C++: Add testcases using the builtin expect operation.

Author: MathiasVP

cpp/ql/test/library-tests/controlflow/guards/Guards.expected

@@ -45,3 +45,7 @@
 | test.cpp:122:9:122:9 | b |
 | test.cpp:125:13:125:20 | ! ... |
 | test.cpp:125:14:125:17 | call to safe |
+| test.cpp:131:6:131:21 | call to __builtin_expect |
+| test.cpp:135:6:135:21 | call to __builtin_expect |
+| test.cpp:141:6:141:21 | call to __builtin_expect |
+| test.cpp:145:6:145:21 | call to __builtin_expect |

cpp/ql/test/library-tests/controlflow/guards/GuardsCompare.expected

@@ -166,8 +166,16 @@
 | 126 | call to test3_condition == 0 when call to test3_condition is false |
 | 131 | b != 0 when b is true |
 | 131 | b == 0 when b is false |
+| 131 | call to __builtin_expect != 0 when call to __builtin_expect is true |
+| 131 | call to __builtin_expect == 0 when call to __builtin_expect is false |
+| 135 | call to __builtin_expect != 0 when call to __builtin_expect is true |
+| 135 | call to __builtin_expect == 0 when call to __builtin_expect is false |
 | 137 | 0 != 0 when 0 is true |
 | 137 | 0 == 0 when 0 is false |
+| 141 | call to __builtin_expect != 0 when call to __builtin_expect is true |
+| 141 | call to __builtin_expect == 0 when call to __builtin_expect is false |
+| 145 | call to __builtin_expect != 0 when call to __builtin_expect is true |
+| 145 | call to __builtin_expect == 0 when call to __builtin_expect is false |
 | 146 | ! ... != 0 when ! ... is true |
 | 146 | ! ... == 0 when ! ... is false |
 | 146 | x != 0 when ! ... is false |

cpp/ql/test/library-tests/controlflow/guards/GuardsControl.expected

@@ -104,3 +104,7 @@
 | test.cpp:122:9:122:9 | b | true | 125 | 125 |
 | test.cpp:125:13:125:20 | ! ... | true | 125 | 125 |
 | test.cpp:125:14:125:17 | call to safe | false | 125 | 125 |
+| test.cpp:131:6:131:21 | call to __builtin_expect | true | 131 | 132 |
+| test.cpp:135:6:135:21 | call to __builtin_expect | true | 135 | 136 |
+| test.cpp:141:6:141:21 | call to __builtin_expect | true | 141 | 142 |
+| test.cpp:145:6:145:21 | call to __builtin_expect | true | 145 | 146 |

cpp/ql/test/library-tests/controlflow/guards/GuardsEnsure.expected

@@ -270,3 +270,7 @@ unary
 | test.cpp:122:9:122:9 | b | test.cpp:122:9:122:9 | b | != | 0 | 125 | 125 |
 | test.cpp:125:13:125:20 | ! ... | test.cpp:125:13:125:20 | ! ... | != | 0 | 125 | 125 |
 | test.cpp:125:14:125:17 | call to safe | test.cpp:125:14:125:17 | call to safe | == | 0 | 125 | 125 |
+| test.cpp:131:6:131:21 | call to __builtin_expect | test.cpp:131:6:131:21 | call to __builtin_expect | != | 0 | 131 | 132 |
+| test.cpp:135:6:135:21 | call to __builtin_expect | test.cpp:135:6:135:21 | call to __builtin_expect | != | 0 | 135 | 136 |
+| test.cpp:141:6:141:21 | call to __builtin_expect | test.cpp:141:6:141:21 | call to __builtin_expect | != | 0 | 141 | 142 |
+| test.cpp:145:6:145:21 | call to __builtin_expect | test.cpp:145:6:145:21 | call to __builtin_expect | != | 0 | 145 | 146 |

cpp/ql/test/library-tests/controlflow/guards/test.cpp

@@ -125,4 +125,24 @@ void test(bool b)
         if (!safe(x)) return;
     }
     use(x);
+}
+
+void binary_test_builtin_expected(int a, int b) {
+  if(__builtin_expect(a == b + 42, 0)) {
+      use(a);
+  }
+
+  if(__builtin_expect(a != b + 42, 0)) {
+      use(a);
+  }
+}
+
+void unary_test_builtin_expected(int a) {
+  if(__builtin_expect(a == 42, 0)) {
+      use(a);
+  }
+
+  if(__builtin_expect(a != 42, 0)) {
+      use(a);
+  }
 }