Revert "VM: New calling convention for generated code."

runtime/vm/assembler_ia32.cc

Index: runtime/vm/assembler_ia32.cc
diff --git a/runtime/vm/assembler_ia32.cc b/runtime/vm/assembler_ia32.cc
index 2da038334bc5822889d40e059e0692bb97139e26..c6c8da8a468aff6b8b5f5b12f092a1f10267af03 100644
--- a/runtime/vm/assembler_ia32.cc
+++ b/runtime/vm/assembler_ia32.cc
@@ -2366,7 +2366,7 @@ void Assembler::StoreIntoObject(Register object,
   if (object != EDX) {
     movl(EDX, object);
   }
-  call(Address(THR, Thread::update_store_buffer_entry_point_offset()));
+  Call(*StubCode::UpdateStoreBuffer_entry());
   if (value != EDX) {
     popl(EDX);  // Restore EDX.
   }
@@ -2622,9 +2622,8 @@ void Assembler::CallRuntime(const RuntimeEntry& entry,
 
 
 void Assembler::Call(const StubEntry& stub_entry) {
-  const Code& target = Code::ZoneHandle(stub_entry.code());
-  LoadObject(CODE_REG, target);
-  call(FieldAddress(CODE_REG, Code::entry_point_offset()));
+  const ExternalLabel label(stub_entry.EntryPoint());
+  call(&label);
 }
 
 
@@ -2870,19 +2869,18 @@ void Assembler::TryAllocateArray(intptr_t cid,
 }
 
 
-void Assembler::PushCodeObject() {
-  ASSERT(code_.IsNotTemporaryScopedHandle());
-  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
-  EmitUint8(0x68);
-  buffer_.EmitObject(code_);
-}
-
-
 void Assembler::EnterDartFrame(intptr_t frame_size) {
   EnterFrame(0);
-
-  PushCodeObject();
-
+  Label dart_entry;
+  call(&dart_entry);
+  Bind(&dart_entry);
+  // The runtime system assumes that the code marker address is
+  // kEntryPointToPcMarkerOffset bytes from the entry.  If there is any code
+  // generated before entering the frame, the address needs to be adjusted.
+  const intptr_t offset = EntryPointToPcMarkerOffset() - CodeSize();
+  if (offset != 0) {
+    addl(Address(ESP, 0), Immediate(offset));
+  }
   if (frame_size != 0) {
     subl(ESP, Immediate(frame_size));
   }
@@ -2891,7 +2889,8 @@ void Assembler::EnterDartFrame(intptr_t frame_size) {
 
 // On entry to a function compiled for OSR, the caller's frame pointer, the
 // stack locals, and any copied parameters are already in place.  The frame
-// pointer is already set up. There may be extra space for spill slots to
+// pointer is already set up.  The PC marker is not correct for the
+// optimized function and there may be extra space for spill slots to
 // allocate.
 void Assembler::EnterOsrFrame(intptr_t extra_size) {
   Comment("EnterOsrFrame");
@@ -2899,7 +2898,17 @@ void Assembler::EnterOsrFrame(intptr_t extra_size) {
     Comment("PrologueOffset = %" Pd "", CodeSize());
     prologue_offset_ = CodeSize();
   }
-
+  Label dart_entry;
+  call(&dart_entry);
+  Bind(&dart_entry);
+  // The runtime system assumes that the code marker address is
+  // kEntryPointToPcMarkerOffset bytes from the entry.  Since there is no
+  // code to set up the frame pointer, the address needs to be adjusted.
+  const intptr_t offset = EntryPointToPcMarkerOffset() - CodeSize();
+  if (offset != 0) {
+    addl(Address(ESP, 0), Immediate(offset));
+  }
+  popl(Address(EBP, kPcMarkerSlotFromFp * kWordSize));
   if (extra_size != 0) {
     subl(ESP, Immediate(extra_size));
   }
@@ -2907,7 +2916,8 @@ void Assembler::EnterOsrFrame(intptr_t extra_size) {
 
 
 void Assembler::EnterStubFrame() {
-  EnterDartFrame(0);
+  EnterFrame(0);
+  pushl(Immediate(0));  // Push 0 in the saved PC area for stub frames.
 }