More compact string representation on 64 bit.

runtime/vm/stub_code_arm.cc

Index: runtime/vm/stub_code_arm.cc
diff --git a/runtime/vm/stub_code_arm.cc b/runtime/vm/stub_code_arm.cc
index 4f2cf296aae709739b3147f3879bda41ac6a831c..17bfc42b4f2bfe4c063809d7f96035e405d3420c 100644
--- a/runtime/vm/stub_code_arm.cc
+++ b/runtime/vm/stub_code_arm.cc
@@ -694,9 +694,10 @@ void StubCode::GenerateAllocateArrayStub(Assembler* assembler) {
   const intptr_t cid = kArrayCid;
   NOT_IN_PRODUCT(__ MaybeTraceAllocation(cid, R4, &slow_case));
 
-  const intptr_t fixed_size = sizeof(RawArray) + kObjectAlignment - 1;
-  __ LoadImmediate(R9, fixed_size);
-  __ add(R9, R9, Operand(R3, LSL, 1));  // R3 is  a Smi.
+  const intptr_t fixed_size_plus_alignment_padding =
+      sizeof(RawArray) + kObjectAlignment - 1;
+  __ LoadImmediate(R9, fixed_size_plus_alignment_padding);
+  __ add(R9, R9, Operand(R3, LSL, 1));  // R3 is a Smi.
   ASSERT(kSmiTagShift == 1);
   __ bic(R9, R9, Operand(kObjectAlignment - 1));
 
@@ -915,8 +916,9 @@ void StubCode::GenerateAllocateContextStub(Assembler* assembler) {
     Label slow_case;
     // First compute the rounded instance size.
     // R1: number of context variables.
-    intptr_t fixed_size = sizeof(RawContext) + kObjectAlignment - 1;
-    __ LoadImmediate(R2, fixed_size);
+    intptr_t fixed_size_plus_alignment_padding =
+        sizeof(RawContext) + kObjectAlignment - 1;
+    __ LoadImmediate(R2, fixed_size_plus_alignment_padding);
     __ add(R2, R2, Operand(R1, LSL, 2));
     ASSERT(kSmiTagShift == 1);
     __ bic(R2, R2, Operand(kObjectAlignment - 1));