More compact string representation on 64 bit.

runtime/vm/stub_code_x64.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"
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
@@ skipping 637 matching lines @@
   // Check for maximum allowed length.
   const Immediate& max_len =
       Immediate(reinterpret_cast<int64_t>(Smi::New(Array::kMaxElements)));
   __ cmpq(RDI, max_len);
   __ j(GREATER, &slow_case);
 
   // Check for allocation tracing.
   NOT_IN_PRODUCT(
       __ MaybeTraceAllocation(kArrayCid, &slow_case, Assembler::kFarJump));
 
-  const intptr_t fixed_size = sizeof(RawArray) + kObjectAlignment - 1;
-  __ leaq(RDI, Address(RDI, TIMES_4, fixed_size));  // RDI is a Smi.
+  const intptr_t fixed_size_plus_alignment_padding =
+      sizeof(RawArray) + kObjectAlignment - 1;
+  // RDI is a Smi.
+  __ leaq(RDI, Address(RDI, TIMES_4, fixed_size_plus_alignment_padding));
   ASSERT(kSmiTagShift == 1);
   __ andq(RDI, Immediate(-kObjectAlignment));
 
   const intptr_t cid = kArrayCid;
   Heap::Space space = Heap::kNew;
   __ movq(R13, Address(THR, Thread::heap_offset()));
   __ movq(RAX, Address(R13, Heap::TopOffset(space)));
 
   // RDI: allocation size.
   __ movq(RCX, RAX);
@@ skipping 220 matching lines @@
 // Input:
 // R10: number of context variables.
 // Output:
 // RAX: new allocated RawContext object.
 void StubCode::GenerateAllocateContextStub(Assembler* assembler) {
   __ LoadObject(R9, Object::null_object());
   if (FLAG_inline_alloc) {
     Label slow_case;
     // First compute the rounded instance size.
     // R10: number of context variables.
-    intptr_t fixed_size = (sizeof(RawContext) + kObjectAlignment - 1);
-    __ leaq(R13, Address(R10, TIMES_8, fixed_size));
+    intptr_t fixed_size_plus_alignment_padding =
+        (sizeof(RawContext) + kObjectAlignment - 1);
+    __ leaq(R13, Address(R10, TIMES_8, fixed_size_plus_alignment_padding));
     __ andq(R13, Immediate(-kObjectAlignment));
 
     // Check for allocation tracing.
     NOT_IN_PRODUCT(
         __ MaybeTraceAllocation(kContextCid, &slow_case, Assembler::kFarJump));
 
     // Now allocate the object.
     // R10: number of context variables.
     const intptr_t cid = kContextCid;
     Heap::Space space = Heap::kNew;
@@ skipping 23 matching lines @@
     __ subq(R13, RAX);
     __ addq(RAX, Immediate(kHeapObjectTag));
     // Generate isolate-independent code to allow sharing between isolates.
     NOT_IN_PRODUCT(__ UpdateAllocationStatsWithSize(cid, R13, space));
 
     // Calculate the size tag.
     // RAX: new object.
     // R10: number of context variables.
     {
       Label size_tag_overflow, done;
-      __ leaq(R13, Address(R10, TIMES_8, fixed_size));
+      __ leaq(R13, Address(R10, TIMES_8, fixed_size_plus_alignment_padding));
       __ andq(R13, Immediate(-kObjectAlignment));
       __ cmpq(R13, Immediate(RawObject::SizeTag::kMaxSizeTag));
       __ j(ABOVE, &size_tag_overflow, Assembler::kNearJump);
       __ shlq(R13, Immediate(RawObject::kSizeTagPos - kObjectAlignmentLog2));
       __ jmp(&done);
 
       __ Bind(&size_tag_overflow);
       // Set overflow size tag value.
       __ movq(R13, Immediate(0));
 
@@ skipping 1297 matching lines @@
 
 
 // Called from switchable IC calls.
 //  RDI: receiver
 //  RBX: SingleTargetCache
 // Passed to target::
 //  CODE_REG: target Code object
 void StubCode::GenerateSingleTargetCallStub(Assembler* assembler) {
   Label miss;
   __ LoadClassIdMayBeSmi(RAX, RDI);
-  __ movl(R9, FieldAddress(RBX, SingleTargetCache::lower_limit_offset()));
-  __ movl(R10, FieldAddress(RBX, SingleTargetCache::upper_limit_offset()));
+  __ movzxw(R9, FieldAddress(RBX, SingleTargetCache::lower_limit_offset()));
+  __ movzxw(R10, FieldAddress(RBX, SingleTargetCache::upper_limit_offset()));
   __ cmpq(RAX, R9);
   __ j(LESS, &miss, Assembler::kNearJump);
   __ cmpq(RAX, R10);
   __ j(GREATER, &miss, Assembler::kNearJump);
   __ movq(RCX, FieldAddress(RBX, SingleTargetCache::entry_point_offset()));
   __ movq(CODE_REG, FieldAddress(RBX, SingleTargetCache::target_offset()));
   __ jmp(RCX);
 
   __ Bind(&miss);
   __ EnterStubFrame();
@@ skipping 41 matching lines @@
 }
 
 
 void StubCode::GenerateAsynchronousGapMarkerStub(Assembler* assembler) {
   __ int3();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64