[PATCH] openjdk/zero: only use FPU opcodes if FPU is available

Sebastian Andrzej Siewior openjdk at ml.breakpoint.cc
Wed Jun 23 02:03:05 PDT 2010

* Gary Benson | 2010-06-23 09:29:21 [+0100]:

>The TCK is the set of tests that checks whether or not a JVM is
>compatible with a specific version of Java.
>This little piece of assembler is there because the Java Language
>Specification [1] states that reads and writes of volatile long and
>volatile double fields must be atomic.  If you remove that bit of
>code then what you build does not conform to the spec.  It will
>work without it, but it's not certifyable.  The reason ARM and
>32-bit MIPS don't have that piece of assembler is that nobody has
>tried to certify them yet so nobody has written that piece of
>assembler for those platforms.
Okay, I understand.

>Basically, if you just want to run stuff then it's ok to bypass
>that piece of assembler, but if you want to certify the builds
>for whatever reason then you will need to figure out some other
>way to do a 64-bit atomic copy.
Is it garanteed that the adress I'm reading from and writing to is
properly aligned on a 64bit address boundary?

>> > Have you signed the SCA?  If so I can (or you can) make a webrev
>> > for this and submit it for inclusion.
>> I haven't.
>Are you able to sign it?
I clicked that link but I ended somewhere at oracle.com with 404.


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