aboutsummaryrefslogtreecommitdiffstats
path: root/unittests/Analysis/ScalarEvolutionTest.cpp
blob: 90f6997e98cda836d2124509c91b72402c16479e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
//===- ScalarEvolutionsTest.cpp - ScalarEvolution unit tests --------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/Analysis/ScalarEvolutionExpressions.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/PassManager.h"
#include "gtest/gtest.h"

namespace llvm {
namespace {

// We use this fixture to ensure that we clean up ScalarEvolution before
// deleting the PassManager.
class ScalarEvolutionsTest : public testing::Test {
protected:
  ScalarEvolutionsTest() : M("", Context), SE(*new ScalarEvolution) {}
  ~ScalarEvolutionsTest() {
    // Manually clean up, since we allocated new SCEV objects after the
    // pass was finished.
    SE.releaseMemory();
  }
  LLVMContext Context;
  Module M;
  PassManager PM;
  ScalarEvolution &SE;
};

TEST_F(ScalarEvolutionsTest, SCEVUnknownRAUW) {
  FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context),
                                              std::vector<Type *>(), false);
  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
  BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
  ReturnInst::Create(Context, nullptr, BB);

  Type *Ty = Type::getInt1Ty(Context);
  Constant *Init = Constant::getNullValue(Ty);
  Value *V0 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V0");
  Value *V1 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V1");
  Value *V2 = new GlobalVariable(M, Ty, false, GlobalValue::ExternalLinkage, Init, "V2");

  // Create a ScalarEvolution and "run" it so that it gets initialized.
  PM.add(&SE);
  PM.run(M);

  const SCEV *S0 = SE.getSCEV(V0);
  const SCEV *S1 = SE.getSCEV(V1);
  const SCEV *S2 = SE.getSCEV(V2);

  const SCEV *P0 = SE.getAddExpr(S0, S0);
  const SCEV *P1 = SE.getAddExpr(S1, S1);
  const SCEV *P2 = SE.getAddExpr(S2, S2);

  const SCEVMulExpr *M0 = cast<SCEVMulExpr>(P0);
  const SCEVMulExpr *M1 = cast<SCEVMulExpr>(P1);
  const SCEVMulExpr *M2 = cast<SCEVMulExpr>(P2);

  EXPECT_EQ(cast<SCEVConstant>(M0->getOperand(0))->getValue()->getZExtValue(),
            2u);
  EXPECT_EQ(cast<SCEVConstant>(M1->getOperand(0))->getValue()->getZExtValue(),
            2u);
  EXPECT_EQ(cast<SCEVConstant>(M2->getOperand(0))->getValue()->getZExtValue(),
            2u);

  // Before the RAUWs, these are all pointing to separate values.
  EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
  EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V1);
  EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V2);

  // Do some RAUWs.
  V2->replaceAllUsesWith(V1);
  V1->replaceAllUsesWith(V0);

  // After the RAUWs, these should all be pointing to V0.
  EXPECT_EQ(cast<SCEVUnknown>(M0->getOperand(1))->getValue(), V0);
  EXPECT_EQ(cast<SCEVUnknown>(M1->getOperand(1))->getValue(), V0);
  EXPECT_EQ(cast<SCEVUnknown>(M2->getOperand(1))->getValue(), V0);
}

TEST_F(ScalarEvolutionsTest, SCEVMultiplyAddRecs) {
  Type *Ty = Type::getInt32Ty(Context);
  SmallVector<Type *, 10> Types;
  Types.append(10, Ty);
  FunctionType *FTy = FunctionType::get(Type::getVoidTy(Context), Types, false);
  Function *F = cast<Function>(M.getOrInsertFunction("f", FTy));
  BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
  ReturnInst::Create(Context, nullptr, BB);

  // Create a ScalarEvolution and "run" it so that it gets initialized.
  PM.add(&SE);
  PM.run(M);

  // It's possible to produce an empty loop through the default constructor,
  // but you can't add any blocks to it without a LoopInfo pass.
  Loop L;
  const_cast<std::vector<BasicBlock*>&>(L.getBlocks()).push_back(BB);

  Function::arg_iterator AI = F->arg_begin();
  SmallVector<const SCEV *, 5> A;
  A.push_back(SE.getSCEV(&*AI++));
  A.push_back(SE.getSCEV(&*AI++));
  A.push_back(SE.getSCEV(&*AI++));
  A.push_back(SE.getSCEV(&*AI++));
  A.push_back(SE.getSCEV(&*AI++));
  const SCEV *A_rec = SE.getAddRecExpr(A, &L, SCEV::FlagAnyWrap);

  SmallVector<const SCEV *, 5> B;
  B.push_back(SE.getSCEV(&*AI++));
  B.push_back(SE.getSCEV(&*AI++));
  B.push_back(SE.getSCEV(&*AI++));
  B.push_back(SE.getSCEV(&*AI++));
  B.push_back(SE.getSCEV(&*AI++));
  const SCEV *B_rec = SE.getAddRecExpr(B, &L, SCEV::FlagAnyWrap);

  /* Spot check that we perform this transformation:
     {A0,+,A1,+,A2,+,A3,+,A4} * {B0,+,B1,+,B2,+,B3,+,B4} =
     {A0*B0,+,
      A1*B0 + A0*B1 + A1*B1,+,
      A2*B0 + 2A1*B1 + A0*B2 + 2A2*B1 + 2A1*B2 + A2*B2,+,
      A3*B0 + 3A2*B1 + 3A1*B2 + A0*B3 + 3A3*B1 + 6A2*B2 + 3A1*B3 + 3A3*B2 +
        3A2*B3 + A3*B3,+,
      A4*B0 + 4A3*B1 + 6A2*B2 + 4A1*B3 + A0*B4 + 4A4*B1 + 12A3*B2 + 12A2*B3 +
        4A1*B4 + 6A4*B2 + 12A3*B3 + 6A2*B4 + 4A4*B3 + 4A3*B4 + A4*B4,+,
      5A4*B1 + 10A3*B2 + 10A2*B3 + 5A1*B4 + 20A4*B2 + 30A3*B3 + 20A2*B4 +
        30A4*B3 + 30A3*B4 + 20A4*B4,+,
      15A4*B2 + 20A3*B3 + 15A2*B4 + 60A4*B3 + 60A3*B4 + 90A4*B4,+,
      35A4*B3 + 35A3*B4 + 140A4*B4,+,
      70A4*B4}
  */

  const SCEVAddRecExpr *Product =
      dyn_cast<SCEVAddRecExpr>(SE.getMulExpr(A_rec, B_rec));
  ASSERT_TRUE(Product);
  ASSERT_EQ(Product->getNumOperands(), 9u);

  SmallVector<const SCEV *, 16> Sum;
  Sum.push_back(SE.getMulExpr(A[0], B[0]));
  EXPECT_EQ(Product->getOperand(0), SE.getAddExpr(Sum));
  Sum.clear();

  // SCEV produces different an equal but different expression for these.
  // Re-enable when PR11052 is fixed.
#if 0
  Sum.push_back(SE.getMulExpr(A[1], B[0]));
  Sum.push_back(SE.getMulExpr(A[0], B[1]));
  Sum.push_back(SE.getMulExpr(A[1], B[1]));
  EXPECT_EQ(Product->getOperand(1), SE.getAddExpr(Sum));
  Sum.clear();

  Sum.push_back(SE.getMulExpr(A[2], B[0]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 2), A[1], B[1]));
  Sum.push_back(SE.getMulExpr(A[0], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 2), A[2], B[1]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 2), A[1], B[2]));
  Sum.push_back(SE.getMulExpr(A[2], B[2]));
  EXPECT_EQ(Product->getOperand(2), SE.getAddExpr(Sum));
  Sum.clear();

  Sum.push_back(SE.getMulExpr(A[3], B[0]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[2], B[1]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[1], B[2]));
  Sum.push_back(SE.getMulExpr(A[0], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[3], B[1]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 6), A[2], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[1], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[3], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 3), A[2], B[3]));
  Sum.push_back(SE.getMulExpr(A[3], B[3]));
  EXPECT_EQ(Product->getOperand(3), SE.getAddExpr(Sum));
  Sum.clear();

  Sum.push_back(SE.getMulExpr(A[4], B[0]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[3], B[1]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 6), A[2], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[1], B[3]));
  Sum.push_back(SE.getMulExpr(A[0], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[4], B[1]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 12), A[3], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 12), A[2], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[1], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 6), A[4], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 12), A[3], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 6), A[2], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[4], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 4), A[3], B[4]));
  Sum.push_back(SE.getMulExpr(A[4], B[4]));
  EXPECT_EQ(Product->getOperand(4), SE.getAddExpr(Sum));
  Sum.clear();

  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 5), A[4], B[1]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 10), A[3], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 10), A[2], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 5), A[1], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 20), A[4], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 30), A[3], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 20), A[2], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 30), A[4], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 30), A[3], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 20), A[4], B[4]));
  EXPECT_EQ(Product->getOperand(5), SE.getAddExpr(Sum));
  Sum.clear();

  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 15), A[4], B[2]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 20), A[3], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 15), A[2], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 60), A[4], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 60), A[3], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 90), A[4], B[4]));
  EXPECT_EQ(Product->getOperand(6), SE.getAddExpr(Sum));
  Sum.clear();

  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 35), A[4], B[3]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 35), A[3], B[4]));
  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 140), A[4], B[4]));
  EXPECT_EQ(Product->getOperand(7), SE.getAddExpr(Sum));
  Sum.clear();
#endif

  Sum.push_back(SE.getMulExpr(SE.getConstant(Ty, 70), A[4], B[4]));
  EXPECT_EQ(Product->getOperand(8), SE.getAddExpr(Sum));
}

}  // end anonymous namespace
}  // end namespace llvm