xref: /llvm-project/llvm/unittests/Analysis/PluginInlineAdvisorAnalysisTest.cpp (revision ab4253f6dff194a1e09448c8628809d21f148df9)
1 #include "llvm/Analysis/CallGraph.h"
2 #include "llvm/AsmParser/Parser.h"
3 #include "llvm/Config/config.h"
4 #include "llvm/IR/Module.h"
5 #include "llvm/Passes/PassBuilder.h"
6 #include "llvm/Passes/PassPlugin.h"
7 #include "llvm/Support/CommandLine.h"
8 #include "llvm/Support/raw_ostream.h"
9 #include "llvm/Testing/Support/Error.h"
10 #include "gtest/gtest.h"
11 
12 namespace llvm {
13 
14 namespace {
15 
16 void anchor() {}
17 
18 static std::string libPath(const std::string Name = "InlineAdvisorPlugin") {
19   const auto &Argvs = testing::internal::GetArgvs();
20   const char *Argv0 =
21       Argvs.size() > 0 ? Argvs[0].c_str() : "PluginInlineAdvisorAnalysisTest";
22   void *Ptr = (void *)(intptr_t)anchor;
23   std::string Path = sys::fs::getMainExecutable(Argv0, Ptr);
24   llvm::SmallString<256> Buf{sys::path::parent_path(Path)};
25   sys::path::append(Buf, (Name + LLVM_PLUGIN_EXT).c_str());
26   return std::string(Buf.str());
27 }
28 
29 // Example of a custom InlineAdvisor that only inlines calls to functions called
30 // "foo".
31 class FooOnlyInlineAdvisor : public InlineAdvisor {
32 public:
33   FooOnlyInlineAdvisor(Module &M, FunctionAnalysisManager &FAM,
34                        InlineParams Params, InlineContext IC)
35       : InlineAdvisor(M, FAM, IC) {}
36 
37   std::unique_ptr<InlineAdvice> getAdviceImpl(CallBase &CB) override {
38     if (CB.getCalledFunction()->getName() == "foo")
39       return std::make_unique<InlineAdvice>(this, CB, getCallerORE(CB), true);
40     return std::make_unique<InlineAdvice>(this, CB, getCallerORE(CB), false);
41   }
42 };
43 
44 static InlineAdvisor *fooOnlyFactory(Module &M, FunctionAnalysisManager &FAM,
45                                      InlineParams Params, InlineContext IC) {
46   return new FooOnlyInlineAdvisor(M, FAM, Params, IC);
47 }
48 
49 struct CompilerInstance {
50   LLVMContext Ctx;
51   ModulePassManager MPM;
52   InlineParams IP;
53 
54   PassBuilder PB;
55   LoopAnalysisManager LAM;
56   FunctionAnalysisManager FAM;
57   CGSCCAnalysisManager CGAM;
58   ModuleAnalysisManager MAM;
59 
60   SMDiagnostic Error;
61 
62   // connect the plugin to our compiler instance
63   void setupPlugin() {
64     auto PluginPath = libPath();
65     ASSERT_NE("", PluginPath);
66     Expected<PassPlugin> Plugin = PassPlugin::Load(PluginPath);
67     ASSERT_TRUE(!!Plugin) << "Plugin path: " << PluginPath;
68     Plugin->registerPassBuilderCallbacks(PB);
69     ASSERT_THAT_ERROR(PB.parsePassPipeline(MPM, "dynamic-inline-advisor"),
70                       Succeeded());
71   }
72 
73   // connect the FooOnlyInlineAdvisor to our compiler instance
74   void setupFooOnly() {
75     MAM.registerPass(
76         [&] { return PluginInlineAdvisorAnalysis(fooOnlyFactory); });
77   }
78 
79   CompilerInstance() {
80     IP = getInlineParams(3, 0);
81     PB.registerModuleAnalyses(MAM);
82     PB.registerCGSCCAnalyses(CGAM);
83     PB.registerFunctionAnalyses(FAM);
84     PB.registerLoopAnalyses(LAM);
85     PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
86     MPM.addPass(ModuleInlinerPass(IP, InliningAdvisorMode::Default,
87                                   ThinOrFullLTOPhase::None));
88   }
89 
90   std::string output;
91   std::unique_ptr<Module> outputM;
92 
93   auto run(StringRef IR) {
94     outputM = parseAssemblyString(IR, Error, Ctx);
95     MPM.run(*outputM, MAM);
96     ASSERT_TRUE(outputM);
97     output.clear();
98     raw_string_ostream o_stream{output};
99     outputM->print(o_stream, nullptr);
100     ASSERT_TRUE(true);
101   }
102 };
103 
104 StringRef TestIRS[] = {
105     // Simple 3 function inline case
106     R"(
107 define void @f1() {
108   call void @foo()
109   ret void
110 }
111 define void @foo() {
112   call void @f3()
113   ret void
114 }
115 define void @f3() {
116   ret void
117 }
118   )",
119     // Test that has 5 functions of which 2 are recursive
120     R"(
121 define void @f1() {
122   call void @foo()
123   ret void
124 }
125 define void @f2() {
126   call void @foo()
127   ret void
128 }
129 define void @foo() {
130   call void @f4()
131   call void @f5()
132   ret void
133 }
134 define void @f4() {
135   ret void
136 }
137 define void @f5() {
138   call void @foo()
139   ret void
140 }
141   )",
142     // test with 2 mutually recursive functions and 1 function with a loop
143     R"(
144 define void @f1() {
145   call void @f2()
146   ret void
147 }
148 define void @f2() {
149   call void @f3()
150   ret void
151 }
152 define void @f3() {
153   call void @f1()
154   ret void
155 }
156 define void @f4() {
157   br label %loop
158 loop:
159   call void @f5()
160   br label %loop
161 }
162 define void @f5() {
163   ret void
164 }
165   )",
166     // test that has a function that computes fibonacci in a loop, one in a
167     // recurisve manner, and one that calls both and compares them
168     R"(
169 define i32 @fib_loop(i32 %n){
170     %curr = alloca i32
171     %last = alloca i32
172     %i = alloca i32
173     store i32 1, i32* %curr
174     store i32 1, i32* %last
175     store i32 2, i32* %i
176     br label %loop_cond
177   loop_cond:
178     %i_val = load i32, i32* %i
179     %cmp = icmp slt i32 %i_val, %n
180     br i1 %cmp, label %loop_body, label %loop_end
181   loop_body:
182     %curr_val = load i32, i32* %curr
183     %last_val = load i32, i32* %last
184     %add = add i32 %curr_val, %last_val
185     store i32 %add, i32* %last
186     store i32 %curr_val, i32* %curr
187     %i_val2 = load i32, i32* %i
188     %add2 = add i32 %i_val2, 1
189     store i32 %add2, i32* %i
190     br label %loop_cond
191   loop_end:
192     %curr_val3 = load i32, i32* %curr
193     ret i32 %curr_val3
194 }
195 
196 define i32 @fib_rec(i32 %n){
197     %cmp = icmp eq i32 %n, 0
198     %cmp2 = icmp eq i32 %n, 1
199     %or = or i1 %cmp, %cmp2
200     br i1 %or, label %if_true, label %if_false
201   if_true:
202     ret i32 1
203   if_false:
204     %sub = sub i32 %n, 1
205     %call = call i32 @fib_rec(i32 %sub)
206     %sub2 = sub i32 %n, 2
207     %call2 = call i32 @fib_rec(i32 %sub2)
208     %add = add i32 %call, %call2
209     ret i32 %add
210 }
211 
212 define i32 @fib_check(){
213     %correct = alloca i32
214     %i = alloca i32
215     store i32 1, i32* %correct
216     store i32 0, i32* %i
217     br label %loop_cond
218   loop_cond:
219     %i_val = load i32, i32* %i
220     %cmp = icmp slt i32 %i_val, 10
221     br i1 %cmp, label %loop_body, label %loop_end
222   loop_body:
223     %i_val2 = load i32, i32* %i
224     %call = call i32 @fib_loop(i32 %i_val2)
225     %i_val3 = load i32, i32* %i
226     %call2 = call i32 @fib_rec(i32 %i_val3)
227     %cmp2 = icmp ne i32 %call, %call2
228     br i1 %cmp2, label %if_true, label %if_false
229   if_true:
230     store i32 0, i32* %correct
231     br label %if_end
232   if_false:
233     br label %if_end
234   if_end:
235     %i_val4 = load i32, i32* %i
236     %add = add i32 %i_val4, 1
237     store i32 %add, i32* %i
238     br label %loop_cond
239   loop_end:
240     %correct_val = load i32, i32* %correct
241     ret i32 %correct_val
242 }
243   )"};
244 
245 } // namespace
246 
247 // check that loading a plugin works
248 // the plugin being loaded acts identically to the default inliner
249 TEST(PluginInlineAdvisorTest, PluginLoad) {
250 #if !defined(LLVM_ENABLE_PLUGINS)
251   // Skip the test if plugins are disabled.
252   GTEST_SKIP();
253 #endif
254   CompilerInstance DefaultCI{};
255 
256   CompilerInstance PluginCI{};
257   PluginCI.setupPlugin();
258 
259   for (StringRef IR : TestIRS) {
260     DefaultCI.run(IR);
261     std::string default_output = DefaultCI.output;
262     PluginCI.run(IR);
263     std::string dynamic_output = PluginCI.output;
264     ASSERT_EQ(default_output, dynamic_output);
265   }
266 }
267 
268 // check that the behaviour of a custom inliner is correct
269 // the custom inliner inlines all functions that are not named "foo"
270 // this testdoes not require plugins to be enabled
271 TEST(PluginInlineAdvisorTest, CustomAdvisor) {
272   CompilerInstance CI{};
273   CI.setupFooOnly();
274 
275   for (StringRef IR : TestIRS) {
276     CI.run(IR);
277     CallGraph CGraph = CallGraph(*CI.outputM);
278     for (auto &node : CGraph) {
279       for (auto &edge : *node.second) {
280         if (!edge.first)
281           continue;
282         ASSERT_NE(edge.second->getFunction()->getName(), "foo");
283       }
284     }
285   }
286 }
287 
288 } // namespace llvm
289