review (XS): 7047491: C1: registers saved incorrectly when calling checkcast_arraycopy stub

[Tom Rodriguez]

On May 26, 2011, at 2:38 AM, Roland Westrelin wrote:

>> Hm, I just assumed it's there because previous code used it. Now that I
>> look at it I don't even see how it worked in 32bit. The space on stack
>> is allocated in java_calling_convention() which is called from
>> ArrayCopyStub::emit_code(). So even in 32bit there should be only space
>> on stack for 3 out of 5 arguments, yet 5 slots are used. Perhaps we get
>> it adjusted but I don't see how...
> 
> _reserved_argument_area_size in FrameMap is initialized with an argument passed to the constructor. The argument is MAX2(4, hir()->max_stack()) (see Compilation::compile_java_method()). I think that's what guarantees that there's space on the stack for 5 arguments, the number of arguments to System.arraycopy()

My fuzzy memory said it was something like that.  Thanks for confirming.  Looks good.

tom

> 
> Roland.