Reproduce spill to fresh local in presence of unused argument
Bug: b/375142715
Change-Id: Ic7fc89b42bb559fb15124c25eb81678419139e4f
diff --git a/src/test/java/com/android/tools/r8/ir/regalloc/SpillToHighUnusedArgumentRegisterTest.java b/src/test/java/com/android/tools/r8/ir/regalloc/SpillToHighUnusedArgumentRegisterTest.java
new file mode 100644
index 0000000..f88127a
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/regalloc/SpillToHighUnusedArgumentRegisterTest.java
@@ -0,0 +1,108 @@
+// Copyright (c) 2024, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+package com.android.tools.r8.ir.regalloc;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.dex.code.DexMoveFrom16;
+import com.android.tools.r8.dex.code.DexMoveResult;
+import com.android.tools.r8.graph.DexCode;
+import com.android.tools.r8.utils.codeinspector.InstructionSubject;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import com.google.common.collect.MoreCollectors;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class SpillToHighUnusedArgumentRegisterTest extends TestBase {
+
+ @Parameter(0)
+ public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withDefaultDexRuntime().withMaximumApiLevel().build();
+ }
+
+ @Test
+ public void testD8() throws Exception {
+ testForD8()
+ .addInnerClasses(getClass())
+ .addOptionsModification(
+ options -> options.getTestingOptions().enableRegisterAllocation8BitRefinement = true)
+ .release()
+ .setMinApi(parameters)
+ .compile()
+ .inspect(
+ inspector -> {
+ MethodSubject testMethodSubject =
+ inspector.clazz(Main.class).uniqueMethodWithOriginalName("test");
+ assertThat(testMethodSubject, isPresent());
+
+ DexCode code = testMethodSubject.getMethod().getCode().asDexCode();
+ DexMoveResult moveResult =
+ testMethodSubject
+ .streamInstructions()
+ .filter(InstructionSubject::isMoveResult)
+ .collect(MoreCollectors.onlyElement())
+ .asDexInstruction()
+ .getInstruction();
+
+ DexMoveFrom16 spillMove =
+ testMethodSubject
+ .streamInstructions()
+ .filter(i -> i.isMoveFrom(moveResult.AA))
+ .collect(MoreCollectors.onlyElement())
+ .asDexInstruction()
+ .getInstruction();
+ int firstArgumentRegister = code.registerSize - code.incomingRegisterSize;
+ // TODO(b/375142715): We could have spilled this value to the unused argument
+ // register, which would have lead to fewer registers being used.
+ assertEquals(firstArgumentRegister - 1, spillMove.AA);
+ });
+ }
+
+ static class Main {
+
+ static void test(long a, long b, long c, long d, long e, long f, long g, long h, int unused) {
+ int i = getInt();
+ forceIntoLowRegister(i, i);
+ forceIntoLowRegister(a, a);
+ forceIntoLowRegister(b, b);
+ forceIntoLowRegister(c, c);
+ forceIntoLowRegister(d, d);
+ forceIntoLowRegister(e, e);
+ forceIntoLowRegister(f, f);
+ forceIntoLowRegister(g, g);
+ forceIntoLowRegister(h, h);
+ unconstrainedUse(i);
+ forceIntoLowRegister(a, a);
+ forceIntoLowRegister(b, b);
+ forceIntoLowRegister(c, c);
+ forceIntoLowRegister(d, d);
+ forceIntoLowRegister(e, e);
+ forceIntoLowRegister(f, f);
+ forceIntoLowRegister(g, g);
+ forceIntoLowRegister(h, h);
+ }
+
+ static int getInt() {
+ return 0;
+ }
+
+ static void forceIntoLowRegister(int a, int b) {}
+
+ static void forceIntoLowRegister(long a, long b) {}
+
+ static void unconstrainedUse(int a) {}
+ }
+}
diff --git a/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/CfInstructionSubject.java b/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/CfInstructionSubject.java
index 2c24643..6cc23c2 100644
--- a/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/CfInstructionSubject.java
+++ b/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/CfInstructionSubject.java
@@ -402,6 +402,16 @@
}
@Override
+ public boolean isMoveFrom(int register) {
+ return false;
+ }
+
+ @Override
+ public boolean isMoveResult() {
+ return false;
+ }
+
+ @Override
public boolean isFilledNewArray() {
return false;
}
diff --git a/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/DexInstructionSubject.java b/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/DexInstructionSubject.java
index f4e6a57..8c1d4a2 100644
--- a/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/DexInstructionSubject.java
+++ b/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/DexInstructionSubject.java
@@ -101,6 +101,9 @@
import com.android.tools.r8.dex.code.DexMoveObject;
import com.android.tools.r8.dex.code.DexMoveObject16;
import com.android.tools.r8.dex.code.DexMoveObjectFrom16;
+import com.android.tools.r8.dex.code.DexMoveResult;
+import com.android.tools.r8.dex.code.DexMoveResultObject;
+import com.android.tools.r8.dex.code.DexMoveResultWide;
import com.android.tools.r8.dex.code.DexMoveWide;
import com.android.tools.r8.dex.code.DexMoveWide16;
import com.android.tools.r8.dex.code.DexMoveWideFrom16;
@@ -664,6 +667,47 @@
}
@Override
+ public boolean isMoveFrom(int register) {
+ if (instruction instanceof DexMove) {
+ DexMove move = getInstruction();
+ return move.B == register;
+ } else if (instruction instanceof DexMove16) {
+ DexMove16 move = getInstruction();
+ return move.BBBB == register;
+ } else if (instruction instanceof DexMoveFrom16) {
+ DexMoveFrom16 move = getInstruction();
+ return move.BBBB == register;
+ } else if (instruction instanceof DexMoveObject) {
+ DexMoveObject move = getInstruction();
+ return move.B == register;
+ } else if (instruction instanceof DexMoveObject16) {
+ DexMoveObject16 move = getInstruction();
+ return move.BBBB == register;
+ } else if (instruction instanceof DexMoveObjectFrom16) {
+ DexMoveObjectFrom16 move = getInstruction();
+ return move.BBBB == register;
+ } else if (instruction instanceof DexMoveWide) {
+ DexMoveWide move = getInstruction();
+ return move.B == register;
+ } else if (instruction instanceof DexMoveWide16) {
+ DexMoveWide16 move = getInstruction();
+ return move.BBBB == register;
+ } else if (instruction instanceof DexMoveWideFrom16) {
+ DexMoveWideFrom16 move = getInstruction();
+ return move.BBBB == register;
+ } else {
+ return false;
+ }
+ }
+
+ @Override
+ public boolean isMoveResult() {
+ return instruction instanceof DexMoveResult
+ || instruction instanceof DexMoveResultObject
+ || instruction instanceof DexMoveResultWide;
+ }
+
+ @Override
public boolean isFilledNewArray() {
return instruction instanceof DexFilledNewArray
|| instruction instanceof DexFilledNewArrayRange;
@@ -705,7 +749,8 @@
return instruction.toString();
}
- public DexInstruction getInstruction() {
- return instruction;
+ @SuppressWarnings("unchecked")
+ public <T extends DexInstruction> T getInstruction() {
+ return (T) instruction;
}
}
diff --git a/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java b/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java
index 1852710..b23719d 100644
--- a/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java
+++ b/src/test/testbase/java/com/android/tools/r8/utils/codeinspector/InstructionSubject.java
@@ -166,6 +166,10 @@
boolean isMove();
+ boolean isMoveFrom(int register);
+
+ boolean isMoveResult();
+
boolean isFilledNewArray();
boolean isFilledNewArrayData();
