ffrankies updated this revision to Diff 312676.
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- removed unnecessary comment
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D72235/new/
https://reviews.llvm.org/D72235
Files:
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/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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: kernel performance 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: 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: 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: 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: 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: 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: 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: 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: 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: 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 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 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 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 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 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 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 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 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 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/checks/list.rst
===================================================================
--- clang-tools-extra/docs/clang-tidy/checks/list.rst
+++ clang-tools-extra/docs/clang-tidy/checks/list.rst
@@ -32,6 +32,7 @@
`abseil-upgrade-duration-conversions <abseil-upgrade-duration-conversions.html>`_, "Yes"
`altera-kernel-name-restriction <altera-kernel-name-restriction.html>`_,
`altera-struct-pack-align <altera-struct-pack-align.html>`_,
+ `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
+=================
+
+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.
+
+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
@@ -102,6 +102,12 @@
Finds structs that are inefficiently packed or aligned, and recommends
packing and/or aligning of said structs as needed.
+- 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:`cppcoreguidelines-prefer-member-initializer
<clang-tidy/checks/cppcoreguidelines-prefer-member-initializer>` 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 "../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 {
+ 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 +1,163 @@
+//===--- 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(),
+ "kernel performance 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(),
+ "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 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))
+ // Both sides are value dependent or constant, so loop bounds are unknown.
+ return false;
+ 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
===================================================================
--- clang-tools-extra/clang-tidy/altera/CMakeLists.txt
+++ clang-tools-extra/clang-tidy/altera/CMakeLists.txt
@@ -7,6 +7,7 @@
AlteraTidyModule.cpp
KernelNameRestrictionCheck.cpp
StructPackAlignCheck.cpp
+ UnrollLoopsCheck.cpp
LINK_LIBS
clangTidy
Index: clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp
===================================================================
--- clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp
+++ clang-tools-extra/clang-tidy/altera/AlteraTidyModule.cpp
@@ -11,6 +11,7 @@
#include "../ClangTidyModuleRegistry.h"
#include "KernelNameRestrictionCheck.h"
#include "StructPackAlignCheck.h"
+#include "UnrollLoopsCheck.h"
using namespace clang::ast_matchers;
@@ -25,6 +26,8 @@
"altera-kernel-name-restriction");
CheckFactories.registerCheck<StructPackAlignCheck>(
"altera-struct-pack-align");
+ CheckFactories.registerCheck<UnrollLoopsCheck>(
+ "altera-unroll-loops");
}
};
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