A64: Add LSubS instruction.

src/a64/lithium-codegen-a64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5229 matching lines @@
   Operand right = ToOperand32I(instr->right());
   if (can_overflow) {
     __ Subs(result, left, right);
     DeoptimizeIf(vs, instr->environment());
   } else {
     __ Sub(result, left, right);
   }
 }
 
 
+void LCodeGen::DoSubS(LSubS* instr) {
+  bool can_overflow = instr->hydrogen()->CheckFlag(HValue::kCanOverflow);
+  Register result = ToRegister(instr->result());
+  Register left = ToRegister(instr->left());
+  Operand right = ToOperand(instr->right());
+  if (can_overflow) {
+    __ Subs(result, left, right);
+    DeoptimizeIf(vs, instr->environment());
+  } else {
+    __ Sub(result, left, right);
+  }
+}
+
+
 void LCodeGen::DoDeferredTaggedToI(LTaggedToI* instr,
                                    LOperand* value,
                                    LOperand* temp1,
                                    LOperand* temp2) {
   Register input = ToRegister(value);
   Register scratch1 = ToRegister(temp1);
   DoubleRegister dbl_scratch1 = double_scratch();
 
   Label done;
 
@@ skipping 402 matching lines @@
   __ Bind(&out_of_object);
   __ Ldr(result, FieldMemOperand(object, JSObject::kPropertiesOffset));
   // Index is equal to negated out of object property index plus 1.
   __ Sub(result, result, Operand::UntagSmiAndScale(index, kPointerSizeLog2));
   __ Ldr(result, FieldMemOperand(result,
                                  FixedArray::kHeaderSize - kPointerSize));
   __ Bind(&done);
 }
 
 } }  // namespace v8::internal