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//===--- UnrollLoopsCheck.h - clang-tidy ------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_UNROLLLOOPSCHECK_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_UNROLLLOOPSCHECK_H
#include "../ClangTidyCheck.h"
namespace clang {
namespace tidy {
namespace altera {
/// Finds inner loops that have not been unrolled, as well as fully unrolled
/// loops with unknown loop bounds or a large number of iterations.
///
/// Unrolling inner loops could improve the performance of OpenCL kernels.
/// However, if they have unknown loop bounds or a large number of iterations,
/// they cannot be fully unrolled, and should be partially unrolled.
///
/// For the user-facing documentation see:
/// http://clang.llvm.org/extra/clang-tidy/checks/altera-unroll-loops.html
class UnrollLoopsCheck : public ClangTidyCheck {
public:
UnrollLoopsCheck(StringRef Name, ClangTidyContext *Context);
void registerMatchers(ast_matchers::MatchFinder *Finder) override;
void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
private:
/// Recommend partial unrolling if number of loop iterations is greater than
/// MaxLoopIterations.
const unsigned MaxLoopIterations;
/// The kind of unrolling, if any, applied to a given loop.
enum UnrollType {
// This loop has no #pragma unroll directive associated with it.
NotUnrolled,
// This loop has a #pragma unroll directive associated with it.
FullyUnrolled,
// This loop has a #pragma unroll <num> directive associated with it.
PartiallyUnrolled
};
/// Attempts to extract an integer value from either side of the
/// BinaryOperator. Returns true and saves the result to &value if successful,
/// returns false otherwise.
bool extractValue(int &Value, const BinaryOperator *Op,
const ASTContext *Context);
/// Returns true if the given loop statement has a large number of iterations,
/// as determined by the integer value in the loop's condition expression,
/// if one exists.
bool hasLargeNumIterations(const Stmt *Statement,
const IntegerLiteral *CXXLoopBound,
const ASTContext *Context);
/// Checks one hand side of the binary operator to ascertain if the upper
/// bound on the number of loops is greater than max_loop_iterations or not.
/// If the expression is not evaluatable or not an integer, returns false.
bool exprHasLargeNumIterations(const Expr *Expression,
const ASTContext *Context);
/// Returns the type of unrolling, if any, associated with the given
/// statement.
enum UnrollType unrollType(const Stmt *Statement, ASTContext *Context);
/// Returns the condition expression within a given for statement. If there is
/// none, or if the Statement is not a loop, then returns a NULL pointer.
const Expr *getCondExpr(const Stmt *Statement);
/// Returns True if the loop statement has known bounds.
bool hasKnownBounds(const Stmt *Statement, const IntegerLiteral *CXXLoopBound,
const ASTContext *Context);
void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
};
} // namespace altera
} // namespace tidy
} // namespace clang
#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_UNROLLLOOPSCHECK_H
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