ARM64: Instruction simplification for array accesses.
HArrayGet and HArraySet with variable indexes generate two
instructions on arm64, like
add temp, obj, #data_offset
ldr out, [temp, index LSL #shift_amount]
When we have multiple accesses to the same array, the initial `add`
instruction is redundant.
This patch introduces the first instruction simplification in the
arm64-specific instruction simplification pass. It splits HArrayGet
and HArraySet using the new arm64-specific IR HIntermediateAddress.
After that we run GVN again to squash the multiple occurrences of
HIntermediateAddress.
Change-Id: I2e3d12fbb07fed07b2cb2f3f47f99f5a032f8312
diff --git a/test/527-checker-array-access-split/src/Main.java b/test/527-checker-array-access-split/src/Main.java
new file mode 100644
index 0000000..ead9446
--- /dev/null
+++ b/test/527-checker-array-access-split/src/Main.java
@@ -0,0 +1,341 @@
+/*
+ * 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 assertIntEquals(int expected, int result) {
+ if (expected != result) {
+ throw new Error("Expected: " + expected + ", found: " + result);
+ }
+ }
+
+ /**
+ * Test that HArrayGet with a constant index is not split.
+ */
+
+ /// CHECK-START-ARM64: int Main.constantIndexGet(int[]) instruction_simplifier_arm64 (before)
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: ArrayGet [<<Array>>,<<Index>>]
+
+ /// CHECK-START-ARM64: int Main.constantIndexGet(int[]) instruction_simplifier_arm64 (after)
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK-NOT: Arm64IntermediateAddress
+ /// CHECK: ArrayGet [<<Array>>,<<Index>>]
+
+ public static int constantIndexGet(int array[]) {
+ return array[1];
+ }
+
+ /**
+ * Test that HArraySet with a constant index is not split.
+ */
+
+ /// CHECK-START-ARM64: void Main.constantIndexSet(int[]) instruction_simplifier_arm64 (before)
+ /// CHECK: <<Const2:i\d+>> IntConstant 2
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: ArraySet [<<Array>>,<<Index>>,<<Const2>>]
+
+ /// CHECK-START-ARM64: void Main.constantIndexSet(int[]) instruction_simplifier_arm64 (after)
+ /// CHECK: <<Const2:i\d+>> IntConstant 2
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK-NOT: Arm64IntermediateAddress
+ /// CHECK: ArraySet [<<Array>>,<<Index>>,<<Const2>>]
+
+
+ public static void constantIndexSet(int array[]) {
+ array[1] = 2;
+ }
+
+ /**
+ * Test basic splitting of HArrayGet.
+ */
+
+ /// CHECK-START-ARM64: int Main.get(int[], int) instruction_simplifier_arm64 (before)
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: ArrayGet [<<Array>>,<<Index>>]
+
+ /// CHECK-START-ARM64: int Main.get(int[], int) instruction_simplifier_arm64 (after)
+ /// CHECK: <<DataOffset:i\d+>> IntConstant
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: <<Address:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-NEXT: ArrayGet [<<Address>>,<<Index>>]
+
+ public static int get(int array[], int index) {
+ return array[index];
+ }
+
+ /**
+ * Test basic splitting of HArraySet.
+ */
+
+ /// CHECK-START-ARM64: void Main.set(int[], int, int) instruction_simplifier_arm64 (before)
+ /// CHECK: ParameterValue
+ /// CHECK: ParameterValue
+ /// CHECK: <<Arg:i\d+>> ParameterValue
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: ArraySet [<<Array>>,<<Index>>,<<Arg>>]
+
+ /// CHECK-START-ARM64: void Main.set(int[], int, int) instruction_simplifier_arm64 (after)
+ /// CHECK: ParameterValue
+ /// CHECK: ParameterValue
+ /// CHECK: <<Arg:i\d+>> ParameterValue
+ /// CHECK: <<DataOffset:i\d+>> IntConstant
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: <<Address:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-NEXT: ArraySet [<<Address>>,<<Index>>,<<Arg>>]
+
+ public static void set(int array[], int index, int value) {
+ array[index] = value;
+ }
+
+ /**
+ * Check that the intermediate address can be shared after GVN.
+ */
+
+ /// CHECK-START-ARM64: void Main.getSet(int[], int) instruction_simplifier_arm64 (before)
+ /// CHECK: <<Const1:i\d+>> IntConstant 1
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: <<ArrayGet:i\d+>> ArrayGet [<<Array>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK: ArraySet [<<Array>>,<<Index>>,<<Add>>]
+
+ /// CHECK-START-ARM64: void Main.getSet(int[], int) instruction_simplifier_arm64 (after)
+ /// CHECK-DAG: <<Const1:i\d+>> IntConstant 1
+ /// CHECK-DAG: <<DataOffset:i\d+>> IntConstant
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: <<Address1:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-NEXT: <<ArrayGet:i\d+>> ArrayGet [<<Address1>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK: <<Address2:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-NEXT: ArraySet [<<Address2>>,<<Index>>,<<Add>>]
+
+ /// CHECK-START-ARM64: void Main.getSet(int[], int) GVN_after_arch (after)
+ /// CHECK-DAG: <<Const1:i\d+>> IntConstant 1
+ /// CHECK-DAG: <<DataOffset:i\d+>> IntConstant
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: <<Address:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK: <<ArrayGet:i\d+>> ArrayGet [<<Address>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK-NOT: Arm64IntermediateAddress
+ /// CHECK: ArraySet [<<Address>>,<<Index>>,<<Add>>]
+
+ public static void getSet(int array[], int index) {
+ array[index] = array[index] + 1;
+ }
+
+ /**
+ * Check that the intermediate address computation is not reordered or merged
+ * across IRs that can trigger GC.
+ */
+
+ /// CHECK-START-ARM64: int[] Main.accrossGC(int[], int) instruction_simplifier_arm64 (before)
+ /// CHECK: <<Const1:i\d+>> IntConstant 1
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: <<ArrayGet:i\d+>> ArrayGet [<<Array>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK: NewArray
+ /// CHECK: ArraySet [<<Array>>,<<Index>>,<<Add>>]
+
+ /// CHECK-START-ARM64: int[] Main.accrossGC(int[], int) instruction_simplifier_arm64 (after)
+ /// CHECK-DAG: <<Const1:i\d+>> IntConstant 1
+ /// CHECK-DAG: <<DataOffset:i\d+>> IntConstant
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: <<Address1:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-NEXT: <<ArrayGet:i\d+>> ArrayGet [<<Address1>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK: NewArray
+ /// CHECK: <<Address2:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-NEXT: ArraySet [<<Address2>>,<<Index>>,<<Add>>]
+
+ /// CHECK-START-ARM64: int[] Main.accrossGC(int[], int) GVN_after_arch (after)
+ /// CHECK-DAG: <<Const1:i\d+>> IntConstant 1
+ /// CHECK-DAG: <<DataOffset:i\d+>> IntConstant
+ /// CHECK: <<Array:l\d+>> NullCheck
+ /// CHECK: <<Index:i\d+>> BoundsCheck
+ /// CHECK: <<Address1:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK: <<ArrayGet:i\d+>> ArrayGet [<<Address1>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK: NewArray
+ /// CHECK: <<Address2:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK: ArraySet [<<Address2>>,<<Index>>,<<Add>>]
+
+ public static int[] accrossGC(int array[], int index) {
+ int tmp = array[index] + 1;
+ int[] new_array = new int[1];
+ array[index] = tmp;
+ return new_array;
+ }
+
+ /**
+ * Test that the intermediate address is shared between array accesses after
+ * the bounds check have been removed by BCE.
+ */
+
+ /// CHECK-START-ARM64: int Main.canMergeAfterBCE1() instruction_simplifier_arm64 (before)
+ /// CHECK: <<Const1:i\d+>> IntConstant 1
+ /// CHECK: <<Array:l\d+>> NewArray
+ /// CHECK: <<Index:i\d+>> Phi
+ /// CHECK: If
+ // -------------- Loop
+ /// CHECK: <<ArrayGet:i\d+>> ArrayGet [<<Array>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK: ArraySet [<<Array>>,<<Index>>,<<Add>>]
+
+ // By the time we reach the architecture-specific instruction simplifier, BCE
+ // has removed the bounds checks in the loop.
+
+ // Note that we do not care that the `DataOffset` is `12`. But if we do not
+ // specify it and any other `IntConstant` appears before that instruction,
+ // checker will match the previous `IntConstant`, and we will thus fail the
+ // check.
+
+ /// CHECK-START-ARM64: int Main.canMergeAfterBCE1() instruction_simplifier_arm64 (after)
+ /// CHECK-DAG: <<Const1:i\d+>> IntConstant 1
+ /// CHECK-DAG: <<DataOffset:i\d+>> IntConstant 12
+ /// CHECK: <<Array:l\d+>> NewArray
+ /// CHECK: <<Index:i\d+>> Phi
+ /// CHECK: If
+ // -------------- Loop
+ /// CHECK: <<Address1:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-NEXT: <<ArrayGet:i\d+>> ArrayGet [<<Address1>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK: <<Address2:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-NEXT: ArraySet [<<Address2>>,<<Index>>,<<Add>>]
+
+ /// CHECK-START-ARM64: int Main.canMergeAfterBCE1() GVN_after_arch (after)
+ /// CHECK-DAG: <<Const1:i\d+>> IntConstant 1
+ /// CHECK-DAG: <<DataOffset:i\d+>> IntConstant 12
+ /// CHECK: <<Array:l\d+>> NewArray
+ /// CHECK: <<Index:i\d+>> Phi
+ /// CHECK: If
+ // -------------- Loop
+ /// CHECK: <<Address:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK: <<ArrayGet:i\d+>> ArrayGet [<<Address>>,<<Index>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGet>>,<<Const1>>]
+ /// CHECK-NOT: Arm64IntermediateAddress
+ /// CHECK: ArraySet [<<Address>>,<<Index>>,<<Add>>]
+
+ public static int canMergeAfterBCE1() {
+ int[] array = {0, 1, 2, 3};
+ for (int i = 0; i < array.length; i++) {
+ array[i] = array[i] + 1;
+ }
+ return array[array.length - 1];
+ }
+
+ /**
+ * This test case is similar to `canMergeAfterBCE1`, but with different
+ * indexes for the accesses.
+ */
+
+ /// CHECK-START-ARM64: int Main.canMergeAfterBCE2() instruction_simplifier_arm64 (before)
+ /// CHECK: <<Const1:i\d+>> IntConstant 1
+ /// CHECK: <<Array:l\d+>> NewArray
+ /// CHECK: <<Index:i\d+>> Phi
+ /// CHECK: If
+ // -------------- Loop
+ /// CHECK-DAG: <<Index1:i\d+>> Add [<<Index>>,<<Const1>>]
+ /// CHECK-DAG: <<ArrayGetI:i\d+>> ArrayGet [<<Array>>,<<Index>>]
+ /// CHECK-DAG: <<ArrayGetI1:i\d+>> ArrayGet [<<Array>>,<<Index1>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGetI>>,<<ArrayGetI1>>]
+ /// CHECK: ArraySet [<<Array>>,<<Index1>>,<<Add>>]
+
+ // Note that we do not care that the `DataOffset` is `12`. But if we do not
+ // specify it and any other `IntConstant` appears before that instruction,
+ // checker will match the previous `IntConstant`, and we will thus fail the
+ // check.
+
+ /// CHECK-START-ARM64: int Main.canMergeAfterBCE2() instruction_simplifier_arm64 (after)
+ /// CHECK-DAG: <<Const1:i\d+>> IntConstant 1
+ /// CHECK-DAG: <<DataOffset:i\d+>> IntConstant 12
+ /// CHECK: <<Array:l\d+>> NewArray
+ /// CHECK: <<Index:i\d+>> Phi
+ /// CHECK: If
+ // -------------- Loop
+ /// CHECK-DAG: <<Index1:i\d+>> Add [<<Index>>,<<Const1>>]
+ /// CHECK-DAG: <<Address1:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-DAG: <<ArrayGetI:i\d+>> ArrayGet [<<Address1>>,<<Index>>]
+ /// CHECK-DAG: <<Address2:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-DAG: <<ArrayGetI1:i\d+>> ArrayGet [<<Address2>>,<<Index1>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGetI>>,<<ArrayGetI1>>]
+ /// CHECK: <<Address3:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK: ArraySet [<<Address3>>,<<Index1>>,<<Add>>]
+
+ /// CHECK-START-ARM64: int Main.canMergeAfterBCE2() GVN_after_arch (after)
+ /// CHECK-DAG: <<Const1:i\d+>> IntConstant 1
+ /// CHECK-DAG: <<DataOffset:i\d+>> IntConstant 12
+ /// CHECK: <<Array:l\d+>> NewArray
+ /// CHECK: <<Index:i\d+>> Phi
+ /// CHECK: If
+ // -------------- Loop
+ /// CHECK-DAG: <<Index1:i\d+>> Add [<<Index>>,<<Const1>>]
+ /// CHECK-DAG: <<Address:l\d+>> Arm64IntermediateAddress [<<Array>>,<<DataOffset>>]
+ /// CHECK-DAG: <<ArrayGetI:i\d+>> ArrayGet [<<Address>>,<<Index>>]
+ /// CHECK-DAG: <<ArrayGetI1:i\d+>> ArrayGet [<<Address>>,<<Index1>>]
+ /// CHECK: <<Add:i\d+>> Add [<<ArrayGetI>>,<<ArrayGetI1>>]
+ /// CHECK: ArraySet [<<Address>>,<<Index1>>,<<Add>>]
+
+ // There should be only one intermediate address computation in the loop.
+
+ /// CHECK-START-ARM64: int Main.canMergeAfterBCE2() GVN_after_arch (after)
+ /// CHECK: Arm64IntermediateAddress
+ /// CHECK-NOT: Arm64IntermediateAddress
+
+ public static int canMergeAfterBCE2() {
+ int[] array = {0, 1, 2, 3};
+ for (int i = 0; i < array.length - 1; i++) {
+ array[i + 1] = array[i] + array[i + 1];
+ }
+ return array[array.length - 1];
+ }
+
+
+ public static void main(String[] args) {
+ int[] array = {123, 456, 789};
+
+ assertIntEquals(456, constantIndexGet(array));
+
+ constantIndexSet(array);
+ assertIntEquals(2, array[1]);
+
+ assertIntEquals(789, get(array, 2));
+
+ set(array, 1, 456);
+ assertIntEquals(456, array[1]);
+
+ getSet(array, 0);
+ assertIntEquals(124, array[0]);
+
+ accrossGC(array, 0);
+ assertIntEquals(125, array[0]);
+
+ assertIntEquals(4, canMergeAfterBCE1());
+ assertIntEquals(6, canMergeAfterBCE2());
+ }
+}