ffrankies updated this revision to Diff 248322.
ffrankies added a comment.
@Eugene.Zelenko It turns out we were using an old mirror
<https://github.com/llvm-mirror/clang-tools-extra> of the clang-tools-extra
repository, that no longer seems to be updated. I switched to the llvm-project
<https://github.com/llvm/llvm-project/> repo, and updated the documentation
accordingly (some of the formatting is different now). Let me know if I missed
anything - if not, I will be switching the other checks over to the
llvm-project repo as well over the coming weeks.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D72235/new/
https://reviews.llvm.org/D72235
Files:
clang-tools-extra/clang-tidy/CMakeLists.txt
clang-tools-extra/clang-tidy/ClangTidyForceLinker.h
clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp
clang-tools-extra/clang-tidy/altera/CMakeLists.txt
clang-tools-extra/clang-tidy/altera/UnrollLoopsCheck.cpp
clang-tools-extra/clang-tidy/altera/UnrollLoopsCheck.h
clang-tools-extra/docs/ReleaseNotes.rst
clang-tools-extra/docs/clang-tidy/checks/altera-unroll-loops.rst
clang-tools-extra/docs/clang-tidy/checks/list.rst
clang-tools-extra/docs/clang-tidy/index.rst
clang-tools-extra/test/clang-tidy/checkers/altera-unroll-loops.cpp
Index: clang-tools-extra/test/clang-tidy/checkers/altera-unroll-loops.cpp
===================================================================
--- /dev/null
+++ clang-tools-extra/test/clang-tidy/checkers/altera-unroll-loops.cpp
@@ -0,0 +1,359 @@
+// RUN: %check_clang_tidy %s altera-unroll-loops %t -- -config="{CheckOptions: [{key: "altera-unroll-loops.MaxLoopIterations", value: 50}]}" -header-filter=.* "--" --include opencl-c.h -cl-std=CL1.2 -c
+
+// Inner loops should be unrolled
+__kernel void nested_simple_loops(__global int *A) {
+ for (int i = 0; i < 1000; ++i) {
+ for (int j = 0; j < 2000; ++j) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[0] += i + j;
+ }
+ }
+
+ for (int i = 0; i < 1000; ++i) {
+ int j = 0;
+ while (j < 2000) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[1] += i + j;
+ j++;
+ }
+ }
+
+ for (int i = 0; i < 1000; ++i) {
+ int j = 0;
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[2] += i + j;
+ j++;
+ } while (j < 2000);
+ }
+
+ int i = 0;
+ while (i < 1000) {
+ for (int j = 0; j < 2000; ++j) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[3] += i + j;
+ }
+ i++;
+ }
+
+ i = 0;
+ while (i < 1000) {
+ int j = 0;
+ while (j < 2000) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[4] += i + j;
+ j++;
+ }
+ i++;
+ }
+
+ i = 0;
+ while (i < 1000) {
+ int j = 0;
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[5] += i + j;
+ j++;
+ } while (j < 2000);
+ i++;
+ }
+
+ i = 0;
+ do {
+ for (int j = 0; j < 2000; ++j) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[6] += i + j;
+ }
+ i++;
+ } while (i < 1000);
+
+ i = 0;
+ do {
+ int j = 0;
+ while (j < 2000) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[7] += i + j;
+ j++;
+ }
+ i++;
+ } while (i < 1000);
+
+ i = 0;
+ do {
+ int j = 0;
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ A[8] += i + j;
+ j++;
+ } while (j < 2000);
+ i++;
+ } while (i < 1000);
+
+ for (int i = 0; i < 100; ++i) {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ printf("Hello");
+ }
+
+ i = 0;
+ while (i < 100) {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ i++;
+ }
+
+ i = 0;
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: The performance of the kernel could be improved by unrolling this loop with a #pragma unroll directive [altera-unroll-loops]
+ i++;
+ } while (i < 100);
+}
+
+// These loops are all correctly unrolled
+__kernel void unrolled_nested_simple_loops(__global int *A) {
+ for (int i = 0; i < 1000; ++i) {
+ #pragma unroll
+ for (int j = 0; j < 50; ++j) {
+ A[0] += i + j;
+ }
+ }
+
+ for (int i = 0; i < 1000; ++i) {
+ int j = 0;
+ #pragma unroll
+ while (j < 50) {
+ A[1] += i + j;
+ j++;
+ }
+ }
+
+ for (int i = 0; i < 1000; ++i) {
+ int j = 0;
+ #pragma unroll
+ do {
+ A[2] += i + j;
+ j++;
+ } while (j < 50);
+ }
+
+ int i = 0;
+ while (i < 1000) {
+ #pragma unroll
+ for (int j = 0; j < 50; ++j) {
+ A[3] += i + j;
+ }
+ i++;
+ }
+
+ i = 0;
+ while (i < 1000) {
+ int j = 0;
+ #pragma unroll
+ while (50 > j) {
+ A[4] += i + j;
+ j++;
+ }
+ i++;
+ }
+
+ i = 0;
+ while (1000 > i) {
+ int j = 0;
+ #pragma unroll
+ do {
+ A[5] += i + j;
+ j++;
+ } while (j < 50);
+ i++;
+ }
+
+ i = 0;
+ do {
+ #pragma unroll
+ for (int j = 0; j < 50; ++j) {
+ A[6] += i + j;
+ }
+ i++;
+ } while (i < 1000);
+
+ i = 0;
+ do {
+ int j = 0;
+ #pragma unroll
+ while (j < 50) {
+ A[7] += i + j;
+ j++;
+ }
+ i++;
+ } while (i < 1000);
+
+ i = 0;
+ do {
+ int j = 0;
+ #pragma unroll
+ do {
+ A[8] += i + j;
+ j++;
+ } while (j < 50);
+ i++;
+ } while (i < 1000);
+}
+
+__kernel void unrolled_nested_simple_loops_large_num_iterations(__global int *A) {
+ for (int i = 0; i < 1000; ++i) {
+ #pragma unroll
+ for (int j = 0; j < 51; ++j) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[0] += i + j;
+ }
+ }
+
+ for (int i = 0; i < 1000; ++i) {
+ int j = 0;
+ #pragma unroll
+ while (j < 51) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[1] += i + j;
+ j++;
+ }
+ }
+
+ for (int i = 0; i < 1000; ++i) {
+ int j = 0;
+ #pragma unroll
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[2] += i + j;
+ j++;
+ } while (j < 51);
+ }
+
+ int i = 0;
+ while (i < 1000) {
+ #pragma unroll
+ for (int j = 0; j < 51; ++j) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[3] += i + j;
+ }
+ i++;
+ }
+
+ i = 0;
+ while (i < 1000) {
+ int j = 0;
+ #pragma unroll
+ while (51 > j) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[4] += i + j;
+ j++;
+ }
+ i++;
+ }
+
+ i = 0;
+ while (1000 > i) {
+ int j = 0;
+ #pragma unroll
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[5] += i + j;
+ j++;
+ } while (j < 51);
+ i++;
+ }
+
+ i = 0;
+ do {
+ #pragma unroll
+ for (int j = 0; j < 51; ++j) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[6] += i + j;
+ }
+ i++;
+ } while (i < 1000);
+
+ i = 0;
+ do {
+ int j = 0;
+ #pragma unroll
+ while (j < 51) {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[7] += i + j;
+ j++;
+ }
+ i++;
+ } while (i < 1000);
+
+ i = 0;
+ do {
+ int j = 0;
+ #pragma unroll
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:9: warning: This loop likely has a large number of iterations and thus cannot be fully unrolled. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ A[8] += i + j;
+ j++;
+ } while (j < 51);
+ i++;
+ } while (i < 1000);
+}
+
+__kernel void fully_unrolled_unknown_bounds(int vectorSize) {
+ int someVector[101];
+
+ // There is no loop condition
+ #pragma unroll
+ for (;;) {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ printf("%d", someVector);
+ }
+
+ // Infinite loop
+ #pragma unroll
+ while (true) {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ printf("%d", someVector);
+ }
+
+ #pragma unroll
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ printf("%d", someVector);
+ } while (true);
+
+ #pragma unroll
+ while (1 < 5) {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ printf("%d", someVector);
+ }
+
+ #pragma unroll
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ printf("%d", someVector);
+ } while (1 < 5);
+
+ #pragma unroll
+ for (int i = 0; 1 < 5; ++i) {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ someVector[i]++;
+ }
+
+ // Both sides are value-dependent
+ #pragma unroll
+ for (int i = 0; i < vectorSize; ++i) {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ printf("%d", someVector);
+ }
+
+ int j = 0;
+ #pragma unroll
+ while (j < vectorSize) {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ printf("%d", someVector);
+ }
+
+ #pragma unroll
+ do {
+// CHECK-MESSAGES: :[[@LINE-1]]:5: warning: Full unrolling was requested, but loop bounds are not known. To partially unroll this loop, use the #pragma unroll <num> directive [altera-unroll-loops]
+ printf("%d", someVector);
+ } while (j < vectorSize);
+}
+// There are no fix-its for this check
Index: clang-tools-extra/docs/clang-tidy/index.rst
===================================================================
--- clang-tools-extra/docs/clang-tidy/index.rst
+++ clang-tools-extra/docs/clang-tidy/index.rst
@@ -58,6 +58,7 @@
Name prefix Description
====================== =========================================================
``abseil-`` Checks related to Abseil library.
+``altera-`` Checks related to OpenCL programming for FPGAs.
``android-`` Checks related to Android.
``boost-`` Checks related to Boost library.
``bugprone-`` Checks that target bugprone code constructs.
Index: clang-tools-extra/docs/clang-tidy/checks/list.rst
===================================================================
--- clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -29,6 +29,7 @@
`abseil-time-comparison <abseil-time-comparison.html>`_, "Yes"
`abseil-time-subtraction <abseil-time-subtraction.html>`_, "Yes"
`abseil-upgrade-duration-conversions <abseil-upgrade-duration-conversions.html>`_, "Yes"
+ `altera-unroll-loops <altera-unroll-loops.html>`_,
`android-cloexec-accept <android-cloexec-accept.html>`_, "Yes"
`android-cloexec-accept4 <android-cloexec-accept4.html>`_,
`android-cloexec-creat <android-cloexec-creat.html>`_, "Yes"
Index: clang-tools-extra/docs/clang-tidy/checks/altera-unroll-loops.rst
===================================================================
--- /dev/null
+++ clang-tools-extra/docs/clang-tidy/checks/altera-unroll-loops.rst
@@ -0,0 +1,72 @@
+.. title:: clang-tidy - altera-unroll-loops
+
+altera-unroll-loops
+=================
+
+Checks for inner loops that have not been unrolled. Unrolling
+these loops could improve the performance of OpenCL kernels.
+
+Also checks for fully unrolled loops with a large number of
+iterations, or unknown loop bounds. These loops cannot be fully
+unrolled, and should be partially unrolled.
+
+Based on the `Altera SDK for OpenCL: Best Practices Guide
+<https://www.altera.com/en_US/pdfs/literature/hb/opencl-sdk/aocl_optimization_guide.pdf>`_.
+
+.. code-block:: c++
+
+ for (int i = 0; i < 10; i++) { // ok: outer loops should not be unrolled
+ int j = 0;
+ do { // warning: this inner do..while loop should be unrolled
+ j++;
+ } while (j < 15);
+
+ int k = 0;
+ #pragma unroll
+ while (k < 20) { // ok: this inner loop is already unrolled
+ k++;
+ }
+ }
+
+ #pragma unroll
+ for (int i = 0; i < 1000; ++i) { // warning: this loop is too large and cannot be fully unrolled
+ printf("%d", i);
+ }
+
+ #pragma unroll 5
+ for (int i = 0; i < 1000; ++i) { // ok: this loop is large, but is partially unrolled
+ printf("%d", i);
+ }
+
+ std::vector<int> someVector (100, 0);
+ int i = 0;
+ #pragma unroll
+ while (i < someVector.size()) { // warning: this loop has unknown bounds and cannot be fully unrolled
+ someVector[i]++;
+ }
+
+ #pragma unroll
+ while (true) { // warning: this loop has unknown bounds and cannot be fully unrolled
+ printf("In loop");
+ }
+
+ #pragma unroll
+ while (i < 5) { // warning: this loop has unknown bounds and cannot be fully unrolled
+ printf("In loop");
+ }
+
+ #pragma unroll 5
+ while (i < someVector.size()) { // ok: this loop has unknown bounds, but is partially unrolled
+ someVector[i]++;
+ }
+
+Options
+-------
+
+.. option:: MaxLoopIterations
+
+ Defines the maximum number of loop iterations that a fully unrolled loop
+ can have. By default, it is set to `100`.
+
+ In practice, this refers to the integer value of the upper bound
+ within the loop statement's condition expression.
Index: clang-tools-extra/docs/ReleaseNotes.rst
===================================================================
--- clang-tools-extra/docs/ReleaseNotes.rst
+++ clang-tools-extra/docs/ReleaseNotes.rst
@@ -67,9 +67,24 @@
Improvements to clang-tidy
--------------------------
+New modules
+^^^^^^^^^^^
+
+- New :doc:`altera <clang-tidy/modules/altera>` module.
+
+ Includes checks related to OpenCL for FPGA coding guidelines, based on the
+ `Altera SDK for OpenCL: Best Practices Guide
+ <https://www.altera.com/en_US/pdfs/literature/hb/opencl-sdk/aocl_optimization_guide.pdf>`_.
+
New checks
^^^^^^^^^^
+- New :doc:`altera-unroll-loops
+ <clang-tidy/checks/altera-unroll-loops>` check.
+
+ Finds inner loops that have not been unrolled, as well as fully unrolled
+ loops with unknown loops bounds or a large number of iterations.
+
- New :doc:`bugprone-misplaced-pointer-arithmetic-in-alloc
<clang-tidy/checks/bugprone-misplaced-pointer-arithmetic-in-alloc>` check.
Index: clang-tools-extra/clang-tidy/altera/UnrollLoopsCheck.h
===================================================================
--- /dev/null
+++ clang-tools-extra/clang-tidy/altera/UnrollLoopsCheck.h
@@ -0,0 +1,71 @@
+//===--- 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_UNROLL_LOOPS_CHECK_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_UNROLL_LOOPS_CHECK_H
+
+#include "../ClangTidy.h"
+
+namespace clang {
+namespace tidy {
+namespace altera {
+
+/// Finds for, while and do..while loop statements that have not been unrolled.
+/// Unrolling these loops could increase the performance of the OpenCL kernel.
+/// Also attempts to find for, while and do..while loops that have been fully
+/// unrolled, but either have unknown bounds or a large number of iterations.
+/// The compiler will not unroll these loops, so partial unrolling is
+/// recommended in these cases.
+///
+/// For the user-facing documentation see:
+/// http://clang.llvm.org/extra/clang-tidy/checks/altera-unroll-loops.html
+class UnrollLoopsCheck : public ClangTidyCheck {
+ const unsigned MaxLoopIterations;
+
+public:
+ UnrollLoopsCheck(StringRef Name, ClangTidyContext *Context)
+ : ClangTidyCheck(Name, Context),
+ MaxLoopIterations(Options.get("MaxLoopIterations", 100U)) {}
+ void registerMatchers(ast_matchers::MatchFinder *Finder) override;
+ void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
+
+private:
+ /// 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
+ };
+ /// 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 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 ASTContext *Context);
+ void storeOptions(ClangTidyOptions::OptionMap &Opts);
+};
+
+} // namespace altera
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ALTERA_UNROLL_LOOPS_CHECK_H
Index: clang-tools-extra/clang-tidy/altera/UnrollLoopsCheck.cpp
===================================================================
--- /dev/null
+++ clang-tools-extra/clang-tidy/altera/UnrollLoopsCheck.cpp
@@ -0,0 +1,172 @@
+//===--- UnrollLoopsCheck.cpp - clang-tidy --------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "UnrollLoopsCheck.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTTypeTraits.h"
+#include "clang/AST/ParentMapContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace altera {
+
+void UnrollLoopsCheck::registerMatchers(MatchFinder *Finder) {
+ const auto ANYLOOP = anyOf(forStmt(), whileStmt(), doStmt());
+ Finder->addMatcher(stmt(allOf(ANYLOOP, // Match all loop types,
+ unless(hasDescendant(forStmt())),
+ unless(hasDescendant(whileStmt())),
+ unless(hasDescendant(doStmt()))))
+ .bind("loop"),
+ this);
+}
+
+void UnrollLoopsCheck::check(const MatchFinder::MatchResult &Result) {
+ const auto *MatchedLoop = Result.Nodes.getNodeAs<Stmt>("loop");
+ const ASTContext *Context = Result.Context;
+ UnrollType Unroll = unrollType(MatchedLoop, Result.Context);
+ if (Unroll == NotUnrolled) {
+ diag(MatchedLoop->getBeginLoc(),
+ "The performance of the kernel could be improved by unrolling this "
+ "loop with a #pragma unroll directive");
+ return;
+ }
+ if (Unroll == PartiallyUnrolled) {
+ return;
+ }
+ if (Unroll == FullyUnrolled) {
+ if (hasKnownBounds(MatchedLoop, Context)) {
+ if (hasLargeNumIterations(MatchedLoop, Context)) {
+ diag(MatchedLoop->getBeginLoc(),
+ "This loop likely has a large number of iterations and thus "
+ "cannot be fully unrolled. To partially unroll this loop, use the "
+ "#pragma unroll <num> directive");
+ return;
+ }
+ return;
+ }
+ diag(MatchedLoop->getBeginLoc(),
+ "Full unrolling was requested, but loop bounds are not known. To "
+ "partially unroll this loop, use the #pragma unroll <num> directive");
+ }
+}
+
+enum UnrollLoopsCheck::UnrollType
+UnrollLoopsCheck::unrollType(const Stmt *Statement, ASTContext *Context) {
+ const clang::DynTypedNodeList Parents = Context->getParents<Stmt>(*Statement);
+ for (const ast_type_traits::DynTypedNode &Parent : Parents) {
+ const auto *ParentStmt = Parent.get<AttributedStmt>();
+ if (!ParentStmt) {
+ continue;
+ }
+ for (const Attr *Attribute : ParentStmt->getAttrs()) {
+ const auto *LoopHint = static_cast<const LoopHintAttr *>(Attribute);
+ if (LoopHint) {
+ switch (LoopHint->getState()) {
+ case LoopHintAttr::Numeric:
+ return PartiallyUnrolled;
+ case LoopHintAttr::Disable:
+ return NotUnrolled;
+ case LoopHintAttr::Full:
+ return FullyUnrolled;
+ case LoopHintAttr::Enable:
+ return FullyUnrolled;
+ default:
+ return NotUnrolled;
+ }
+ }
+ }
+ }
+ return NotUnrolled;
+}
+
+bool UnrollLoopsCheck::hasKnownBounds(const Stmt *Statement,
+ const ASTContext *Context) {
+ const Expr *Conditional = getCondExpr(Statement);
+ if (!Conditional) {
+ return false;
+ }
+ if (isa<BinaryOperator>(Conditional)) {
+ const auto *BinaryOp = static_cast<const BinaryOperator *>(Conditional);
+ const Expr *LHS = BinaryOp->getLHS();
+ const Expr *RHS = BinaryOp->getRHS();
+ if (LHS->isEvaluatable(*Context) == RHS->isEvaluatable(*Context)) {
+ return false; // Both sides are value dependent or constant, so loop
+ // bounds are not known.
+ }
+ return true; // At least 1 side isn't value dependent, so we know the loop
+ // bounds.
+ }
+ return false; // If it's not a binary operator, we don't know the loop bounds.
+}
+
+const Expr *UnrollLoopsCheck::getCondExpr(const Stmt *Statement) {
+ const Expr *Conditional;
+ if (isa<ForStmt>(Statement)) {
+ const auto *ForLoop = static_cast<const ForStmt *>(Statement);
+ Conditional = ForLoop->getCond();
+ }
+ if (isa<WhileStmt>(Statement)) {
+ const auto *WhileLoop = static_cast<const WhileStmt *>(Statement);
+ Conditional = WhileLoop->getCond();
+ }
+ if (isa<DoStmt>(Statement)) {
+ const auto *DoWhileLoop = static_cast<const DoStmt *>(Statement);
+ Conditional = DoWhileLoop->getCond();
+ }
+ return Conditional;
+}
+
+bool UnrollLoopsCheck::hasLargeNumIterations(const Stmt *Statement,
+ const ASTContext *Context) {
+ const Expr *Conditional = getCondExpr(Statement);
+ if (!Conditional) {
+ return false;
+ }
+ if (isa<BinaryOperator>(Conditional)) {
+ const auto *BinaryOp = static_cast<const BinaryOperator *>(Conditional);
+ const Expr *LHS = BinaryOp->getLHS();
+ const Expr *RHS = BinaryOp->getRHS();
+ Expr::EvalResult result;
+ if (LHS->isEvaluatable(*Context) && !(RHS->isEvaluatable(*Context))) {
+ return exprHasLargeNumIterations(LHS, Context);
+ }
+ if (RHS->isEvaluatable(*Context) && !(LHS->isEvaluatable(*Context))) {
+ return exprHasLargeNumIterations(RHS, Context);
+ }
+ }
+ return false; // Cannot check number of iteration, return false to be safe.
+}
+
+bool UnrollLoopsCheck::exprHasLargeNumIterations(const Expr *Expression,
+ const ASTContext *Context) {
+ Expr::EvalResult Result;
+ if (Expression->EvaluateAsRValue(Result, *Context)) {
+ if (!(Result.Val.isInt())) {
+ return false; // Cannot check number of iterations, return false to be
+ // safe.
+ }
+ if (Result.Val.getInt() > MaxLoopIterations) {
+ return true; // Assumes values go from 0 to Val in increments of 1.
+ }
+ return false; // Number of iterations likely less than MaxLoopIterations.
+ }
+ // Cannot evaluate Expression as an r-value, so cannot check number of
+ // iterations.
+ return false;
+}
+
+void UnrollLoopsCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
+ Options.store(Opts, "MaxLoopIterations", MaxLoopIterations);
+}
+
+} // namespace altera
+} // namespace tidy
+} // namespace clang
Index: clang-tools-extra/clang-tidy/altera/CMakeLists.txt
===================================================================
--- /dev/null
+++ clang-tools-extra/clang-tidy/altera/CMakeLists.txt
@@ -0,0 +1,15 @@
+set(LLVM_LINK_COMPONENTS support)
+
+add_clang_library(clangTidyAlteraModule
+ AlteraTidyModule.cpp
+ UnrollLoopsCheck.cpp
+
+ LINK_LIBS
+ clangAnalysis
+ clangAST
+ clangASTMatchers
+ clangBasic
+ clangLex
+ clangTidy
+ clangTidyUtils
+ )
Index: clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp
===================================================================
--- /dev/null
+++ clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp
@@ -0,0 +1,39 @@
+//===--- AlteraTidyModule.cpp - clang-tidy --------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "../ClangTidy.h"
+#include "../ClangTidyModule.h"
+#include "../ClangTidyModuleRegistry.h"
+#include "UnrollLoopsCheck.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang {
+namespace tidy {
+namespace altera {
+
+class AlteraModule : public ClangTidyModule {
+public:
+ void addCheckFactories(ClangTidyCheckFactories &CheckFactories) override {
+ CheckFactories.registerCheck<UnrollLoopsCheck>(
+ "altera-unroll-loops");
+ }
+};
+
+} // namespace altera
+
+// Register the AlteraTidyModule using this statically initialized variable.
+static ClangTidyModuleRegistry::Add<altera::AlteraModule>
+ X("altera-module", "Adds Altera FPGA OpenCL lint checks.");
+
+// This anchor is used to force the linker to link in the generated object file
+// and thus register the AlteraModule.
+volatile int AlteraModuleAnchorSource = 0;
+
+} // namespace tidy
+} // namespace clang
Index: clang-tools-extra/clang-tidy/ClangTidyForceLinker.h
===================================================================
--- clang-tools-extra/clang-tidy/ClangTidyForceLinker.h
+++ clang-tools-extra/clang-tidy/ClangTidyForceLinker.h
@@ -25,6 +25,11 @@
static int LLVM_ATTRIBUTE_UNUSED AbseilModuleAnchorDestination =
AbseilModuleAnchorSource;
+// This anchor is used to force the linker to link the AlteraModule.
+extern volatile int AlteraModuleAnchorSource;
+static int LLVM_ATTRIBUTE_UNUSED AlteraModuleAnchorDestination =
+ AlteraModuleAnchorSource;
+
// This anchor is used to force the linker to link the BoostModule.
extern volatile int BoostModuleAnchorSource;
static int LLVM_ATTRIBUTE_UNUSED BoostModuleAnchorDestination =
Index: clang-tools-extra/clang-tidy/CMakeLists.txt
===================================================================
--- clang-tools-extra/clang-tidy/CMakeLists.txt
+++ clang-tools-extra/clang-tidy/CMakeLists.txt
@@ -41,6 +41,7 @@
# If you add a check, also add it to ClangTidyForceLinker.h in this directory.
add_subdirectory(android)
add_subdirectory(abseil)
+add_subdirectory(altera)
add_subdirectory(boost)
add_subdirectory(bugprone)
add_subdirectory(cert)
@@ -65,6 +66,7 @@
set(ALL_CLANG_TIDY_CHECKS
clangTidyAndroidModule
clangTidyAbseilModule
+ clangTidyAlteraModule
clangTidyBoostModule
clangTidyBugproneModule
clangTidyCERTModule
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