ART: General-case negation in boolean simplifier
Code transformations on the HGraph may optimize out the condition
instruction of an If and replace it with a boolean value. In such
case, the boolean simplifier would not know how to negate the
condition and would fail. This patch implements negation in this
general case with 'equals 0' as a substitute for the non-existing
boolean Not instruction.
Bug: 19992954
Change-Id: I152036fcc6bbecccc767d3024a5c060177597d88
diff --git a/compiler/optimizing/boolean_simplifier.cc b/compiler/optimizing/boolean_simplifier.cc
index ab77505..be432c5 100644
--- a/compiler/optimizing/boolean_simplifier.cc
+++ b/compiler/optimizing/boolean_simplifier.cc
@@ -59,7 +59,8 @@
return new (allocator) HGreaterThan(lhs, rhs);
} else if (cond->IsGreaterThan()) {
return new (allocator) HLessThanOrEqual(lhs, rhs);
- } else if (cond->IsGreaterThanOrEqual()) {
+ } else {
+ DCHECK(cond->IsGreaterThanOrEqual());
return new (allocator) HLessThan(lhs, rhs);
}
} else if (cond->IsIntConstant()) {
@@ -70,10 +71,11 @@
DCHECK(int_const->IsOne());
return graph->GetIntConstant(0);
}
+ } else {
+ // General case when 'cond' is another instruction of type boolean.
+ // Negate with 'cond == 0'.
+ return new (allocator) HEqual(cond, graph->GetIntConstant(0));
}
-
- // TODO: b/19992954
- return nullptr;
}
void HBooleanSimplifier::Run() {
@@ -105,10 +107,6 @@
HInstruction* replacement;
if (NegatesCondition(true_value, false_value)) {
replacement = GetOppositeCondition(if_condition);
- if (replacement == nullptr) {
- // Something we could not handle.
- continue;
- }
if (replacement->GetBlock() == nullptr) {
block->InsertInstructionBefore(replacement, if_instruction);
}
diff --git a/test/468-bool-simplifier-regression/expected.txt b/test/468-bool-simplifier-regression/expected.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/test/468-bool-simplifier-regression/expected.txt
diff --git a/test/468-bool-simplifier-regression/info.txt b/test/468-bool-simplifier-regression/info.txt
new file mode 100644
index 0000000..0a46584
--- /dev/null
+++ b/test/468-bool-simplifier-regression/info.txt
@@ -0,0 +1,2 @@
+Regression test for optimizing's boolean simplifier
+that used to trip when a boolean value was the input of an If.
diff --git a/test/468-bool-simplifier-regression/smali/TestCase.smali b/test/468-bool-simplifier-regression/smali/TestCase.smali
new file mode 100644
index 0000000..f36304d
--- /dev/null
+++ b/test/468-bool-simplifier-regression/smali/TestCase.smali
@@ -0,0 +1,32 @@
+# Copyright (C) 2015 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+.class public LTestCase;
+
+.super Ljava/lang/Object;
+
+.field public static value:Z
+
+.method public static testCase()Z
+ .registers 2
+ sget-boolean v0, LTestCase;->value:Z
+ const/4 v1, 1
+ if-eq v0, v1, :label1
+ const/4 v1, 1
+ goto :label2
+ :label1
+ const/4 v1, 0
+ :label2
+ return v1
+.end method
diff --git a/test/468-bool-simplifier-regression/src/Main.java b/test/468-bool-simplifier-regression/src/Main.java
new file mode 100644
index 0000000..1dd27c9
--- /dev/null
+++ b/test/468-bool-simplifier-regression/src/Main.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.lang.reflect.*;
+
+public class Main {
+ public static boolean runTest(boolean input) throws Exception {
+ Class<?> c = Class.forName("TestCase");
+ Method m = c.getMethod("testCase");
+ Field f = c.getField("value");
+ f.set(null, (Boolean) input);
+ return (Boolean) m.invoke(null);
+ }
+
+ public static void main(String[] args) throws Exception {
+ if (runTest(true) != false) {
+ throw new Error("Expected false, got true");
+ }
+
+ if (runTest(false) != true) {
+ throw new Error("Expected true, got false");
+ }
+ }
+}