[v8-dev] ARM: Optimize TypeofIsAndBranch

src/arm/macro-assembler-arm.cc

 // Copyright 2012 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 1998 matching lines @@
                       Heap::kSlicedAsciiStringMapRootIndex,
                       scratch1,
                       scratch2);
 }
 
 
 void MacroAssembler::CompareObjectType(Register object,
                                        Register map,
                                        Register type_reg,
                                        InstanceType type) {
+  const Register temp = type_reg.is(no_reg) ? ip : type_reg;
+
   ldr(map, FieldMemOperand(object, HeapObject::kMapOffset));
-  CompareInstanceType(map, type_reg, type);
+  CompareInstanceType(map, temp, type);
+}
+
+
+void MacroAssembler::CheckObjectTypeRange(Register object,
+                                          Register map,
+                                          InstanceType min_type,
+                                          InstanceType max_type,
+                                          Label* false_label) {
+  STATIC_ASSERT(Map::kInstanceTypeOffset < 4096);
+  STATIC_ASSERT(LAST_TYPE < 256);
+  ldr(map, FieldMemOperand(object, HeapObject::kMapOffset));
+  ldrb(ip, FieldMemOperand(map, Map::kInstanceTypeOffset));
+  sub(ip, ip, Operand(min_type));
+  cmp(ip, Operand(max_type - min_type));
+  b(hi, false_label);
 }
 
 
 void MacroAssembler::CompareInstanceType(Register map,
                                          Register type_reg,
                                          InstanceType type) {
+  // Registers map and type_reg can be ip. These two lines assert
+  // that ip can be used with the two instructions (the constants
+  // won't never need ip).

[ulan, 2013/11/22 15:43:46]

nit: either "won't ever need" or "will never need".

+  STATIC_ASSERT(Map::kInstanceTypeOffset < 4096);
+  STATIC_ASSERT(LAST_TYPE < 256);
   ldrb(type_reg, FieldMemOperand(map, Map::kInstanceTypeOffset));
   cmp(type_reg, Operand(type));
 }
 
 
 void MacroAssembler::CompareRoot(Register obj,
                                  Heap::RootListIndex index) {
   ASSERT(!obj.is(ip));
   LoadRoot(ip, index);
   cmp(obj, ip);
@@ skipping 2013 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM