Add an explicit push-argument instruction to the IL.

Add an explicit push-argument instruction to the IL.

It is used in ClosureCall and CreateClosure. Refactoring the other call-instruction
will be done in a separate CL.

These instructions do not have their arguments as input operands anymore since they
are really call-arguments passed on the stack.

This allows us to optimize a function with closure calls with SSA. For example:

foo() {
  bar() { return 42; }
  return bar();
}
Committed: https://code.google.com/p/dart/source/detail?r=9935

[Kevin Millikin (Google), 2012-07-26 13:03:18]

LGTM.

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/flow_graph_builder.cc
File vm/flow_graph_builder.cc (right):

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/flow_graph_builder....
vm/flow_graph_builder.cc:1394: ReturnComputation(new CreateClosureComp(node,
owner()->try_index()));
I imagine we'll also want a list of the push argument instructions here (e.g.,
for inlining) so we don't have to go searching for them or simulate the argument
stack.

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/flow_graph_compiler.cc
File vm/flow_graph_compiler.cc (right):

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/flow_graph_compiler...
vm/flow_graph_compiler.cc:602: if (!instr->IsPushArgument()) Pop(reg,
instr->InputAt(i));
This deserves some small comment like: "Inputs are consumed immediately at their
use except for outgoing arguments, which are consumed after the call is
completed."

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/intermediate_langua...
File vm/intermediate_language.cc (left):

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/intermediate_langua...
vm/intermediate_language.cc:1118: ASSERT(VerifyCallComputation(this));
We can still do this, can't we?  Or do you think it's not useful anymore?

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/intermediate_langua...
File vm/intermediate_language.cc (right):

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/intermediate_langua...
vm/intermediate_language.cc:1334: // where PushArgument is handled in
EmitInstructionPrologue.
Comment is a bit off.  It's not handled in EmitInstructionPrologue but in
FrameRegisterAllocator::AllocateRegisters.  There it's handled by leaving its
input on the (simulated) frame and relying on the call to spill all registers.

[Florian Schneider, 2012-07-26 13:45:22]

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/flow_graph_builder.cc
File vm/flow_graph_builder.cc (right):

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/flow_graph_builder....
vm/flow_graph_builder.cc:1394: ReturnComputation(new CreateClosureComp(node,
owner()->try_index()));
On 2012/07/26 13:03:18, kmillikin wrote:
> I imagine we'll also want a list of the push argument instructions here (e.g.,
> for inlining) so we don't have to go searching for them or simulate the
argument
> stack.

Done.

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/flow_graph_compiler.cc
File vm/flow_graph_compiler.cc (right):

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/flow_graph_compiler...
vm/flow_graph_compiler.cc:602: if (!instr->IsPushArgument()) Pop(reg,
instr->InputAt(i));
On 2012/07/26 13:03:18, kmillikin wrote:
> This deserves some small comment like: "Inputs are consumed immediately at
their
> use except for outgoing arguments, which are consumed after the call is
> completed."

Done.

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/intermediate_langua...
File vm/intermediate_language.cc (left):

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/intermediate_langua...
vm/intermediate_language.cc:1118: ASSERT(VerifyCallComputation(this));
On 2012/07/26 13:03:18, kmillikin wrote:
> We can still do this, can't we?  Or do you think it's not useful anymore?

With the new way of handling arguments, the argument expressions won't have
consecutive temp-indices anymore.

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/intermediate_langua...
File vm/intermediate_language.cc (right):

https://chromiumcodereview.appspot.com/10825035/diff/1/vm/intermediate_langua...
vm/intermediate_language.cc:1334: // where PushArgument is handled in
EmitInstructionPrologue.
On 2012/07/26 13:03:18, kmillikin wrote:
> Comment is a bit off.  It's not handled in EmitInstructionPrologue but in
> FrameRegisterAllocator::AllocateRegisters.  There it's handled by leaving its
> input on the (simulated) frame and relying on the call to spill all registers.

Done.