xref: /freebsd/contrib/llvm-project/llvm/lib/Frontend/OpenMP/OMPContext.cpp (revision a7623790fb345e6dc986dfd31df0ace115e6f2e4)
1 //===- OMPContext.cpp ------ Collection of helpers for OpenMP contexts ----===//
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 /// \file
9 ///
10 /// This file implements helper functions and classes to deal with OpenMP
11 /// contexts as used by `[begin/end] declare variant` and `metadirective`.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/Frontend/OpenMP/OMPContext.h"
16 #include "llvm/ADT/SetOperations.h"
17 #include "llvm/ADT/StringSwitch.h"
18 #include "llvm/Support/Debug.h"
19 #include "llvm/Support/raw_ostream.h"
20 
21 #define DEBUG_TYPE "openmp-ir-builder"
22 
23 using namespace llvm;
24 using namespace omp;
25 
26 OMPContext::OMPContext(bool IsDeviceCompilation, Triple TargetTriple) {
27   // Add the appropriate device kind trait based on the triple and the
28   // IsDeviceCompilation flag.
29   ActiveTraits.set(unsigned(IsDeviceCompilation
30                                 ? TraitProperty::device_kind_nohost
31                                 : TraitProperty::device_kind_host));
32   switch (TargetTriple.getArch()) {
33   case Triple::arm:
34   case Triple::armeb:
35   case Triple::aarch64:
36   case Triple::aarch64_be:
37   case Triple::aarch64_32:
38   case Triple::mips:
39   case Triple::mipsel:
40   case Triple::mips64:
41   case Triple::mips64el:
42   case Triple::ppc:
43   case Triple::ppc64:
44   case Triple::ppc64le:
45   case Triple::x86:
46   case Triple::x86_64:
47     ActiveTraits.set(unsigned(TraitProperty::device_kind_cpu));
48     break;
49   case Triple::amdgcn:
50   case Triple::nvptx:
51   case Triple::nvptx64:
52     ActiveTraits.set(unsigned(TraitProperty::device_kind_gpu));
53     break;
54   default:
55     break;
56   }
57 
58   // Add the appropriate device architecture trait based on the triple.
59 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
60   if (TraitSelector::TraitSelectorEnum == TraitSelector::device_arch)          \
61     if (TargetTriple.getArch() == TargetTriple.getArchTypeForLLVMName(Str))    \
62       ActiveTraits.set(unsigned(TraitProperty::Enum));
63 #include "llvm/Frontend/OpenMP/OMPKinds.def"
64 
65   // TODO: What exactly do we want to see as device ISA trait?
66   //       The discussion on the list did not seem to have come to an agreed
67   //       upon solution.
68 
69   // LLVM is the "OpenMP vendor" but we could also interpret vendor as the
70   // target vendor.
71   ActiveTraits.set(unsigned(TraitProperty::implementation_vendor_llvm));
72 
73   // The user condition true is accepted but not false.
74   ActiveTraits.set(unsigned(TraitProperty::user_condition_true));
75 
76   // This is for sure some device.
77   ActiveTraits.set(unsigned(TraitProperty::device_kind_any));
78 
79   LLVM_DEBUG({
80     dbgs() << "[" << DEBUG_TYPE
81            << "] New OpenMP context with the following properties:\n";
82     for (unsigned Bit : ActiveTraits.set_bits()) {
83       TraitProperty Property = TraitProperty(Bit);
84       dbgs() << "\t " << getOpenMPContextTraitPropertyFullName(Property)
85              << "\n";
86     }
87   });
88 }
89 
90 /// Return true if \p C0 is a subset of \p C1. Note that both arrays are
91 /// expected to be sorted.
92 template <typename T> static bool isSubset(ArrayRef<T> C0, ArrayRef<T> C1) {
93 #ifdef EXPENSIVE_CHECKS
94   assert(llvm::is_sorted(C0) && llvm::is_sorted(C1) &&
95          "Expected sorted arrays!");
96 #endif
97   if (C0.size() > C1.size())
98     return false;
99   auto It0 = C0.begin(), End0 = C0.end();
100   auto It1 = C1.begin(), End1 = C1.end();
101   while (It0 != End0) {
102     if (It1 == End1)
103       return false;
104     if (*It0 == *It1) {
105       ++It0;
106       ++It1;
107       continue;
108     }
109     ++It0;
110   }
111   return true;
112 }
113 
114 /// Return true if \p C0 is a strict subset of \p C1. Note that both arrays are
115 /// expected to be sorted.
116 template <typename T>
117 static bool isStrictSubset(ArrayRef<T> C0, ArrayRef<T> C1) {
118   if (C0.size() >= C1.size())
119     return false;
120   return isSubset<T>(C0, C1);
121 }
122 
123 static bool isStrictSubset(const VariantMatchInfo &VMI0,
124                            const VariantMatchInfo &VMI1) {
125   // If all required traits are a strict subset and the ordered vectors storing
126   // the construct traits, we say it is a strict subset. Note that the latter
127   // relation is not required to be strict.
128   if (VMI0.RequiredTraits.count() >= VMI1.RequiredTraits.count())
129     return false;
130   for (unsigned Bit : VMI0.RequiredTraits.set_bits())
131     if (!VMI1.RequiredTraits.test(Bit))
132       return false;
133   if (!isSubset<TraitProperty>(VMI0.ConstructTraits, VMI1.ConstructTraits))
134     return false;
135   return true;
136 }
137 
138 static int isVariantApplicableInContextHelper(
139     const VariantMatchInfo &VMI, const OMPContext &Ctx,
140     SmallVectorImpl<unsigned> *ConstructMatches, bool DeviceSetOnly) {
141 
142   // The match kind determines if we need to match all traits, any of the
143   // traits, or none of the traits for it to be an applicable context.
144   enum MatchKind { MK_ALL, MK_ANY, MK_NONE };
145 
146   MatchKind MK = MK_ALL;
147   // Determine the match kind the user wants, "all" is the default and provided
148   // to the user only for completeness.
149   if (VMI.RequiredTraits.test(
150           unsigned(TraitProperty::implementation_extension_match_any)))
151     MK = MK_ANY;
152   if (VMI.RequiredTraits.test(
153           unsigned(TraitProperty::implementation_extension_match_none)))
154     MK = MK_NONE;
155 
156   // Helper to deal with a single property that was (not) found in the OpenMP
157   // context based on the match kind selected by the user via
158   // `implementation={extensions(match_[all,any,none])}'
159   auto HandleTrait = [MK](TraitProperty Property,
160                           bool WasFound) -> Optional<bool> /* Result */ {
161     // For kind "any" a single match is enough but we ignore non-matched
162     // properties.
163     if (MK == MK_ANY) {
164       if (WasFound)
165         return true;
166       return None;
167     }
168 
169     // In "all" or "none" mode we accept a matching or non-matching property
170     // respectively and move on. We are not done yet!
171     if ((WasFound && MK == MK_ALL) || (!WasFound && MK == MK_NONE))
172       return None;
173 
174     // We missed a property, provide some debug output and indicate failure.
175     LLVM_DEBUG({
176       if (MK == MK_ALL)
177         dbgs() << "[" << DEBUG_TYPE << "] Property "
178                << getOpenMPContextTraitPropertyName(Property)
179                << " was not in the OpenMP context but match kind is all.\n";
180       if (MK == MK_NONE)
181         dbgs() << "[" << DEBUG_TYPE << "] Property "
182                << getOpenMPContextTraitPropertyName(Property)
183                << " was in the OpenMP context but match kind is none.\n";
184     });
185     return false;
186   };
187 
188   for (unsigned Bit : VMI.RequiredTraits.set_bits()) {
189     TraitProperty Property = TraitProperty(Bit);
190     if (DeviceSetOnly &&
191         getOpenMPContextTraitSetForProperty(Property) != TraitSet::device)
192       continue;
193 
194     // So far all extensions are handled elsewhere, we skip them here as they
195     // are not part of the OpenMP context.
196     if (getOpenMPContextTraitSelectorForProperty(Property) ==
197         TraitSelector::implementation_extension)
198       continue;
199 
200     bool IsActiveTrait = Ctx.ActiveTraits.test(unsigned(Property));
201     Optional<bool> Result = HandleTrait(Property, IsActiveTrait);
202     if (Result.hasValue())
203       return Result.getValue();
204   }
205 
206   if (!DeviceSetOnly) {
207     // We could use isSubset here but we also want to record the match
208     // locations.
209     unsigned ConstructIdx = 0, NoConstructTraits = Ctx.ConstructTraits.size();
210     for (TraitProperty Property : VMI.ConstructTraits) {
211       assert(getOpenMPContextTraitSetForProperty(Property) ==
212                  TraitSet::construct &&
213              "Variant context is ill-formed!");
214 
215       // Verify the nesting.
216       bool FoundInOrder = false;
217       while (!FoundInOrder && ConstructIdx != NoConstructTraits)
218         FoundInOrder = (Ctx.ConstructTraits[ConstructIdx++] == Property);
219       if (ConstructMatches)
220         ConstructMatches->push_back(ConstructIdx - 1);
221 
222       Optional<bool> Result = HandleTrait(Property, FoundInOrder);
223       if (Result.hasValue())
224         return Result.getValue();
225 
226       if (!FoundInOrder) {
227         LLVM_DEBUG(dbgs() << "[" << DEBUG_TYPE << "] Construct property "
228                           << getOpenMPContextTraitPropertyName(Property)
229                           << " was not nested properly.\n");
230         return false;
231       }
232 
233       // TODO: Verify SIMD
234     }
235 
236     assert(isSubset<TraitProperty>(VMI.ConstructTraits, Ctx.ConstructTraits) &&
237            "Broken invariant!");
238   }
239 
240   if (MK == MK_ANY) {
241     LLVM_DEBUG(dbgs() << "[" << DEBUG_TYPE
242                       << "] None of the properties was in the OpenMP context "
243                          "but match kind is any.\n");
244     return false;
245   }
246 
247   return true;
248 }
249 
250 bool llvm::omp::isVariantApplicableInContext(const VariantMatchInfo &VMI,
251                                              const OMPContext &Ctx,
252                                              bool DeviceSetOnly) {
253   return isVariantApplicableInContextHelper(
254       VMI, Ctx, /* ConstructMatches */ nullptr, DeviceSetOnly);
255 }
256 
257 static APInt getVariantMatchScore(const VariantMatchInfo &VMI,
258                                   const OMPContext &Ctx,
259                                   SmallVectorImpl<unsigned> &ConstructMatches) {
260   APInt Score(64, 1);
261 
262   unsigned NoConstructTraits = VMI.ConstructTraits.size();
263   for (unsigned Bit : VMI.RequiredTraits.set_bits()) {
264     TraitProperty Property = TraitProperty(Bit);
265     // If there is a user score attached, use it.
266     if (VMI.ScoreMap.count(Property)) {
267       const APInt &UserScore = VMI.ScoreMap.lookup(Property);
268       assert(UserScore.uge(0) && "Expect non-negative user scores!");
269       Score += UserScore.getZExtValue();
270       continue;
271     }
272 
273     switch (getOpenMPContextTraitSetForProperty(Property)) {
274     case TraitSet::construct:
275       // We handle the construct traits later via the VMI.ConstructTraits
276       // container.
277       continue;
278     case TraitSet::implementation:
279       // No effect on the score (implementation defined).
280       continue;
281     case TraitSet::user:
282       // No effect on the score.
283       continue;
284     case TraitSet::device:
285       // Handled separately below.
286       break;
287     case TraitSet::invalid:
288       llvm_unreachable("Unknown trait set is not to be used!");
289     }
290 
291     // device={kind(any)} is "as if" no kind selector was specified.
292     if (Property == TraitProperty::device_kind_any)
293       continue;
294 
295     switch (getOpenMPContextTraitSelectorForProperty(Property)) {
296     case TraitSelector::device_kind:
297       Score += (1ULL << (NoConstructTraits + 0));
298       continue;
299     case TraitSelector::device_arch:
300       Score += (1ULL << (NoConstructTraits + 1));
301       continue;
302     case TraitSelector::device_isa:
303       Score += (1ULL << (NoConstructTraits + 2));
304       continue;
305     default:
306       continue;
307     }
308   }
309 
310   unsigned ConstructIdx = 0;
311   assert(NoConstructTraits == ConstructMatches.size() &&
312          "Mismatch in the construct traits!");
313   for (TraitProperty Property : VMI.ConstructTraits) {
314     assert(getOpenMPContextTraitSetForProperty(Property) ==
315                TraitSet::construct &&
316            "Ill-formed variant match info!");
317     (void)Property;
318     // ConstructMatches is the position p - 1 and we need 2^(p-1).
319     Score += (1ULL << ConstructMatches[ConstructIdx++]);
320   }
321 
322   LLVM_DEBUG(dbgs() << "[" << DEBUG_TYPE << "] Variant has a score of " << Score
323                     << "\n");
324   return Score;
325 }
326 
327 int llvm::omp::getBestVariantMatchForContext(
328     const SmallVectorImpl<VariantMatchInfo> &VMIs, const OMPContext &Ctx) {
329 
330   APInt BestScore(64, 0);
331   int BestVMIIdx = -1;
332   const VariantMatchInfo *BestVMI = nullptr;
333 
334   for (unsigned u = 0, e = VMIs.size(); u < e; ++u) {
335     const VariantMatchInfo &VMI = VMIs[u];
336 
337     SmallVector<unsigned, 8> ConstructMatches;
338     // If the variant is not applicable its not the best.
339     if (!isVariantApplicableInContextHelper(VMI, Ctx, &ConstructMatches,
340                                             /* DeviceSetOnly */ false))
341       continue;
342     // Check if its clearly not the best.
343     APInt Score = getVariantMatchScore(VMI, Ctx, ConstructMatches);
344     if (Score.ult(BestScore))
345       continue;
346     // Equal score need subset checks.
347     if (Score.eq(BestScore)) {
348       // Strict subset are never best.
349       if (isStrictSubset(VMI, *BestVMI))
350         continue;
351       // Same score and the current best is no strict subset so we keep it.
352       if (!isStrictSubset(*BestVMI, VMI))
353         continue;
354     }
355     // New best found.
356     BestVMI = &VMI;
357     BestVMIIdx = u;
358     BestScore = Score;
359   }
360 
361   return BestVMIIdx;
362 }
363 
364 TraitSet llvm::omp::getOpenMPContextTraitSetKind(StringRef S) {
365   return StringSwitch<TraitSet>(S)
366 #define OMP_TRAIT_SET(Enum, Str) .Case(Str, TraitSet::Enum)
367 #include "llvm/Frontend/OpenMP/OMPKinds.def"
368       .Default(TraitSet::invalid);
369 }
370 
371 TraitSet
372 llvm::omp::getOpenMPContextTraitSetForSelector(TraitSelector Selector) {
373   switch (Selector) {
374 #define OMP_TRAIT_SELECTOR(Enum, TraitSetEnum, Str, ReqProp)                   \
375   case TraitSelector::Enum:                                                    \
376     return TraitSet::TraitSetEnum;
377 #include "llvm/Frontend/OpenMP/OMPKinds.def"
378   }
379   llvm_unreachable("Unknown trait selector!");
380 }
381 TraitSet
382 llvm::omp::getOpenMPContextTraitSetForProperty(TraitProperty Property) {
383   switch (Property) {
384 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
385   case TraitProperty::Enum:                                                    \
386     return TraitSet::TraitSetEnum;
387 #include "llvm/Frontend/OpenMP/OMPKinds.def"
388   }
389   llvm_unreachable("Unknown trait set!");
390 }
391 StringRef llvm::omp::getOpenMPContextTraitSetName(TraitSet Kind) {
392   switch (Kind) {
393 #define OMP_TRAIT_SET(Enum, Str)                                               \
394   case TraitSet::Enum:                                                         \
395     return Str;
396 #include "llvm/Frontend/OpenMP/OMPKinds.def"
397   }
398   llvm_unreachable("Unknown trait set!");
399 }
400 
401 TraitSelector llvm::omp::getOpenMPContextTraitSelectorKind(StringRef S) {
402   return StringSwitch<TraitSelector>(S)
403 #define OMP_TRAIT_SELECTOR(Enum, TraitSetEnum, Str, ReqProp)                   \
404   .Case(Str, TraitSelector::Enum)
405 #include "llvm/Frontend/OpenMP/OMPKinds.def"
406       .Default(TraitSelector::invalid);
407 }
408 TraitSelector
409 llvm::omp::getOpenMPContextTraitSelectorForProperty(TraitProperty Property) {
410   switch (Property) {
411 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
412   case TraitProperty::Enum:                                                    \
413     return TraitSelector::TraitSelectorEnum;
414 #include "llvm/Frontend/OpenMP/OMPKinds.def"
415   }
416   llvm_unreachable("Unknown trait set!");
417 }
418 StringRef llvm::omp::getOpenMPContextTraitSelectorName(TraitSelector Kind) {
419   switch (Kind) {
420 #define OMP_TRAIT_SELECTOR(Enum, TraitSetEnum, Str, ReqProp)                   \
421   case TraitSelector::Enum:                                                    \
422     return Str;
423 #include "llvm/Frontend/OpenMP/OMPKinds.def"
424   }
425   llvm_unreachable("Unknown trait selector!");
426 }
427 
428 TraitProperty llvm::omp::getOpenMPContextTraitPropertyKind(TraitSet Set,
429                                                            StringRef S) {
430 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
431   if (Set == TraitSet::TraitSetEnum && Str == S)                               \
432     return TraitProperty::Enum;
433 #include "llvm/Frontend/OpenMP/OMPKinds.def"
434   return TraitProperty::invalid;
435 }
436 TraitProperty
437 llvm::omp::getOpenMPContextTraitPropertyForSelector(TraitSelector Selector) {
438   return StringSwitch<TraitProperty>(
439              getOpenMPContextTraitSelectorName(Selector))
440 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
441   .Case(Str, Selector == TraitSelector::TraitSelectorEnum                      \
442                  ? TraitProperty::Enum                                         \
443                  : TraitProperty::invalid)
444 #include "llvm/Frontend/OpenMP/OMPKinds.def"
445       .Default(TraitProperty::invalid);
446 }
447 StringRef llvm::omp::getOpenMPContextTraitPropertyName(TraitProperty Kind) {
448   switch (Kind) {
449 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
450   case TraitProperty::Enum:                                                    \
451     return Str;
452 #include "llvm/Frontend/OpenMP/OMPKinds.def"
453   }
454   llvm_unreachable("Unknown trait property!");
455 }
456 StringRef llvm::omp::getOpenMPContextTraitPropertyFullName(TraitProperty Kind) {
457   switch (Kind) {
458 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
459   case TraitProperty::Enum:                                                    \
460     return "(" #TraitSetEnum "," #TraitSelectorEnum "," Str ")";
461 #include "llvm/Frontend/OpenMP/OMPKinds.def"
462   }
463   llvm_unreachable("Unknown trait property!");
464 }
465 
466 bool llvm::omp::isValidTraitSelectorForTraitSet(TraitSelector Selector,
467                                                 TraitSet Set,
468                                                 bool &AllowsTraitScore,
469                                                 bool &RequiresProperty) {
470   AllowsTraitScore = Set != TraitSet::construct && Set != TraitSet::device;
471   switch (Selector) {
472 #define OMP_TRAIT_SELECTOR(Enum, TraitSetEnum, Str, ReqProp)                   \
473   case TraitSelector::Enum:                                                    \
474     RequiresProperty = ReqProp;                                                \
475     return Set == TraitSet::TraitSetEnum;
476 #include "llvm/Frontend/OpenMP/OMPKinds.def"
477   }
478   llvm_unreachable("Unknown trait selector!");
479 }
480 
481 bool llvm::omp::isValidTraitPropertyForTraitSetAndSelector(
482     TraitProperty Property, TraitSelector Selector, TraitSet Set) {
483   switch (Property) {
484 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
485   case TraitProperty::Enum:                                                    \
486     return Set == TraitSet::TraitSetEnum &&                                    \
487            Selector == TraitSelector::TraitSelectorEnum;
488 #include "llvm/Frontend/OpenMP/OMPKinds.def"
489   }
490   llvm_unreachable("Unknown trait property!");
491 }
492 
493 std::string llvm::omp::listOpenMPContextTraitSets() {
494   std::string S;
495 #define OMP_TRAIT_SET(Enum, Str)                                               \
496   if (StringRef(Str) != "invalid")                                             \
497     S.append("'").append(Str).append("'").append(" ");
498 #include "llvm/Frontend/OpenMP/OMPKinds.def"
499   S.pop_back();
500   return S;
501 }
502 
503 std::string llvm::omp::listOpenMPContextTraitSelectors(TraitSet Set) {
504   std::string S;
505 #define OMP_TRAIT_SELECTOR(Enum, TraitSetEnum, Str, ReqProp)                   \
506   if (TraitSet::TraitSetEnum == Set && StringRef(Str) != "Invalid")            \
507     S.append("'").append(Str).append("'").append(" ");
508 #include "llvm/Frontend/OpenMP/OMPKinds.def"
509   S.pop_back();
510   return S;
511 }
512 
513 std::string
514 llvm::omp::listOpenMPContextTraitProperties(TraitSet Set,
515                                             TraitSelector Selector) {
516   std::string S;
517 #define OMP_TRAIT_PROPERTY(Enum, TraitSetEnum, TraitSelectorEnum, Str)         \
518   if (TraitSet::TraitSetEnum == Set &&                                         \
519       TraitSelector::TraitSelectorEnum == Selector &&                          \
520       StringRef(Str) != "invalid")                                             \
521     S.append("'").append(Str).append("'").append(" ");
522 #include "llvm/Frontend/OpenMP/OMPKinds.def"
523   if (S.empty())
524     return "<none>";
525   S.pop_back();
526   return S;
527 }
528