Merge "Compensate in compiler for verifier shortcomings."

5 files changed, 43 insertions, 12 deletions

diff --git a/compiler/optimizing/instruction_builder.cc b/compiler/optimizing/instruction_builder.cc
index 5a6a212cc9..f7dc2377be 100644
--- a/compiler/optimizing/instruction_builder.cc
+++ b/compiler/optimizing/instruction_builder.cc
@@ -1815,7 +1815,20 @@ bool HInstructionBuilder::ProcessDexInstruction(const Instruction& instruction,
     case Instruction::MOVE_OBJECT:
     case Instruction::MOVE_OBJECT_16:
     case Instruction::MOVE_OBJECT_FROM16: {
-      HInstruction* value = LoadLocal(instruction.VRegB(), Primitive::kPrimNot);
+      // The verifier has no notion of a null type, so a move-object of constant 0
+      // will lead to the same constant 0 in the destination register. To mimic
+      // this behavior, we just pretend we haven't seen a type change (int to reference)
+      // for the 0 constant and phis. We rely on our type propagation to eventually get the
+      // types correct.
+      uint32_t reg_number = instruction.VRegB();
+      HInstruction* value = (*current_locals_)[reg_number];
+      if (value->IsIntConstant()) {
+        DCHECK_EQ(value->AsIntConstant()->GetValue(), 0);
+      } else if (value->IsPhi()) {
+        DCHECK(value->GetType() == Primitive::kPrimInt || value->GetType() == Primitive::kPrimNot);
+      } else {
+        value = LoadLocal(reg_number, Primitive::kPrimNot);
+      }
       UpdateLocal(instruction.VRegA(), value);
       break;
     }
diff --git a/compiler/optimizing/ssa_builder.cc b/compiler/optimizing/ssa_builder.cc
index f7dc112d00..03807ba1ee 100644
--- a/compiler/optimizing/ssa_builder.cc
+++ b/compiler/optimizing/ssa_builder.cc
@@ -163,18 +163,12 @@ static bool TypePhiFromInputs(HPhi* phi) {
 // Replace inputs of `phi` to match its type. Return false if conflict is identified.
 bool SsaBuilder::TypeInputsOfPhi(HPhi* phi, ArenaVector<HPhi*>* worklist) {
   Primitive::Type common_type = phi->GetType();
-  if (common_type == Primitive::kPrimVoid || Primitive::IsIntegralType(common_type)) {
-    // Phi either contains only other untyped phis (common_type == kPrimVoid),
-    // or `common_type` is integral and we do not need to retype ambiguous inputs
-    // because they are always constructed with the integral type candidate.
+  if (Primitive::IsIntegralType(common_type)) {
+    // We do not need to retype ambiguous inputs because they are always constructed
+    // with the integral type candidate.
     if (kIsDebugBuild) {
       for (HInstruction* input : phi->GetInputs()) {
-        if (common_type == Primitive::kPrimVoid) {
-          DCHECK(input->IsPhi() && input->GetType() == Primitive::kPrimVoid);
-        } else {
-          DCHECK((input->IsPhi() && input->GetType() == Primitive::kPrimVoid) ||
-                 HPhi::ToPhiType(input->GetType()) == common_type);
-        }
+        DCHECK(HPhi::ToPhiType(input->GetType()) == common_type);
       }
     }
     // Inputs did not need to be replaced, hence no conflict. Report success.
diff --git a/test/800-smali/expected.txt b/test/800-smali/expected.txt
index 3bb372529f..b8324e54e3 100644
--- a/test/800-smali/expected.txt
+++ b/test/800-smali/expected.txt
@@ -70,4 +70,5 @@ b/28187158
 b/29778499 (1)
 b/29778499 (2)
 b/30458218
+b/31313170
 Done!
diff --git a/test/800-smali/smali/b_31313170.smali b/test/800-smali/smali/b_31313170.smali
new file mode 100644
index 0000000000..327942a365
--- /dev/null
+++ b/test/800-smali/smali/b_31313170.smali
@@ -0,0 +1,22 @@
+.class public LB31313170;
+.super Ljava/lang/Object;
+
+
+.method public constructor <init>()V
+.registers 1
+       invoke-direct {p0}, Ljava/lang/Object;-><init>()V
+       return-void
+.end method
+
+.method public static run()I
+.registers 4
+       const/4 v0, 0
+       const/4 v1, 1
+       sget v2, LB31313170;->a:I
+       if-nez v2, :exit
+       move-object v1, v0
+       :exit
+       return v1
+.end method
+
+.field static public a:I
diff --git a/test/800-smali/src/Main.java b/test/800-smali/src/Main.java
index 34f2580dde..8d39f0971f 100644
--- a/test/800-smali/src/Main.java
+++ b/test/800-smali/src/Main.java
@@ -181,6 +181,7 @@ public class Main {
         testCases.add(new TestCase("b/29778499 (2)", "B29778499_2", "run", null,
                 new IncompatibleClassChangeError(), null));
         testCases.add(new TestCase("b/30458218", "B30458218", "run", null, null, null));
+        testCases.add(new TestCase("b/31313170", "B31313170", "run", null, null, 0));
     }
 
     public void runTests() {
@@ -228,7 +229,7 @@ public class Main {
                                                             tc.testName);
                 } else if (tc.expectedReturn == null && retValue != null) {
                     errorReturn = new IllegalStateException("Expected a null result in test " +
-                                                            tc.testName);
+                                                            tc.testName + " got " + retValue);
                 } else if (tc.expectedReturn != null &&
                            (retValue == null || !tc.expectedReturn.equals(retValue))) {
                     errorReturn = new IllegalStateException("Expected return " +