clang-tools  10.0.0git
SIMDIntrinsicsCheck.cpp
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1 //===--- SIMDIntrinsicsCheck.cpp - clang-tidy------------------------------===//
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 #include "SIMDIntrinsicsCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "llvm/ADT/StringMap.h"
13 #include "llvm/ADT/Triple.h"
14 #include "llvm/Support/Regex.h"
15 
16 using namespace clang::ast_matchers;
17 
18 namespace clang {
19 namespace tidy {
20 namespace portability {
21 
22 namespace {
23 
24 // If the callee has parameter of VectorType or pointer to VectorType,
25 // or the return type is VectorType, we consider it a vector function
26 // and a candidate for checking.
27 AST_MATCHER(FunctionDecl, isVectorFunction) {
28  bool IsVector = Node.getReturnType()->isVectorType();
29  for (const ParmVarDecl *Parm : Node.parameters()) {
30  QualType Type = Parm->getType();
31  if (Type->isPointerType())
32  Type = Type->getPointeeType();
33  if (Type->isVectorType())
34  IsVector = true;
35  }
36  return IsVector;
37 }
38 
39 } // namespace
40 
41 static StringRef TrySuggestPPC(StringRef Name) {
42  if (!Name.consume_front("vec_"))
43  return {};
44 
45  static const llvm::StringMap<StringRef> Mapping{
46  // [simd.alg]
47  {"max", "$std::max"},
48  {"min", "$std::min"},
49 
50  // [simd.binary]
51  {"add", "operator+ on $simd objects"},
52  {"sub", "operator- on $simd objects"},
53  {"mul", "operator* on $simd objects"},
54  };
55 
56  auto It = Mapping.find(Name);
57  if (It != Mapping.end())
58  return It->second;
59  return {};
60 }
61 
62 static StringRef TrySuggestX86(StringRef Name) {
63  if (!(Name.consume_front("_mm_") || Name.consume_front("_mm256_") ||
64  Name.consume_front("_mm512_")))
65  return {};
66 
67  // [simd.alg]
68  if (Name.startswith("max_"))
69  return "$simd::max";
70  if (Name.startswith("min_"))
71  return "$simd::min";
72 
73  // [simd.binary]
74  if (Name.startswith("add_"))
75  return "operator+ on $simd objects";
76  if (Name.startswith("sub_"))
77  return "operator- on $simd objects";
78  if (Name.startswith("mul_"))
79  return "operator* on $simd objects";
80 
81  return {};
82 }
83 
84 SIMDIntrinsicsCheck::SIMDIntrinsicsCheck(StringRef Name,
85  ClangTidyContext *Context)
86  : ClangTidyCheck(Name, Context), Std(Options.get("Std", "")),
87  Suggest(Options.get("Suggest", 0) != 0) {}
88 
90  Options.store(Opts, "Std", "");
91  Options.store(Opts, "Suggest", 0);
92 }
93 
94 void SIMDIntrinsicsCheck::registerMatchers(MatchFinder *Finder) {
95  if (!getLangOpts().CPlusPlus11)
96  return;
97  // If Std is not specified, infer it from the language options.
98  // libcxx implementation backports it to C++11 std::experimental::simd.
99  if (Std.empty())
100  Std = getLangOpts().CPlusPlus2a ? "std" : "std::experimental";
101 
102  Finder->addMatcher(callExpr(callee(functionDecl(
103  matchesName("^::(_mm_|_mm256_|_mm512_|vec_)"),
104  isVectorFunction())),
105  unless(isExpansionInSystemHeader()))
106  .bind("call"),
107  this);
108 }
109 
110 void SIMDIntrinsicsCheck::check(const MatchFinder::MatchResult &Result) {
111  const auto *Call = Result.Nodes.getNodeAs<CallExpr>("call");
112  assert(Call != nullptr);
113  const FunctionDecl *Callee = Call->getDirectCallee();
114  if (!Callee)
115  return;
116 
117  StringRef Old = Callee->getName();
118  StringRef New;
119  llvm::Triple::ArchType Arch =
120  Result.Context->getTargetInfo().getTriple().getArch();
121 
122  // We warn or suggest if this SIMD intrinsic function has a std::simd
123  // replacement.
124  switch (Arch) {
125  default:
126  break;
127  case llvm::Triple::ppc:
128  case llvm::Triple::ppc64:
129  case llvm::Triple::ppc64le:
130  New = TrySuggestPPC(Old);
131  break;
132  case llvm::Triple::x86:
133  case llvm::Triple::x86_64:
134  New = TrySuggestX86(Old);
135  break;
136  }
137 
138  // We have found a std::simd replacement.
139  if (!New.empty()) {
140  std::string Message;
141  // If Suggest is true, give a P0214 alternative, otherwise point it out it
142  // is non-portable.
143  if (Suggest) {
144  Message = (Twine("'") + Old + "' can be replaced by " + New).str();
145  Message = llvm::Regex("\\$std").sub(Std, Message);
146  Message =
147  llvm::Regex("\\$simd").sub((Std.str() + "::simd").str(), Message);
148  } else {
149  Message = (Twine("'") + Old + "' is a non-portable " +
150  llvm::Triple::getArchTypeName(Arch) + " intrinsic function")
151  .str();
152  }
153  diag(Call->getExprLoc(), Message);
154  }
155 }
156 
157 } // namespace portability
158 } // namespace tidy
159 } // namespace clang
constexpr llvm::StringLiteral Message
Base class for all clang-tidy checks.
const LangOptions & getLangOpts() const
Returns the language options from the context.
static StringRef TrySuggestX86(StringRef Name)
void store(ClangTidyOptions::OptionMap &Options, StringRef LocalName, StringRef Value) const
Stores an option with the check-local name LocalName with string value Value to Options.
static constexpr llvm::StringLiteral Name
std::map< std::string, std::string > OptionMap
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
static StringRef TrySuggestPPC(StringRef Name)
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
void storeOptions(ClangTidyOptions::OptionMap &Opts) override
Should store all options supported by this check with their current values or default values for opti...
NodeType Type
DiagnosticBuilder diag(SourceLocation Loc, StringRef Description, DiagnosticIDs::Level Level=DiagnosticIDs::Warning)
Add a diagnostic with the check&#39;s name.