ARM: Optimize TypeofIsAndBranch

Optimize register constraints and code generated for TypeofIsAndBranch Lithium
instruction.

TEST=none
BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/78583002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18063 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-arm.cc

@@ -2570,7 +2570,7 @@ LInstruction* LChunkBuilder::DoTypeofIsAndBranch(HTypeofIsAndBranch* instr) {
   LInstruction* goto_instr = CheckElideControlInstruction(instr);
   if (goto_instr != NULL) return goto_instr;
 
-  return new(zone()) LTypeofIsAndBranch(UseTempRegister(instr->value()));
+  return new(zone()) LTypeofIsAndBranch(UseRegister(instr->value()));
 }
 
 

src/arm/lithium-codegen-arm.cc

@@ -5557,22 +5557,21 @@ Condition LCodeGen::EmitTypeofIs(Label* true_label,
   Register scratch = scratch0();
   if (type_name->Equals(heap()->number_string())) {
     __ JumpIfSmi(input, true_label);
-    __ ldr(input, FieldMemOperand(input, HeapObject::kMapOffset));
-    __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
-    __ cmp(input, Operand(ip));
+    __ ldr(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
+    __ CompareRoot(scratch, Heap::kHeapNumberMapRootIndex);
     final_branch_condition = eq;
 
   } else if (type_name->Equals(heap()->string_string())) {
     __ JumpIfSmi(input, false_label);
-    __ CompareObjectType(input, input, scratch, FIRST_NONSTRING_TYPE);
+    __ CompareObjectType(input, scratch, no_reg, FIRST_NONSTRING_TYPE);
     __ b(ge, false_label);
-    __ ldrb(ip, FieldMemOperand(input, Map::kBitFieldOffset));
-    __ tst(ip, Operand(1 << Map::kIsUndetectable));
+    __ ldrb(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
+    __ tst(scratch, Operand(1 << Map::kIsUndetectable));
     final_branch_condition = eq;
 
   } else if (type_name->Equals(heap()->symbol_string())) {
     __ JumpIfSmi(input, false_label);
-    __ CompareObjectType(input, input, scratch, SYMBOL_TYPE);
+    __ CompareObjectType(input, scratch, no_reg, SYMBOL_TYPE);
     final_branch_condition = eq;
 
   } else if (type_name->Equals(heap()->boolean_string())) {
@@ -5590,33 +5589,35 @@ Condition LCodeGen::EmitTypeofIs(Label* true_label,
     __ b(eq, true_label);
     __ JumpIfSmi(input, false_label);
     // Check for undetectable objects => true.
-    __ ldr(input, FieldMemOperand(input, HeapObject::kMapOffset));
-    __ ldrb(ip, FieldMemOperand(input, Map::kBitFieldOffset));
-    __ tst(ip, Operand(1 << Map::kIsUndetectable));
+    __ ldr(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
+    __ ldrb(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
+    __ tst(scratch, Operand(1 << Map::kIsUndetectable));
     final_branch_condition = ne;
 
   } else if (type_name->Equals(heap()->function_string())) {
     STATIC_ASSERT(NUM_OF_CALLABLE_SPEC_OBJECT_TYPES == 2);
+    Register type_reg = scratch;
     __ JumpIfSmi(input, false_label);
-    __ CompareObjectType(input, scratch, input, JS_FUNCTION_TYPE);
+    __ CompareObjectType(input, scratch, type_reg, JS_FUNCTION_TYPE);
     __ b(eq, true_label);
-    __ cmp(input, Operand(JS_FUNCTION_PROXY_TYPE));
+    __ cmp(type_reg, Operand(JS_FUNCTION_PROXY_TYPE));
     final_branch_condition = eq;
 
   } else if (type_name->Equals(heap()->object_string())) {
+    Register map = scratch;
     __ JumpIfSmi(input, false_label);
     if (!FLAG_harmony_typeof) {
       __ CompareRoot(input, Heap::kNullValueRootIndex);
       __ b(eq, true_label);
     }
-    __ CompareObjectType(input, input, scratch,
-                         FIRST_NONCALLABLE_SPEC_OBJECT_TYPE);
-    __ b(lt, false_label);
-    __ CompareInstanceType(input, scratch, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
-    __ b(gt, false_label);
+    __ CheckObjectTypeRange(input,
+                            map,
+                            FIRST_NONCALLABLE_SPEC_OBJECT_TYPE,
+                            LAST_NONCALLABLE_SPEC_OBJECT_TYPE,
+                            false_label);
     // Check for undetectable objects => false.
-    __ ldrb(ip, FieldMemOperand(input, Map::kBitFieldOffset));
-    __ tst(ip, Operand(1 << Map::kIsUndetectable));
+    __ ldrb(scratch, FieldMemOperand(map, Map::kBitFieldOffset));
+    __ tst(scratch, Operand(1 << Map::kIsUndetectable));
     final_branch_condition = eq;
 
   } else {

src/arm/macro-assembler-arm.cc

@@ -2022,14 +2022,36 @@ 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, 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));
-  CompareInstanceType(map, type_reg, type);
+  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
+  // will never need ip).
+  STATIC_ASSERT(Map::kInstanceTypeOffset < 4096);
+  STATIC_ASSERT(LAST_TYPE < 256);
   ldrb(type_reg, FieldMemOperand(map, Map::kInstanceTypeOffset));
   cmp(type_reg, Operand(type));
 }

src/arm/macro-assembler-arm.h

@@ -845,11 +845,21 @@ class MacroAssembler: public Assembler {
   // are the same register).  It leaves the heap object in the heap_object
   // register unless the heap_object register is the same register as one of the
   // other registers.
+  // Type_reg can be no_reg. In that case ip is used.
   void CompareObjectType(Register heap_object,
                          Register map,
                          Register type_reg,
                          InstanceType type);
 
+  // Compare object type for heap object. Branch to false_label if type
+  // is lower than min_type or greater than max_type.
+  // Load map into the register map.
+  void CheckObjectTypeRange(Register heap_object,
+                            Register map,
+                            InstanceType min_type,
+                            InstanceType max_type,
+                            Label* false_label);
+
   // Compare instance type in a map.  map contains a valid map object whose
   // object type should be compared with the given type.  This both
   // sets the flags and leaves the object type in the type_reg register.