ART: ARM64: Fix saved fpu stack offsets for SIMD.

Fix the bug when a wrong stack offset was recorded for a FP
saved in a SlowPathCode: this happened when graph had SIMD
loops and some regular FP registers live across a slow path.

Test: test-art-target, test-art-host.

Change-Id: I08b32c9877fcd468dafa6027c156e544d730f1f7

5 files changed, 183 insertions, 54 deletions

diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index aeef90ac96..492fe4da8e 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -224,12 +224,13 @@ void SlowPathCodeARM64::SaveLiveRegisters(CodeGenerator* codegen, LocationSummar
     stack_offset += kXRegSizeInBytes;
   }
 
+  const size_t fp_reg_size = codegen->GetGraph()->HasSIMD() ? kQRegSizeInBytes : kDRegSizeInBytes;
   const uint32_t fp_spills = codegen->GetSlowPathSpills(locations, /* core_registers= */ false);
   for (uint32_t i : LowToHighBits(fp_spills)) {
     DCHECK_LT(stack_offset, codegen->GetFrameSize() - codegen->FrameEntrySpillSize());
     DCHECK_LT(i, kMaximumNumberOfExpectedRegisters);
     saved_fpu_stack_offsets_[i] = stack_offset;
-    stack_offset += kDRegSizeInBytes;
+    stack_offset += fp_reg_size;
   }
 
   SaveRestoreLiveRegistersHelper(codegen,
@@ -1279,16 +1280,18 @@ size_t CodeGeneratorARM64::RestoreCoreRegister(size_t stack_index, uint32_t reg_
   return kArm64WordSize;
 }
 
-size_t CodeGeneratorARM64::SaveFloatingPointRegister(size_t stack_index, uint32_t reg_id) {
-  FPRegister reg = FPRegister(reg_id, kDRegSize);
-  __ Str(reg, MemOperand(sp, stack_index));
-  return kArm64WordSize;
+size_t CodeGeneratorARM64::SaveFloatingPointRegister(size_t stack_index ATTRIBUTE_UNUSED,
+                                                     uint32_t reg_id ATTRIBUTE_UNUSED) {
+  LOG(FATAL) << "FP registers shouldn't be saved/restored individually, "
+             << "use SaveRestoreLiveRegistersHelper";
+  UNREACHABLE();
 }
 
-size_t CodeGeneratorARM64::RestoreFloatingPointRegister(size_t stack_index, uint32_t reg_id) {
-  FPRegister reg = FPRegister(reg_id, kDRegSize);
-  __ Ldr(reg, MemOperand(sp, stack_index));
-  return kArm64WordSize;
+size_t CodeGeneratorARM64::RestoreFloatingPointRegister(size_t stack_index ATTRIBUTE_UNUSED,
+                                                        uint32_t reg_id ATTRIBUTE_UNUSED) {
+  LOG(FATAL) << "FP registers shouldn't be saved/restored individually, "
+             << "use SaveRestoreLiveRegistersHelper";
+  UNREACHABLE();
 }
 
 void CodeGeneratorARM64::DumpCoreRegister(std::ostream& stream, int reg) const {
diff --git a/test/597-deopt-busy-loop/expected.txt b/test/597-deopt-busy-loop/expected.txt
index f993efcdad..6e2fc8e25e 100644
--- a/test/597-deopt-busy-loop/expected.txt
+++ b/test/597-deopt-busy-loop/expected.txt
@@ -1,2 +1,3 @@
 JNI_OnLoad called
-Finishing
+Simple loop finishing
+Float loop finishing
diff --git a/test/597-deopt-busy-loop/src/FloatLoop.java b/test/597-deopt-busy-loop/src/FloatLoop.java
new file mode 100644
index 0000000000..57667a68a4
--- /dev/null
+++ b/test/597-deopt-busy-loop/src/FloatLoop.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+// This test checks that FP registers spill offset is correctly recorded in the SlowPath; by causing
+// asynchronous deoptimization in debuggable mode we observe the FP values in the interpreter.
+public class FloatLoop implements Runnable {
+    static final int numberOfThreads = 2;
+    volatile static boolean sExitFlag = false;
+    volatile static boolean sEntered = false;
+    int threadIndex;
+
+    FloatLoop(int index) {
+        threadIndex = index;
+    }
+
+    public static void main() throws Exception {
+        final Thread[] threads = new Thread[numberOfThreads];
+        for (int t = 0; t < threads.length; t++) {
+            threads[t] = new Thread(new FloatLoop(t));
+            threads[t].start();
+        }
+        for (Thread t : threads) {
+            t.join();
+        }
+
+        System.out.println("Float loop finishing");
+    }
+
+    static final float kFloatConst0 = 256.0f;
+    static final float kFloatConst1 = 128.0f;
+    static final int kArraySize = 128;
+    volatile static float floatField;
+
+    public void expectEqualToEither(float value, float expected0, float expected1) {
+        if (value != expected0 && value != expected1) {
+            throw new Error("Expected:  " + expected0 + " or "+ expected1 +
+                            ", found: " + value);
+        }
+    }
+
+    public void $noinline$busyLoop() {
+        Main.assertIsManaged();
+
+        // On Arm64:
+        // This loop is likely to be vectorized which causes the full 16-byte Q-register to be saved
+        // across slow paths.
+        int[] array = new int[kArraySize];
+        for (int i = 0; i < kArraySize; i++) {
+            array[i]++;
+        }
+
+        sEntered = true;
+        float s0 = kFloatConst0;
+        float s1 = kFloatConst1;
+        for (int i = 0; !sExitFlag; i++) {
+            if (i % 2 == 0) {
+                s0 += 2.0;
+                s1 += 2.0;
+            } else {
+                s0 -= 2.0;
+                s1 -= 2.0;
+            }
+            // SuspendCheckSlowPath must record correct stack offset for spilled FP registers.
+        }
+        Main.assertIsInterpreted();
+
+        expectEqualToEither(s0, kFloatConst0, kFloatConst0 + 2.0f);
+        expectEqualToEither(s1, kFloatConst1, kFloatConst1 + 2.0f);
+
+        floatField = s0 + s1;
+    }
+
+    public void run() {
+        if (threadIndex == 0) {
+            while (!sEntered) {
+              Thread.yield();
+            }
+            Main.deoptimizeAll();
+            sExitFlag = true;
+        } else {
+            $noinline$busyLoop();
+        }
+    }
+}
diff --git a/test/597-deopt-busy-loop/src/Main.java b/test/597-deopt-busy-loop/src/Main.java
index 46b6bbf4f3..d15c6c7835 100644
--- a/test/597-deopt-busy-loop/src/Main.java
+++ b/test/597-deopt-busy-loop/src/Main.java
@@ -14,56 +14,22 @@
  * limitations under the License.
  */
 
-public class Main implements Runnable {
-    static final int numberOfThreads = 2;
-    volatile static boolean sExitFlag = false;
-    volatile static boolean sEntered = false;
-    int threadIndex;
+public class Main {
 
-    private static native void deoptimizeAll();
-    private static native void assertIsInterpreted();
-    private static native void assertIsManaged();
+    public static native void deoptimizeAll();
+    public static native void undeoptimizeAll();
+    public static native void assertIsInterpreted();
+    public static native void assertIsManaged();
     private static native void ensureJitCompiled(Class<?> cls, String methodName);
 
-    Main(int index) {
-        threadIndex = index;
-    }
-
     public static void main(String[] args) throws Exception {
         System.loadLibrary(args[0]);
 
-        final Thread[] threads = new Thread[numberOfThreads];
-        for (int t = 0; t < threads.length; t++) {
-            threads[t] = new Thread(new Main(t));
-            threads[t].start();
-        }
-        for (Thread t : threads) {
-            t.join();
-        }
-        System.out.println("Finishing");
-    }
-
-    public void $noinline$busyLoop() {
-        assertIsManaged();
-        sEntered = true;
-        for (;;) {
-            if (sExitFlag) {
-                break;
-            }
-        }
-        assertIsInterpreted();
-    }
+        ensureJitCompiled(SimpleLoop.class, "$noinline$busyLoop");
+        SimpleLoop.main();
 
-    public void run() {
-        if (threadIndex == 0) {
-            while (!sEntered) {
-              Thread.yield();
-            }
-            deoptimizeAll();
-            sExitFlag = true;
-        } else {
-            ensureJitCompiled(Main.class, "$noinline$busyLoop");
-            $noinline$busyLoop();
-        }
+        undeoptimizeAll();
+        ensureJitCompiled(FloatLoop.class, "$noinline$busyLoop");
+        FloatLoop.main();
     }
 }
diff --git a/test/597-deopt-busy-loop/src/SimpleLoop.java b/test/597-deopt-busy-loop/src/SimpleLoop.java
new file mode 100644
index 0000000000..12298a90d9
--- /dev/null
+++ b/test/597-deopt-busy-loop/src/SimpleLoop.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2017 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 SimpleLoop implements Runnable {
+    static final int numberOfThreads = 2;
+    volatile static boolean sExitFlag = false;
+    volatile static boolean sEntered = false;
+    int threadIndex;
+
+    SimpleLoop(int index) {
+        threadIndex = index;
+    }
+
+    public static void main() throws Exception {
+        final Thread[] threads = new Thread[numberOfThreads];
+        for (int t = 0; t < threads.length; t++) {
+            threads[t] = new Thread(new SimpleLoop(t));
+            threads[t].start();
+        }
+        for (Thread t : threads) {
+            t.join();
+        }
+
+        System.out.println("Simple loop finishing");
+    }
+
+    public void $noinline$busyLoop() {
+        Main.assertIsManaged();
+        sEntered = true;
+        for (;;) {
+            if (sExitFlag) {
+                break;
+            }
+        }
+        Main.assertIsInterpreted();
+    }
+
+    public void run() {
+        if (threadIndex == 0) {
+            while (!sEntered) {
+              Thread.yield();
+            }
+            Main.deoptimizeAll();
+            sExitFlag = true;
+        } else {
+            $noinline$busyLoop();
+        }
+    }
+}