clang-tools  14.0.0git
UnrollLoopsCheck.h
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1 //===--- UnrollLoopsCheck.h - clang-tidy ------------------------*- 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 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_UNROLLLOOPSCHECK_H
10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_UNROLLLOOPSCHECK_H
11 
12 #include "../ClangTidyCheck.h"
13 
14 namespace clang {
15 namespace tidy {
16 namespace altera {
17 
18 /// Finds inner loops that have not been unrolled, as well as fully unrolled
19 /// loops with unknown loop bounds or a large number of iterations.
20 ///
21 /// Unrolling inner loops could improve the performance of OpenCL kernels.
22 /// However, if they have unknown loop bounds or a large number of iterations,
23 /// they cannot be fully unrolled, and should be partially unrolled.
24 ///
25 /// For the user-facing documentation see:
26 /// http://clang.llvm.org/extra/clang-tidy/checks/altera-unroll-loops.html
28 public:
29  UnrollLoopsCheck(StringRef Name, ClangTidyContext *Context);
30  void registerMatchers(ast_matchers::MatchFinder *Finder) override;
31  void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
32 
33 private:
34  /// Recommend partial unrolling if number of loop iterations is greater than
35  /// MaxLoopIterations.
36  const unsigned MaxLoopIterations;
37  /// The kind of unrolling, if any, applied to a given loop.
38  enum UnrollType {
39  // This loop has no #pragma unroll directive associated with it.
40  NotUnrolled,
41  // This loop has a #pragma unroll directive associated with it.
42  FullyUnrolled,
43  // This loop has a #pragma unroll <num> directive associated with it.
44  PartiallyUnrolled
45  };
46  /// Attempts to extract an integer value from either side of the
47  /// BinaryOperator. Returns true and saves the result to &value if successful,
48  /// returns false otherwise.
49  bool extractValue(int &Value, const BinaryOperator *Op,
50  const ASTContext *Context);
51  /// Returns true if the given loop statement has a large number of iterations,
52  /// as determined by the integer value in the loop's condition expression,
53  /// if one exists.
54  bool hasLargeNumIterations(const Stmt *Statement,
55  const IntegerLiteral *CXXLoopBound,
56  const ASTContext *Context);
57  /// Checks one hand side of the binary operator to ascertain if the upper
58  /// bound on the number of loops is greater than max_loop_iterations or not.
59  /// If the expression is not evaluatable or not an integer, returns false.
60  bool exprHasLargeNumIterations(const Expr *Expression,
61  const ASTContext *Context);
62  /// Returns the type of unrolling, if any, associated with the given
63  /// statement.
64  enum UnrollType unrollType(const Stmt *Statement, ASTContext *Context);
65  /// Returns the condition expression within a given for statement. If there is
66  /// none, or if the Statement is not a loop, then returns a NULL pointer.
67  const Expr *getCondExpr(const Stmt *Statement);
68  /// Returns True if the loop statement has known bounds.
69  bool hasKnownBounds(const Stmt *Statement, const IntegerLiteral *CXXLoopBound,
70  const ASTContext *Context);
71  void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
72 };
73 
74 } // namespace altera
75 } // namespace tidy
76 } // namespace clang
77 
78 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_UNROLLLOOPSCHECK_H
clang::tidy::ClangTidyOptions::OptionMap
llvm::StringMap< ClangTidyValue > OptionMap
Definition: ClangTidyOptions.h:115
clang::tidy::altera::UnrollLoopsCheck::registerMatchers
void registerMatchers(ast_matchers::MatchFinder *Finder) override
Override this to register AST matchers with Finder.
Definition: UnrollLoopsCheck.cpp:28
clang::tidy::ClangTidyCheck
Base class for all clang-tidy checks.
Definition: ClangTidyCheck.h:54
clang::tidy::altera::UnrollLoopsCheck::UnrollLoopsCheck
UnrollLoopsCheck(StringRef Name, ClangTidyContext *Context)
Definition: UnrollLoopsCheck.cpp:24
clang::tidy::ClangTidyContext
Every ClangTidyCheck reports errors through a DiagnosticsEngine provided by this context.
Definition: ClangTidyDiagnosticConsumer.h:72
Name
static constexpr llvm::StringLiteral Name
Definition: UppercaseLiteralSuffixCheck.cpp:28
clang::tidy::altera::UnrollLoopsCheck::check
void check(const ast_matchers::MatchFinder::MatchResult &Result) override
ClangTidyChecks that register ASTMatchers should do the actual work in here.
Definition: UnrollLoopsCheck.cpp:40
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
clang::tidy::altera::UnrollLoopsCheck
Finds inner loops that have not been unrolled, as well as fully unrolled loops with unknown loop boun...
Definition: UnrollLoopsCheck.h:27