1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17/**
18 * Tests for last value of a few periodic sequences
19 * (found by fuzz testing).
20 */
21public class Main {
22
23  /// CHECK-START: int Main.doitUpInt(int) loop_optimization (before)
24  /// CHECK-DAG: <<Phi:i\d+>> Phi  loop:<<Loop:B\d+>> outer_loop:none
25  /// CHECK-DAG:              Phi  loop:<<Loop>>      outer_loop:none
26  //
27  /// CHECK-START: int Main.doitUpInt(int) loop_optimization (after)
28  /// CHECK-NOT: Phi
29  static int doitUpInt(int n) {
30    // Complete loop is replaced by last-value.
31    int lI = 1;
32    for (int i1 = 0; i1  < n; i1++) {
33      lI = (1486662021 - lI);
34    }
35    return lI;
36  }
37
38  /// CHECK-START: int Main.doitDownInt(int) loop_optimization (before)
39  /// CHECK-DAG: <<Phi:i\d+>> Phi  loop:<<Loop:B\d+>> outer_loop:none
40  /// CHECK-DAG:              Phi  loop:<<Loop>>      outer_loop:none
41  //
42  /// CHECK-START: int Main.doitDownInt(int) loop_optimization (after)
43  /// CHECK-NOT: Phi
44  static int doitDownInt(int n) {
45    // Complete loop is replaced by last-value.
46    int lI = 1;
47    for (int i1 = n - 1; i1 >= 0; i1--) {
48      lI = (1486662021 - lI);
49    }
50    return lI;
51  }
52
53  /// CHECK-START: float Main.doitUpFloat(int) loop_optimization (before)
54  /// CHECK-DAG: <<Phi:i\d+>> Phi  loop:<<Loop:B\d+>> outer_loop:none
55  /// CHECK-DAG:              Phi  loop:<<Loop>>      outer_loop:none
56  //
57  /// CHECK-START: float Main.doitUpFloat(int) loop_optimization (after)
58  /// CHECK-DAG: <<Phi:i\d+>> Phi  loop:<<Loop:B\d+>> outer_loop:none
59  /// CHECK-DAG:              Phi  loop:<<Loop>>      outer_loop:none
60  static float doitUpFloat(int n) {
61    // FP arithmetic is not sufficiently precise.
62    // The loop remains.
63    float lF = 1.0f;
64    for (int i1 = 0; i1  < n; i1++) {
65      lF = (1486662021.0f - lF);
66    }
67    return lF;
68  }
69
70  /// CHECK-START: float Main.doitDownFloat(int) loop_optimization (before)
71  /// CHECK-DAG: <<Phi:i\d+>> Phi  loop:<<Loop:B\d+>> outer_loop:none
72  /// CHECK-DAG:              Phi  loop:<<Loop>>      outer_loop:none
73  //
74  /// CHECK-START: float Main.doitDownFloat(int) loop_optimization (after)
75  /// CHECK-DAG: <<Phi:i\d+>> Phi  loop:<<Loop:B\d+>> outer_loop:none
76  /// CHECK-DAG:              Phi  loop:<<Loop>>      outer_loop:none
77  static float doitDownFloat(int n) {
78    // FP arithmetic is not sufficiently precise.
79    // The loop remains.
80    float lF = 1.0f;
81    for (int i1 = n - 1; i1 >= 0; i1--) {
82      lF = (1486662021.0f - lF);
83    }
84    return lF;
85  }
86
87  /// CHECK-START: float Main.doitUpFloatAlt(int) loop_optimization (before)
88  /// CHECK-DAG: <<Phi:i\d+>> Phi  loop:<<Loop:B\d+>> outer_loop:none
89  /// CHECK-DAG:              Phi  loop:<<Loop>>      outer_loop:none
90  //
91  /// CHECK-START: float Main.doitUpFloatAlt(int) loop_optimization (after)
92  /// CHECK-NOT: Phi
93  static float doitUpFloatAlt(int n) {
94    // Complete loop is replaced by last-value
95    // since the values are now precise.
96    float lF = 1.0f;
97    float l2 = 1486662020.0f;
98    for (int i1 = 0; i1  < n; i1++) {
99      float old = lF;
100      lF = l2;
101      l2 = old;
102    }
103    return lF;
104  }
105
106  /// CHECK-START: float Main.doitDownFloatAlt(int) loop_optimization (before)
107  /// CHECK-DAG: <<Phi:i\d+>> Phi  loop:<<Loop:B\d+>> outer_loop:none
108  /// CHECK-DAG:              Phi  loop:<<Loop>>      outer_loop:none
109  //
110  /// CHECK-START: float Main.doitDownFloatAlt(int) loop_optimization (after)
111  /// CHECK-NOT: Phi
112  static float doitDownFloatAlt(int n) {
113    // Complete loop is replaced by last-value
114    // since the values are now precise.
115    float lF = 1.0f;
116    float l2 = 1486662020.0f;
117    for (int i1 = n - 1; i1 >= 0; i1--) {
118      float old = lF;
119      lF = l2;
120      l2 = old;
121    }
122    return lF;
123  }
124
125  // Main driver.
126  public static void main(String[] args) {
127    for (int i = 0; i < 10; i++) {
128      int ei = (i & 1) == 0 ? 1 : 1486662020;
129      int ci = doitUpInt(i);
130      expectEquals(ei, ci);
131    }
132    for (int i = 0; i < 10; i++) {
133      int ei = (i & 1) == 0 ? 1 : 1486662020;
134      int ci = doitDownInt(i);
135      expectEquals(ei, ci);
136    }
137    for (int i = 0; i < 10; i++) {
138      float ef = i == 0 ? 1.0f : ((i & 1) == 0 ? 0.0f : 1486662021.0f);
139      float cf = doitUpFloat(i);
140      expectEquals(ef, cf);
141    }
142    for (int i = 0; i < 10; i++) {
143      float ef = i == 0 ? 1.0f : ((i & 1) == 0 ? 0.0f : 1486662021.0f);
144      float cf = doitDownFloat(i);
145      expectEquals(ef, cf);
146    }
147    for (int i = 0; i < 10; i++) {
148      float ef = (i & 1) == 0 ? 1.0f : 1486662020.0f;
149      float cf = doitUpFloatAlt(i);
150      expectEquals(ef, cf);
151    }
152    for (int i = 0; i < 10; i++) {
153      float ef = (i & 1) == 0 ? 1.0f : 1486662020.0f;
154      float cf = doitDownFloatAlt(i);
155      expectEquals(ef, cf);
156    }
157    System.out.println("passed");
158  }
159
160  private static void expectEquals(int expected, int result) {
161    if (expected != result) {
162      throw new Error("Expected: " + expected + ", found: " + result);
163    }
164  }
165
166  private static void expectEquals(float expected, float result) {
167    if (expected != result) {
168      throw new Error("Expected: " + expected + ", found: " + result);
169    }
170  }
171}
172
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174