[8u-dev] RFA: 8186461: Zero's atomic_copy64() should use SPE instructions on linux-powerpcspe

[Severin Gehwolf]

Hi,

Please approve this Zero-only patch for JDK 8u which fixes a build
issue on PPC 32-bit systems which don't have FPUs. The patch from JDK
10 applies as is with minor context changes after JDK-8185723[1] has
been applied:

JDK 8:
static void atomic_copy64(volatile void *src, volatile void *dst)

vs:

JDK 10:
static void atomic_copy64(const volatile void *src, volatile void *dst)

Bug: https://bugs.openjdk.java.net/browse/JDK-8186461
webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8186461/webrev.01/
Original review-thread:
http://mail.openjdk.java.net/pipermail/hotspot-dev/2017-November/029265.html

Thanks,
Severin

[1] http://mail.openjdk.java.net/pipermail/jdk8u-dev/2018-June/007579.html