Materialize all constant operands on the stack in the non-optimizing compiler.

runtime/vm/flow_graph_compiler_x64.cc

 // Copyright (c) 2012, 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_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "lib/error.h"
@@ skipping 1208 matching lines @@
 
 void FlowGraphCompiler::VisitBind(BindInstr* instr) {
   instr->computation()->Accept(this);
   __ pushq(RAX);
 }
 
 
 void FlowGraphCompiler::VisitReturn(ReturnInstr* instr) {
   LoadValue(RAX, instr->value());
 
-#ifdef DEBUG

[Kevin Millikin (Google), 2012/04/30 14:54:53]

This assert doesn't work anymore because we can have un-popped expression values
on the stack when we return.  Example:

try {
  return 0;
} finally {
  return 1;
}

The value of 0 is sitting on the stack at the return from the finally.  (It
didn't really work before either).

We can reintroduce it when (if) we add stack height tracking and assert the
expected height.

[srdjan, 2012/05/01 00:56:10]

This assert code is/was essential for tracking/locating bugs so far (catches
bugs that otherwise wold go unnoticed). There is difference between what we
track and what the reality is.

Is there a way that we could keep it? Maybe disable it temporarily for now?

-  // Check that the entry stack size matches the exit stack size.
-  __ movq(R10, RBP);
-  __ subq(R10, RSP);
-  __ cmpq(R10, Immediate(StackSize() * kWordSize));
-  Label stack_ok;
-  __ j(EQUAL, &stack_ok, Assembler::kNearJump);
-  __ Stop("Exit stack size does not match the entry stack size.");
-  __ Bind(&stack_ok);
-#endif  // DEBUG.
-
   if (FLAG_trace_functions) {
     __ pushq(RAX);  // Preserve result.
     const Function& function =
         Function::ZoneHandle(parsed_function_.function().raw());
     __ LoadObject(RBX, function);
     __ pushq(RBX);
     GenerateCallRuntime(AstNode::kNoId,
                         0,
                         CatchClauseNode::kInvalidTryIndex,
                         kTraceFunctionExitRuntimeEntry);
@@ skipping 472 matching lines @@
   ASSERT(exception_handlers_list_ != NULL);
   const ExceptionHandlers& handlers = ExceptionHandlers::Handle(
       exception_handlers_list_->FinalizeExceptionHandlers(code.EntryPoint()));
   code.set_exception_handlers(handlers);
 }
 
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64