Fix kStoreBufferBlockProcessRuntimeEntry call sequence.

runtime/vm/assembler_x64.cc

Index: runtime/vm/assembler_x64.cc
diff --git a/runtime/vm/assembler_x64.cc b/runtime/vm/assembler_x64.cc
index ccc142f41aa907c621872d41a70dd0aaa33f7047..1d4914e09873747724e398a59bab030850e5409e 100644
--- a/runtime/vm/assembler_x64.cc
+++ b/runtime/vm/assembler_x64.cc
@@ -1674,7 +1674,9 @@ void Assembler::ReserveAlignedFrameSpace(intptr_t frame_space) {
 }
 
 
-void Assembler::PreserveCallerSavedRegisters() {
+void Assembler::EnterCallRuntimeFrame(intptr_t frame_space) {
+  enter(Immediate(0));
+  // Preserve volatile registers.

[siva, 2012/07/27 20:41:21]

ASSERT(kNumberOfVolatileRegisters == 9);

   // Based on http://x86-64.org/documentation/abi.pdf Fig. 3.4
   pushq(RAX);
   pushq(RCX);
@@ -1686,12 +1688,20 @@ void Assembler::PreserveCallerSavedRegisters() {
   pushq(R10);
   pushq(R11);
   // TODO(srdjan): Add XMM registers once they are used by the compiler.
+
+  ReserveAlignedFrameSpace(frame_space);
 }
 
 
-void Assembler::RestoreCallerSavedRegisters() {
+void Assembler::LeaveCallRuntimeFrame() {
+  // RSP might have been modified to reserve space for arguments
+  // and ensure proper alignment of the stack frame.
+  // We need to restore it before restoring registers.
+  const intptr_t kNumberOfVolatileRegisters = 9;

[siva, 2012/07/27 20:41:21]

ditto comment regarding kNumberOfVolatileRegisters.

+  leaq(RSP, Address(RBP, -kNumberOfVolatileRegisters * kWordSize));
+
+  // Restore volatile registers.
   // Based on http://x86-64.org/documentation/abi.pdf Fig. 3.4
-  // TODO(srdjan): Add XMM registers once they are used by the compiler.
   popq(R11);
   popq(R10);
   popq(R9);
@@ -1701,6 +1711,7 @@ void Assembler::RestoreCallerSavedRegisters() {
   popq(RDX);
   popq(RCX);
   popq(RAX);

[siva, 2012/07/27 20:41:21]

ditto comment regarding kNumberOfVolatileRegisters

+  leave();
 }