1 //===-- llvm/Target/TargetOptions.h - Target Options ------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines command line option flags that are shared across various 10 // targets. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_TARGET_TARGETOPTIONS_H 15 #define LLVM_TARGET_TARGETOPTIONS_H 16 17 #include "llvm/ADT/FloatingPointMode.h" 18 #include "llvm/MC/MCTargetOptions.h" 19 20 #include <memory> 21 22 namespace llvm { 23 struct fltSemantics; 24 class MachineFunction; 25 class MemoryBuffer; 26 27 namespace FloatABI { 28 enum ABIType { 29 Default, // Target-specific (either soft or hard depending on triple, etc). 30 Soft, // Soft float. 31 Hard // Hard float. 32 }; 33 } 34 35 namespace FPOpFusion { 36 enum FPOpFusionMode { 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. 40 }; 41 } 42 43 namespace JumpTable { 44 enum JumpTableType { 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 51 }; 52 } 53 54 namespace ThreadModel { 55 enum Model { 56 POSIX, // POSIX Threads 57 Single // Single Threaded Environment 58 }; 59 } 60 61 enum class BasicBlockSection { 62 All, // Use Basic Block Sections for all basic blocks. A section 63 // for every basic block can significantly bloat object file sizes. 64 List, // Get list of functions & BBs from a file. Selectively enables 65 // basic block sections for a subset of basic blocks which can be 66 // used to control object size bloats from creating sections. 67 Labels, // Do not use Basic Block Sections but label basic blocks. This 68 // is useful when associating profile counts from virtual addresses 69 // to basic blocks. 70 Preset, // Similar to list but the blocks are identified by passes which 71 // seek to use Basic Block Sections, e.g. MachineFunctionSplitter. 72 // This option cannot be set via the command line. 73 None // Do not use Basic Block Sections. 74 }; 75 76 enum class EABI { 77 Unknown, 78 Default, // Default means not specified 79 EABI4, // Target-specific (either 4, 5 or gnu depending on triple). 80 EABI5, 81 GNU 82 }; 83 84 /// Identify a debugger for "tuning" the debug info. 85 /// 86 /// The "debugger tuning" concept allows us to present a more intuitive 87 /// interface that unpacks into different sets of defaults for the various 88 /// individual feature-flag settings, that suit the preferences of the 89 /// various debuggers. However, it's worth remembering that debuggers are 90 /// not the only consumers of debug info, and some variations in DWARF might 91 /// better be treated as target/platform issues. Fundamentally, 92 /// o if the feature is useful (or not) to a particular debugger, regardless 93 /// of the target, that's a tuning decision; 94 /// o if the feature is useful (or not) on a particular platform, regardless 95 /// of the debugger, that's a target decision. 96 /// It's not impossible to see both factors in some specific case. 97 enum class DebuggerKind { 98 Default, ///< No specific tuning requested. 99 GDB, ///< Tune debug info for gdb. 100 LLDB, ///< Tune debug info for lldb. 101 SCE, ///< Tune debug info for SCE targets (e.g. PS4). 102 DBX ///< Tune debug info for dbx. 103 }; 104 105 /// Enable abort calls when global instruction selection fails to lower/select 106 /// an instruction. 107 enum class GlobalISelAbortMode { 108 Disable, // Disable the abort. 109 Enable, // Enable the abort. 110 DisableWithDiag // Disable the abort but emit a diagnostic on failure. 111 }; 112 113 /// Indicates when and how the Swift async frame pointer bit should be set. 114 enum class SwiftAsyncFramePointerMode { 115 /// Determine whether to set the bit statically or dynamically based 116 /// on the deployment target. 117 DeploymentBased, 118 /// Always set the bit. 119 Always, 120 /// Never set the bit. 121 Never, 122 }; 123 124 class TargetOptions { 125 public: TargetOptions()126 TargetOptions() 127 : UnsafeFPMath(false), NoInfsFPMath(false), NoNaNsFPMath(false), 128 NoTrappingFPMath(true), NoSignedZerosFPMath(false), 129 ApproxFuncFPMath(false), EnableAIXExtendedAltivecABI(false), 130 HonorSignDependentRoundingFPMathOption(false), NoZerosInBSS(false), 131 GuaranteedTailCallOpt(false), StackSymbolOrdering(true), 132 EnableFastISel(false), EnableGlobalISel(false), UseInitArray(false), 133 DisableIntegratedAS(false), RelaxELFRelocations(false), 134 FunctionSections(false), DataSections(false), 135 IgnoreXCOFFVisibility(false), XCOFFTracebackTable(true), 136 UniqueSectionNames(true), UniqueBasicBlockSectionNames(false), 137 TrapUnreachable(false), NoTrapAfterNoreturn(false), TLSSize(0), 138 EmulatedTLS(false), ExplicitEmulatedTLS(false), EnableIPRA(false), 139 EmitStackSizeSection(false), EnableMachineOutliner(false), 140 EnableMachineFunctionSplitter(false), SupportsDefaultOutlining(false), 141 EmitAddrsig(false), EmitCallSiteInfo(false), 142 SupportsDebugEntryValues(false), EnableDebugEntryValues(false), 143 ValueTrackingVariableLocations(false), 144 ForceDwarfFrameSection(false), XRayOmitFunctionIndex(false), 145 DebugStrictDwarf(false), 146 FPDenormalMode(DenormalMode::IEEE, DenormalMode::IEEE) {} 147 148 /// DisableFramePointerElim - This returns true if frame pointer elimination 149 /// optimization should be disabled for the given machine function. 150 bool DisableFramePointerElim(const MachineFunction &MF) const; 151 152 /// If greater than 0, override the default value of 153 /// MCAsmInfo::BinutilsVersion. 154 std::pair<int, int> BinutilsVersion{0, 0}; 155 156 /// UnsafeFPMath - This flag is enabled when the 157 /// -enable-unsafe-fp-math flag is specified on the command line. When 158 /// this flag is off (the default), the code generator is not allowed to 159 /// produce results that are "less precise" than IEEE allows. This includes 160 /// use of X86 instructions like FSIN and FCOS instead of libcalls. 161 unsigned UnsafeFPMath : 1; 162 163 /// NoInfsFPMath - This flag is enabled when the 164 /// -enable-no-infs-fp-math flag is specified on the command line. When 165 /// this flag is off (the default), the code generator is not allowed to 166 /// assume the FP arithmetic arguments and results are never +-Infs. 167 unsigned NoInfsFPMath : 1; 168 169 /// NoNaNsFPMath - This flag is enabled when the 170 /// -enable-no-nans-fp-math flag is specified on the command line. When 171 /// this flag is off (the default), the code generator is not allowed to 172 /// assume the FP arithmetic arguments and results are never NaNs. 173 unsigned NoNaNsFPMath : 1; 174 175 /// NoTrappingFPMath - This flag is enabled when the 176 /// -enable-no-trapping-fp-math is specified on the command line. This 177 /// specifies that there are no trap handlers to handle exceptions. 178 unsigned NoTrappingFPMath : 1; 179 180 /// NoSignedZerosFPMath - This flag is enabled when the 181 /// -enable-no-signed-zeros-fp-math is specified on the command line. This 182 /// specifies that optimizations are allowed to treat the sign of a zero 183 /// argument or result as insignificant. 184 unsigned NoSignedZerosFPMath : 1; 185 186 /// ApproxFuncFPMath - This flag is enabled when the 187 /// -enable-approx-func-fp-math is specified on the command line. This 188 /// specifies that optimizations are allowed to substitute math functions 189 /// with approximate calculations 190 unsigned ApproxFuncFPMath : 1; 191 192 /// EnableAIXExtendedAltivecABI - This flag returns true when -vec-extabi is 193 /// specified. The code generator is then able to use both volatile and 194 /// nonvolitle vector registers. When false, the code generator only uses 195 /// volatile vector registers which is the default setting on AIX. 196 unsigned EnableAIXExtendedAltivecABI : 1; 197 198 /// HonorSignDependentRoundingFPMath - This returns true when the 199 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns 200 /// false (the default), the code generator is allowed to assume that the 201 /// rounding behavior is the default (round-to-zero for all floating point 202 /// to integer conversions, and round-to-nearest for all other arithmetic 203 /// truncations). If this is enabled (set to true), the code generator must 204 /// assume that the rounding mode may dynamically change. 205 unsigned HonorSignDependentRoundingFPMathOption : 1; 206 bool HonorSignDependentRoundingFPMath() const; 207 208 /// NoZerosInBSS - By default some codegens place zero-initialized data to 209 /// .bss section. This flag disables such behaviour (necessary, e.g. for 210 /// crt*.o compiling). 211 unsigned NoZerosInBSS : 1; 212 213 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is 214 /// specified on the commandline. When the flag is on, participating targets 215 /// will perform tail call optimization on all calls which use the fastcc 216 /// calling convention and which satisfy certain target-independent 217 /// criteria (being at the end of a function, having the same return type 218 /// as their parent function, etc.), using an alternate ABI if necessary. 219 unsigned GuaranteedTailCallOpt : 1; 220 221 /// StackSymbolOrdering - When true, this will allow CodeGen to order 222 /// the local stack symbols (for code size, code locality, or any other 223 /// heuristics). When false, the local symbols are left in whatever order 224 /// they were generated. Default is true. 225 unsigned StackSymbolOrdering : 1; 226 227 /// EnableFastISel - This flag enables fast-path instruction selection 228 /// which trades away generated code quality in favor of reducing 229 /// compile time. 230 unsigned EnableFastISel : 1; 231 232 /// EnableGlobalISel - This flag enables global instruction selection. 233 unsigned EnableGlobalISel : 1; 234 235 /// EnableGlobalISelAbort - Control abort behaviour when global instruction 236 /// selection fails to lower/select an instruction. 237 GlobalISelAbortMode GlobalISelAbort = GlobalISelAbortMode::Enable; 238 239 /// Control when and how the Swift async frame pointer bit should 240 /// be set. 241 SwiftAsyncFramePointerMode SwiftAsyncFramePointer = 242 SwiftAsyncFramePointerMode::Always; 243 244 /// UseInitArray - Use .init_array instead of .ctors for static 245 /// constructors. 246 unsigned UseInitArray : 1; 247 248 /// Disable the integrated assembler. 249 unsigned DisableIntegratedAS : 1; 250 251 /// Compress DWARF debug sections. 252 DebugCompressionType CompressDebugSections = DebugCompressionType::None; 253 254 unsigned RelaxELFRelocations : 1; 255 256 /// Emit functions into separate sections. 257 unsigned FunctionSections : 1; 258 259 /// Emit data into separate sections. 260 unsigned DataSections : 1; 261 262 /// Do not emit visibility attribute for xcoff. 263 unsigned IgnoreXCOFFVisibility : 1; 264 265 /// Emit XCOFF traceback table. 266 unsigned XCOFFTracebackTable : 1; 267 268 unsigned UniqueSectionNames : 1; 269 270 /// Use unique names for basic block sections. 271 unsigned UniqueBasicBlockSectionNames : 1; 272 273 /// Emit target-specific trap instruction for 'unreachable' IR instructions. 274 unsigned TrapUnreachable : 1; 275 276 /// Do not emit a trap instruction for 'unreachable' IR instructions behind 277 /// noreturn calls, even if TrapUnreachable is true. 278 unsigned NoTrapAfterNoreturn : 1; 279 280 /// Bit size of immediate TLS offsets (0 == use the default). 281 unsigned TLSSize : 8; 282 283 /// EmulatedTLS - This flag enables emulated TLS model, using emutls 284 /// function in the runtime library.. 285 unsigned EmulatedTLS : 1; 286 287 /// Whether -emulated-tls or -no-emulated-tls is set. 288 unsigned ExplicitEmulatedTLS : 1; 289 290 /// This flag enables InterProcedural Register Allocation (IPRA). 291 unsigned EnableIPRA : 1; 292 293 /// Emit section containing metadata on function stack sizes. 294 unsigned EmitStackSizeSection : 1; 295 296 /// Enables the MachineOutliner pass. 297 unsigned EnableMachineOutliner : 1; 298 299 /// Enables the MachineFunctionSplitter pass. 300 unsigned EnableMachineFunctionSplitter : 1; 301 302 /// Set if the target supports default outlining behaviour. 303 unsigned SupportsDefaultOutlining : 1; 304 305 /// Emit address-significance table. 306 unsigned EmitAddrsig : 1; 307 308 /// Emit basic blocks into separate sections. 309 BasicBlockSection BBSections = BasicBlockSection::None; 310 311 /// Memory Buffer that contains information on sampled basic blocks and used 312 /// to selectively generate basic block sections. 313 std::shared_ptr<MemoryBuffer> BBSectionsFuncListBuf; 314 315 /// The flag enables call site info production. It is used only for debug 316 /// info, and it is restricted only to optimized code. This can be used for 317 /// something else, so that should be controlled in the frontend. 318 unsigned EmitCallSiteInfo : 1; 319 /// Set if the target supports the debug entry values by default. 320 unsigned SupportsDebugEntryValues : 1; 321 /// When set to true, the EnableDebugEntryValues option forces production 322 /// of debug entry values even if the target does not officially support 323 /// it. Useful for testing purposes only. This flag should never be checked 324 /// directly, always use \ref ShouldEmitDebugEntryValues instead. 325 unsigned EnableDebugEntryValues : 1; 326 /// NOTE: There are targets that still do not support the debug entry values 327 /// production. 328 bool ShouldEmitDebugEntryValues() const; 329 330 // When set to true, use experimental new debug variable location tracking, 331 // which seeks to follow the values of variables rather than their location, 332 // post isel. 333 unsigned ValueTrackingVariableLocations : 1; 334 335 /// Emit DWARF debug frame section. 336 unsigned ForceDwarfFrameSection : 1; 337 338 /// Emit XRay Function Index section 339 unsigned XRayOmitFunctionIndex : 1; 340 341 /// When set to true, don't use DWARF extensions in later DWARF versions. 342 /// By default, it is set to false. 343 unsigned DebugStrictDwarf : 1; 344 345 /// Name of the stack usage file (i.e., .su file) if user passes 346 /// -fstack-usage. If empty, it can be implied that -fstack-usage is not 347 /// passed on the command line. 348 std::string StackUsageOutput; 349 350 /// If greater than 0, override TargetLoweringBase::PrefLoopAlignment. 351 unsigned LoopAlignment = 0; 352 353 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied 354 /// on the command line. This setting may either be Default, Soft, or Hard. 355 /// Default selects the target's default behavior. Soft selects the ABI for 356 /// software floating point, but does not indicate that FP hardware may not 357 /// be used. Such a combination is unfortunately popular (e.g. 358 /// arm-apple-darwin). Hard presumes that the normal FP ABI is used. 359 FloatABI::ABIType FloatABIType = FloatABI::Default; 360 361 /// AllowFPOpFusion - This flag is set by the -fp-contract=xxx option. 362 /// This controls the creation of fused FP ops that store intermediate 363 /// results in higher precision than IEEE allows (E.g. FMAs). 364 /// 365 /// Fast mode - allows formation of fused FP ops whenever they're 366 /// profitable. 367 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the 368 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops 369 /// may be added. 370 /// Strict mode - allow fusion only if/when it can be proven that the excess 371 /// precision won't effect the result. 372 /// 373 /// Note: This option only controls formation of fused ops by the 374 /// optimizers. Fused operations that are explicitly specified (e.g. FMA 375 /// via the llvm.fma.* intrinsic) will always be honored, regardless of 376 /// the value of this option. 377 FPOpFusion::FPOpFusionMode AllowFPOpFusion = FPOpFusion::Standard; 378 379 /// ThreadModel - This flag specifies the type of threading model to assume 380 /// for things like atomics 381 ThreadModel::Model ThreadModel = ThreadModel::POSIX; 382 383 /// EABIVersion - This flag specifies the EABI version 384 EABI EABIVersion = EABI::Default; 385 386 /// Which debugger to tune for. 387 DebuggerKind DebuggerTuning = DebuggerKind::Default; 388 389 private: 390 /// Flushing mode to assume in default FP environment. 391 DenormalMode FPDenormalMode; 392 393 /// Flushing mode to assume in default FP environment, for float/vector of 394 /// float. 395 DenormalMode FP32DenormalMode; 396 397 public: setFPDenormalMode(DenormalMode Mode)398 void setFPDenormalMode(DenormalMode Mode) { 399 FPDenormalMode = Mode; 400 } 401 setFP32DenormalMode(DenormalMode Mode)402 void setFP32DenormalMode(DenormalMode Mode) { 403 FP32DenormalMode = Mode; 404 } 405 getRawFPDenormalMode()406 DenormalMode getRawFPDenormalMode() const { 407 return FPDenormalMode; 408 } 409 getRawFP32DenormalMode()410 DenormalMode getRawFP32DenormalMode() const { 411 return FP32DenormalMode; 412 } 413 414 DenormalMode getDenormalMode(const fltSemantics &FPType) const; 415 416 /// What exception model to use 417 ExceptionHandling ExceptionModel = ExceptionHandling::None; 418 419 /// Machine level options. 420 MCTargetOptions MCOptions; 421 }; 422 423 } // End llvm namespace 424 425 #endif 426