1 //===-- CommandFlags.cpp - Command Line Flags Interface ---------*- 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 contains codegen-specific flags that are shared between different
10 // command line tools. The tools "llc" and "opt" both use this file to prevent
11 // flag duplication.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/CodeGen/CommandFlags.h"
16 #include "llvm/ADT/StringExtras.h"
17 #include "llvm/ADT/Triple.h"
18 #include "llvm/IR/Instructions.h"
19 #include "llvm/IR/Intrinsics.h"
20 #include "llvm/IR/Module.h"
21 #include "llvm/MC/MCTargetOptionsCommandFlags.h"
22 #include "llvm/MC/SubtargetFeature.h"
23 #include "llvm/Support/CommandLine.h"
24 #include "llvm/Support/Host.h"
25 #include "llvm/Support/MemoryBuffer.h"
26 #include <optional>
27 
28 using namespace llvm;
29 
30 #define CGOPT(TY, NAME)                                                        \
31   static cl::opt<TY> *NAME##View;                                              \
32   TY codegen::get##NAME() {                                                    \
33     assert(NAME##View && "RegisterCodeGenFlags not created.");                 \
34     return *NAME##View;                                                        \
35   }
36 
37 #define CGLIST(TY, NAME)                                                       \
38   static cl::list<TY> *NAME##View;                                             \
39   std::vector<TY> codegen::get##NAME() {                                       \
40     assert(NAME##View && "RegisterCodeGenFlags not created.");                 \
41     return *NAME##View;                                                        \
42   }
43 
44 // Temporary macro for incremental transition to std::optional.
45 #define CGOPT_EXP(TY, NAME)                                                    \
46   CGOPT(TY, NAME)                                                              \
47   std::optional<TY> codegen::getExplicit##NAME() {                             \
48     if (NAME##View->getNumOccurrences()) {                                     \
49       TY res = *NAME##View;                                                    \
50       return res;                                                              \
51     }                                                                          \
52     return std::nullopt;                                                       \
53   }
54 
CGOPT(std::string,MArch)55 CGOPT(std::string, MArch)
56 CGOPT(std::string, MCPU)
57 CGLIST(std::string, MAttrs)
58 CGOPT_EXP(Reloc::Model, RelocModel)
59 CGOPT(ThreadModel::Model, ThreadModel)
60 CGOPT_EXP(CodeModel::Model, CodeModel)
61 CGOPT(ExceptionHandling, ExceptionModel)
62 CGOPT_EXP(CodeGenFileType, FileType)
63 CGOPT(FramePointerKind, FramePointerUsage)
64 CGOPT(bool, EnableUnsafeFPMath)
65 CGOPT(bool, EnableNoInfsFPMath)
66 CGOPT(bool, EnableNoNaNsFPMath)
67 CGOPT(bool, EnableNoSignedZerosFPMath)
68 CGOPT(bool, EnableApproxFuncFPMath)
69 CGOPT(bool, EnableNoTrappingFPMath)
70 CGOPT(bool, EnableAIXExtendedAltivecABI)
71 CGOPT(DenormalMode::DenormalModeKind, DenormalFPMath)
72 CGOPT(DenormalMode::DenormalModeKind, DenormalFP32Math)
73 CGOPT(bool, EnableHonorSignDependentRoundingFPMath)
74 CGOPT(FloatABI::ABIType, FloatABIForCalls)
75 CGOPT(FPOpFusion::FPOpFusionMode, FuseFPOps)
76 CGOPT(SwiftAsyncFramePointerMode, SwiftAsyncFramePointer)
77 CGOPT(bool, DontPlaceZerosInBSS)
78 CGOPT(bool, EnableGuaranteedTailCallOpt)
79 CGOPT(bool, DisableTailCalls)
80 CGOPT(bool, StackSymbolOrdering)
81 CGOPT(bool, StackRealign)
82 CGOPT(std::string, TrapFuncName)
83 CGOPT(bool, UseCtors)
84 CGOPT(bool, LowerGlobalDtorsViaCxaAtExit)
85 CGOPT(bool, RelaxELFRelocations)
86 CGOPT_EXP(bool, DataSections)
87 CGOPT_EXP(bool, FunctionSections)
88 CGOPT(bool, IgnoreXCOFFVisibility)
89 CGOPT(bool, XCOFFTracebackTable)
90 CGOPT(std::string, BBSections)
91 CGOPT(unsigned, TLSSize)
92 CGOPT(bool, EmulatedTLS)
93 CGOPT(bool, UniqueSectionNames)
94 CGOPT(bool, UniqueBasicBlockSectionNames)
95 CGOPT(EABI, EABIVersion)
96 CGOPT(DebuggerKind, DebuggerTuningOpt)
97 CGOPT(bool, EnableStackSizeSection)
98 CGOPT(bool, EnableAddrsig)
99 CGOPT(bool, EmitCallSiteInfo)
100 CGOPT(bool, EnableMachineFunctionSplitter)
101 CGOPT(bool, EnableDebugEntryValues)
102 CGOPT(bool, ForceDwarfFrameSection)
103 CGOPT(bool, XRayOmitFunctionIndex)
104 CGOPT(bool, DebugStrictDwarf)
105 CGOPT(unsigned, AlignLoops)
106 CGOPT(bool, JMCInstrument)
107 
108 codegen::RegisterCodeGenFlags::RegisterCodeGenFlags() {
109 #define CGBINDOPT(NAME)                                                        \
110   do {                                                                         \
111     NAME##View = std::addressof(NAME);                                         \
112   } while (0)
113 
114   static cl::opt<std::string> MArch(
115       "march", cl::desc("Architecture to generate code for (see --version)"));
116   CGBINDOPT(MArch);
117 
118   static cl::opt<std::string> MCPU(
119       "mcpu", cl::desc("Target a specific cpu type (-mcpu=help for details)"),
120       cl::value_desc("cpu-name"), cl::init(""));
121   CGBINDOPT(MCPU);
122 
123   static cl::list<std::string> MAttrs(
124       "mattr", cl::CommaSeparated,
125       cl::desc("Target specific attributes (-mattr=help for details)"),
126       cl::value_desc("a1,+a2,-a3,..."));
127   CGBINDOPT(MAttrs);
128 
129   static cl::opt<Reloc::Model> RelocModel(
130       "relocation-model", cl::desc("Choose relocation model"),
131       cl::values(
132           clEnumValN(Reloc::Static, "static", "Non-relocatable code"),
133           clEnumValN(Reloc::PIC_, "pic",
134                      "Fully relocatable, position independent code"),
135           clEnumValN(Reloc::DynamicNoPIC, "dynamic-no-pic",
136                      "Relocatable external references, non-relocatable code"),
137           clEnumValN(
138               Reloc::ROPI, "ropi",
139               "Code and read-only data relocatable, accessed PC-relative"),
140           clEnumValN(
141               Reloc::RWPI, "rwpi",
142               "Read-write data relocatable, accessed relative to static base"),
143           clEnumValN(Reloc::ROPI_RWPI, "ropi-rwpi",
144                      "Combination of ropi and rwpi")));
145   CGBINDOPT(RelocModel);
146 
147   static cl::opt<ThreadModel::Model> ThreadModel(
148       "thread-model", cl::desc("Choose threading model"),
149       cl::init(ThreadModel::POSIX),
150       cl::values(
151           clEnumValN(ThreadModel::POSIX, "posix", "POSIX thread model"),
152           clEnumValN(ThreadModel::Single, "single", "Single thread model")));
153   CGBINDOPT(ThreadModel);
154 
155   static cl::opt<CodeModel::Model> CodeModel(
156       "code-model", cl::desc("Choose code model"),
157       cl::values(clEnumValN(CodeModel::Tiny, "tiny", "Tiny code model"),
158                  clEnumValN(CodeModel::Small, "small", "Small code model"),
159                  clEnumValN(CodeModel::Kernel, "kernel", "Kernel code model"),
160                  clEnumValN(CodeModel::Medium, "medium", "Medium code model"),
161                  clEnumValN(CodeModel::Large, "large", "Large code model")));
162   CGBINDOPT(CodeModel);
163 
164   static cl::opt<ExceptionHandling> ExceptionModel(
165       "exception-model", cl::desc("exception model"),
166       cl::init(ExceptionHandling::None),
167       cl::values(
168           clEnumValN(ExceptionHandling::None, "default",
169                      "default exception handling model"),
170           clEnumValN(ExceptionHandling::DwarfCFI, "dwarf",
171                      "DWARF-like CFI based exception handling"),
172           clEnumValN(ExceptionHandling::SjLj, "sjlj",
173                      "SjLj exception handling"),
174           clEnumValN(ExceptionHandling::ARM, "arm", "ARM EHABI exceptions"),
175           clEnumValN(ExceptionHandling::WinEH, "wineh",
176                      "Windows exception model"),
177           clEnumValN(ExceptionHandling::Wasm, "wasm",
178                      "WebAssembly exception handling")));
179   CGBINDOPT(ExceptionModel);
180 
181   static cl::opt<CodeGenFileType> FileType(
182       "filetype", cl::init(CGFT_AssemblyFile),
183       cl::desc(
184           "Choose a file type (not all types are supported by all targets):"),
185       cl::values(
186           clEnumValN(CGFT_AssemblyFile, "asm", "Emit an assembly ('.s') file"),
187           clEnumValN(CGFT_ObjectFile, "obj",
188                      "Emit a native object ('.o') file"),
189           clEnumValN(CGFT_Null, "null",
190                      "Emit nothing, for performance testing")));
191   CGBINDOPT(FileType);
192 
193   static cl::opt<FramePointerKind> FramePointerUsage(
194       "frame-pointer",
195       cl::desc("Specify frame pointer elimination optimization"),
196       cl::init(FramePointerKind::None),
197       cl::values(
198           clEnumValN(FramePointerKind::All, "all",
199                      "Disable frame pointer elimination"),
200           clEnumValN(FramePointerKind::NonLeaf, "non-leaf",
201                      "Disable frame pointer elimination for non-leaf frame"),
202           clEnumValN(FramePointerKind::None, "none",
203                      "Enable frame pointer elimination")));
204   CGBINDOPT(FramePointerUsage);
205 
206   static cl::opt<bool> EnableUnsafeFPMath(
207       "enable-unsafe-fp-math",
208       cl::desc("Enable optimizations that may decrease FP precision"),
209       cl::init(false));
210   CGBINDOPT(EnableUnsafeFPMath);
211 
212   static cl::opt<bool> EnableNoInfsFPMath(
213       "enable-no-infs-fp-math",
214       cl::desc("Enable FP math optimizations that assume no +-Infs"),
215       cl::init(false));
216   CGBINDOPT(EnableNoInfsFPMath);
217 
218   static cl::opt<bool> EnableNoNaNsFPMath(
219       "enable-no-nans-fp-math",
220       cl::desc("Enable FP math optimizations that assume no NaNs"),
221       cl::init(false));
222   CGBINDOPT(EnableNoNaNsFPMath);
223 
224   static cl::opt<bool> EnableNoSignedZerosFPMath(
225       "enable-no-signed-zeros-fp-math",
226       cl::desc("Enable FP math optimizations that assume "
227                "the sign of 0 is insignificant"),
228       cl::init(false));
229   CGBINDOPT(EnableNoSignedZerosFPMath);
230 
231   static cl::opt<bool> EnableApproxFuncFPMath(
232       "enable-approx-func-fp-math",
233       cl::desc("Enable FP math optimizations that assume approx func"),
234       cl::init(false));
235   CGBINDOPT(EnableApproxFuncFPMath);
236 
237   static cl::opt<bool> EnableNoTrappingFPMath(
238       "enable-no-trapping-fp-math",
239       cl::desc("Enable setting the FP exceptions build "
240                "attribute not to use exceptions"),
241       cl::init(false));
242   CGBINDOPT(EnableNoTrappingFPMath);
243 
244   static const auto DenormFlagEnumOptions =
245   cl::values(clEnumValN(DenormalMode::IEEE, "ieee",
246                         "IEEE 754 denormal numbers"),
247              clEnumValN(DenormalMode::PreserveSign, "preserve-sign",
248                         "the sign of a  flushed-to-zero number is preserved "
249                         "in the sign of 0"),
250              clEnumValN(DenormalMode::PositiveZero, "positive-zero",
251                         "denormals are flushed to positive zero"));
252 
253   // FIXME: Doesn't have way to specify separate input and output modes.
254   static cl::opt<DenormalMode::DenormalModeKind> DenormalFPMath(
255     "denormal-fp-math",
256     cl::desc("Select which denormal numbers the code is permitted to require"),
257     cl::init(DenormalMode::IEEE),
258     DenormFlagEnumOptions);
259   CGBINDOPT(DenormalFPMath);
260 
261   static cl::opt<DenormalMode::DenormalModeKind> DenormalFP32Math(
262     "denormal-fp-math-f32",
263     cl::desc("Select which denormal numbers the code is permitted to require for float"),
264     cl::init(DenormalMode::Invalid),
265     DenormFlagEnumOptions);
266   CGBINDOPT(DenormalFP32Math);
267 
268   static cl::opt<bool> EnableHonorSignDependentRoundingFPMath(
269       "enable-sign-dependent-rounding-fp-math", cl::Hidden,
270       cl::desc("Force codegen to assume rounding mode can change dynamically"),
271       cl::init(false));
272   CGBINDOPT(EnableHonorSignDependentRoundingFPMath);
273 
274   static cl::opt<FloatABI::ABIType> FloatABIForCalls(
275       "float-abi", cl::desc("Choose float ABI type"),
276       cl::init(FloatABI::Default),
277       cl::values(clEnumValN(FloatABI::Default, "default",
278                             "Target default float ABI type"),
279                  clEnumValN(FloatABI::Soft, "soft",
280                             "Soft float ABI (implied by -soft-float)"),
281                  clEnumValN(FloatABI::Hard, "hard",
282                             "Hard float ABI (uses FP registers)")));
283   CGBINDOPT(FloatABIForCalls);
284 
285   static cl::opt<FPOpFusion::FPOpFusionMode> FuseFPOps(
286       "fp-contract", cl::desc("Enable aggressive formation of fused FP ops"),
287       cl::init(FPOpFusion::Standard),
288       cl::values(
289           clEnumValN(FPOpFusion::Fast, "fast",
290                      "Fuse FP ops whenever profitable"),
291           clEnumValN(FPOpFusion::Standard, "on", "Only fuse 'blessed' FP ops."),
292           clEnumValN(FPOpFusion::Strict, "off",
293                      "Only fuse FP ops when the result won't be affected.")));
294   CGBINDOPT(FuseFPOps);
295 
296   static cl::opt<SwiftAsyncFramePointerMode> SwiftAsyncFramePointer(
297       "swift-async-fp",
298       cl::desc("Determine when the Swift async frame pointer should be set"),
299       cl::init(SwiftAsyncFramePointerMode::Always),
300       cl::values(clEnumValN(SwiftAsyncFramePointerMode::DeploymentBased, "auto",
301                             "Determine based on deployment target"),
302                  clEnumValN(SwiftAsyncFramePointerMode::Always, "always",
303                             "Always set the bit"),
304                  clEnumValN(SwiftAsyncFramePointerMode::Never, "never",
305                             "Never set the bit")));
306   CGBINDOPT(SwiftAsyncFramePointer);
307 
308   static cl::opt<bool> DontPlaceZerosInBSS(
309       "nozero-initialized-in-bss",
310       cl::desc("Don't place zero-initialized symbols into bss section"),
311       cl::init(false));
312   CGBINDOPT(DontPlaceZerosInBSS);
313 
314   static cl::opt<bool> EnableAIXExtendedAltivecABI(
315       "vec-extabi", cl::desc("Enable the AIX Extended Altivec ABI."),
316       cl::init(false));
317   CGBINDOPT(EnableAIXExtendedAltivecABI);
318 
319   static cl::opt<bool> EnableGuaranteedTailCallOpt(
320       "tailcallopt",
321       cl::desc(
322           "Turn fastcc calls into tail calls by (potentially) changing ABI."),
323       cl::init(false));
324   CGBINDOPT(EnableGuaranteedTailCallOpt);
325 
326   static cl::opt<bool> DisableTailCalls(
327       "disable-tail-calls", cl::desc("Never emit tail calls"), cl::init(false));
328   CGBINDOPT(DisableTailCalls);
329 
330   static cl::opt<bool> StackSymbolOrdering(
331       "stack-symbol-ordering", cl::desc("Order local stack symbols."),
332       cl::init(true));
333   CGBINDOPT(StackSymbolOrdering);
334 
335   static cl::opt<bool> StackRealign(
336       "stackrealign",
337       cl::desc("Force align the stack to the minimum alignment"),
338       cl::init(false));
339   CGBINDOPT(StackRealign);
340 
341   static cl::opt<std::string> TrapFuncName(
342       "trap-func", cl::Hidden,
343       cl::desc("Emit a call to trap function rather than a trap instruction"),
344       cl::init(""));
345   CGBINDOPT(TrapFuncName);
346 
347   static cl::opt<bool> UseCtors("use-ctors",
348                                 cl::desc("Use .ctors instead of .init_array."),
349                                 cl::init(false));
350   CGBINDOPT(UseCtors);
351 
352   static cl::opt<bool> LowerGlobalDtorsViaCxaAtExit(
353       "lower-global-dtors-via-cxa-atexit",
354       cl::desc("Lower llvm.global_dtors (global destructors) via __cxa_atexit"),
355       cl::init(true));
356   CGBINDOPT(LowerGlobalDtorsViaCxaAtExit);
357 
358   static cl::opt<bool> RelaxELFRelocations(
359       "relax-elf-relocations",
360       cl::desc(
361           "Emit GOTPCRELX/REX_GOTPCRELX instead of GOTPCREL on x86-64 ELF"),
362       cl::init(true));
363   CGBINDOPT(RelaxELFRelocations);
364 
365   static cl::opt<bool> DataSections(
366       "data-sections", cl::desc("Emit data into separate sections"),
367       cl::init(false));
368   CGBINDOPT(DataSections);
369 
370   static cl::opt<bool> FunctionSections(
371       "function-sections", cl::desc("Emit functions into separate sections"),
372       cl::init(false));
373   CGBINDOPT(FunctionSections);
374 
375   static cl::opt<bool> IgnoreXCOFFVisibility(
376       "ignore-xcoff-visibility",
377       cl::desc("Not emit the visibility attribute for asm in AIX OS or give "
378                "all symbols 'unspecified' visibility in XCOFF object file"),
379       cl::init(false));
380   CGBINDOPT(IgnoreXCOFFVisibility);
381 
382   static cl::opt<bool> XCOFFTracebackTable(
383       "xcoff-traceback-table", cl::desc("Emit the XCOFF traceback table"),
384       cl::init(true));
385   CGBINDOPT(XCOFFTracebackTable);
386 
387   static cl::opt<std::string> BBSections(
388       "basic-block-sections",
389       cl::desc("Emit basic blocks into separate sections"),
390       cl::value_desc("all | <function list (file)> | labels | none"),
391       cl::init("none"));
392   CGBINDOPT(BBSections);
393 
394   static cl::opt<unsigned> TLSSize(
395       "tls-size", cl::desc("Bit size of immediate TLS offsets"), cl::init(0));
396   CGBINDOPT(TLSSize);
397 
398   static cl::opt<bool> EmulatedTLS(
399       "emulated-tls", cl::desc("Use emulated TLS model"), cl::init(false));
400   CGBINDOPT(EmulatedTLS);
401 
402   static cl::opt<bool> UniqueSectionNames(
403       "unique-section-names", cl::desc("Give unique names to every section"),
404       cl::init(true));
405   CGBINDOPT(UniqueSectionNames);
406 
407   static cl::opt<bool> UniqueBasicBlockSectionNames(
408       "unique-basic-block-section-names",
409       cl::desc("Give unique names to every basic block section"),
410       cl::init(false));
411   CGBINDOPT(UniqueBasicBlockSectionNames);
412 
413   static cl::opt<EABI> EABIVersion(
414       "meabi", cl::desc("Set EABI type (default depends on triple):"),
415       cl::init(EABI::Default),
416       cl::values(
417           clEnumValN(EABI::Default, "default", "Triple default EABI version"),
418           clEnumValN(EABI::EABI4, "4", "EABI version 4"),
419           clEnumValN(EABI::EABI5, "5", "EABI version 5"),
420           clEnumValN(EABI::GNU, "gnu", "EABI GNU")));
421   CGBINDOPT(EABIVersion);
422 
423   static cl::opt<DebuggerKind> DebuggerTuningOpt(
424       "debugger-tune", cl::desc("Tune debug info for a particular debugger"),
425       cl::init(DebuggerKind::Default),
426       cl::values(
427           clEnumValN(DebuggerKind::GDB, "gdb", "gdb"),
428           clEnumValN(DebuggerKind::LLDB, "lldb", "lldb"),
429           clEnumValN(DebuggerKind::DBX, "dbx", "dbx"),
430           clEnumValN(DebuggerKind::SCE, "sce", "SCE targets (e.g. PS4)")));
431   CGBINDOPT(DebuggerTuningOpt);
432 
433   static cl::opt<bool> EnableStackSizeSection(
434       "stack-size-section",
435       cl::desc("Emit a section containing stack size metadata"),
436       cl::init(false));
437   CGBINDOPT(EnableStackSizeSection);
438 
439   static cl::opt<bool> EnableAddrsig(
440       "addrsig", cl::desc("Emit an address-significance table"),
441       cl::init(false));
442   CGBINDOPT(EnableAddrsig);
443 
444   static cl::opt<bool> EmitCallSiteInfo(
445       "emit-call-site-info",
446       cl::desc(
447           "Emit call site debug information, if debug information is enabled."),
448       cl::init(false));
449   CGBINDOPT(EmitCallSiteInfo);
450 
451   static cl::opt<bool> EnableDebugEntryValues(
452       "debug-entry-values",
453       cl::desc("Enable debug info for the debug entry values."),
454       cl::init(false));
455   CGBINDOPT(EnableDebugEntryValues);
456 
457   static cl::opt<bool> EnableMachineFunctionSplitter(
458       "split-machine-functions",
459       cl::desc("Split out cold basic blocks from machine functions based on "
460                "profile information"),
461       cl::init(false));
462   CGBINDOPT(EnableMachineFunctionSplitter);
463 
464   static cl::opt<bool> ForceDwarfFrameSection(
465       "force-dwarf-frame-section",
466       cl::desc("Always emit a debug frame section."), cl::init(false));
467   CGBINDOPT(ForceDwarfFrameSection);
468 
469   static cl::opt<bool> XRayOmitFunctionIndex(
470       "no-xray-index", cl::desc("Don't emit xray_fn_idx section"),
471       cl::init(false));
472   CGBINDOPT(XRayOmitFunctionIndex);
473 
474   static cl::opt<bool> DebugStrictDwarf(
475       "strict-dwarf", cl::desc("use strict dwarf"), cl::init(false));
476   CGBINDOPT(DebugStrictDwarf);
477 
478   static cl::opt<unsigned> AlignLoops("align-loops",
479                                       cl::desc("Default alignment for loops"));
480   CGBINDOPT(AlignLoops);
481 
482   static cl::opt<bool> JMCInstrument(
483       "enable-jmc-instrument",
484       cl::desc("Instrument functions with a call to __CheckForDebuggerJustMyCode"),
485       cl::init(false));
486   CGBINDOPT(JMCInstrument);
487 
488 #undef CGBINDOPT
489 
490   mc::RegisterMCTargetOptionsFlags();
491 }
492 
493 llvm::BasicBlockSection
getBBSectionsMode(llvm::TargetOptions & Options)494 codegen::getBBSectionsMode(llvm::TargetOptions &Options) {
495   if (getBBSections() == "all")
496     return BasicBlockSection::All;
497   else if (getBBSections() == "labels")
498     return BasicBlockSection::Labels;
499   else if (getBBSections() == "none")
500     return BasicBlockSection::None;
501   else {
502     ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
503         MemoryBuffer::getFile(getBBSections());
504     if (!MBOrErr) {
505       errs() << "Error loading basic block sections function list file: "
506              << MBOrErr.getError().message() << "\n";
507     } else {
508       Options.BBSectionsFuncListBuf = std::move(*MBOrErr);
509     }
510     return BasicBlockSection::List;
511   }
512 }
513 
514 // Common utility function tightly tied to the options listed here. Initializes
515 // a TargetOptions object with CodeGen flags and returns it.
516 TargetOptions
InitTargetOptionsFromCodeGenFlags(const Triple & TheTriple)517 codegen::InitTargetOptionsFromCodeGenFlags(const Triple &TheTriple) {
518   TargetOptions Options;
519   Options.AllowFPOpFusion = getFuseFPOps();
520   Options.UnsafeFPMath = getEnableUnsafeFPMath();
521   Options.NoInfsFPMath = getEnableNoInfsFPMath();
522   Options.NoNaNsFPMath = getEnableNoNaNsFPMath();
523   Options.NoSignedZerosFPMath = getEnableNoSignedZerosFPMath();
524   Options.ApproxFuncFPMath = getEnableApproxFuncFPMath();
525   Options.NoTrappingFPMath = getEnableNoTrappingFPMath();
526 
527   DenormalMode::DenormalModeKind DenormKind = getDenormalFPMath();
528 
529   // FIXME: Should have separate input and output flags
530   Options.setFPDenormalMode(DenormalMode(DenormKind, DenormKind));
531 
532   Options.HonorSignDependentRoundingFPMathOption =
533       getEnableHonorSignDependentRoundingFPMath();
534   if (getFloatABIForCalls() != FloatABI::Default)
535     Options.FloatABIType = getFloatABIForCalls();
536   Options.EnableAIXExtendedAltivecABI = getEnableAIXExtendedAltivecABI();
537   Options.NoZerosInBSS = getDontPlaceZerosInBSS();
538   Options.GuaranteedTailCallOpt = getEnableGuaranteedTailCallOpt();
539   Options.StackSymbolOrdering = getStackSymbolOrdering();
540   Options.UseInitArray = !getUseCtors();
541   Options.LowerGlobalDtorsViaCxaAtExit = getLowerGlobalDtorsViaCxaAtExit();
542   Options.RelaxELFRelocations = getRelaxELFRelocations();
543   Options.DataSections =
544       getExplicitDataSections().value_or(TheTriple.hasDefaultDataSections());
545   Options.FunctionSections = getFunctionSections();
546   Options.IgnoreXCOFFVisibility = getIgnoreXCOFFVisibility();
547   Options.XCOFFTracebackTable = getXCOFFTracebackTable();
548   Options.BBSections = getBBSectionsMode(Options);
549   Options.UniqueSectionNames = getUniqueSectionNames();
550   Options.UniqueBasicBlockSectionNames = getUniqueBasicBlockSectionNames();
551   Options.TLSSize = getTLSSize();
552   Options.EmulatedTLS = getEmulatedTLS();
553   Options.ExplicitEmulatedTLS = EmulatedTLSView->getNumOccurrences() > 0;
554   Options.ExceptionModel = getExceptionModel();
555   Options.EmitStackSizeSection = getEnableStackSizeSection();
556   Options.EnableMachineFunctionSplitter = getEnableMachineFunctionSplitter();
557   Options.EmitAddrsig = getEnableAddrsig();
558   Options.EmitCallSiteInfo = getEmitCallSiteInfo();
559   Options.EnableDebugEntryValues = getEnableDebugEntryValues();
560   Options.ForceDwarfFrameSection = getForceDwarfFrameSection();
561   Options.XRayOmitFunctionIndex = getXRayOmitFunctionIndex();
562   Options.DebugStrictDwarf = getDebugStrictDwarf();
563   Options.LoopAlignment = getAlignLoops();
564   Options.JMCInstrument = getJMCInstrument();
565 
566   Options.MCOptions = mc::InitMCTargetOptionsFromFlags();
567 
568   Options.ThreadModel = getThreadModel();
569   Options.EABIVersion = getEABIVersion();
570   Options.DebuggerTuning = getDebuggerTuningOpt();
571   Options.SwiftAsyncFramePointer = getSwiftAsyncFramePointer();
572   return Options;
573 }
574 
getCPUStr()575 std::string codegen::getCPUStr() {
576   // If user asked for the 'native' CPU, autodetect here. If autodection fails,
577   // this will set the CPU to an empty string which tells the target to
578   // pick a basic default.
579   if (getMCPU() == "native")
580     return std::string(sys::getHostCPUName());
581 
582   return getMCPU();
583 }
584 
getFeaturesStr()585 std::string codegen::getFeaturesStr() {
586   SubtargetFeatures Features;
587 
588   // If user asked for the 'native' CPU, we need to autodetect features.
589   // This is necessary for x86 where the CPU might not support all the
590   // features the autodetected CPU name lists in the target. For example,
591   // not all Sandybridge processors support AVX.
592   if (getMCPU() == "native") {
593     StringMap<bool> HostFeatures;
594     if (sys::getHostCPUFeatures(HostFeatures))
595       for (const auto &[Feature, IsEnabled] : HostFeatures)
596         Features.AddFeature(Feature, IsEnabled);
597   }
598 
599   for (auto const &MAttr : getMAttrs())
600     Features.AddFeature(MAttr);
601 
602   return Features.getString();
603 }
604 
getFeatureList()605 std::vector<std::string> codegen::getFeatureList() {
606   SubtargetFeatures Features;
607 
608   // If user asked for the 'native' CPU, we need to autodetect features.
609   // This is necessary for x86 where the CPU might not support all the
610   // features the autodetected CPU name lists in the target. For example,
611   // not all Sandybridge processors support AVX.
612   if (getMCPU() == "native") {
613     StringMap<bool> HostFeatures;
614     if (sys::getHostCPUFeatures(HostFeatures))
615       for (const auto &[Feature, IsEnabled] : HostFeatures)
616         Features.AddFeature(Feature, IsEnabled);
617   }
618 
619   for (auto const &MAttr : getMAttrs())
620     Features.AddFeature(MAttr);
621 
622   return Features.getFeatures();
623 }
624 
renderBoolStringAttr(AttrBuilder & B,StringRef Name,bool Val)625 void codegen::renderBoolStringAttr(AttrBuilder &B, StringRef Name, bool Val) {
626   B.addAttribute(Name, Val ? "true" : "false");
627 }
628 
629 #define HANDLE_BOOL_ATTR(CL, AttrName)                                         \
630   do {                                                                         \
631     if (CL->getNumOccurrences() > 0 && !F.hasFnAttribute(AttrName))            \
632       renderBoolStringAttr(NewAttrs, AttrName, *CL);                           \
633   } while (0)
634 
635 /// Set function attributes of function \p F based on CPU, Features, and command
636 /// line flags.
setFunctionAttributes(StringRef CPU,StringRef Features,Function & F)637 void codegen::setFunctionAttributes(StringRef CPU, StringRef Features,
638                                     Function &F) {
639   auto &Ctx = F.getContext();
640   AttributeList Attrs = F.getAttributes();
641   AttrBuilder NewAttrs(Ctx);
642 
643   if (!CPU.empty() && !F.hasFnAttribute("target-cpu"))
644     NewAttrs.addAttribute("target-cpu", CPU);
645   if (!Features.empty()) {
646     // Append the command line features to any that are already on the function.
647     StringRef OldFeatures =
648         F.getFnAttribute("target-features").getValueAsString();
649     if (OldFeatures.empty())
650       NewAttrs.addAttribute("target-features", Features);
651     else {
652       SmallString<256> Appended(OldFeatures);
653       Appended.push_back(',');
654       Appended.append(Features);
655       NewAttrs.addAttribute("target-features", Appended);
656     }
657   }
658   if (FramePointerUsageView->getNumOccurrences() > 0 &&
659       !F.hasFnAttribute("frame-pointer")) {
660     if (getFramePointerUsage() == FramePointerKind::All)
661       NewAttrs.addAttribute("frame-pointer", "all");
662     else if (getFramePointerUsage() == FramePointerKind::NonLeaf)
663       NewAttrs.addAttribute("frame-pointer", "non-leaf");
664     else if (getFramePointerUsage() == FramePointerKind::None)
665       NewAttrs.addAttribute("frame-pointer", "none");
666   }
667   if (DisableTailCallsView->getNumOccurrences() > 0)
668     NewAttrs.addAttribute("disable-tail-calls",
669                           toStringRef(getDisableTailCalls()));
670   if (getStackRealign())
671     NewAttrs.addAttribute("stackrealign");
672 
673   HANDLE_BOOL_ATTR(EnableUnsafeFPMathView, "unsafe-fp-math");
674   HANDLE_BOOL_ATTR(EnableNoInfsFPMathView, "no-infs-fp-math");
675   HANDLE_BOOL_ATTR(EnableNoNaNsFPMathView, "no-nans-fp-math");
676   HANDLE_BOOL_ATTR(EnableNoSignedZerosFPMathView, "no-signed-zeros-fp-math");
677   HANDLE_BOOL_ATTR(EnableApproxFuncFPMathView, "approx-func-fp-math");
678 
679   if (DenormalFPMathView->getNumOccurrences() > 0 &&
680       !F.hasFnAttribute("denormal-fp-math")) {
681     DenormalMode::DenormalModeKind DenormKind = getDenormalFPMath();
682 
683     // FIXME: Command line flag should expose separate input/output modes.
684     NewAttrs.addAttribute("denormal-fp-math",
685                           DenormalMode(DenormKind, DenormKind).str());
686   }
687 
688   if (DenormalFP32MathView->getNumOccurrences() > 0 &&
689       !F.hasFnAttribute("denormal-fp-math-f32")) {
690     // FIXME: Command line flag should expose separate input/output modes.
691     DenormalMode::DenormalModeKind DenormKind = getDenormalFP32Math();
692 
693     NewAttrs.addAttribute(
694       "denormal-fp-math-f32",
695       DenormalMode(DenormKind, DenormKind).str());
696   }
697 
698   if (TrapFuncNameView->getNumOccurrences() > 0)
699     for (auto &B : F)
700       for (auto &I : B)
701         if (auto *Call = dyn_cast<CallInst>(&I))
702           if (const auto *F = Call->getCalledFunction())
703             if (F->getIntrinsicID() == Intrinsic::debugtrap ||
704                 F->getIntrinsicID() == Intrinsic::trap)
705               Call->addFnAttr(
706                   Attribute::get(Ctx, "trap-func-name", getTrapFuncName()));
707 
708   // Let NewAttrs override Attrs.
709   F.setAttributes(Attrs.addFnAttributes(Ctx, NewAttrs));
710 }
711 
712 /// Set function attributes of functions in Module M based on CPU,
713 /// Features, and command line flags.
setFunctionAttributes(StringRef CPU,StringRef Features,Module & M)714 void codegen::setFunctionAttributes(StringRef CPU, StringRef Features,
715                                     Module &M) {
716   for (Function &F : M)
717     setFunctionAttributes(CPU, Features, F);
718 }
719