RFR: 8186166: Generalize Atomic::cmpxchg with templates

[Kim Barrett]

> On Aug 18, 2017, at 9:23 AM, Andrew Haley <aph at redhat.com> wrote:
> 
> This hunk was missing the parameter declaration of order.  Fixed thusly:
> 
> diff -r 214a94e9366c src/os_cpu/linux_aarch64/vm/atomic_linux_aarch64.hpp
> --- a/src/os_cpu/linux_aarch64/vm/atomic_linux_aarch64.hpp	Mon Jul 17 12:11:32 2017 +0000
> +++ b/src/os_cpu/linux_aarch64/vm/atomic_linux_aarch64.hpp	Fri Aug 18 14:22:19 2017 +0100
> @@ -85,9 +85,12 @@
>                            (volatile intptr_t*) dest);
> }
> 
> -template <typename T> T generic_cmpxchg(T exchange_value, volatile T* dest,
> -                                        T compare_value, cmpxchg_memory_order order)
> -{
> +template<size_t byte_size>
> +template<typename T>
> +inline T Atomic::PlatformCmpxchg<byte_size>::operator()(T exchange_value,
> +                                                        T volatile* dest,
> +                                                        T compare_value,
> +                                                        cmpxchg_memory_order order) const {
>   if (order == memory_order_relaxed) {
>     T value = compare_value;
>     __atomic_compare_exchange(dest, &value, &exchange_value, /*weak*/false,
> @@ -98,17 +101,6 @@
>   }
> }


Drat.  Thanks for finding this.

It's a nuisance having to send out for review code that I've not been
able to test at all.  And yes, I know non-Oracle folks trying to deal
with jprt have it *much* worse.

Some new webrevs:

Rename IntegerTypes to PrimitiveConversions.  This is the change I
said I was going to leave until the end.  Looks like I could have done
it earlier; webrev did a fine job with the moved file.
full: http://cr.openjdk.java.net/~kbarrett/8186166/hotspot.03/
incr: http://cr.openjdk.java.net/~kbarrett/8186166/hotspot.03.inc/

linux_aarch fix, rename test_integerTypes.cpp to test_primitiveConversions.cpp.
full: http://cr.openjdk.java.net/~kbarrett/8186166/hotspot.04/
incr: http://cr.openjdk.java.net/~kbarrett/8186166/hotspot.04.inc/

I'm hoping hotspot.04 will be the final version that I'll be handing
off to Erik, as he returns from vacation and I start mine.

I'm working on a change in a similar style for Atomic::add, and hope
to send out an RFR later today.  I'll be handing that off to Erik as
well.