Eliminate overflow check for non-overflowing smi << operations.

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 2488 matching lines @@
     __ LoadImmediate(TMP, 0x20000000000000LL, PP);
     __ add(TMP2, result, Operand(TMP));
     __ cmp(TMP2, Operand(TMP, LSL, 1));
     __ b(overflow, HI);
   }
 }
 
 
 static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
                              BinarySmiOpInstr* shift_left) {
-  const bool is_truncating = shift_left->is_truncating();
+  const bool is_truncating = shift_left->IsTruncating();
   const LocationSummary& locs = *shift_left->locs();
   const Register left = locs.in(0).reg();
   const Register result = locs.out(0).reg();
   Label* deopt = shift_left->CanDeoptimize() ?
       compiler->AddDeoptStub(shift_left->deopt_id(), ICData::kDeoptBinarySmiOp)
       : NULL;
   if (locs.in(1).IsConstant()) {
     const Object& constant = locs.in(1).constant();
     ASSERT(constant.IsSmi());
     // Immediate shift operation takes 6 bits for the count.
@@ skipping 103 matching lines @@
   if (FLAG_throw_on_javascript_int_overflow) {
     EmitJavascriptOverflowCheck(compiler, shift_left->range(), deopt, result);
   }
 }
 
 
 LocationSummary* BinarySmiOpInstr::MakeLocationSummary(Isolate* isolate,
                                                        bool opt) const {
   const intptr_t kNumInputs = 2;
   const intptr_t kNumTemps =
-      (((op_kind() == Token::kSHL) && !is_truncating()) ||
+      (((op_kind() == Token::kSHL) && !IsTruncating()) ||
        (op_kind() == Token::kSHR)) ? 1 : 0;
   LocationSummary* summary = new(isolate) LocationSummary(
       isolate, kNumInputs, kNumTemps, LocationSummary::kNoCall);
   if (op_kind() == Token::kTRUNCDIV) {
     summary->set_in(0, Location::RequiresRegister());
     if (RightIsPowerOfTwoConstant()) {
       ConstantInstr* right_constant = right()->definition()->AsConstant();
       summary->set_in(1, Location::Constant(right_constant->value()));
     } else {
       summary->set_in(1, Location::RequiresRegister());
     }
     summary->set_out(0, Location::RequiresRegister());
     return summary;
   }
   if (op_kind() == Token::kMOD) {
     summary->set_in(0, Location::RequiresRegister());
     summary->set_in(1, Location::RequiresRegister());
     summary->set_out(0, Location::RequiresRegister());
     return summary;
   }
   summary->set_in(0, Location::RequiresRegister());
   summary->set_in(1, Location::RegisterOrSmiConstant(right()));
-  if (((op_kind() == Token::kSHL) && !is_truncating()) ||
+  if (((op_kind() == Token::kSHL) && !IsTruncating()) ||
       (op_kind() == Token::kSHR)) {
     summary->set_temp(0, Location::RequiresRegister());
   }
   // We make use of 3-operand instructions by not requiring result register
   // to be identical to first input register as on Intel.
   summary->set_out(0, Location::RequiresRegister());
   return summary;
 }
 
 
 void BinarySmiOpInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
   if (op_kind() == Token::kSHL) {
     EmitSmiShiftLeft(compiler, this);
     return;
   }
 
-  ASSERT(!is_truncating());
   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());
@@ skipping 2661 matching lines @@
   compiler->GenerateCall(token_pos(), &label, stub_kind_, locs());
 #if defined(DEBUG)
   __ LoadImmediate(R4, kInvalidObjectPointer, kNoPP);
   __ LoadImmediate(R5, kInvalidObjectPointer, kNoPP);
 #endif
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM64