More compact string representation on 64 bit.

runtime/vm/intrinsifier_mips.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_MIPS.
 #if defined(TARGET_ARCH_MIPS)
 
 #include "vm/intrinsifier.h"
 
 #include "vm/assembler.h"
@@ skipping 149 matching lines @@
   /* Check that length is a positive Smi. */                                   \
   /* T2: requested array length argument. */                                   \
   __ andi(CMPRES1, T2, Immediate(kSmiTagMask));                                \
   __ bne(CMPRES1, ZR, &fall_through);                                          \
   __ BranchSignedLess(T2, Immediate(0), &fall_through);                        \
   __ SmiUntag(T2);                                                             \
   /* Check for maximum allowed length. */                                      \
   /* T2: untagged array length. */                                             \
   __ BranchSignedGreater(T2, Immediate(max_len), &fall_through);               \
   __ sll(T2, T2, scale_shift);                                                 \
-  const intptr_t fixed_size = sizeof(Raw##type_name) + kObjectAlignment - 1;   \
-  __ AddImmediate(T2, fixed_size);                                             \
+  const intptr_t fixed_size_plus_alignment_padding =                           \
+      sizeof(Raw##type_name) + kObjectAlignment - 1;                           \
+  __ AddImmediate(T2, fixed_size_plus_alignment_padding);                      \
   __ LoadImmediate(TMP, -kObjectAlignment);                                    \
   __ and_(T2, T2, TMP);                                                        \
   Heap::Space space = Heap::kNew;                                              \
   __ lw(T3, Address(THR, Thread::heap_offset()));                              \
   __ lw(V0, Address(T3, Heap::TopOffset(space)));                              \
                                                                                \
   /* T2: allocation size. */                                                   \
   __ addu(T1, V0, T2);                                                         \
   /* Branch on unsigned overflow. */                                           \
   __ BranchUnsignedLess(T1, V0, &fall_through);                                \
@@ skipping 1942 matching lines @@
 // 'length-reg' (T2) contains tagged length.
 // Returns new string as tagged pointer in V0.
 static void TryAllocateOnebyteString(Assembler* assembler,
                                      Label* ok,
                                      Label* failure) {
   const Register length_reg = T2;
   NOT_IN_PRODUCT(__ MaybeTraceAllocation(kOneByteStringCid, V0, failure));
   __ mov(T6, length_reg);  // Save the length register.
   // TODO(koda): Protect against negative length and overflow here.
   __ SmiUntag(length_reg);
-  const intptr_t fixed_size = sizeof(RawString) + kObjectAlignment - 1;
-  __ AddImmediate(length_reg, fixed_size);
+  const intptr_t fixed_size_plus_alignment_padding =
+      sizeof(RawString) + kObjectAlignment - 1;
+  __ AddImmediate(length_reg, fixed_size_plus_alignment_padding);
   __ LoadImmediate(TMP, ~(kObjectAlignment - 1));
   __ and_(length_reg, length_reg, TMP);
 
   const intptr_t cid = kOneByteStringCid;
   Heap::Space space = Heap::kNew;
   __ lw(T3, Address(THR, Thread::heap_offset()));
   __ lw(V0, Address(T3, Heap::TopOffset(space)));
 
   // length_reg: allocation size.
   __ addu(T1, V0, length_reg);
@@ skipping 287 matching lines @@
 
 void Intrinsifier::SetAsyncThreadStackTrace(Assembler* assembler) {
   __ lw(V0, Address(THR, Thread::async_stack_trace_offset()));
   __ LoadObject(V0, Object::null_object());
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_MIPS