Account for early exit loop.
Rationale:
last value computation is obviously only right if
the loop does not have early exits; only needed
if cycle leaks to outside loop in any way.
Bug:32633772
Test: 623-checker-loop-regressions
Change-Id: Id60beca4704491cff611ad12a24bfc63c09d32c3
diff --git a/test/623-checker-loop-regressions/src/Main.java b/test/623-checker-loop-regressions/src/Main.java
new file mode 100644
index 0000000..ce5bda1
--- /dev/null
+++ b/test/623-checker-loop-regressions/src/Main.java
@@ -0,0 +1,109 @@
+/*
+ * 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.
+ */
+
+/**
+ * Regression tests for loop optimizations.
+ */
+public class Main {
+
+ /// CHECK-START: int Main.earlyExitFirst(int) loop_optimization (before)
+ /// CHECK-DAG: Phi loop:<<Loop:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop>> outer_loop:none
+ //
+ /// CHECK-START: int Main.earlyExitFirst(int) loop_optimization (after)
+ /// CHECK-DAG: Phi loop:<<Loop:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop>> outer_loop:none
+ static int earlyExitFirst(int m) {
+ int k = 0;
+ for (int i = 0; i < 10; i++) {
+ if (i == m) {
+ return k;
+ }
+ k++;
+ }
+ return k;
+ }
+
+ /// CHECK-START: int Main.earlyExitLast(int) loop_optimization (before)
+ /// CHECK-DAG: Phi loop:<<Loop:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop>> outer_loop:none
+ //
+ /// CHECK-START: int Main.earlyExitLast(int) loop_optimization (after)
+ /// CHECK-DAG: Phi loop:<<Loop:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop>> outer_loop:none
+ static int earlyExitLast(int m) {
+ int k = 0;
+ for (int i = 0; i < 10; i++) {
+ k++;
+ if (i == m) {
+ return k;
+ }
+ }
+ return k;
+ }
+
+ /// CHECK-START: int Main.earlyExitNested() loop_optimization (before)
+ /// CHECK-DAG: Phi loop:<<Loop1:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop1>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop2:B\d+>> outer_loop:<<Loop1>>
+ /// CHECK-DAG: Phi loop:<<Loop2>> outer_loop:<<Loop1>>
+ //
+ /// CHECK-START: int Main.earlyExitNested() loop_optimization (after)
+ /// CHECK-DAG: Phi loop:<<Loop1:B\d+>> outer_loop:none
+ /// CHECK-DAG: Phi loop:<<Loop1>> outer_loop:none
+ //
+ /// CHECK-START: int Main.earlyExitNested() loop_optimization (after)
+ /// CHECK-NOT: Phi loop:{{B\d+}} outer_loop:{{B\d+}}
+ static int earlyExitNested() {
+ int offset = 0;
+ for (int i = 0; i < 2; i++) {
+ int start = offset;
+ // This loop can be removed.
+ for (int j = 0; j < 2; j++) {
+ offset++;
+ }
+ if (i == 1) {
+ return start;
+ }
+ }
+ return 0;
+ }
+
+ public static void main(String[] args) {
+ expectEquals(10, earlyExitFirst(-1));
+ for (int i = 0; i <= 10; i++) {
+ expectEquals(i, earlyExitFirst(i));
+ }
+ expectEquals(10, earlyExitFirst(11));
+
+ expectEquals(10, earlyExitLast(-1));
+ for (int i = 0; i < 10; i++) {
+ expectEquals(i + 1, earlyExitLast(i));
+ }
+ expectEquals(10, earlyExitLast(10));
+ expectEquals(10, earlyExitLast(11));
+
+ expectEquals(2, earlyExitNested());
+
+ System.out.println("passed");
+ }
+
+ private static void expectEquals(int expected, int result) {
+ if (expected != result) {
+ throw new Error("Expected: " + expected + ", found: " + result);
+ }
+ }
+}