Reland r22247 "ARM64: Use UntagSmi helpers and clean up assertions."

src/arm64/full-codegen-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/code-stubs.h"
 #include "src/codegen.h"
@@ skipping 2011 matching lines @@
       __ B(vs, &stub_call);
       __ Mov(result, x10);
       break;
     case Token::SUB:
       __ Subs(x10, left, right);
       __ B(vs, &stub_call);
       __ Mov(result, x10);
       break;
     case Token::MUL: {
       Label not_minus_zero, done;
+      STATIC_ASSERT(static_cast<unsigned>(kSmiShift) == (kXRegSizeInBits / 2));
+      STATIC_ASSERT(kSmiTag == 0);
       __ Smulh(x10, left, right);
       __ Cbnz(x10, &not_minus_zero);
       __ Eor(x11, left, right);
       __ Tbnz(x11, kXSignBit, &stub_call);
-      STATIC_ASSERT(kSmiTag == 0);
       __ Mov(result, x10);
       __ B(&done);
       __ Bind(&not_minus_zero);
       __ Cls(x11, x10);
       __ Cmp(x11, kXRegSizeInBits - kSmiShift);
       __ B(lt, &stub_call);
       __ SmiTag(result, x10);
       __ Bind(&done);
       break;
     }
@@ skipping 538 matching lines @@
 
   VisitForAccumulatorValue(args->at(0));
 
   Label materialize_true, materialize_false;
   Label* if_true = NULL;
   Label* if_false = NULL;
   Label* fall_through = NULL;
   context()->PrepareTest(&materialize_true, &materialize_false,
                          &if_true, &if_false, &fall_through);
 
+  uint64_t sign_mask = V8_UINT64_C(1) << (kSmiShift + kSmiValueSize - 1);
+
   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  __ TestAndSplit(x0, kSmiTagMask | (0x80000000UL << kSmiShift), if_true,
-                  if_false, fall_through);
+  __ TestAndSplit(x0, kSmiTagMask | sign_mask, if_true, if_false, fall_through);
 
   context()->Plug(if_true, if_false);
 }
 
 
 void FullCodeGenerator::EmitIsObject(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   ASSERT(args->length() == 1);
 
   VisitForAccumulatorValue(args->at(0));
@@ skipping 2281 matching lines @@
   return previous_;
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64