Assume fp operations can also take a constant on x86.

Because irreducible loops disable the constant pool optimization
on x86, we need to handle cases where a fp operation gets one.

Change-Id: I43387f31aa2589d02112953baa62fd0994d0a6d7
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 18d70da..da054ba 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -2688,6 +2688,8 @@
       locations->SetInAt(0, Location::RequiresFpuRegister());
       if (add->InputAt(1)->IsX86LoadFromConstantTable()) {
         DCHECK(add->InputAt(1)->IsEmittedAtUseSite());
+      } else if (add->InputAt(1)->IsConstant()) {
+        locations->SetInAt(1, Location::RequiresFpuRegister());
       } else {
         locations->SetInAt(1, Location::Any());
       }
@@ -2804,6 +2806,8 @@
       locations->SetInAt(0, Location::RequiresFpuRegister());
       if (sub->InputAt(1)->IsX86LoadFromConstantTable()) {
         DCHECK(sub->InputAt(1)->IsEmittedAtUseSite());
+      } else if (sub->InputAt(1)->IsConstant()) {
+        locations->SetInAt(1, Location::RequiresFpuRegister());
       } else {
         locations->SetInAt(1, Location::Any());
       }
@@ -2918,6 +2922,8 @@
       locations->SetInAt(0, Location::RequiresFpuRegister());
       if (mul->InputAt(1)->IsX86LoadFromConstantTable()) {
         DCHECK(mul->InputAt(1)->IsEmittedAtUseSite());
+      } else if (mul->InputAt(1)->IsConstant()) {
+        locations->SetInAt(1, Location::RequiresFpuRegister());
       } else {
         locations->SetInAt(1, Location::Any());
       }
@@ -3415,6 +3421,8 @@
       locations->SetInAt(0, Location::RequiresFpuRegister());
       if (div->InputAt(1)->IsX86LoadFromConstantTable()) {
         DCHECK(div->InputAt(1)->IsEmittedAtUseSite());
+      } else if (div->InputAt(1)->IsConstant()) {
+        locations->SetInAt(1, Location::RequiresFpuRegister());
       } else {
         locations->SetInAt(1, Location::Any());
       }
diff --git a/test/571-irreducible-loop/expected.txt b/test/571-irreducible-loop/expected.txt
new file mode 100644
index 0000000..3a71184
--- /dev/null
+++ b/test/571-irreducible-loop/expected.txt
@@ -0,0 +1 @@
+5.9E-44
diff --git a/test/571-irreducible-loop/info.txt b/test/571-irreducible-loop/info.txt
new file mode 100644
index 0000000..1e0dd02
--- /dev/null
+++ b/test/571-irreducible-loop/info.txt
@@ -0,0 +1,2 @@
+Regression test for optimizing in the presence of
+an irreducible loop.
diff --git a/test/571-irreducible-loop/smali/IrreducibleLoop.smali b/test/571-irreducible-loop/smali/IrreducibleLoop.smali
new file mode 100644
index 0000000..737a18b
--- /dev/null
+++ b/test/571-irreducible-loop/smali/IrreducibleLoop.smali
@@ -0,0 +1,47 @@
+# Copyright (C) 2016 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 LIrreducibleLoop;
+
+.super Ljava/lang/Object;
+
+# Check that on x86 we don't crash because irreducible loops
+# disabled the constant pool optimization.
+.method public static test1(IF)F
+   .registers 5
+   const/16 v0, 1
+   const/16 v1, 42
+
+   if-nez p0, :loop_entry
+   goto :other_loop_pre_entry
+
+   # The then part: beginning of the irreducible loop.
+   :loop_entry
+   if-eqz p0, :exit
+   add-float v2, p1, v1
+   sub-float v2, v2, v1
+   div-float v2, v2, v1
+   mul-float v2, v2, v1
+   :other_loop_entry
+   sub-int p0, p0, v0
+   goto :loop_entry
+
+   # The other block branching to the irreducible loop.
+   # In that block, v4 has no live range.
+   :other_loop_pre_entry
+   goto :other_loop_entry
+
+   :exit
+   return v1
+.end method
diff --git a/test/571-irreducible-loop/src/Main.java b/test/571-irreducible-loop/src/Main.java
new file mode 100644
index 0000000..ff22f67
--- /dev/null
+++ b/test/571-irreducible-loop/src/Main.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2016 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.Method;
+
+public class Main {
+  // Workaround for b/18051191.
+  class InnerClass {}
+
+  public static void main(String[] args) throws Exception {
+    Class<?> c = Class.forName("IrreducibleLoop");
+    Method m = c.getMethod("test1", int.class, float.class);
+    Object[] arguments = { 42, 31.0f };
+    System.out.println(m.invoke(null, arguments));
+  }
+}