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
22namespace 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:
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(true),
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), EnableIPRA(false), EmitStackSizeSection(false),
139 EnableMachineOutliner(false), EnableMachineFunctionSplitter(false),
140 SupportsDefaultOutlining(false), EmitAddrsig(false),
141 EmitCallSiteInfo(false), SupportsDebugEntryValues(false),
142 EnableDebugEntryValues(false), ValueTrackingVariableLocations(false),
143 ForceDwarfFrameSection(false), XRayFunctionIndex(true),
144 DebugStrictDwarf(false), Hotpatch(false),
145 PPCGenScalarMASSEntries(false), JMCInstrument(false),
146 EnableCFIFixup(false), MisExpect(false), XCOFFReadOnlyPointers(false),
147 FPDenormalMode(DenormalMode::IEEE, DenormalMode::IEEE) {}
148
149 /// DisableFramePointerElim - This returns true if frame pointer elimination
150 /// optimization should be disabled for the given machine function.
151 bool DisableFramePointerElim(const MachineFunction &MF) const;
152
153 /// If greater than 0, override the default value of
154 /// MCAsmInfo::BinutilsVersion.
155 std::pair<int, int> BinutilsVersion{0, 0};
156
157 /// UnsafeFPMath - This flag is enabled when the
158 /// -enable-unsafe-fp-math flag is specified on the command line. When
159 /// this flag is off (the default), the code generator is not allowed to
160 /// produce results that are "less precise" than IEEE allows. This includes
161 /// use of X86 instructions like FSIN and FCOS instead of libcalls.
162 unsigned UnsafeFPMath : 1;
163
164 /// NoInfsFPMath - This flag is enabled when the
165 /// -enable-no-infs-fp-math flag is specified on the command line. When
166 /// this flag is off (the default), the code generator is not allowed to
167 /// assume the FP arithmetic arguments and results are never +-Infs.
168 unsigned NoInfsFPMath : 1;
169
170 /// NoNaNsFPMath - This flag is enabled when the
171 /// -enable-no-nans-fp-math flag is specified on the command line. When
172 /// this flag is off (the default), the code generator is not allowed to
173 /// assume the FP arithmetic arguments and results are never NaNs.
174 unsigned NoNaNsFPMath : 1;
175
176 /// NoTrappingFPMath - This flag is enabled when the
177 /// -enable-no-trapping-fp-math is specified on the command line. This
178 /// specifies that there are no trap handlers to handle exceptions.
179 unsigned NoTrappingFPMath : 1;
180
181 /// NoSignedZerosFPMath - This flag is enabled when the
182 /// -enable-no-signed-zeros-fp-math is specified on the command line. This
183 /// specifies that optimizations are allowed to treat the sign of a zero
184 /// argument or result as insignificant.
185 unsigned NoSignedZerosFPMath : 1;
186
187 /// ApproxFuncFPMath - This flag is enabled when the
188 /// -enable-approx-func-fp-math is specified on the command line. This
189 /// specifies that optimizations are allowed to substitute math functions
190 /// with approximate calculations
191 unsigned ApproxFuncFPMath : 1;
192
193 /// EnableAIXExtendedAltivecABI - This flag returns true when -vec-extabi is
194 /// specified. The code generator is then able to use both volatile and
195 /// nonvolitle vector registers. When false, the code generator only uses
196 /// volatile vector registers which is the default setting on AIX.
197 unsigned EnableAIXExtendedAltivecABI : 1;
198
199 /// HonorSignDependentRoundingFPMath - This returns true when the
200 /// -enable-sign-dependent-rounding-fp-math is specified. If this returns
201 /// false (the default), the code generator is allowed to assume that the
202 /// rounding behavior is the default (round-to-zero for all floating point
203 /// to integer conversions, and round-to-nearest for all other arithmetic
204 /// truncations). If this is enabled (set to true), the code generator must
205 /// assume that the rounding mode may dynamically change.
206 unsigned HonorSignDependentRoundingFPMathOption : 1;
207 bool HonorSignDependentRoundingFPMath() const;
208
209 /// NoZerosInBSS - By default some codegens place zero-initialized data to
210 /// .bss section. This flag disables such behaviour (necessary, e.g. for
211 /// crt*.o compiling).
212 unsigned NoZerosInBSS : 1;
213
214 /// GuaranteedTailCallOpt - This flag is enabled when -tailcallopt is
215 /// specified on the commandline. When the flag is on, participating targets
216 /// will perform tail call optimization on all calls which use the fastcc
217 /// calling convention and which satisfy certain target-independent
218 /// criteria (being at the end of a function, having the same return type
219 /// as their parent function, etc.), using an alternate ABI if necessary.
220 unsigned GuaranteedTailCallOpt : 1;
221
222 /// StackSymbolOrdering - When true, this will allow CodeGen to order
223 /// the local stack symbols (for code size, code locality, or any other
224 /// heuristics). When false, the local symbols are left in whatever order
225 /// they were generated. Default is true.
226 unsigned StackSymbolOrdering : 1;
227
228 /// EnableFastISel - This flag enables fast-path instruction selection
229 /// which trades away generated code quality in favor of reducing
230 /// compile time.
231 unsigned EnableFastISel : 1;
232
233 /// EnableGlobalISel - This flag enables global instruction selection.
234 unsigned EnableGlobalISel : 1;
235
236 /// EnableGlobalISelAbort - Control abort behaviour when global instruction
237 /// selection fails to lower/select an instruction.
238 GlobalISelAbortMode GlobalISelAbort = GlobalISelAbortMode::Enable;
239
240 /// Control when and how the Swift async frame pointer bit should
241 /// be set.
242 SwiftAsyncFramePointerMode SwiftAsyncFramePointer =
243 SwiftAsyncFramePointerMode::Always;
244
245 /// UseInitArray - Use .init_array instead of .ctors for static
246 /// constructors.
247 unsigned UseInitArray : 1;
248
249 /// Disable the integrated assembler.
250 unsigned DisableIntegratedAS : 1;
251
252 /// Compress DWARF debug sections.
253 DebugCompressionType CompressDebugSections = DebugCompressionType::None;
254
255 unsigned RelaxELFRelocations : 1;
256
257 /// Emit functions into separate sections.
258 unsigned FunctionSections : 1;
259
260 /// Emit data into separate sections.
261 unsigned DataSections : 1;
262
263 /// Do not emit visibility attribute for xcoff.
264 unsigned IgnoreXCOFFVisibility : 1;
265
266 /// Emit XCOFF traceback table.
267 unsigned XCOFFTracebackTable : 1;
268
269 unsigned UniqueSectionNames : 1;
270
271 /// Use unique names for basic block sections.
272 unsigned UniqueBasicBlockSectionNames : 1;
273
274 /// Emit target-specific trap instruction for 'unreachable' IR instructions.
275 unsigned TrapUnreachable : 1;
276
277 /// Do not emit a trap instruction for 'unreachable' IR instructions behind
278 /// noreturn calls, even if TrapUnreachable is true.
279 unsigned NoTrapAfterNoreturn : 1;
280
281 /// Bit size of immediate TLS offsets (0 == use the default).
282 unsigned TLSSize : 8;
283
284 /// EmulatedTLS - This flag enables emulated TLS model, using emutls
285 /// function in the runtime library..
286 unsigned EmulatedTLS : 1;
287
288 /// This flag enables InterProcedural Register Allocation (IPRA).
289 unsigned EnableIPRA : 1;
290
291 /// Emit section containing metadata on function stack sizes.
292 unsigned EmitStackSizeSection : 1;
293
294 /// Enables the MachineOutliner pass.
295 unsigned EnableMachineOutliner : 1;
296
297 /// Enables the MachineFunctionSplitter pass.
298 unsigned EnableMachineFunctionSplitter : 1;
299
300 /// Set if the target supports default outlining behaviour.
301 unsigned SupportsDefaultOutlining : 1;
302
303 /// Emit address-significance table.
304 unsigned EmitAddrsig : 1;
305
306 /// Emit basic blocks into separate sections.
307 BasicBlockSection BBSections = BasicBlockSection::None;
308
309 /// Memory Buffer that contains information on sampled basic blocks and used
310 /// to selectively generate basic block sections.
311 std::shared_ptr<MemoryBuffer> BBSectionsFuncListBuf;
312
313 /// The flag enables call site info production. It is used only for debug
314 /// info, and it is restricted only to optimized code. This can be used for
315 /// something else, so that should be controlled in the frontend.
316 unsigned EmitCallSiteInfo : 1;
317 /// Set if the target supports the debug entry values by default.
318 unsigned SupportsDebugEntryValues : 1;
319 /// When set to true, the EnableDebugEntryValues option forces production
320 /// of debug entry values even if the target does not officially support
321 /// it. Useful for testing purposes only. This flag should never be checked
322 /// directly, always use \ref ShouldEmitDebugEntryValues instead.
323 unsigned EnableDebugEntryValues : 1;
324 /// NOTE: There are targets that still do not support the debug entry values
325 /// production.
326 bool ShouldEmitDebugEntryValues() const;
327
328 // When set to true, use experimental new debug variable location tracking,
329 // which seeks to follow the values of variables rather than their location,
330 // post isel.
331 unsigned ValueTrackingVariableLocations : 1;
332
333 /// Emit DWARF debug frame section.
334 unsigned ForceDwarfFrameSection : 1;
335
336 /// Emit XRay Function Index section
337 unsigned XRayFunctionIndex : 1;
338
339 /// When set to true, don't use DWARF extensions in later DWARF versions.
340 /// By default, it is set to false.
341 unsigned DebugStrictDwarf : 1;
342
343 /// Emit the hotpatch flag in CodeView debug.
344 unsigned Hotpatch : 1;
345
346 /// Enables scalar MASS conversions
347 unsigned PPCGenScalarMASSEntries : 1;
348
349 /// Enable JustMyCode instrumentation.
350 unsigned JMCInstrument : 1;
351
352 /// Enable the CFIFixup pass.
353 unsigned EnableCFIFixup : 1;
354
355 /// When set to true, enable MisExpect Diagnostics
356 /// By default, it is set to false
357 unsigned MisExpect : 1;
358
359 /// When set to true, const objects with relocatable address values are put
360 /// into the RO data section.
361 unsigned XCOFFReadOnlyPointers : 1;
362
363 /// Name of the stack usage file (i.e., .su file) if user passes
364 /// -fstack-usage. If empty, it can be implied that -fstack-usage is not
365 /// passed on the command line.
366 std::string StackUsageOutput;
367
368 /// If greater than 0, override TargetLoweringBase::PrefLoopAlignment.
369 unsigned LoopAlignment = 0;
370
371 /// FloatABIType - This setting is set by -float-abi=xxx option is specfied
372 /// on the command line. This setting may either be Default, Soft, or Hard.
373 /// Default selects the target's default behavior. Soft selects the ABI for
374 /// software floating point, but does not indicate that FP hardware may not
375 /// be used. Such a combination is unfortunately popular (e.g.
376 /// arm-apple-darwin). Hard presumes that the normal FP ABI is used.
377 FloatABI::ABIType FloatABIType = FloatABI::Default;
378
379 /// AllowFPOpFusion - This flag is set by the -fp-contract=xxx option.
380 /// This controls the creation of fused FP ops that store intermediate
381 /// results in higher precision than IEEE allows (E.g. FMAs).
382 ///
383 /// Fast mode - allows formation of fused FP ops whenever they're
384 /// profitable.
385 /// Standard mode - allow fusion only for 'blessed' FP ops. At present the
386 /// only blessed op is the fmuladd intrinsic. In the future more blessed ops
387 /// may be added.
388 /// Strict mode - allow fusion only if/when it can be proven that the excess
389 /// precision won't effect the result.
390 ///
391 /// Note: This option only controls formation of fused ops by the
392 /// optimizers. Fused operations that are explicitly specified (e.g. FMA
393 /// via the llvm.fma.* intrinsic) will always be honored, regardless of
394 /// the value of this option.
395 FPOpFusion::FPOpFusionMode AllowFPOpFusion = FPOpFusion::Standard;
396
397 /// ThreadModel - This flag specifies the type of threading model to assume
398 /// for things like atomics
399 ThreadModel::Model ThreadModel = ThreadModel::POSIX;
400
401 /// EABIVersion - This flag specifies the EABI version
402 EABI EABIVersion = EABI::Default;
403
404 /// Which debugger to tune for.
405 DebuggerKind DebuggerTuning = DebuggerKind::Default;
406
407 private:
408 /// Flushing mode to assume in default FP environment.
409 DenormalMode FPDenormalMode;
410
411 /// Flushing mode to assume in default FP environment, for float/vector of
412 /// float.
413 DenormalMode FP32DenormalMode;
414
415 public:
416 void setFPDenormalMode(DenormalMode Mode) {
417 FPDenormalMode = Mode;
418 }
419
420 void setFP32DenormalMode(DenormalMode Mode) {
421 FP32DenormalMode = Mode;
422 }
423
424 DenormalMode getRawFPDenormalMode() const {
425 return FPDenormalMode;
426 }
427
428 DenormalMode getRawFP32DenormalMode() const {
429 return FP32DenormalMode;
430 }
431
432 DenormalMode getDenormalMode(const fltSemantics &FPType) const;
433
434 /// What exception model to use
435 ExceptionHandling ExceptionModel = ExceptionHandling::None;
436
437 /// Machine level options.
438 MCTargetOptions MCOptions;
439
440 /// Stores the filename/path of the final .o/.obj file, to be written in the
441 /// debug information. This is used for emitting the CodeView S_OBJNAME
442 /// record.
443 std::string ObjectFilenameForDebug;
444 };
445
446} // End llvm namespace
447
448#endif
449

source code of include/llvm-17/llvm/Target/TargetOptions.h