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;
29 Default, // Target-specific (either soft or hard depending on triple, etc).
35 namespace FPOpFusion {
37 Fast, // Enable fusion of FP ops wherever it's profitable.
38 Standard, // Only allow fusion of 'blessed' ops (currently just fmuladd).
39 Strict // Never fuse FP-ops.
45 Single, // Use a single table for all indirect jumptable calls.
46 Arity, // Use one table per number of function parameters.
47 Simplified, // Use one table per function type, with types projected
48 // into 4 types: pointer to non-function, struct,
49 // primitive, and function pointer.
50 Full // Use one table per unique function type
54 namespace ThreadModel {
56 POSIX, // POSIX Threads
57 Single // Single Threaded Environment
63 Default, // Default means not specified
64 EABI4, // Target-specific (either 4, 5 or gnu depending on triple).
69 /// Identify a debugger for "tuning" the debug info.
71 /// The "debugger tuning" concept allows us to present a more intuitive
72 /// interface that unpacks into different sets of defaults for the various
73 /// individual feature-flag settings, that suit the preferences of the
74 /// various debuggers. However, it's worth remembering that debuggers are
75 /// not the only consumers of debug info, and some variations in DWARF might
76 /// better be treated as target/platform issues. Fundamentally,
77 /// o if the feature is useful (or not) to a particular debugger, regardless
78 /// of the target, that's a tuning decision;
79 /// o if the feature is useful (or not) on a particular platform, regardless
80 /// of the debugger, that's a target decision.
81 /// It's not impossible to see both factors in some specific case.
83 /// The "tuning" should be used to set defaults for individual feature flags
84 /// in DwarfDebug; if a given feature has a more specific command-line option,
85 /// that option should take precedence over the tuning.
86 enum class DebuggerKind {
87 Default, // No specific tuning requested.
88 GDB, // Tune debug info for gdb.
89 LLDB, // Tune debug info for lldb.
90 SCE // Tune debug info for SCE targets (e.g. PS4).
96 : PrintMachineCode(false), LessPreciseFPMADOption(false),
97 UnsafeFPMath(false), NoInfsFPMath(false), NoNaNsFPMath(false),
98 HonorSignDependentRoundingFPMathOption(false), NoZerosInBSS(false),
99 GuaranteedTailCallOpt(false), StackAlignmentOverride(0),
100 EnableFastISel(false), PositionIndependentExecutable(false),
101 UseInitArray(false), DisableIntegratedAS(false),
102 CompressDebugSections(false), FunctionSections(false),
103 DataSections(false), UniqueSectionNames(true), TrapUnreachable(false),
104 EmulatedTLS(false), FloatABIType(FloatABI::Default),
105 AllowFPOpFusion(FPOpFusion::Standard), Reciprocals(TargetRecip()),
106 JTType(JumpTable::Single), ThreadModel(ThreadModel::POSIX),
107 EABIVersion(EABI::Default), DebuggerTuning(DebuggerKind::Default) {}
109 /// PrintMachineCode - This flag is enabled when the -print-machineinstrs
110 /// option is specified on the command line, and should enable debugging
111 /// output from the code generator.
112 unsigned PrintMachineCode : 1;
114 /// DisableFramePointerElim - This returns true if frame pointer elimination
115 /// optimization should be disabled for the given machine function.
116 bool DisableFramePointerElim(const MachineFunction &MF) const;
118 /// LessPreciseFPMAD - This flag is enabled when the
119 /// -enable-fp-mad is specified on the command line. When this flag is off
120 /// (the default), the code generator is not allowed to generate mad
121 /// (multiply add) if the result is "less precise" than doing those
122 /// operations individually.
123 unsigned LessPreciseFPMADOption : 1;
124 bool LessPreciseFPMAD() const;
126 /// UnsafeFPMath - This flag is enabled when the
127 /// -enable-unsafe-fp-math flag is specified on the command line. When
128 /// this flag is off (the default), the code generator is not allowed to
129 /// produce results that are "less precise" than IEEE allows. This includes
130 /// use of X86 instructions like FSIN and FCOS instead of libcalls.
131 /// UnsafeFPMath implies LessPreciseFPMAD.
132 unsigned UnsafeFPMath : 1;
134 /// NoInfsFPMath - This flag is enabled when the
135 /// -enable-no-infs-fp-math flag is specified on the command line. When
136 /// this flag is off (the default), the code generator is not allowed to
137 /// assume the FP arithmetic arguments and results are never +-Infs.
138 unsigned NoInfsFPMath : 1;
140 /// NoNaNsFPMath - This flag is enabled when the
141 /// -enable-no-nans-fp-math flag is specified on the command line. When
142 /// this flag is off (the default), the code generator is not allowed to
143 /// assume the FP arithmetic arguments and results are never NaNs.
144 unsigned NoNaNsFPMath : 1;
146 /// HonorSignDependentRoundingFPMath - This returns true when the
147 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns
148 /// false (the default), the code generator is allowed to assume that the
149 /// rounding behavior is the default (round-to-zero for all floating point
150 /// to integer conversions, and round-to-nearest for all other arithmetic
151 /// truncations). If this is enabled (set to true), the code generator must
152 /// assume that the rounding mode may dynamically change.
153 unsigned HonorSignDependentRoundingFPMathOption : 1;
154 bool HonorSignDependentRoundingFPMath() const;
156 /// NoZerosInBSS - By default some codegens place zero-initialized data to
157 /// .bss section. This flag disables such behaviour (necessary, e.g. for
158 /// crt*.o compiling).
159 unsigned NoZerosInBSS : 1;
161 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is
162 /// specified on the commandline. When the flag is on, participating targets
163 /// will perform tail call optimization on all calls which use the fastcc
164 /// calling convention and which satisfy certain target-independent
165 /// criteria (being at the end of a function, having the same return type
166 /// as their parent function, etc.), using an alternate ABI if necessary.
167 unsigned GuaranteedTailCallOpt : 1;
169 /// StackAlignmentOverride - Override default stack alignment for target.
170 unsigned StackAlignmentOverride;
172 /// EnableFastISel - This flag enables fast-path instruction selection
173 /// which trades away generated code quality in favor of reducing
175 unsigned EnableFastISel : 1;
177 /// PositionIndependentExecutable - This flag indicates whether the code
178 /// will eventually be linked into a single executable, despite the PIC
179 /// relocation model being in use. It's value is undefined (and irrelevant)
180 /// if the relocation model is anything other than PIC.
181 unsigned PositionIndependentExecutable : 1;
183 /// UseInitArray - Use .init_array instead of .ctors for static
185 unsigned UseInitArray : 1;
187 /// Disable the integrated assembler.
188 unsigned DisableIntegratedAS : 1;
190 /// Compress DWARF debug sections.
191 unsigned CompressDebugSections : 1;
193 /// Emit functions into separate sections.
194 unsigned FunctionSections : 1;
196 /// Emit data into separate sections.
197 unsigned DataSections : 1;
199 unsigned UniqueSectionNames : 1;
201 /// Emit target-specific trap instruction for 'unreachable' IR instructions.
202 unsigned TrapUnreachable : 1;
204 /// EmulatedTLS - This flag enables emulated TLS model, using emutls
205 /// function in the runtime library..
206 unsigned EmulatedTLS : 1;
208 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
209 /// on the command line. This setting may either be Default, Soft, or Hard.
210 /// Default selects the target's default behavior. Soft selects the ABI for
211 /// software floating point, but does not indicate that FP hardware may not
212 /// be used. Such a combination is unfortunately popular (e.g.
213 /// arm-apple-darwin). Hard presumes that the normal FP ABI is used.
214 FloatABI::ABIType FloatABIType;
216 /// AllowFPOpFusion - This flag is set by the -fuse-fp-ops=xxx option.
217 /// This controls the creation of fused FP ops that store intermediate
218 /// results in higher precision than IEEE allows (E.g. FMAs).
220 /// Fast mode - allows formation of fused FP ops whenever they're
222 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the
223 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops
225 /// Strict mode - allow fusion only if/when it can be proven that the excess
226 /// precision won't effect the result.
228 /// Note: This option only controls formation of fused ops by the
229 /// optimizers. Fused operations that are explicitly specified (e.g. FMA
230 /// via the llvm.fma.* intrinsic) will always be honored, regardless of
231 /// the value of this option.
232 FPOpFusion::FPOpFusionMode AllowFPOpFusion;
234 /// This class encapsulates options for reciprocal-estimate code generation.
235 TargetRecip Reciprocals;
237 /// JTType - This flag specifies the type of jump-instruction table to
238 /// create for functions that have the jumptable attribute.
239 JumpTable::JumpTableType JTType;
241 /// ThreadModel - This flag specifies the type of threading model to assume
242 /// for things like atomics
243 ThreadModel::Model ThreadModel;
245 /// EABIVersion - This flag specifies the EABI version
248 /// Which debugger to tune for.
249 DebuggerKind DebuggerTuning;
251 /// Machine level options.
252 MCTargetOptions MCOptions;
255 // Comparison operators:
258 inline bool operator==(const TargetOptions &LHS,
259 const TargetOptions &RHS) {
260 #define ARE_EQUAL(X) LHS.X == RHS.X
262 ARE_EQUAL(UnsafeFPMath) &&
263 ARE_EQUAL(NoInfsFPMath) &&
264 ARE_EQUAL(NoNaNsFPMath) &&
265 ARE_EQUAL(HonorSignDependentRoundingFPMathOption) &&
266 ARE_EQUAL(NoZerosInBSS) &&
267 ARE_EQUAL(GuaranteedTailCallOpt) &&
268 ARE_EQUAL(StackAlignmentOverride) &&
269 ARE_EQUAL(EnableFastISel) &&
270 ARE_EQUAL(PositionIndependentExecutable) &&
271 ARE_EQUAL(UseInitArray) &&
272 ARE_EQUAL(TrapUnreachable) &&
273 ARE_EQUAL(EmulatedTLS) &&
274 ARE_EQUAL(FloatABIType) &&
275 ARE_EQUAL(AllowFPOpFusion) &&
276 ARE_EQUAL(Reciprocals) &&
278 ARE_EQUAL(ThreadModel) &&
279 ARE_EQUAL(EABIVersion) &&
280 ARE_EQUAL(DebuggerTuning) &&
281 ARE_EQUAL(MCOptions);
285 inline bool operator!=(const TargetOptions &LHS,
286 const TargetOptions &RHS) {
287 return !(LHS == RHS);
290 } // End llvm namespace