1 //===--- SingleWorkItemBarrierCheck.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 "SingleWorkItemBarrierCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12
13 using namespace clang::ast_matchers;
14
15 namespace clang {
16 namespace tidy {
17 namespace altera {
18
registerMatchers(MatchFinder * Finder)19 void SingleWorkItemBarrierCheck::registerMatchers(MatchFinder *Finder) {
20 // Find any function that calls barrier but does not call an ID function.
21 // hasAttr(attr::Kind::OpenCLKernel) restricts it to only kernel functions.
22 // FIXME: Have it accept all functions but check for a parameter that gets an
23 // ID from one of the four ID functions.
24 Finder->addMatcher(
25 // Find function declarations...
26 functionDecl(
27 allOf(
28 // That are OpenCL kernels...
29 hasAttr(attr::Kind::OpenCLKernel),
30 // And call a barrier function (either 1.x or 2.x version)...
31 forEachDescendant(callExpr(callee(functionDecl(hasAnyName(
32 "barrier", "work_group_barrier"))))
33 .bind("barrier")),
34 // But do not call an ID function.
35 unless(hasDescendant(callExpr(callee(functionDecl(
36 hasAnyName("get_global_id", "get_local_id", "get_group_id",
37 "get_local_linear_id"))))))))
38 .bind("function"),
39 this);
40 }
41
check(const MatchFinder::MatchResult & Result)42 void SingleWorkItemBarrierCheck::check(const MatchFinder::MatchResult &Result) {
43 const auto *MatchedDecl = Result.Nodes.getNodeAs<FunctionDecl>("function");
44 const auto *MatchedBarrier = Result.Nodes.getNodeAs<CallExpr>("barrier");
45 if (AOCVersion < 1701) {
46 // get_group_id and get_local_linear_id were added at/after v17.01
47 diag(MatchedDecl->getLocation(),
48 "kernel function %0 does not call 'get_global_id' or 'get_local_id' "
49 "and will be treated as a single work-item")
50 << MatchedDecl;
51 diag(MatchedBarrier->getBeginLoc(),
52 "barrier call is in a single work-item and may error out",
53 DiagnosticIDs::Note);
54 } else {
55 // If reqd_work_group_size is anything other than (1,1,1), it will be
56 // interpreted as an NDRange in AOC version >= 17.1.
57 bool IsNDRange = false;
58 if (MatchedDecl->hasAttr<ReqdWorkGroupSizeAttr>()) {
59 const auto *Attribute = MatchedDecl->getAttr<ReqdWorkGroupSizeAttr>();
60 if (Attribute->getXDim() > 1 || Attribute->getYDim() > 1 ||
61 Attribute->getZDim() > 1)
62 IsNDRange = true;
63 }
64 if (IsNDRange) // No warning if kernel is treated as an NDRange.
65 return;
66 diag(MatchedDecl->getLocation(),
67 "kernel function %0 does not call an ID function and may be a viable "
68 "single work-item, but will be forced to execute as an NDRange")
69 << MatchedDecl;
70 diag(MatchedBarrier->getBeginLoc(),
71 "barrier call will force NDRange execution; if single work-item "
72 "semantics are desired a mem_fence may be more efficient",
73 DiagnosticIDs::Note);
74 }
75 }
76
storeOptions(ClangTidyOptions::OptionMap & Opts)77 void SingleWorkItemBarrierCheck::storeOptions(
78 ClangTidyOptions::OptionMap &Opts) {
79 Options.store(Opts, "AOCVersion", AOCVersion);
80 }
81
82 } // namespace altera
83 } // namespace tidy
84 } // namespace clang
85