commit e5c71f98cb74943157d22f7cf408847156eae402
author Mingyao Yang <mingyao@google.com> Tue Feb 02 20:10:32 2016 -0800
committer Mingyao Yang <mingyao@google.com> Tue Feb 02 20:53:21 2016 -0800
tree 995beca986d038ac499e07fad59b94a362083216
parent 88df4892c8b48de3019fd48c2ea2f49cf8eed098

Handle HSelect in LSE.

HSelect essentially creates an alias which breaks the singleton
assumption. Need to handle the case in singleton detection.

Bug: 26922558
Change-Id: I259deefe16e1e16c08179a10369cfe5ae23ae155

compiler/optimizing/load_store_elimination.cc

diff --git a/compiler/optimizing/load_store_elimination.cc b/compiler/optimizing/load_store_elimination.cc
index c4492c8..9a97f54 100644
--- a/compiler/optimizing/load_store_elimination.cc
+++ b/compiler/optimizing/load_store_elimination.cc
@@ -55,13 +55,13 @@
         is_singleton_and_not_returned_ = false;
         return;
       }
-      if (use->IsPhi() || use->IsInvoke() ||
+      if (use->IsPhi() || use->IsSelect() || use->IsInvoke() ||
           (use->IsInstanceFieldSet() && (reference_ == use->InputAt(1))) ||
           (use->IsUnresolvedInstanceFieldSet() && (reference_ == use->InputAt(1))) ||
           (use->IsStaticFieldSet() && (reference_ == use->InputAt(1))) ||
           (use->IsUnresolvedStaticFieldSet() && (reference_ == use->InputAt(0))) ||
           (use->IsArraySet() && (reference_ == use->InputAt(2)))) {
-        // reference_ is merged to a phi, passed to a callee, or stored to heap.
+        // reference_ is merged to a phi/HSelect, passed to a callee, or stored to heap.
         // reference_ isn't the only name that can refer to its value anymore.
         is_singleton_ = false;
         is_singleton_and_not_returned_ = false;

test/530-checker-lse/src/Main.java

diff --git a/test/530-checker-lse/src/Main.java b/test/530-checker-lse/src/Main.java
index f87326c..d647683 100644
--- a/test/530-checker-lse/src/Main.java
+++ b/test/530-checker-lse/src/Main.java
@@ -664,19 +664,50 @@
     System.out.println("testFinalizableByForcingGc() failed to force gc.");
   }
 
-  public static void assertIntEquals(int expected, int result) {
+  /// CHECK-START: int Main.testHSelect(boolean) load_store_elimination (before)
+  /// CHECK: InstanceFieldSet
+  /// CHECK: Select
+
+  /// CHECK-START: int Main.testHSelect(boolean) load_store_elimination (after)
+  /// CHECK: InstanceFieldSet
+  /// CHECK: Select
+
+  // Test that HSelect creates alias.
+  public static int testHSelect(boolean b) {
+    // Disable inlining.
+    System.out.print("");
+    System.out.print("");
+    System.out.print("");
+    System.out.print("");
+    System.out.print("");
+    System.out.print("");
+    System.out.print("");
+    System.out.print("");
+    System.out.print("");
+    System.out.print("");
+
+    TestClass obj = new TestClass();
+    TestClass obj2 = null;
+    obj.i = 0xdead;
+    if (b) {
+      obj2 = obj;
+    }
+    return obj2.i;
+  }
+
+  public static void assertIntEquals(int result, int expected) {
     if (expected != result) {
       throw new Error("Expected: " + expected + ", found: " + result);
     }
   }
 
-  public static void assertFloatEquals(float expected, float result) {
+  public static void assertFloatEquals(float result, float expected) {
     if (expected != result) {
       throw new Error("Expected: " + expected + ", found: " + result);
     }
   }
 
-  public static void assertDoubleEquals(double expected, double result) {
+  public static void assertDoubleEquals(double result, double expected) {
     if (expected != result) {
       throw new Error("Expected: " + expected + ", found: " + result);
     }
@@ -723,5 +754,6 @@
     assertIntEquals(test23(false), 5);
     assertFloatEquals(test24(), 8.0f);
     testFinalizableByForcingGc();
+    assertIntEquals(testHSelect(true), 0xdead);
   }
 }