Changes to run "Hello, world!" on MIPS hardware.

Changes to run "Hello, world!" on MIPS hardware.

R=regis@google.com

Committed: https://code.google.com/p/dart/source/detail?r=23484

[zra, 2013-05-31 16:19:24]

The CallNativeCFunctionStub on ARM also appears to reserve stack space for
arguments that it doesn't use, but it might make more sense to take a look at
argument passing more closely for ARM and MIPS in a subsequent CL.

Cheers,
Zach

[regis, 2013-05-31 16:44:13]

LGTM

> The CallNativeCFunctionStub on ARM also appears to reserve stack space for
arguments that it doesn't use, ...

Note that the instruction saving the arguments is not a push (no writeback to
SP):
  __ stm(IA, SP,  (1 << R0) | (1 << R1) | (1 << R2) | (1 << R3));

So I think the reserved space is used.

-- Regis

https://codereview.chromium.org/16160013/diff/1/runtime/vm/assembler_mips.cc
File runtime/vm/assembler_mips.cc (right):

https://codereview.chromium.org/16160013/diff/1/runtime/vm/assembler_mips.cc#...
runtime/vm/assembler_mips.cc:466: AddImmediate(SP, -frame_space);
On ARM, AddImmediate of 0 to the same register will be ignored.
It is also ignored on ia32 and x64. You should rather fix AddImmediate.

[zra, 2013-05-31 18:41:17]

Yes, now that I look again, I think you're right about the stack space on ARM.

Thanks!
Zach

https://codereview.chromium.org/16160013/diff/1/runtime/vm/assembler_mips.cc
File runtime/vm/assembler_mips.cc (right):

https://codereview.chromium.org/16160013/diff/1/runtime/vm/assembler_mips.cc#...
runtime/vm/assembler_mips.cc:466: AddImmediate(SP, -frame_space);
On 2013/05/31 16:44:13, regis wrote:
> On ARM, AddImmediate of 0 to the same register will be ignored.
> It is also ignored on ia32 and x64. You should rather fix AddImmediate.

Done.

[zra, 2013-05-31 18:41:54]

Committed patchset #3 manually as r23484.