1//===-- llvm/Target/TargetOptions.h - Target Options ------------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines command line option flags that are shared across various
11// targets.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_TARGET_TARGETOPTIONS_H
16#define LLVM_TARGET_TARGETOPTIONS_H
17
18#include "llvm/MC/MCTargetOptions.h"
19
20namespace llvm {
21 class MachineFunction;
22 class Module;
23
24 namespace FloatABI {
25 enum ABIType {
26 Default, // Target-specific (either soft or hard depending on triple, etc).
27 Soft, // Soft float.
28 Hard // Hard float.
29 };
30 }
31
32 namespace FPOpFusion {
33 enum FPOpFusionMode {
34 Fast, // Enable fusion of FP ops wherever it's profitable.
35 Standard, // Only allow fusion of 'blessed' ops (currently just fmuladd).
36 Strict // Never fuse FP-ops.
37 };
38 }
39
40 namespace JumpTable {
41 enum JumpTableType {
42 Single, // Use a single table for all indirect jumptable calls.
43 Arity, // Use one table per number of function parameters.
44 Simplified, // Use one table per function type, with types projected
45 // into 4 types: pointer to non-function, struct,
46 // primitive, and function pointer.
47 Full // Use one table per unique function type
48 };
49 }
50
51 namespace ThreadModel {
52 enum Model {
53 POSIX, // POSIX Threads
54 Single // Single Threaded Environment
55 };
56 }
57
58 namespace FPDenormal {
59 enum DenormalMode {
60 IEEE, // IEEE 754 denormal numbers
61 PreserveSign, // the sign of a flushed-to-zero number is preserved in
62 // the sign of 0
63 PositiveZero // denormals are flushed to positive zero
64 };
65 }
66
67 enum class EABI {
68 Unknown,
69 Default, // Default means not specified
70 EABI4, // Target-specific (either 4, 5 or gnu depending on triple).
71 EABI5,
72 GNU
73 };
74
75 /// Identify a debugger for "tuning" the debug info.
76 ///
77 /// The "debugger tuning" concept allows us to present a more intuitive
78 /// interface that unpacks into different sets of defaults for the various
79 /// individual feature-flag settings, that suit the preferences of the
80 /// various debuggers. However, it's worth remembering that debuggers are
81 /// not the only consumers of debug info, and some variations in DWARF might
82 /// better be treated as target/platform issues. Fundamentally,
83 /// o if the feature is useful (or not) to a particular debugger, regardless
84 /// of the target, that's a tuning decision;
85 /// o if the feature is useful (or not) on a particular platform, regardless
86 /// of the debugger, that's a target decision.
87 /// It's not impossible to see both factors in some specific case.
88 ///
89 /// The "tuning" should be used to set defaults for individual feature flags
90 /// in DwarfDebug; if a given feature has a more specific command-line option,
91 /// that option should take precedence over the tuning.
92 enum class DebuggerKind {
93 Default, // No specific tuning requested.
94 GDB, // Tune debug info for gdb.
95 LLDB, // Tune debug info for lldb.
96 SCE // Tune debug info for SCE targets (e.g. PS4).
97 };
98
99 /// Enable abort calls when global instruction selection fails to lower/select
100 /// an instruction.
101 enum class GlobalISelAbortMode {
102 Disable, // Disable the abort.
103 Enable, // Enable the abort.
104 DisableWithDiag // Disable the abort but emit a diagnostic on failure.
105 };
106
107 class TargetOptions {
108 public:
109 TargetOptions()
110 : PrintMachineCode(false), UnsafeFPMath(false), NoInfsFPMath(false),
111 NoNaNsFPMath(false), NoTrappingFPMath(false),
112 NoSignedZerosFPMath(false),
113 HonorSignDependentRoundingFPMathOption(false), NoZerosInBSS(false),
114 GuaranteedTailCallOpt(false), StackSymbolOrdering(true),
115 EnableFastISel(false), EnableGlobalISel(false), UseInitArray(false),
116 DisableIntegratedAS(false), RelaxELFRelocations(false),
117 FunctionSections(false), DataSections(false),
118 UniqueSectionNames(true), TrapUnreachable(false),
119 NoTrapAfterNoreturn(false), EmulatedTLS(false),
120 ExplicitEmulatedTLS(false), EnableIPRA(false),
121 EmitStackSizeSection(false), EnableMachineOutliner(false),
122 SupportsDefaultOutlining(false), EmitAddrsig(false) {}
123
124 /// PrintMachineCode - This flag is enabled when the -print-machineinstrs
125 /// option is specified on the command line, and should enable debugging
126 /// output from the code generator.
127 unsigned PrintMachineCode : 1;
128
129 /// DisableFramePointerElim - This returns true if frame pointer elimination
130 /// optimization should be disabled for the given machine function.
131 bool DisableFramePointerElim(const MachineFunction &MF) const;
132
133 /// UnsafeFPMath - This flag is enabled when the
134 /// -enable-unsafe-fp-math flag is specified on the command line. When
135 /// this flag is off (the default), the code generator is not allowed to
136 /// produce results that are "less precise" than IEEE allows. This includes
137 /// use of X86 instructions like FSIN and FCOS instead of libcalls.
138 unsigned UnsafeFPMath : 1;
139
140 /// NoInfsFPMath - This flag is enabled when the
141 /// -enable-no-infs-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 +-Infs.
144 unsigned NoInfsFPMath : 1;
145
146 /// NoNaNsFPMath - This flag is enabled when the
147 /// -enable-no-nans-fp-math flag is specified on the command line. When
148 /// this flag is off (the default), the code generator is not allowed to
149 /// assume the FP arithmetic arguments and results are never NaNs.
150 unsigned NoNaNsFPMath : 1;
151
152 /// NoTrappingFPMath - This flag is enabled when the
153 /// -enable-no-trapping-fp-math is specified on the command line. This
154 /// specifies that there are no trap handlers to handle exceptions.
155 unsigned NoTrappingFPMath : 1;
156
157 /// NoSignedZerosFPMath - This flag is enabled when the
158 /// -enable-no-signed-zeros-fp-math is specified on the command line. This
159 /// specifies that optimizations are allowed to treat the sign of a zero
160 /// argument or result as insignificant.
161 unsigned NoSignedZerosFPMath : 1;
162
163 /// HonorSignDependentRoundingFPMath - This returns true when the
164 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns
165 /// false (the default), the code generator is allowed to assume that the
166 /// rounding behavior is the default (round-to-zero for all floating point
167 /// to integer conversions, and round-to-nearest for all other arithmetic
168 /// truncations). If this is enabled (set to true), the code generator must
169 /// assume that the rounding mode may dynamically change.
170 unsigned HonorSignDependentRoundingFPMathOption : 1;
171 bool HonorSignDependentRoundingFPMath() const;
172
173 /// NoZerosInBSS - By default some codegens place zero-initialized data to
174 /// .bss section. This flag disables such behaviour (necessary, e.g. for
175 /// crt*.o compiling).
176 unsigned NoZerosInBSS : 1;
177
178 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is
179 /// specified on the commandline. When the flag is on, participating targets
180 /// will perform tail call optimization on all calls which use the fastcc
181 /// calling convention and which satisfy certain target-independent
182 /// criteria (being at the end of a function, having the same return type
183 /// as their parent function, etc.), using an alternate ABI if necessary.
184 unsigned GuaranteedTailCallOpt : 1;
185
186 /// StackAlignmentOverride - Override default stack alignment for target.
187 unsigned StackAlignmentOverride = 0;
188
189 /// StackSymbolOrdering - When true, this will allow CodeGen to order
190 /// the local stack symbols (for code size, code locality, or any other
191 /// heuristics). When false, the local symbols are left in whatever order
192 /// they were generated. Default is true.
193 unsigned StackSymbolOrdering : 1;
194
195 /// EnableFastISel - This flag enables fast-path instruction selection
196 /// which trades away generated code quality in favor of reducing
197 /// compile time.
198 unsigned EnableFastISel : 1;
199
200 /// EnableGlobalISel - This flag enables global instruction selection.
201 unsigned EnableGlobalISel : 1;
202
203 /// EnableGlobalISelAbort - Control abort behaviour when global instruction
204 /// selection fails to lower/select an instruction.
205 GlobalISelAbortMode GlobalISelAbort = GlobalISelAbortMode::Enable;
206
207 /// UseInitArray - Use .init_array instead of .ctors for static
208 /// constructors.
209 unsigned UseInitArray : 1;
210
211 /// Disable the integrated assembler.
212 unsigned DisableIntegratedAS : 1;
213
214 /// Compress DWARF debug sections.
215 DebugCompressionType CompressDebugSections = DebugCompressionType::None;
216
217 unsigned RelaxELFRelocations : 1;
218
219 /// Emit functions into separate sections.
220 unsigned FunctionSections : 1;
221
222 /// Emit data into separate sections.
223 unsigned DataSections : 1;
224
225 unsigned UniqueSectionNames : 1;
226
227 /// Emit target-specific trap instruction for 'unreachable' IR instructions.
228 unsigned TrapUnreachable : 1;
229
230 /// Do not emit a trap instruction for 'unreachable' IR instructions behind
231 /// noreturn calls, even if TrapUnreachable is true.
232 unsigned NoTrapAfterNoreturn : 1;
233
234 /// EmulatedTLS - This flag enables emulated TLS model, using emutls
235 /// function in the runtime library..
236 unsigned EmulatedTLS : 1;
237
238 /// Whether -emulated-tls or -no-emulated-tls is set.
239 unsigned ExplicitEmulatedTLS : 1;
240
241 /// This flag enables InterProcedural Register Allocation (IPRA).
242 unsigned EnableIPRA : 1;
243
244 /// Emit section containing metadata on function stack sizes.
245 unsigned EmitStackSizeSection : 1;
246
247 /// Enables the MachineOutliner pass.
248 unsigned EnableMachineOutliner : 1;
249
250 /// Set if the target supports default outlining behaviour.
251 unsigned SupportsDefaultOutlining : 1;
252
253 /// Emit address-significance table.
254 unsigned EmitAddrsig : 1;
255
256 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
257 /// on the command line. This setting may either be Default, Soft, or Hard.
258 /// Default selects the target's default behavior. Soft selects the ABI for
259 /// software floating point, but does not indicate that FP hardware may not
260 /// be used. Such a combination is unfortunately popular (e.g.
261 /// arm-apple-darwin). Hard presumes that the normal FP ABI is used.
262 FloatABI::ABIType FloatABIType = FloatABI::Default;
263
264 /// AllowFPOpFusion - This flag is set by the -fuse-fp-ops=xxx option.
265 /// This controls the creation of fused FP ops that store intermediate
266 /// results in higher precision than IEEE allows (E.g. FMAs).
267 ///
268 /// Fast mode - allows formation of fused FP ops whenever they're
269 /// profitable.
270 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the
271 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops
272 /// may be added.
273 /// Strict mode - allow fusion only if/when it can be proven that the excess
274 /// precision won't effect the result.
275 ///
276 /// Note: This option only controls formation of fused ops by the
277 /// optimizers. Fused operations that are explicitly specified (e.g. FMA
278 /// via the llvm.fma.* intrinsic) will always be honored, regardless of
279 /// the value of this option.
280 FPOpFusion::FPOpFusionMode AllowFPOpFusion = FPOpFusion::Standard;
281
282 /// ThreadModel - This flag specifies the type of threading model to assume
283 /// for things like atomics
284 ThreadModel::Model ThreadModel = ThreadModel::POSIX;
285
286 /// EABIVersion - This flag specifies the EABI version
287 EABI EABIVersion = EABI::Default;
288
289 /// Which debugger to tune for.
290 DebuggerKind DebuggerTuning = DebuggerKind::Default;
291
292 /// FPDenormalMode - This flags specificies which denormal numbers the code
293 /// is permitted to require.
294 FPDenormal::DenormalMode FPDenormalMode = FPDenormal::IEEE;
295
296 /// What exception model to use
297 ExceptionHandling ExceptionModel = ExceptionHandling::None;
298
299 /// Machine level options.
300 MCTargetOptions MCOptions;
301 };
302
303} // End llvm namespace
304
305#endif
306