Revise assertions and fix bug in the implementation of shifts

runtime/vm/intermediate_language_ia32.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_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/compiler.h"
@@ skipping 6067 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 int32_t shift =
         reinterpret_cast<int32_t>(locs()->in(1).constant().raw()) >> 1;
-    // TODO(alexmarkov): figure out why the following assertion fails on ia32
-    // ASSERT(!has_shift_count_check());
-    // ASSERT(shift >= 0);
+    ASSERT(shift >= 0);
     switch (op_kind()) {
       case Token::kSHR: {
         if (shift > 31) {
           __ movl(left_lo, left_hi);        // Shift by 32.
           __ sarl(left_hi, Immediate(31));  // Sign extend left hi.
           if (shift > 32) {
             __ sarl(left_lo, Immediate(shift > 63 ? 31 : shift - 32));
           }
         } else {
           __ shrdl(left_lo, left_hi, Immediate(shift));
@@ skipping 53 matching lines @@
       }
       default:
         UNREACHABLE();
     }
   } else {
     // Code for a variable shift amount.
     // Deoptimize if shift count is > 63.
     // sarl operation masks the count to 5 bits and
     // shrdl is undefined with count > operand size (32)
     __ SmiUntag(ECX);
-    if (has_shift_count_check()) {
+    if (!IsShiftCountInRange()) {
       __ cmpl(ECX, Immediate(kMintShiftCountLimit));
       __ j(ABOVE, deopt);
     }
     Label done, large_shift;
     switch (op_kind()) {
       case Token::kSHR: {
         __ cmpl(ECX, Immediate(31));
         __ j(ABOVE, &large_shift);
 
         __ shrdl(left_lo, left_hi, ECX);  // Shift count in CL.
@@ skipping 613 matching lines @@
   __ Call(*StubCode::DebugStepCheck_entry());
   compiler->EmitCallsiteMetaData(token_pos(), deopt_id_, stub_kind_, locs());
 }
 
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_IA32