MIPS64: Use BOVC/BNVC for overflow checking on r6.

src/full-codegen/mips64/full-codegen-mips64.cc

 // Copyright 2012 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.
 
 #if V8_TARGET_ARCH_MIPS64
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 2065 matching lines @@
     case Token::SHR: {
       __ SmiUntag(scratch1, left);
       __ GetLeastBitsFromSmi(scratch2, right, 5);
       __ dsrlv(scratch1, scratch1, scratch2);
       __ And(scratch2, scratch1, 0x80000000);
       __ Branch(&stub_call, ne, scratch2, Operand(zero_reg));
       __ SmiTag(v0, scratch1);
       break;
     }
     case Token::ADD:
-      __ DadduAndCheckForOverflow(v0, left, right, scratch1);
-      __ BranchOnOverflow(&stub_call, scratch1);
+      __ DaddBranchOvf(v0, left, Operand(right), &stub_call);
       break;
     case Token::SUB:
-      __ DsubuAndCheckForOverflow(v0, left, right, scratch1);
-      __ BranchOnOverflow(&stub_call, scratch1);
+      __ DsubBranchOvf(v0, left, Operand(right), &stub_call);
       break;
     case Token::MUL: {
       __ Dmulh(v0, left, right);
       __ dsra32(scratch2, v0, 0);
       __ sra(scratch1, v0, 31);
       __ Branch(USE_DELAY_SLOT, &stub_call, ne, scratch2, Operand(scratch1));
       __ SmiTag(v0);
       __ Branch(USE_DELAY_SLOT, &done, ne, v0, Operand(zero_reg));
       __ Daddu(scratch2, right, left);
       __ Branch(&stub_call, lt, scratch2, Operand(zero_reg));
@@ skipping 1563 matching lines @@
             __ sd(v0, MemOperand(sp, 2 * kPointerSize));
             break;
           case KEYED_SUPER_PROPERTY:
             __ sd(v0, MemOperand(sp, 3 * kPointerSize));
             break;
         }
       }
     }
 
     Register scratch1 = a1;
-    Register scratch2 = a4;
     __ li(scratch1, Operand(Smi::FromInt(count_value)));
-    __ DadduAndCheckForOverflow(v0, v0, scratch1, scratch2);
-    __ BranchOnNoOverflow(&done, scratch2);
+    __ DaddBranchNoOvf(v0, v0, Operand(scratch1), &done);
     // Call stub. Undo operation first.
     __ Move(v0, a0);
     __ jmp(&stub_call);
     __ bind(&slow);
   }
 
   // Convert old value into a number.
   ToNumberStub convert_stub(isolate());
   __ CallStub(&convert_stub);
   PrepareForBailoutForId(expr->ToNumberId(), TOS_REG);
@@ skipping 486 matching lines @@
          reinterpret_cast<uint64_t>(
              isolate->builtins()->OnStackReplacement()->entry()));
   return ON_STACK_REPLACEMENT;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64