Introduce MakeSureDoubleAlignedHelper for x64 port.

src/x64/macro-assembler-x64.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 "v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "bootstrapper.h"
 #include "codegen.h"
@@ skipping 4275 matching lines @@
   // and keep address in scratch until call to UpdateAllocationTopHelper.
   if (scratch.is_valid()) {
     LoadAddress(scratch, allocation_top);
     movp(result, Operand(scratch, 0));
   } else {
     Load(result, allocation_top);
   }
 }
 
 
+void MacroAssembler::MakeSureDoubleAlignedHelper(Register result,
+                                                 Register scratch,
+                                                 Label* gc_required,
+                                                 AllocationFlags flags) {
+  if (kPointerSize == kDoubleSize) {
+    if (FLAG_debug_code) {
+      testl(result, Immediate(kDoubleAlignmentMask));
+      Check(zero, kAllocationIsNotDoubleAligned);
+    }
+  } else {
+    // 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.
+    ASSERT(kPointerSize * 2 == kDoubleSize);
+    ASSERT((flags & PRETENURE_OLD_POINTER_SPACE) == 0);
+    ASSERT(kPointerAlignment * 2 == kDoubleAlignment);
+    // Make sure scratch is not clobbered by this function as it might be
+    // used in UpdateAllocationTopHelper later.
+    ASSERT(!scratch.is(kScratchRegister));
+    Label aligned;
+    testl(result, Immediate(kDoubleAlignmentMask));
+    j(zero, &aligned, Label::kNear);
+    if ((flags & PRETENURE_OLD_DATA_SPACE) != 0) {
+      ExternalReference allocation_limit =
+          AllocationUtils::GetAllocationLimitReference(isolate(), flags);
+      cmpp(result, ExternalOperand(allocation_limit));
+      j(above_equal, gc_required);
+    }
+    LoadRoot(kScratchRegister, Heap::kOnePointerFillerMapRootIndex);
+    movp(Operand(result, 0), kScratchRegister);
+    addp(result, Immediate(kDoubleSize / 2));
+    bind(&aligned);
+  }
+}
+
+
 void MacroAssembler::UpdateAllocationTopHelper(Register result_end,
                                                Register scratch,
                                                AllocationFlags flags) {
   if (emit_debug_code()) {
     testp(result_end, Immediate(kObjectAlignmentMask));
     Check(zero, kUnalignedAllocationInNewSpace);
   }
 
   ExternalReference allocation_top =
       AllocationUtils::GetAllocationTopReference(isolate(), flags);
@@ skipping 28 matching lines @@
       }
     }
     jmp(gc_required);
     return;
   }
   ASSERT(!result.is(result_end));
 
   // Load address of new object into result.
   LoadAllocationTopHelper(result, scratch, flags);
 
-  // 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.
-  if (((flags & DOUBLE_ALIGNMENT) != 0) && FLAG_debug_code) {
-    testq(result, Immediate(kDoubleAlignmentMask));
-    Check(zero, kAllocationIsNotDoubleAligned);
+  if ((flags & DOUBLE_ALIGNMENT) != 0) {
+    MakeSureDoubleAlignedHelper(result, scratch, gc_required, flags);
   }
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference allocation_limit =
       AllocationUtils::GetAllocationLimitReference(isolate(), flags);
 
   Register top_reg = result_end.is_valid() ? result_end : result;
 
   if (!top_reg.is(result)) {
     movp(top_reg, result);
@@ skipping 54 matching lines @@
       // object_size is left unchanged by this function.
     }
     jmp(gc_required);
     return;
   }
   ASSERT(!result.is(result_end));
 
   // Load address of new object into result.
   LoadAllocationTopHelper(result, scratch, flags);
 
-  // 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.
-  if (((flags & DOUBLE_ALIGNMENT) != 0) && FLAG_debug_code) {
-    testq(result, Immediate(kDoubleAlignmentMask));
-    Check(zero, kAllocationIsNotDoubleAligned);
+  if ((flags & DOUBLE_ALIGNMENT) != 0) {
+    MakeSureDoubleAlignedHelper(result, scratch, gc_required, flags);
   }
 
   // Calculate new top and bail out if new space is exhausted.
   ExternalReference allocation_limit =
       AllocationUtils::GetAllocationLimitReference(isolate(), flags);
   if (!object_size.is(result_end)) {
     movp(result_end, object_size);
   }
   addp(result_end, result);
   j(carry, gc_required);
@@ skipping 808 matching lines @@
   if (ms.shift() > 0) sarl(rdx, Immediate(ms.shift()));
   movl(rax, dividend);
   shrl(rax, Immediate(31));
   addl(rdx, rax);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64