Fix object initialization when slack tracking for it's map is still enabled.

src/arm/macro-assembler-arm.cc

 // Copyright 2012 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 <limits.h>  // For LONG_MIN, LONG_MAX.
 
 #if V8_TARGET_ARCH_ARM
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
@@ skipping 1742 matching lines @@
   b(hi, gc_required);
   str(scratch2, MemOperand(topaddr));
 
   // Tag object if requested.
   if ((flags & TAG_OBJECT) != 0) {
     add(result, result, Operand(kHeapObjectTag));
   }
 }
 
 
-void MacroAssembler::Allocate(Register object_size,
-                              Register result,
-                              Register scratch1,
-                              Register scratch2,
-                              Label* gc_required,
-                              AllocationFlags flags) {
+void MacroAssembler::Allocate(Register object_size, Register result,
+                              Register result_end, Register scratch,
+                              Label* gc_required, AllocationFlags flags) {
   if (!FLAG_inline_new) {
     if (emit_debug_code()) {
       // Trash the registers to simulate an allocation failure.
       mov(result, Operand(0x7091));
-      mov(scratch1, Operand(0x7191));
-      mov(scratch2, Operand(0x7291));
+      mov(scratch, Operand(0x7191));
+      mov(result_end, Operand(0x7291));
     }
     jmp(gc_required);
     return;
   }
 
   // Assert that the register arguments are different and that none of
   // them are ip. ip is used explicitly in the code generated below.
-  DCHECK(!result.is(scratch1));
-  DCHECK(!result.is(scratch2));
-  DCHECK(!scratch1.is(scratch2));
+  DCHECK(!result.is(scratch));
+  DCHECK(!result.is(result_end));
+  DCHECK(!scratch.is(result_end));
   DCHECK(!object_size.is(ip));
   DCHECK(!result.is(ip));
-  DCHECK(!scratch1.is(ip));
-  DCHECK(!scratch2.is(ip));
+  DCHECK(!scratch.is(ip));
+  DCHECK(!result_end.is(ip));
 
   // Check relative positions of allocation top and limit addresses.
   // The values must be adjacent in memory to allow the use of LDM.
   // Also, assert that the registers are numbered such that the values
   // are loaded in the correct order.
   ExternalReference allocation_top =
       AllocationUtils::GetAllocationTopReference(isolate(), flags);
   ExternalReference allocation_limit =
       AllocationUtils::GetAllocationLimitReference(isolate(), flags);
   intptr_t top =
       reinterpret_cast<intptr_t>(allocation_top.address());
   intptr_t limit =
       reinterpret_cast<intptr_t>(allocation_limit.address());
   DCHECK((limit - top) == kPointerSize);
   DCHECK(result.code() < ip.code());
 
   // Set up allocation top address.
-  Register topaddr = scratch1;
+  Register topaddr = scratch;
   mov(topaddr, Operand(allocation_top));
 
   // This code stores a temporary value in ip. This is OK, as the code below
   // does not need ip for implicit literal generation.
   if ((flags & RESULT_CONTAINS_TOP) == 0) {
     // Load allocation top into result and allocation limit into ip.
     ldm(ia, topaddr, result.bit() | ip.bit());
   } else {
     if (emit_debug_code()) {
       // Assert that result actually contains top on entry. ip is used
       // immediately below so this use of ip does not cause difference with
       // respect to register content between debug and release mode.
       ldr(ip, MemOperand(topaddr));
       cmp(result, ip);
       Check(eq, kUnexpectedAllocationTop);
     }
     // Load allocation limit into ip. Result already contains allocation top.
     ldr(ip, MemOperand(topaddr, limit - top));
   }
 
   if ((flags & DOUBLE_ALIGNMENT) != 0) {
     // Align the next allocation. Storing the filler map without checking top is
     // safe in new-space because the limit of the heap is aligned there.
     DCHECK(kPointerAlignment * 2 == kDoubleAlignment);
-    and_(scratch2, result, Operand(kDoubleAlignmentMask), SetCC);
+    and_(result_end, result, Operand(kDoubleAlignmentMask), SetCC);
     Label aligned;
     b(eq, &aligned);
     if ((flags & PRETENURE) != 0) {
       cmp(result, Operand(ip));
       b(hs, gc_required);
     }
-    mov(scratch2, Operand(isolate()->factory()->one_pointer_filler_map()));
-    str(scratch2, MemOperand(result, kDoubleSize / 2, PostIndex));
+    mov(result_end, Operand(isolate()->factory()->one_pointer_filler_map()));
+    str(result_end, MemOperand(result, kDoubleSize / 2, PostIndex));
     bind(&aligned);
   }
 
   // Calculate new top and bail out if new space is exhausted. Use result
   // to calculate the new top. Object size may be in words so a shift is
   // required to get the number of bytes.
   if ((flags & SIZE_IN_WORDS) != 0) {
-    add(scratch2, result, Operand(object_size, LSL, kPointerSizeLog2), SetCC);
+    add(result_end, result, Operand(object_size, LSL, kPointerSizeLog2), SetCC);
   } else {
-    add(scratch2, result, Operand(object_size), SetCC);
+    add(result_end, result, Operand(object_size), SetCC);
   }
   b(cs, gc_required);
-  cmp(scratch2, Operand(ip));
+  cmp(result_end, Operand(ip));
   b(hi, gc_required);
 
   // Update allocation top. result temporarily holds the new top.
   if (emit_debug_code()) {
-    tst(scratch2, Operand(kObjectAlignmentMask));
+    tst(result_end, Operand(kObjectAlignmentMask));
     Check(eq, kUnalignedAllocationInNewSpace);
   }
-  str(scratch2, MemOperand(topaddr));
+  str(result_end, MemOperand(topaddr));
 
   // Tag object if requested.
   if ((flags & TAG_OBJECT) != 0) {
     add(result, result, Operand(kHeapObjectTag));
   }
 }
 
 
 void MacroAssembler::AllocateTwoByteString(Register result,
                                            Register length,
@@ skipping 1144 matching lines @@
   b(eq, &done);
   bind(&byte_loop_1);
   ldrb(scratch, MemOperand(src, 1, PostIndex));
   strb(scratch, MemOperand(dst, 1, PostIndex));
   sub(length, length, Operand(1), SetCC);
   b(ne, &byte_loop_1);
   bind(&done);
 }
 
 
-void MacroAssembler::InitializeFieldsWithFiller(Register start_offset,
-                                                Register end_offset,
+void MacroAssembler::InitializeFieldsWithFiller(Register current_address,
+                                                Register end_address,
                                                 Register filler) {
   Label loop, entry;
   b(&entry);
   bind(&loop);
-  str(filler, MemOperand(start_offset, kPointerSize, PostIndex));
+  str(filler, MemOperand(current_address, kPointerSize, PostIndex));
   bind(&entry);
-  cmp(start_offset, end_offset);
+  cmp(current_address, end_address);
   b(lo, &loop);
 }
 
 
 void MacroAssembler::CheckFor32DRegs(Register scratch) {
   mov(scratch, Operand(ExternalReference::cpu_features()));
   ldr(scratch, MemOperand(scratch));
   tst(scratch, Operand(1u << VFP32DREGS));
 }
 
@@ skipping 679 matching lines @@
     }
   }
   if (mag.shift > 0) mov(result, Operand(result, ASR, mag.shift));
   add(result, result, Operand(dividend, LSR, 31));
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM