1 //===- UnrollAnalyzerTest.cpp - UnrollAnalyzer unit tests -----------------===//
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 "llvm/Analysis/LoopInfo.h"
10 #include "llvm/Analysis/LoopUnrollAnalyzer.h"
11 #include "llvm/AsmParser/Parser.h"
12 #include "llvm/IR/Dominators.h"
13 #include "llvm/IR/LegacyPassManager.h"
14 #include "llvm/InitializePasses.h"
15 #include "llvm/Support/SourceMgr.h"
16 #include "gtest/gtest.h"
17
18 using namespace llvm;
19 namespace llvm {
20 void initializeUnrollAnalyzerTestPass(PassRegistry &);
21
22 static SmallVector<DenseMap<Value *, Constant *>, 16> SimplifiedValuesVector;
23 static unsigned TripCount = 0;
24
25 namespace {
26 struct UnrollAnalyzerTest : public FunctionPass {
27 static char ID;
runOnFunctionllvm::__anon1a9323780111::UnrollAnalyzerTest28 bool runOnFunction(Function &F) override {
29 LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo();
30 ScalarEvolution *SE = &getAnalysis<ScalarEvolutionWrapperPass>().getSE();
31
32 Function::iterator FI = F.begin();
33 FI++; // First basic block is entry - skip it.
34 BasicBlock *Header = &*FI++;
35 Loop *L = LI->getLoopFor(Header);
36 BasicBlock *Exiting = L->getExitingBlock();
37
38 SimplifiedValuesVector.clear();
39 TripCount = SE->getSmallConstantTripCount(L, Exiting);
40 for (unsigned Iteration = 0; Iteration < TripCount; Iteration++) {
41 DenseMap<Value *, Constant *> SimplifiedValues;
42 UnrolledInstAnalyzer Analyzer(Iteration, SimplifiedValues, *SE, L);
43 for (auto *BB : L->getBlocks())
44 for (Instruction &I : *BB)
45 Analyzer.visit(I);
46 SimplifiedValuesVector.push_back(SimplifiedValues);
47 }
48 return false;
49 }
getAnalysisUsagellvm::__anon1a9323780111::UnrollAnalyzerTest50 void getAnalysisUsage(AnalysisUsage &AU) const override {
51 AU.addRequired<DominatorTreeWrapperPass>();
52 AU.addRequired<LoopInfoWrapperPass>();
53 AU.addRequired<ScalarEvolutionWrapperPass>();
54 AU.setPreservesAll();
55 }
UnrollAnalyzerTestllvm::__anon1a9323780111::UnrollAnalyzerTest56 UnrollAnalyzerTest() : FunctionPass(ID) {
57 initializeUnrollAnalyzerTestPass(*PassRegistry::getPassRegistry());
58 }
59 };
60 }
61
62 char UnrollAnalyzerTest::ID = 0;
63
makeLLVMModule(LLVMContext & Context,const char * ModuleStr)64 std::unique_ptr<Module> makeLLVMModule(LLVMContext &Context,
65 const char *ModuleStr) {
66 SMDiagnostic Err;
67 return parseAssemblyString(ModuleStr, Err, Context);
68 }
69
TEST(UnrollAnalyzerTest,BasicSimplifications)70 TEST(UnrollAnalyzerTest, BasicSimplifications) {
71 const char *ModuleStr =
72 "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
73 "define i64 @propagate_loop_phis() {\n"
74 "entry:\n"
75 " br label %loop\n"
76 "loop:\n"
77 " %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]\n"
78 " %x0 = phi i64 [ 0, %entry ], [ %x2, %loop ]\n"
79 " %x1 = or i64 %x0, 1\n"
80 " %x2 = or i64 %x1, 2\n"
81 " %inc = add nuw nsw i64 %iv, 1\n"
82 " %cond = icmp sge i64 %inc, 8\n"
83 " br i1 %cond, label %loop.end, label %loop\n"
84 "loop.end:\n"
85 " %x.lcssa = phi i64 [ %x2, %loop ]\n"
86 " ret i64 %x.lcssa\n"
87 "}\n";
88 UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
89 LLVMContext Context;
90 std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
91 legacy::PassManager Passes;
92 Passes.add(P);
93 Passes.run(*M);
94
95 // Perform checks
96 Module::iterator MI = M->begin();
97 Function *F = &*MI++;
98 Function::iterator FI = F->begin();
99 FI++; // First basic block is entry - skip it.
100 BasicBlock *Header = &*FI++;
101
102 BasicBlock::iterator BBI = Header->begin();
103 std::advance(BBI, 4);
104 Instruction *Y1 = &*BBI++;
105 Instruction *Y2 = &*BBI++;
106 // Check simplification expected on the 1st iteration.
107 // Check that "%inc = add nuw nsw i64 %iv, 1" is simplified to 1
108 auto I1 = SimplifiedValuesVector[0].find(Y1);
109 EXPECT_TRUE(I1 != SimplifiedValuesVector[0].end());
110 EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 1U);
111
112 // Check that "%cond = icmp sge i64 %inc, 10" is simplified to false
113 auto I2 = SimplifiedValuesVector[0].find(Y2);
114 EXPECT_TRUE(I2 != SimplifiedValuesVector[0].end());
115 EXPECT_FALSE(cast<ConstantInt>((*I2).second)->getZExtValue());
116
117 // Check simplification expected on the last iteration.
118 // Check that "%inc = add nuw nsw i64 %iv, 1" is simplified to 8
119 I1 = SimplifiedValuesVector[TripCount - 1].find(Y1);
120 EXPECT_TRUE(I1 != SimplifiedValuesVector[TripCount - 1].end());
121 EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), TripCount);
122
123 // Check that "%cond = icmp sge i64 %inc, 10" is simplified to false
124 I2 = SimplifiedValuesVector[TripCount - 1].find(Y2);
125 EXPECT_TRUE(I2 != SimplifiedValuesVector[TripCount - 1].end());
126 EXPECT_TRUE(cast<ConstantInt>((*I2).second)->getZExtValue());
127 }
128
TEST(UnrollAnalyzerTest,OuterLoopSimplification)129 TEST(UnrollAnalyzerTest, OuterLoopSimplification) {
130 const char *ModuleStr =
131 "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
132 "define void @foo() {\n"
133 "entry:\n"
134 " br label %outer.loop\n"
135 "outer.loop:\n"
136 " %iv.outer = phi i64 [ 0, %entry ], [ %iv.outer.next, %outer.loop.latch ]\n"
137 " %iv.outer.next = add nuw nsw i64 %iv.outer, 1\n"
138 " br label %inner.loop\n"
139 "inner.loop:\n"
140 " %iv.inner = phi i64 [ 0, %outer.loop ], [ %iv.inner.next, %inner.loop ]\n"
141 " %iv.inner.next = add nuw nsw i64 %iv.inner, 1\n"
142 " %exitcond.inner = icmp eq i64 %iv.inner.next, 1000\n"
143 " br i1 %exitcond.inner, label %outer.loop.latch, label %inner.loop\n"
144 "outer.loop.latch:\n"
145 " %exitcond.outer = icmp eq i64 %iv.outer.next, 40\n"
146 " br i1 %exitcond.outer, label %exit, label %outer.loop\n"
147 "exit:\n"
148 " ret void\n"
149 "}\n";
150
151 UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
152 LLVMContext Context;
153 std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
154 legacy::PassManager Passes;
155 Passes.add(P);
156 Passes.run(*M);
157
158 Module::iterator MI = M->begin();
159 Function *F = &*MI++;
160 Function::iterator FI = F->begin();
161 FI++;
162 BasicBlock *Header = &*FI++;
163 BasicBlock *InnerBody = &*FI++;
164
165 BasicBlock::iterator BBI = Header->begin();
166 BBI++;
167 Instruction *Y1 = &*BBI;
168 BBI = InnerBody->begin();
169 BBI++;
170 Instruction *Y2 = &*BBI;
171 // Check that we can simplify IV of the outer loop, but can't simplify the IV
172 // of the inner loop if we only know the iteration number of the outer loop.
173 //
174 // Y1 is %iv.outer.next, Y2 is %iv.inner.next
175 auto I1 = SimplifiedValuesVector[0].find(Y1);
176 EXPECT_TRUE(I1 != SimplifiedValuesVector[0].end());
177 auto I2 = SimplifiedValuesVector[0].find(Y2);
178 EXPECT_TRUE(I2 == SimplifiedValuesVector[0].end());
179 }
TEST(UnrollAnalyzerTest,CmpSimplifications)180 TEST(UnrollAnalyzerTest, CmpSimplifications) {
181 const char *ModuleStr =
182 "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
183 "define void @branch_iv_trunc() {\n"
184 "entry:\n"
185 " br label %for.body\n"
186 "for.body:\n"
187 " %indvars.iv = phi i64 [ 0, %entry ], [ %tmp3, %for.body ]\n"
188 " %tmp2 = trunc i64 %indvars.iv to i32\n"
189 " %cmp3 = icmp eq i32 %tmp2, 5\n"
190 " %tmp3 = add nuw nsw i64 %indvars.iv, 1\n"
191 " %exitcond = icmp eq i64 %tmp3, 10\n"
192 " br i1 %exitcond, label %for.end, label %for.body\n"
193 "for.end:\n"
194 " ret void\n"
195 "}\n";
196 UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
197 LLVMContext Context;
198 std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
199 legacy::PassManager Passes;
200 Passes.add(P);
201 Passes.run(*M);
202
203 // Perform checks
204 Module::iterator MI = M->begin();
205 Function *F = &*MI++;
206 Function::iterator FI = F->begin();
207 FI++; // First basic block is entry - skip it.
208 BasicBlock *Header = &*FI++;
209
210 BasicBlock::iterator BBI = Header->begin();
211 BBI++;
212 Instruction *Y1 = &*BBI++;
213 Instruction *Y2 = &*BBI++;
214 // Check simplification expected on the 5th iteration.
215 // Check that "%tmp2 = trunc i64 %indvars.iv to i32" is simplified to 5
216 // and "%cmp3 = icmp eq i32 %tmp2, 5" is simplified to 1 (i.e. true).
217 auto I1 = SimplifiedValuesVector[5].find(Y1);
218 EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
219 EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 5U);
220 auto I2 = SimplifiedValuesVector[5].find(Y2);
221 EXPECT_TRUE(I2 != SimplifiedValuesVector[5].end());
222 EXPECT_EQ(cast<ConstantInt>((*I2).second)->getZExtValue(), 1U);
223 }
TEST(UnrollAnalyzerTest,PtrCmpSimplifications)224 TEST(UnrollAnalyzerTest, PtrCmpSimplifications) {
225 const char *ModuleStr =
226 "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
227 "define void @ptr_cmp(i8 *%a) {\n"
228 "entry:\n"
229 " %limit = getelementptr i8, i8* %a, i64 40\n"
230 " %start.iv2 = getelementptr i8, i8* %a, i64 7\n"
231 " br label %loop.body\n"
232 "loop.body:\n"
233 " %iv.0 = phi i8* [ %a, %entry ], [ %iv.1, %loop.body ]\n"
234 " %iv2.0 = phi i8* [ %start.iv2, %entry ], [ %iv2.1, %loop.body ]\n"
235 " %cmp = icmp eq i8* %iv2.0, %iv.0\n"
236 " %iv.1 = getelementptr inbounds i8, i8* %iv.0, i64 1\n"
237 " %iv2.1 = getelementptr inbounds i8, i8* %iv2.0, i64 1\n"
238 " %exitcond = icmp ne i8* %iv.1, %limit\n"
239 " br i1 %exitcond, label %loop.body, label %loop.exit\n"
240 "loop.exit:\n"
241 " ret void\n"
242 "}\n";
243 UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
244 LLVMContext Context;
245 std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
246 legacy::PassManager Passes;
247 Passes.add(P);
248 Passes.run(*M);
249
250 // Perform checks
251 Module::iterator MI = M->begin();
252 Function *F = &*MI++;
253 Function::iterator FI = F->begin();
254 FI++; // First basic block is entry - skip it.
255 BasicBlock *Header = &*FI;
256
257 BasicBlock::iterator BBI = Header->begin();
258 std::advance(BBI, 2);
259 Instruction *Y1 = &*BBI;
260 // Check simplification expected on the 5th iteration.
261 // Check that "%cmp = icmp eq i8* %iv2.0, %iv.0" is simplified to 0.
262 auto I1 = SimplifiedValuesVector[5].find(Y1);
263 EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
264 EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 0U);
265 }
TEST(UnrollAnalyzerTest,CastSimplifications)266 TEST(UnrollAnalyzerTest, CastSimplifications) {
267 const char *ModuleStr =
268 "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n"
269 "@known_constant = internal unnamed_addr constant [10 x i32] [i32 0, i32 1, i32 0, i32 1, i32 0, i32 259, i32 0, i32 1, i32 0, i32 1], align 16\n"
270 "define void @const_load_cast() {\n"
271 "entry:\n"
272 " br label %loop\n"
273 "\n"
274 "loop:\n"
275 " %iv = phi i64 [ 0, %entry ], [ %inc, %loop ]\n"
276 " %array_const_idx = getelementptr inbounds [10 x i32], [10 x i32]* @known_constant, i64 0, i64 %iv\n"
277 " %const_array_element = load i32, i32* %array_const_idx, align 4\n"
278 " %se = sext i32 %const_array_element to i64\n"
279 " %ze = zext i32 %const_array_element to i64\n"
280 " %tr = trunc i32 %const_array_element to i8\n"
281 " %inc = add nuw nsw i64 %iv, 1\n"
282 " %exitcond86.i = icmp eq i64 %inc, 10\n"
283 " br i1 %exitcond86.i, label %loop.end, label %loop\n"
284 "\n"
285 "loop.end:\n"
286 " ret void\n"
287 "}\n";
288
289 UnrollAnalyzerTest *P = new UnrollAnalyzerTest();
290 LLVMContext Context;
291 std::unique_ptr<Module> M = makeLLVMModule(Context, ModuleStr);
292 legacy::PassManager Passes;
293 Passes.add(P);
294 Passes.run(*M);
295
296 // Perform checks
297 Module::iterator MI = M->begin();
298 Function *F = &*MI++;
299 Function::iterator FI = F->begin();
300 FI++; // First basic block is entry - skip it.
301 BasicBlock *Header = &*FI++;
302
303 BasicBlock::iterator BBI = Header->begin();
304 std::advance(BBI, 3);
305 Instruction *Y1 = &*BBI++;
306 Instruction *Y2 = &*BBI++;
307 Instruction *Y3 = &*BBI++;
308 // Check simplification expected on the 5th iteration.
309 // "%se = sext i32 %const_array_element to i64" should be simplified to 259,
310 // "%ze = zext i32 %const_array_element to i64" should be simplified to 259,
311 // "%tr = trunc i32 %const_array_element to i8" should be simplified to 3.
312 auto I1 = SimplifiedValuesVector[5].find(Y1);
313 EXPECT_TRUE(I1 != SimplifiedValuesVector[5].end());
314 EXPECT_EQ(cast<ConstantInt>((*I1).second)->getZExtValue(), 259U);
315 auto I2 = SimplifiedValuesVector[5].find(Y2);
316 EXPECT_TRUE(I2 != SimplifiedValuesVector[5].end());
317 EXPECT_EQ(cast<ConstantInt>((*I2).second)->getZExtValue(), 259U);
318 auto I3 = SimplifiedValuesVector[5].find(Y3);
319 EXPECT_TRUE(I3 != SimplifiedValuesVector[5].end());
320 EXPECT_EQ(cast<ConstantInt>((*I3).second)->getZExtValue(), 3U);
321 }
322
323 } // end namespace llvm
324
325 INITIALIZE_PASS_BEGIN(UnrollAnalyzerTest, "unrollanalyzertestpass",
326 "unrollanalyzertestpass", false, false)
327 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
328 INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)
329 INITIALIZE_PASS_DEPENDENCY(ScalarEvolutionWrapperPass)
330 INITIALIZE_PASS_END(UnrollAnalyzerTest, "unrollanalyzertestpass",
331 "unrollanalyzertestpass", false, false)
332