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 class TargetOptions { 114 public: TargetOptions()115 TargetOptions() 116 : UnsafeFPMath(false), NoInfsFPMath(false), NoNaNsFPMath(false), 117 NoTrappingFPMath(true), NoSignedZerosFPMath(false), 118 EnableAIXExtendedAltivecABI(false), 119 HonorSignDependentRoundingFPMathOption(false), NoZerosInBSS(false), 120 GuaranteedTailCallOpt(false), StackSymbolOrdering(true), 121 EnableFastISel(false), EnableGlobalISel(false), UseInitArray(false), 122 DisableIntegratedAS(false), RelaxELFRelocations(false), 123 FunctionSections(false), DataSections(false), 124 IgnoreXCOFFVisibility(false), XCOFFTracebackTable(true), 125 UniqueSectionNames(true), UniqueBasicBlockSectionNames(false), 126 TrapUnreachable(false), NoTrapAfterNoreturn(false), TLSSize(0), 127 EmulatedTLS(false), ExplicitEmulatedTLS(false), EnableIPRA(false), 128 EmitStackSizeSection(false), EnableMachineOutliner(false), 129 EnableMachineFunctionSplitter(false), SupportsDefaultOutlining(false), 130 EmitAddrsig(false), EmitCallSiteInfo(false), 131 SupportsDebugEntryValues(false), EnableDebugEntryValues(false), 132 PseudoProbeForProfiling(false), ValueTrackingVariableLocations(false), 133 ForceDwarfFrameSection(false), XRayOmitFunctionIndex(false), 134 DebugStrictDwarf(false), 135 FPDenormalMode(DenormalMode::IEEE, DenormalMode::IEEE) {} 136 137 /// DisableFramePointerElim - This returns true if frame pointer elimination 138 /// optimization should be disabled for the given machine function. 139 bool DisableFramePointerElim(const MachineFunction &MF) const; 140 141 /// If greater than 0, override the default value of 142 /// MCAsmInfo::BinutilsVersion. 143 std::pair<int, int> BinutilsVersion{0, 0}; 144 145 /// UnsafeFPMath - This flag is enabled when the 146 /// -enable-unsafe-fp-math flag is specified on the command line. When 147 /// this flag is off (the default), the code generator is not allowed to 148 /// produce results that are "less precise" than IEEE allows. This includes 149 /// use of X86 instructions like FSIN and FCOS instead of libcalls. 150 unsigned UnsafeFPMath : 1; 151 152 /// NoInfsFPMath - This flag is enabled when the 153 /// -enable-no-infs-fp-math flag is specified on the command line. When 154 /// this flag is off (the default), the code generator is not allowed to 155 /// assume the FP arithmetic arguments and results are never +-Infs. 156 unsigned NoInfsFPMath : 1; 157 158 /// NoNaNsFPMath - This flag is enabled when the 159 /// -enable-no-nans-fp-math flag is specified on the command line. When 160 /// this flag is off (the default), the code generator is not allowed to 161 /// assume the FP arithmetic arguments and results are never NaNs. 162 unsigned NoNaNsFPMath : 1; 163 164 /// NoTrappingFPMath - This flag is enabled when the 165 /// -enable-no-trapping-fp-math is specified on the command line. This 166 /// specifies that there are no trap handlers to handle exceptions. 167 unsigned NoTrappingFPMath : 1; 168 169 /// NoSignedZerosFPMath - This flag is enabled when the 170 /// -enable-no-signed-zeros-fp-math is specified on the command line. This 171 /// specifies that optimizations are allowed to treat the sign of a zero 172 /// argument or result as insignificant. 173 unsigned NoSignedZerosFPMath : 1; 174 175 /// EnableAIXExtendedAltivecABI - This flag returns true when -vec-extabi is 176 /// specified. The code generator is then able to use both volatile and 177 /// nonvolitle vector regisers. When false, the code generator only uses 178 /// volatile vector registers which is the default setting on AIX. 179 unsigned EnableAIXExtendedAltivecABI : 1; 180 181 /// HonorSignDependentRoundingFPMath - This returns true when the 182 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns 183 /// false (the default), the code generator is allowed to assume that the 184 /// rounding behavior is the default (round-to-zero for all floating point 185 /// to integer conversions, and round-to-nearest for all other arithmetic 186 /// truncations). If this is enabled (set to true), the code generator must 187 /// assume that the rounding mode may dynamically change. 188 unsigned HonorSignDependentRoundingFPMathOption : 1; 189 bool HonorSignDependentRoundingFPMath() const; 190 191 /// NoZerosInBSS - By default some codegens place zero-initialized data to 192 /// .bss section. This flag disables such behaviour (necessary, e.g. for 193 /// crt*.o compiling). 194 unsigned NoZerosInBSS : 1; 195 196 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is 197 /// specified on the commandline. When the flag is on, participating targets 198 /// will perform tail call optimization on all calls which use the fastcc 199 /// calling convention and which satisfy certain target-independent 200 /// criteria (being at the end of a function, having the same return type 201 /// as their parent function, etc.), using an alternate ABI if necessary. 202 unsigned GuaranteedTailCallOpt : 1; 203 204 /// StackSymbolOrdering - When true, this will allow CodeGen to order 205 /// the local stack symbols (for code size, code locality, or any other 206 /// heuristics). When false, the local symbols are left in whatever order 207 /// they were generated. Default is true. 208 unsigned StackSymbolOrdering : 1; 209 210 /// EnableFastISel - This flag enables fast-path instruction selection 211 /// which trades away generated code quality in favor of reducing 212 /// compile time. 213 unsigned EnableFastISel : 1; 214 215 /// EnableGlobalISel - This flag enables global instruction selection. 216 unsigned EnableGlobalISel : 1; 217 218 /// EnableGlobalISelAbort - Control abort behaviour when global instruction 219 /// selection fails to lower/select an instruction. 220 GlobalISelAbortMode GlobalISelAbort = GlobalISelAbortMode::Enable; 221 222 /// UseInitArray - Use .init_array instead of .ctors for static 223 /// constructors. 224 unsigned UseInitArray : 1; 225 226 /// Disable the integrated assembler. 227 unsigned DisableIntegratedAS : 1; 228 229 /// Compress DWARF debug sections. 230 DebugCompressionType CompressDebugSections = DebugCompressionType::None; 231 232 unsigned RelaxELFRelocations : 1; 233 234 /// Emit functions into separate sections. 235 unsigned FunctionSections : 1; 236 237 /// Emit data into separate sections. 238 unsigned DataSections : 1; 239 240 /// Do not emit visibility attribute for xcoff. 241 unsigned IgnoreXCOFFVisibility : 1; 242 243 /// Emit XCOFF traceback table. 244 unsigned XCOFFTracebackTable : 1; 245 246 unsigned UniqueSectionNames : 1; 247 248 /// Use unique names for basic block sections. 249 unsigned UniqueBasicBlockSectionNames : 1; 250 251 /// Emit target-specific trap instruction for 'unreachable' IR instructions. 252 unsigned TrapUnreachable : 1; 253 254 /// Do not emit a trap instruction for 'unreachable' IR instructions behind 255 /// noreturn calls, even if TrapUnreachable is true. 256 unsigned NoTrapAfterNoreturn : 1; 257 258 /// Bit size of immediate TLS offsets (0 == use the default). 259 unsigned TLSSize : 8; 260 261 /// EmulatedTLS - This flag enables emulated TLS model, using emutls 262 /// function in the runtime library.. 263 unsigned EmulatedTLS : 1; 264 265 /// Whether -emulated-tls or -no-emulated-tls is set. 266 unsigned ExplicitEmulatedTLS : 1; 267 268 /// This flag enables InterProcedural Register Allocation (IPRA). 269 unsigned EnableIPRA : 1; 270 271 /// Emit section containing metadata on function stack sizes. 272 unsigned EmitStackSizeSection : 1; 273 274 /// Enables the MachineOutliner pass. 275 unsigned EnableMachineOutliner : 1; 276 277 /// Enables the MachineFunctionSplitter pass. 278 unsigned EnableMachineFunctionSplitter : 1; 279 280 /// Set if the target supports default outlining behaviour. 281 unsigned SupportsDefaultOutlining : 1; 282 283 /// Emit address-significance table. 284 unsigned EmitAddrsig : 1; 285 286 /// Emit basic blocks into separate sections. 287 BasicBlockSection BBSections = BasicBlockSection::None; 288 289 /// Memory Buffer that contains information on sampled basic blocks and used 290 /// to selectively generate basic block sections. 291 std::shared_ptr<MemoryBuffer> BBSectionsFuncListBuf; 292 293 /// The flag enables call site info production. It is used only for debug 294 /// info, and it is restricted only to optimized code. This can be used for 295 /// something else, so that should be controlled in the frontend. 296 unsigned EmitCallSiteInfo : 1; 297 /// Set if the target supports the debug entry values by default. 298 unsigned SupportsDebugEntryValues : 1; 299 /// When set to true, the EnableDebugEntryValues option forces production 300 /// of debug entry values even if the target does not officially support 301 /// it. Useful for testing purposes only. This flag should never be checked 302 /// directly, always use \ref ShouldEmitDebugEntryValues instead. 303 unsigned EnableDebugEntryValues : 1; 304 /// NOTE: There are targets that still do not support the debug entry values 305 /// production. 306 bool ShouldEmitDebugEntryValues() const; 307 308 /// Emit pseudo probes into the binary for sample profiling 309 unsigned PseudoProbeForProfiling : 1; 310 311 // When set to true, use experimental new debug variable location tracking, 312 // which seeks to follow the values of variables rather than their location, 313 // post isel. 314 unsigned ValueTrackingVariableLocations : 1; 315 316 /// Emit DWARF debug frame section. 317 unsigned ForceDwarfFrameSection : 1; 318 319 /// Emit XRay Function Index section 320 unsigned XRayOmitFunctionIndex : 1; 321 322 /// When set to true, don't use DWARF extensions in later DWARF versions. 323 /// By default, it is set to false. 324 unsigned DebugStrictDwarf : 1; 325 326 /// Name of the stack usage file (i.e., .su file) if user passes 327 /// -fstack-usage. If empty, it can be implied that -fstack-usage is not 328 /// passed on the command line. 329 std::string StackUsageOutput; 330 331 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied 332 /// on the command line. This setting may either be Default, Soft, or Hard. 333 /// Default selects the target's default behavior. Soft selects the ABI for 334 /// software floating point, but does not indicate that FP hardware may not 335 /// be used. Such a combination is unfortunately popular (e.g. 336 /// arm-apple-darwin). Hard presumes that the normal FP ABI is used. 337 FloatABI::ABIType FloatABIType = FloatABI::Default; 338 339 /// AllowFPOpFusion - This flag is set by the -fp-contract=xxx option. 340 /// This controls the creation of fused FP ops that store intermediate 341 /// results in higher precision than IEEE allows (E.g. FMAs). 342 /// 343 /// Fast mode - allows formation of fused FP ops whenever they're 344 /// profitable. 345 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the 346 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops 347 /// may be added. 348 /// Strict mode - allow fusion only if/when it can be proven that the excess 349 /// precision won't effect the result. 350 /// 351 /// Note: This option only controls formation of fused ops by the 352 /// optimizers. Fused operations that are explicitly specified (e.g. FMA 353 /// via the llvm.fma.* intrinsic) will always be honored, regardless of 354 /// the value of this option. 355 FPOpFusion::FPOpFusionMode AllowFPOpFusion = FPOpFusion::Standard; 356 357 /// ThreadModel - This flag specifies the type of threading model to assume 358 /// for things like atomics 359 ThreadModel::Model ThreadModel = ThreadModel::POSIX; 360 361 /// EABIVersion - This flag specifies the EABI version 362 EABI EABIVersion = EABI::Default; 363 364 /// Which debugger to tune for. 365 DebuggerKind DebuggerTuning = DebuggerKind::Default; 366 367 private: 368 /// Flushing mode to assume in default FP environment. 369 DenormalMode FPDenormalMode; 370 371 /// Flushing mode to assume in default FP environment, for float/vector of 372 /// float. 373 DenormalMode FP32DenormalMode; 374 375 public: setFPDenormalMode(DenormalMode Mode)376 void setFPDenormalMode(DenormalMode Mode) { 377 FPDenormalMode = Mode; 378 } 379 setFP32DenormalMode(DenormalMode Mode)380 void setFP32DenormalMode(DenormalMode Mode) { 381 FP32DenormalMode = Mode; 382 } 383 getRawFPDenormalMode()384 DenormalMode getRawFPDenormalMode() const { 385 return FPDenormalMode; 386 } 387 getRawFP32DenormalMode()388 DenormalMode getRawFP32DenormalMode() const { 389 return FP32DenormalMode; 390 } 391 392 DenormalMode getDenormalMode(const fltSemantics &FPType) const; 393 394 /// What exception model to use 395 ExceptionHandling ExceptionModel = ExceptionHandling::None; 396 397 /// Machine level options. 398 MCTargetOptions MCOptions; 399 }; 400 401 } // End llvm namespace 402 403 #endif 404