VM: Small generated code size improvements on x64.

runtime/vm/assembler_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"  // NOLINT
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/assembler.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
@@ skipping 133 matching lines @@
     EmitUint8(0xB8 | (TMP & 7));
     EmitInt64(label->address());
   }
   call(TMP);
 }
 
 
 void Assembler::CallPatchable(const ExternalLabel* label) {
   ASSERT(allow_constant_pool());
   intptr_t call_start = buffer_.GetPosition();
-  LoadExternalLabel(TMP, label, kPatchable, PP);
-  call(TMP);
+  const int32_t offset =
+      Array::element_offset(FindExternalLabel(label, kPatchable));
+  call(Address::AddressBaseImm32(PP, offset - kHeapObjectTag));
   ASSERT((buffer_.GetPosition() - call_start) == kCallExternalLabelSize);
 }
 
 
 void Assembler::Call(const ExternalLabel* label, Register pp) {
   if (Isolate::Current() == Dart::vm_isolate()) {
     call(label);
   } else {
-    LoadExternalLabel(TMP, label, kNotPatchable, pp);
-    call(TMP);
+    const int32_t offset =
+        Array::element_offset(FindExternalLabel(label, kNotPatchable));
+    call(Address::AddressBaseImm32(pp, offset - kHeapObjectTag));
   }
 }
 
 
 void Assembler::pushq(Register reg) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitRegisterREX(reg, REX_NONE);
   EmitUint8(0x50 | (reg & 7));
 }
 
@@ skipping 2407 matching lines @@
   }
   jmp(TMP);
 }
 
 
 void Assembler::JmpPatchable(const ExternalLabel* label, Register pp) {
   ASSERT(allow_constant_pool());
   intptr_t call_start = buffer_.GetPosition();
   LoadExternalLabel(TMP, label, kPatchable, pp);
   jmp(TMP);
-  ASSERT((buffer_.GetPosition() - call_start) == kCallExternalLabelSize);
+  ASSERT((buffer_.GetPosition() - call_start) == kJmpExternalLabelSize);
 }
 
 
 void Assembler::Jmp(const ExternalLabel* label, Register pp) {
   LoadExternalLabel(TMP, label, kNotPatchable, pp);
   jmp(TMP);
 }
 
 
 void Assembler::lock() {
@@ skipping 129 matching lines @@
       } else {
         subq(address, imm);
       }
     }
   } else {
     AddImmediate(address, Immediate(-value), pp);
   }
 }
 
 
-void Assembler::Drop(intptr_t stack_elements) {
+void Assembler::Drop(intptr_t stack_elements, Register tmp) {
   ASSERT(stack_elements >= 0);
   if (stack_elements <= 4) {
     for (intptr_t i = 0; i < stack_elements; i++) {
-      popq(TMP);
+      popq(tmp);
     }
     return;
   }
   addq(RSP, Immediate(stack_elements * kWordSize));
 }
 
 
 intptr_t Assembler::FindObject(const Object& obj, Patchability patchable) {
   // The object pool cannot be used in the vm isolate.
   ASSERT(Isolate::Current() != Dart::vm_isolate());
@@ skipping 1169 matching lines @@
 
 
 const char* Assembler::FpuRegisterName(FpuRegister reg) {
   ASSERT((0 <= reg) && (reg < kNumberOfXmmRegisters));
   return xmm_reg_names[reg];
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64