diff --git a/compiler/common_compiler_test.cc b/compiler/common_compiler_test.cc
index 359d6af..7e19e15 100644
--- a/compiler/common_compiler_test.cc
+++ b/compiler/common_compiler_test.cc
@@ -111,7 +111,7 @@
 #else
   // Only warn if not Intel as Intel doesn't have cache flush instructions.
 #if !defined(__i386__) && !defined(__x86_64__)
-  LOG(WARNING) << "UNIMPLEMENTED: cache flush";
+  UNIMPLEMENTED(WARNING) << "cache flush";
 #endif
 #endif
 }
diff --git a/compiler/compiler.cc b/compiler/compiler.cc
index fbfd8e6..36213ca 100644
--- a/compiler/compiler.cc
+++ b/compiler/compiler.cc
@@ -75,8 +75,8 @@
 
     default:
       LOG(FATAL) << "UNREACHABLE";
+      UNREACHABLE();
   }
-  return nullptr;
 }
 
 }  // namespace art
diff --git a/compiler/dex/quick/arm64/utility_arm64.cc b/compiler/dex/quick/arm64/utility_arm64.cc
index 0883694..6985b73 100644
--- a/compiler/dex/quick/arm64/utility_arm64.cc
+++ b/compiler/dex/quick/arm64/utility_arm64.cc
@@ -768,8 +768,8 @@
       opcode = kA64Sub4RRre;
       break;
     default:
-      LOG(FATAL) << "Unimplemented opcode: " << op;
-      break;
+      UNIMPLEMENTED(FATAL) << "Unimplemented opcode: " << op;
+      UNREACHABLE();
   }
   A64Opcode widened_opcode = r_dest.Is64Bit() ? WIDE(opcode) : opcode;
 
diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc
index 35a3d4b..235aba8 100644
--- a/compiler/image_writer.cc
+++ b/compiler/image_writer.cc
@@ -206,7 +206,7 @@
       break;
     default:
       LOG(FATAL) << "Unreachable.";
-      break;
+      UNREACHABLE();
   }
   object->SetLockWord(LockWord::FromForwardingAddress(offset), false);
   DCHECK(IsImageOffsetAssigned(object));
diff --git a/compiler/jni/portable/jni_compiler.cc b/compiler/jni/portable/jni_compiler.cc
index d2f54f8..ff37d85 100644
--- a/compiler/jni/portable/jni_compiler.cc
+++ b/compiler/jni/portable/jni_compiler.cc
@@ -298,6 +298,7 @@
     case 'D': ret_type =  irb_.getJDoubleTy(); break;
     case 'L': ret_type =  irb_.getJObjectTy(); break;
     default: LOG(FATAL)  << "Unreachable: unexpected return type in shorty " << shorty;
+      UNREACHABLE();
   }
   // Get argument type
   std::vector< ::llvm::Type*> args_type;
diff --git a/compiler/utils/arena_object.h b/compiler/utils/arena_object.h
index 50909f75..8f6965e 100644
--- a/compiler/utils/arena_object.h
+++ b/compiler/utils/arena_object.h
@@ -31,6 +31,7 @@
 
   void operator delete(void*, size_t) {
     LOG(FATAL) << "UNREACHABLE";
+    UNREACHABLE();
   }
 };
 
diff --git a/compiler/utils/arm/assembler_arm.cc b/compiler/utils/arm/assembler_arm.cc
index b430c7e..db42b46 100644
--- a/compiler/utils/arm/assembler_arm.cc
+++ b/compiler/utils/arm/assembler_arm.cc
@@ -324,7 +324,7 @@
       return IsAbsoluteUint(10, offset);  // VFP addressing mode.
     default:
       LOG(FATAL) << "UNREACHABLE";
-      return false;
+      UNREACHABLE();
   }
 }
 
@@ -342,7 +342,7 @@
       return IsAbsoluteUint(10, offset);  // VFP addressing mode.
     default:
       LOG(FATAL) << "UNREACHABLE";
-      return false;
+      UNREACHABLE();
   }
 }
 
@@ -359,9 +359,9 @@
       return IsAbsoluteUint(10, offset);  // VFP addressing mode.
     case kLoadWordPair:
       return IsAbsoluteUint(10, offset);
-  default:
+    default:
       LOG(FATAL) << "UNREACHABLE";
-      return false;
+      UNREACHABLE();
   }
 }
 
@@ -377,9 +377,9 @@
       return IsAbsoluteUint(10, offset);  // VFP addressing mode.
     case kStoreWordPair:
       return IsAbsoluteUint(10, offset);
-  default:
+    default:
       LOG(FATAL) << "UNREACHABLE";
-      return false;
+      UNREACHABLE();
   }
 }
 
diff --git a/compiler/utils/arm/assembler_arm32.cc b/compiler/utils/arm/assembler_arm32.cc
index 6af69c8..3d46617 100644
--- a/compiler/utils/arm/assembler_arm32.cc
+++ b/compiler/utils/arm/assembler_arm32.cc
@@ -1356,6 +1356,7 @@
       break;
     default:
       LOG(FATAL) << "UNREACHABLE";
+      UNREACHABLE();
   }
 }
 
@@ -1427,6 +1428,7 @@
       break;
     default:
       LOG(FATAL) << "UNREACHABLE";
+      UNREACHABLE();
   }
 }
 
diff --git a/compiler/utils/arm/assembler_thumb2.cc b/compiler/utils/arm/assembler_thumb2.cc
index 7968a77..37478c4 100644
--- a/compiler/utils/arm/assembler_thumb2.cc
+++ b/compiler/utils/arm/assembler_thumb2.cc
@@ -2406,6 +2406,7 @@
       break;
     default:
       LOG(FATAL) << "UNREACHABLE";
+      UNREACHABLE();
   }
 }
 
@@ -2477,6 +2478,7 @@
       break;
     default:
       LOG(FATAL) << "UNREACHABLE";
+      UNREACHABLE();
   }
 }