Simplify test for typeof x == 'Object' on all platforms.

src/arm/full-codegen-arm.cc

 // Copyright 2011 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 3157 matching lines @@
   __ str(scratch2, MemOperand(index1, 0));
 
   Label new_space;
   __ InNewSpace(elements, scratch1, eq, &new_space);
   // Possible optimization: do a check that both values are Smis
   // (or them and test against Smi mask.)
 
   __ mov(scratch1, elements);
   __ RecordWriteHelper(elements, index1, scratch2);
   __ RecordWriteHelper(scratch1, index2, scratch2);  // scratch1 holds elements.
-  __ bind(&done);
 
   __ bind(&new_space);
   // We are done. Drop elements from the stack, and return undefined.
   __ Drop(3);
   __ LoadRoot(r0, Heap::kUndefinedValueRootIndex);
   __ jmp(&done);
 
   __ bind(&slow_case);
   __ CallRuntime(Runtime::kSwapElements, 3);
 
@@ skipping 782 matching lines @@
   UnaryOperation* left_unary = left->AsUnaryOperation();
   if (left_unary == NULL || left_unary->op() != Token::TYPEOF) return false;
   Handle<String> check = Handle<String>::cast(right_literal_value);
 
   { AccumulatorValueContext context(this);
     VisitForTypeofValue(left_unary->expression());
   }
   PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
 
   if (check->Equals(Heap::number_symbol())) {
-    __ tst(r0, Operand(kSmiTagMask));
-    __ b(eq, if_true);
+    __ JumpIfSmi(r0, if_true);
     __ ldr(r0, FieldMemOperand(r0, HeapObject::kMapOffset));
     __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
     __ cmp(r0, ip);
     Split(eq, if_true, if_false, fall_through);
   } else if (check->Equals(Heap::string_symbol())) {
-    __ tst(r0, Operand(kSmiTagMask));
-    __ b(eq, if_false);
+    __ JumpIfSmi(r0, if_false);
     // Check for undetectable objects => false.
-    __ ldr(r0, FieldMemOperand(r0, HeapObject::kMapOffset));
+    __ CompareObjectType(r0, r0, r1, FIRST_NONSTRING_TYPE);
+    __ b(ge, if_false);
     __ ldrb(r1, FieldMemOperand(r0, Map::kBitFieldOffset));
-    __ and_(r1, r1, Operand(1 << Map::kIsUndetectable));
-    __ cmp(r1, Operand(1 << Map::kIsUndetectable));
-    __ b(eq, if_false);
-    __ ldrb(r1, FieldMemOperand(r0, Map::kInstanceTypeOffset));
-    __ cmp(r1, Operand(FIRST_NONSTRING_TYPE));
-    Split(lt, if_true, if_false, fall_through);
+    __ tst(r1, Operand(1 << Map::kIsUndetectable));
+    Split(eq, if_true, if_false, fall_through);
   } else if (check->Equals(Heap::boolean_symbol())) {
-    __ LoadRoot(ip, Heap::kTrueValueRootIndex);
-    __ cmp(r0, ip);
+    __ CompareRoot(r0, Heap::kTrueValueRootIndex);
     __ b(eq, if_true);
-    __ LoadRoot(ip, Heap::kFalseValueRootIndex);
-    __ cmp(r0, ip);
+    __ CompareRoot(r0, Heap::kFalseValueRootIndex);
     Split(eq, if_true, if_false, fall_through);
   } else if (check->Equals(Heap::undefined_symbol())) {
-    __ LoadRoot(ip, Heap::kUndefinedValueRootIndex);
-    __ cmp(r0, ip);
+    __ CompareRoot(r0, Heap::kUndefinedValueRootIndex);
     __ b(eq, if_true);
-    __ tst(r0, Operand(kSmiTagMask));
-    __ b(eq, if_false);
+    __ JumpIfSmi(r0, if_false);
     // Check for undetectable objects => true.
     __ ldr(r0, FieldMemOperand(r0, HeapObject::kMapOffset));
     __ ldrb(r1, FieldMemOperand(r0, Map::kBitFieldOffset));
-    __ and_(r1, r1, Operand(1 << Map::kIsUndetectable));
-    __ cmp(r1, Operand(1 << Map::kIsUndetectable));
+    __ tst(r1, Operand(1 << Map::kIsUndetectable));
+    Split(ne, if_true, if_false, fall_through);
+
+  } else if (check->Equals(Heap::function_symbol())) {
+    __ JumpIfSmi(r0, if_false);
+    __ CompareObjectType(r0, r1, r0, FIRST_FUNCTION_CLASS_TYPE);
+    Split(ge, if_true, if_false, fall_through);
+
+  } else if (check->Equals(Heap::object_symbol())) {
+    __ JumpIfSmi(r0, if_false);
+    __ CompareRoot(r0, Heap::kNullValueRootIndex);
+    __ b(eq, if_true);
+    // Check for JS objects => true.
+    __ CompareObjectType(r0, r0, r1, FIRST_JS_OBJECT_TYPE);
+    __ b(lo, if_false);
+    __ CompareInstanceType(r0, r1, FIRST_FUNCTION_CLASS_TYPE);

[fschneider, 2011/03/03 12:05:02]

Could you reuse the value of the instance type from r1 left by CompareObjectType
here?

[William Hesse, 2011/03/03 12:16:13]

It is being reused, and it is in r0.  R1 is just a scratch register, not the map
register.

+    __ b(hs, if_false);
+    // Check for undetectable objects => false.
+    __ ldrb(r1, FieldMemOperand(r0, Map::kBitFieldOffset));
+    __ tst(r1, Operand(1 << Map::kIsUndetectable));
     Split(eq, if_true, if_false, fall_through);
-  } else if (check->Equals(Heap::function_symbol())) {
-    __ tst(r0, Operand(kSmiTagMask));
-    __ b(eq, if_false);
-    __ CompareObjectType(r0, r1, r0, JS_FUNCTION_TYPE);
-    __ b(eq, if_true);
-    // Regular expressions => 'function' (they are callable).
-    __ CompareInstanceType(r1, r0, JS_REGEXP_TYPE);
-    Split(eq, if_true, if_false, fall_through);
-  } else if (check->Equals(Heap::object_symbol())) {
-    __ tst(r0, Operand(kSmiTagMask));
-    __ b(eq, if_false);
-    __ LoadRoot(ip, Heap::kNullValueRootIndex);
-    __ cmp(r0, ip);
-    __ b(eq, if_true);
-    // Regular expressions => 'function', not 'object'.
-    __ CompareObjectType(r0, r1, r0, JS_REGEXP_TYPE);
-    __ b(eq, if_false);
-    // Check for undetectable objects => false.
-    __ ldrb(r0, FieldMemOperand(r1, Map::kBitFieldOffset));
-    __ and_(r0, r0, Operand(1 << Map::kIsUndetectable));
-    __ cmp(r0, Operand(1 << Map::kIsUndetectable));
-    __ b(eq, if_false);
-    // Check for JS objects => true.
-    __ ldrb(r0, FieldMemOperand(r1, Map::kInstanceTypeOffset));
-    __ cmp(r0, Operand(FIRST_JS_OBJECT_TYPE));
-    __ b(lt, if_false);
-    __ cmp(r0, Operand(LAST_JS_OBJECT_TYPE));
-    Split(le, if_true, if_false, fall_through);
   } else {
     if (if_false != fall_through) __ jmp(if_false);
   }
 
   return true;
 }
 
 
 void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   Comment cmnt(masm_, "[ CompareOperation");
@@ skipping 241 matching lines @@
   __ mov(r1, Operand(r1, ASR, 1));  // Un-smi-tag value.
   __ add(pc, r1, Operand(masm_->CodeObject()));
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM