Option to truncate integers to 64 bits, part 1 (core VM changes)

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2013, 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_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/compiler.h"
@@ skipping 6054 matching lines @@
 
   Label* deopt = NULL;
   if (CanDeoptimize()) {
     deopt = compiler->AddDeoptStub(deopt_id(), ICData::kDeoptBinaryMintOp);
   }
   if (locs()->in(1).IsConstant()) {
     // Code for a constant shift amount.
     ASSERT(locs()->in(1).constant().IsSmi());
     const int64_t shift =
         reinterpret_cast<int64_t>(locs()->in(1).constant().raw()) >> 1;
+    ASSERT(!has_shift_count_check());
+    ASSERT((0 <= shift) && (shift < 64));
     switch (op_kind()) {
       case Token::kSHR:
         __ sarq(left, Immediate(shift));
         break;
       case Token::kSHL: {
         if (can_overflow()) {
           // Check for overflow.
           Register temp = locs()->temp(0).reg();
           __ movq(temp, left);
           __ shlq(left, Immediate(shift));
@@ skipping 561 matching lines @@
   compiler->AddCurrentDescriptor(stub_kind_, deopt_id_, token_pos());
   compiler->RecordSafepoint(locs());
 }
 
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64