Fix an undetected Smi overflow on ARM.

runtime/vm/intermediate_language_arm64.cc

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_ARM64.
 #if defined(TARGET_ARCH_ARM64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/dart_entry.h"
@@ skipping 2590 matching lines @@
   const Register left = locs()->in(0).reg();
   const Register result = locs()->out(0).reg();
   Label* deopt = NULL;
   if (CanDeoptimize()) {
     deopt = compiler->AddDeoptStub(deopt_id(), ICData::kDeoptBinarySmiOp);
   }
 
   if (locs()->in(1).IsConstant()) {
     const Object& constant = locs()->in(1).constant();
     ASSERT(constant.IsSmi());
-    int64_t imm = reinterpret_cast<int64_t>(constant.raw());
+    const int64_t imm = reinterpret_cast<int64_t>(constant.raw());
     switch (op_kind()) {
-      case Token::kSUB: {
-        imm = -imm;  // TODO(regis): What if deopt != NULL && imm == 0x80000000?
-        // Fall through.
-      }
       case Token::kADD: {
         if (deopt == NULL) {
           __ AddImmediate(result, left, imm, PP);
         } else {
           __ AddImmediateSetFlags(result, left, imm, PP);
-          __ b(deopt, VS);        }
+          __ b(deopt, VS);
+        }
+        break;
+      }
+      case Token::kSUB: {
+        if (deopt == NULL) {
+          __ AddImmediate(result, left, -imm, PP);
+        } else {
+          // Negating imm and using AddImmediateSetFlags would not detect the
+          // overflow when imm == kMinInt64.
+          __ SubImmediateSetFlags(result, left, imm, PP);
+          __ b(deopt, VS);
+        }
         break;
       }
       case Token::kMUL: {
         // Keep left value tagged and untag right value.
         const intptr_t value = Smi::Cast(constant).Value();
         if (deopt == NULL) {
           if (value == 2) {
             __ Lsl(result, left, 1);
           } else {
             __ LoadImmediate(TMP, value, PP);
@@ skipping 1800 matching lines @@
   compiler->GenerateCall(token_pos(),
                          &label,
                          PcDescriptors::kOther,
                          locs());
   __ Drop(ArgumentCount());  // Discard arguments.
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64