Ported SubStringStub to X64.

src/x64/macro-assembler-x64.cc

 // Copyright 2009 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 563 matching lines @@
   if (first.is(second)) {
     return CheckSmi(first);
   }
   movl(kScratchRegister, first);
   orl(kScratchRegister, second);
   testb(kScratchRegister, Immediate(kSmiTagMask));
   return zero;
 }
 
 
+Condition MacroAssembler::CheckBothPositiveSmi(Register first,
+                                               Register second) {
+  if (first.is(second)) {
+    return CheckPositiveSmi(first);
+  }
+  movl(kScratchRegister, first);
+  orl(kScratchRegister, second);
+  rol(kScratchRegister, Immediate(1));
+  testl(kScratchRegister, Immediate(0x03));
+  return zero;
+}
+
+
+
 Condition MacroAssembler::CheckEitherSmi(Register first, Register second) {
   if (first.is(second)) {
     return CheckSmi(first);
   }
   movl(kScratchRegister, first);
   andl(kScratchRegister, second);
   testb(kScratchRegister, Immediate(kSmiTagMask));
   return zero;
 }
 
@@ skipping 59 matching lines @@
     j(overflow, on_not_smi_result);
   }
 }
 
 
 void MacroAssembler::SmiSub(Register dst,
                             Register src1,
                             Register src2,
                             Label* on_not_smi_result) {
   ASSERT(!dst.is(src2));
-  if (dst.is(src1)) {
+  if (on_not_smi_result == NULL) {
+    // No overflow checking. Use only when it's known that
+    // overflowing is impossible (e.g., subtracting two positive smis).
+    if (dst.is(src1)) {
+      subq(dst, src2);
+    } else {
+      movq(dst, src1);
+      subq(dst, src2);
+    }
+    Assert(no_overflow, "Smi substraction onverflow");
+  } else if (dst.is(src1)) {
     subq(dst, src2);
     Label smi_result;
     j(no_overflow, &smi_result);
     // Restore src1.
     addq(src1, src2);
     jmp(on_not_smi_result);
     bind(&smi_result);
   } else {
     movq(dst, src1);
     subq(dst, src2);
@@ skipping 611 matching lines @@
 }
 
 
 void MacroAssembler::JumpIfNotBothSmi(Register src1, Register src2,
                                       Label* on_not_both_smi) {
   Condition both_smi = CheckBothSmi(src1, src2);
   j(NegateCondition(both_smi), on_not_both_smi);
 }
 
 
+void MacroAssembler::JumpIfNotBothPositiveSmi(Register src1, Register src2,
+                                              Label* on_not_both_smi) {
+  Condition both_smi = CheckBothPositiveSmi(src1, src2);
+  j(NegateCondition(both_smi), on_not_both_smi);
+}
+
+
+
 void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(Register first_object,
                                                          Register second_object,
                                                          Register scratch1,
                                                          Register scratch2,
                                                          Label* on_fail) {
   // Check that both objects are not smis.
   Condition either_smi = CheckEitherSmi(first_object, second_object);
   j(either_smi, on_fail);
 
   // Load instance type for both strings.
@@ skipping 205 matching lines @@
   CmpInstanceType(map, type);
 }
 
 
 void MacroAssembler::CmpInstanceType(Register map, InstanceType type) {
   cmpb(FieldOperand(map, Map::kInstanceTypeOffset),
        Immediate(static_cast<int8_t>(type)));
 }
 
 
+Condition MacroAssembler::IsObjectStringType(Register heap_object,
+                                             Register map,
+                                             Register instance_type) {
+  movq(map, FieldOperand(heap_object, HeapObject::kMapOffset));
+  movzxbq(instance_type, FieldOperand(map, Map::kInstanceTypeOffset));
+  ASSERT(kNotStringTag != 0);
+  testb(instance_type, Immediate(kIsNotStringMask));
+  return zero;
+}
+
+
 void MacroAssembler::TryGetFunctionPrototype(Register function,
                                              Register result,
                                              Label* miss) {
   // Check that the receiver isn't a smi.
   testl(function, Immediate(kSmiTagMask));
   j(zero, miss);
 
   // Check that the function really is a function.
   CmpObjectType(function, JS_FUNCTION_TYPE, result);
   j(not_equal, miss);
@@ skipping 913 matching lines @@
 CodePatcher::~CodePatcher() {
   // Indicate that code has changed.
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 } }  // namespace v8::internal