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 "clang/Basic/TargetInfo.h"
13#include "llvm/Support/Regex.h"
14#include "llvm/TargetParser/Triple.h"
15
16using namespace clang::ast_matchers;
17
18namespace clang::tidy::portability {
19
20namespace {
21
22// If the callee has parameter of VectorType or pointer to VectorType,
23// or the return type is VectorType, we consider it a vector function
24// and a candidate for checking.
25AST_MATCHER(FunctionDecl, isVectorFunction) {
26 bool IsVector = Node.getReturnType()->isVectorType();
27 for (const ParmVarDecl *Parm : Node.parameters()) {
28 QualType Type = Parm->getType();
29 if (Type->isPointerType())
30 Type = Type->getPointeeType();
31 if (Type->isVectorType())
32 IsVector = true;
33 }
34 return IsVector;
35}
36
37} // namespace
38
39static StringRef trySuggestPpc(StringRef Name) {
40 if (!Name.consume_front(Prefix: "vec_"))
41 return {};
42
43 return llvm::StringSwitch<StringRef>(Name)
44 // [simd.alg]
45 .Case(S: "max", Value: "$std::max")
46 .Case(S: "min", Value: "$std::min")
47 // [simd.binary]
48 .Case(S: "add", Value: "operator+ on $simd objects")
49 .Case(S: "sub", Value: "operator- on $simd objects")
50 .Case(S: "mul", Value: "operator* on $simd objects")
51 .Default(Value: {});
52}
53
54static StringRef trySuggestX86(StringRef Name) {
55 if (!(Name.consume_front(Prefix: "_mm_") || Name.consume_front(Prefix: "_mm256_") ||
56 Name.consume_front(Prefix: "_mm512_")))
57 return {};
58
59 // [simd.alg]
60 if (Name.starts_with(Prefix: "max_"))
61 return "$simd::max";
62 if (Name.starts_with(Prefix: "min_"))
63 return "$simd::min";
64
65 // [simd.binary]
66 if (Name.starts_with(Prefix: "add_"))
67 return "operator+ on $simd objects";
68 if (Name.starts_with(Prefix: "sub_"))
69 return "operator- on $simd objects";
70 if (Name.starts_with(Prefix: "mul_"))
71 return "operator* on $simd objects";
72
73 return {};
74}
75
76SIMDIntrinsicsCheck::SIMDIntrinsicsCheck(StringRef Name,
77 ClangTidyContext *Context)
78 : ClangTidyCheck(Name, Context), Std(Options.get(LocalName: "Std", Default: "")),
79 Suggest(Options.get(LocalName: "Suggest", Default: false)) {}
80
81void SIMDIntrinsicsCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
82 Options.store(Options&: Opts, LocalName: "Std", Value: Std);
83 Options.store(Options&: Opts, LocalName: "Suggest", Value: Suggest);
84}
85
86void SIMDIntrinsicsCheck::registerMatchers(MatchFinder *Finder) {
87 // If Std is not specified, infer it from the language options.
88 // libcxx implementation backports it to C++11 std::experimental::simd.
89 if (Std.empty())
90 Std = getLangOpts().CPlusPlus20 ? "std" : "std::experimental";
91
92 Finder->addMatcher(NodeMatch: callExpr(callee(InnerMatcher: functionDecl(
93 matchesName(RegExp: "^::(_mm_|_mm256_|_mm512_|vec_)"),
94 isVectorFunction())),
95 unless(isExpansionInSystemHeader()))
96 .bind(ID: "call"),
97 Action: this);
98}
99
100void SIMDIntrinsicsCheck::check(const MatchFinder::MatchResult &Result) {
101 const auto *Call = Result.Nodes.getNodeAs<CallExpr>(ID: "call");
102 assert(Call != nullptr);
103 const FunctionDecl *Callee = Call->getDirectCallee();
104 if (!Callee)
105 return;
106
107 StringRef Old = Callee->getName();
108 StringRef New;
109 llvm::Triple::ArchType Arch =
110 Result.Context->getTargetInfo().getTriple().getArch();
111
112 // We warn or suggest if this SIMD intrinsic function has a std::simd
113 // replacement.
114 switch (Arch) {
115 default:
116 break;
117 case llvm::Triple::ppc:
118 case llvm::Triple::ppc64:
119 case llvm::Triple::ppc64le:
120 New = trySuggestPpc(Name: Old);
121 break;
122 case llvm::Triple::x86:
123 case llvm::Triple::x86_64:
124 New = trySuggestX86(Name: Old);
125 break;
126 }
127
128 // We have found a std::simd replacement.
129 if (!New.empty()) {
130 // If Suggest is true, give a P0214 alternative, otherwise point it out it
131 // is non-portable.
132 if (Suggest) {
133 static const llvm::Regex StdRegex("\\$std"), SimdRegex("\\$simd");
134 diag(Call->getExprLoc(), "'%0' can be replaced by %1")
135 << Old
136 << SimdRegex.sub(Repl: SmallString<32>({Std, "::simd"}),
137 String: StdRegex.sub(Repl: Std, String: New));
138 } else {
139 diag(Call->getExprLoc(), "'%0' is a non-portable %1 intrinsic function")
140 << Old << llvm::Triple::getArchTypeName(Kind: Arch);
141 }
142 }
143}
144
145} // namespace clang::tidy::portability
146

source code of clang-tools-extra/clang-tidy/portability/SIMDIntrinsicsCheck.cpp