Refactor and improve inlined double-aligned allocations

src/arm/codegen-arm.cc

Index: src/arm/codegen-arm.cc
diff --git a/src/arm/codegen-arm.cc b/src/arm/codegen-arm.cc
index 5e8739cd6a5d89ff47e5213f68bb0e150ade3675..3f1791c394efd50fcf7a15b56215182d9b8ae3ac 100644
--- a/src/arm/codegen-arm.cc
+++ b/src/arm/codegen-arm.cc
@@ -193,27 +193,10 @@ void ElementsTransitionGenerator::GenerateSmiToDouble(
   // Allocate new FixedDoubleArray.
   // Use lr as a temporary register.
   __ mov(lr, Operand(r5, LSL, 2));
-  __ add(lr, lr, Operand(FixedDoubleArray::kHeaderSize + kPointerSize));
-  __ AllocateInNewSpace(lr, r6, r7, r9, &gc_required, NO_ALLOCATION_FLAGS);
+  __ add(lr, lr, Operand(FixedDoubleArray::kHeaderSize));
+  __ AllocateInNewSpace(lr, r6, r7, r9, &gc_required, DOUBLE_ALIGNMENT);
   // r6: destination FixedDoubleArray, not tagged as heap object.
 
-  // Align the array conveniently for doubles.
-  // Store a filler value in the unused memory.
-  Label aligned, aligned_done;
-  __ tst(r6, Operand(kDoubleAlignmentMask));
-  __ mov(ip, Operand(masm->isolate()->factory()->one_pointer_filler_map()));
-  __ b(eq, &aligned);
-  // Store at the beginning of the allocated memory and update the base pointer.
-  __ str(ip, MemOperand(r6, kPointerSize, PostIndex));
-  __ b(&aligned_done);
-
-  __ bind(&aligned);
-  // Store the filler at the end of the allocated memory.
-  __ sub(lr, lr, Operand(kPointerSize));
-  __ str(ip, MemOperand(r6, lr));
-
-  __ bind(&aligned_done);
-
   // Set destination FixedDoubleArray's length and map.
   __ LoadRoot(r9, Heap::kFixedDoubleArrayMapRootIndex);
   __ str(r5, MemOperand(r6, FixedDoubleArray::kLengthOffset));