// AllowFPOpFusion - This flag is set by the -fuse-fp-ops=xxx option.
198 /// This controls the creation of fused FP ops that store intermediate
199 /// results in higher precision than IEEE allows (E.g. FMAs).
201 /// Fast mode - allows formation of fused FP ops whenever they're
203 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the
204 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops
206 /// Strict mode - allow fusion only if/when it can be proven that the excess
207 /// precision won't effect the result.
209 /// Note: This option only controls formation of fused ops by the
210 /// optimizers. Fused operations that are explicitly specified (e.g. FMA
211 /// via the llvm.fma.* intrinsic) will always be honored, regardless of
212 /// the value of this option.
213 FPOpFusion::FPOpFusionMode AllowFPOpFusion;
215 /// This class encapsulates options for reciprocal-estimate code generation.
216 TargetRecip Reciprocals;
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 // Comparison operators:
233 inline bool operator==(const TargetOptions &LHS,
234 const TargetOptions &RHS) {
235 #define ARE_EQUAL(X) LHS.X == RHS.X
237 ARE_EQUAL(UnsafeFPMath) &&
238 ARE_EQUAL(NoInfsFPMath) &&
239 ARE_EQUAL(NoNaNsFPMath) &&
240 ARE_EQUAL(HonorSignDependentRoundingFPMathOption) &&
241 ARE_EQUAL(NoZerosInBSS) &&
242 ARE_EQUAL(GuaranteedTailCallOpt) &&
243 ARE_EQUAL(DisableTailCalls) &&
244 ARE_EQUAL(StackAlignmentOverride) &&
245 ARE_EQUAL(EnableFastISel) &&
246 ARE_EQUAL(PositionIndependentExecutable) &&
247 ARE_EQUAL(UseInitArray) &&
248 ARE_EQUAL(TrapUnreachable) &&
249 ARE_EQUAL(TrapFuncName) &&
250 ARE_EQUAL(FloatABIType) &&
251 ARE_EQUAL(AllowFPOpFusion) &&
252 ARE_EQUAL(Reciprocals) &&
254 ARE_EQUAL(ThreadModel) &&
255 ARE_EQUAL(MCOptions);
259 inline bool operator!=(const TargetOptions &LHS,
260 const TargetOptions &RHS) {
261 return !(LHS == RHS);
264 } // End llvm namespace