Merge "Incorrect transformation of (sub,neg) to (sub) for fp"
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index b8ae1f6..f30c9a6 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -467,7 +467,8 @@
return;
}
- if (input->IsSub() && input->HasOnlyOneNonEnvironmentUse()) {
+ if (input->IsSub() && input->HasOnlyOneNonEnvironmentUse() &&
+ !Primitive::IsFloatingPointType(input->GetType())) {
// Replace code looking like
// SUB tmp, a, b
// NEG dst, tmp
@@ -478,6 +479,7 @@
// worse code. In particular, we do not want the live ranges of `a` and `b`
// to be extended if we are not sure the initial 'SUB' instruction can be
// removed.
+ // We do not perform optimization for fp because we could lose the sign of zero.
HSub* sub = input->AsSub();
HSub* new_sub =
new (GetGraph()->GetArena()) HSub(instruction->GetType(), sub->GetRight(), sub->GetLeft());
diff --git a/test/474-fp-sub-neg/expected.txt b/test/474-fp-sub-neg/expected.txt
new file mode 100644
index 0000000..e6ffe0d
--- /dev/null
+++ b/test/474-fp-sub-neg/expected.txt
@@ -0,0 +1,2 @@
+-0.0
+-0.0
diff --git a/test/474-fp-sub-neg/info.txt b/test/474-fp-sub-neg/info.txt
new file mode 100644
index 0000000..eced93f
--- /dev/null
+++ b/test/474-fp-sub-neg/info.txt
@@ -0,0 +1,5 @@
+Regression check for optimizing simplify instruction pass.
+A pair (sub, neg) should not be transforemd to (sub) for
+fp calculation because we can lose the sign of zero for
+the following expression:
+ - ( A - B ) != B - A ; if B == A
diff --git a/test/474-fp-sub-neg/src/Main.java b/test/474-fp-sub-neg/src/Main.java
new file mode 100644
index 0000000..e6bce67
--- /dev/null
+++ b/test/474-fp-sub-neg/src/Main.java
@@ -0,0 +1,45 @@
+/*
+ * 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.
+ */
+
+public class Main {
+ public static void floatTest() {
+ float f = 0;
+ float fc = 1f;
+ for (int i = 0; i < 2; i++) {
+ f -= fc;
+ f = -f;
+ }
+
+ System.out.println(f);
+ }
+
+ public static void doubleTest() {
+ double d = 0;
+ double dc = 1f;
+ for (int i = 0; i < 2; i++) {
+ d -= dc;
+ d = -d;
+ }
+
+ System.out.println(d);
+ }
+
+ public static void main(String[] args) {
+ doubleTest();
+ floatTest();
+ }
+
+}
