[arm64] cleanup heap numbers detection

src/arm64/macro-assembler-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 2229 matching lines @@
   DCHECK(rmode != RelocInfo::NONE32);
 
   if (rmode == RelocInfo::NONE64) {
     return kCallSizeWithoutRelocation;
   } else {
     return kCallSizeWithRelocation;
   }
 }
 
 
+void MacroAssembler::JumpIfHeapNumber(Register object, Label* on_heap_number,
+                                      SmiCheckType smi_check_type) {
+  Label on_not_heap_number;
 
+  if (smi_check_type == DO_SMI_CHECK) {
+    JumpIfSmi(object, &on_not_heap_number);
+  }
 
-
-void MacroAssembler::JumpForHeapNumber(Register object,
-                                       Register heap_number_map,
-                                       Label* on_heap_number,
-                                       Label* on_not_heap_number) {
-  DCHECK(on_heap_number || on_not_heap_number);
   AssertNotSmi(object);
 
   UseScratchRegisterScope temps(this);
   Register temp = temps.AcquireX();
+  Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
+  JumpIfRoot(temp, Heap::kHeapNumberMapRootIndex, on_heap_number);
 
-  // Load the HeapNumber map if it is not passed.
-  if (heap_number_map.Is(NoReg)) {
-    heap_number_map = temps.AcquireX();
-    LoadRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
-  } else {
-    AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
-  }
-
-  DCHECK(!AreAliased(temp, heap_number_map));
-
-  Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
-  Cmp(temp, heap_number_map);
-
-  if (on_heap_number) {
-    B(eq, on_heap_number);
-  }
-  if (on_not_heap_number) {
-    B(ne, on_not_heap_number);
-  }
-}
-
-
-void MacroAssembler::JumpIfHeapNumber(Register object,
-                                      Label* on_heap_number,
-                                      Register heap_number_map) {
-  JumpForHeapNumber(object,
-                    heap_number_map,
-                    on_heap_number,
-                    NULL);
+  Bind(&on_not_heap_number);
 }
 
 
 void MacroAssembler::JumpIfNotHeapNumber(Register object,
                                          Label* on_not_heap_number,
-                                         Register heap_number_map) {
-  JumpForHeapNumber(object,
-                    heap_number_map,
-                    NULL,
-                    on_not_heap_number);
+                                         SmiCheckType smi_check_type) {
+  if (smi_check_type == DO_SMI_CHECK) {
+    JumpIfSmi(object, on_not_heap_number);
+  }
+
+  AssertNotSmi(object);
+
+  UseScratchRegisterScope temps(this);
+  Register temp = temps.AcquireX();
+  Ldr(temp, FieldMemOperand(object, HeapObject::kMapOffset));
+  JumpIfNotRoot(temp, Heap::kHeapNumberMapRootIndex, on_not_heap_number);
 }
 
 
 void MacroAssembler::LookupNumberStringCache(Register object,
                                              Register result,
                                              Register scratch1,
                                              Register scratch2,
                                              Register scratch3,
                                              Label* not_found) {
   DCHECK(!AreAliased(object, result, scratch1, scratch2, scratch3));
@@ skipping 13 matching lines @@
   Sub(mask, mask, 1);  // Make mask.
 
   // Calculate the entry in the number string cache. The hash value in the
   // number string cache for smis is just the smi value, and the hash for
   // doubles is the xor of the upper and lower words. See
   // Heap::GetNumberStringCache.
   Label is_smi;
   Label load_result_from_cache;
 
   JumpIfSmi(object, &is_smi);
-  CheckMap(object, scratch1, Heap::kHeapNumberMapRootIndex, not_found,
-           DONT_DO_SMI_CHECK);
+  JumpIfNotHeapNumber(object, not_found);
 
   STATIC_ASSERT(kDoubleSize == (kWRegSize * 2));
   Add(scratch1, object, HeapNumber::kValueOffset - kHeapObjectTag);
   Ldp(scratch1.W(), scratch2.W(), MemOperand(scratch1));
   Eor(scratch1, scratch1, scratch2);
   And(scratch1, scratch1, mask);
 
   // Calculate address of entry in string cache: each entry consists of two
   // pointer sized fields.
   Add(scratch1, number_string_cache,
@@ skipping 1387 matching lines @@
 
 // Sets condition flags based on comparison, and returns type in type_reg.
 void MacroAssembler::CompareInstanceType(Register map,
                                          Register type_reg,
                                          InstanceType type) {
   Ldrb(type_reg, FieldMemOperand(map, Map::kInstanceTypeOffset));
   Cmp(type_reg, type);
 }
 
 
-void MacroAssembler::CompareMap(Register obj,
-                                Register scratch,
-                                Handle<Map> map) {
+void MacroAssembler::CompareObjectMap(Register obj, Heap::RootListIndex index) {
+  UseScratchRegisterScope temps(this);
+  Register obj_map = temps.AcquireX();
+  Ldr(obj_map, FieldMemOperand(obj, HeapObject::kMapOffset));
+  CompareRoot(obj_map, index);
+}
+
+
+void MacroAssembler::CompareObjectMap(Register obj, Register scratch,
+                                      Handle<Map> map) {
   Ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
   CompareMap(scratch, map);
 }
 
 
 void MacroAssembler::CompareMap(Register obj_map,
                                 Handle<Map> map) {
   Cmp(obj_map, Operand(map));
 }
 
 
 void MacroAssembler::CheckMap(Register obj,
                               Register scratch,
                               Handle<Map> map,
                               Label* fail,
                               SmiCheckType smi_check_type) {
   if (smi_check_type == DO_SMI_CHECK) {
     JumpIfSmi(obj, fail);
   }
 
-  CompareMap(obj, scratch, map);
+  CompareObjectMap(obj, scratch, map);
   B(ne, fail);
 }
 
 
 void MacroAssembler::CheckMap(Register obj,
                               Register scratch,
                               Heap::RootListIndex index,
                               Label* fail,
                               SmiCheckType smi_check_type) {
   if (smi_check_type == DO_SMI_CHECK) {
@@ skipping 219 matching lines @@
   Label store_num;
 
   // Speculatively convert the smi to a double - all smis can be exactly
   // represented as a double.
   SmiUntagToDouble(fpscratch1, value_reg, kSpeculativeUntag);
 
   // If value_reg is a smi, we're done.
   JumpIfSmi(value_reg, &store_num);
 
   // Ensure that the object is a heap number.
-  CheckMap(value_reg, scratch1, isolate()->factory()->heap_number_map(),
-           fail, DONT_DO_SMI_CHECK);
+  JumpIfNotHeapNumber(value_reg, fail);
 
   Ldr(fpscratch1, FieldMemOperand(value_reg, HeapNumber::kValueOffset));
 
   // Canonicalize NaNs.
   CanonicalizeNaN(fpscratch1);
 
   // Store the result.
   Bind(&store_num);
   Add(scratch1, elements_reg,
       Operand::UntagSmiAndScale(key_reg, kDoubleSizeLog2));
@@ skipping 404 matching lines @@
                                        Register dst,
                                        LinkRegisterStatus lr_status,
                                        SaveFPRegsMode fp_mode) {
   ASM_LOCATION("MacroAssembler::RecordWrite");
   DCHECK(!AreAliased(object, map));
 
   if (emit_debug_code()) {
     UseScratchRegisterScope temps(this);
     Register temp = temps.AcquireX();
 
-    CompareMap(map, temp, isolate()->factory()->meta_map());
+    CompareObjectMap(map, temp, isolate()->factory()->meta_map());
     Check(eq, kWrongAddressOrValuePassedToRecordWrite);
   }
 
   if (!FLAG_incremental_marking) {
     return;
   }
 
   if (emit_debug_code()) {
     UseScratchRegisterScope temps(this);
     Register temp = temps.AcquireX();
@@ skipping 952 matching lines @@
   }
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64