RFR(XS): 8196868 - AARCH64: ld/st instructions hit guarantee assert while using sp

[Dmitrij Pochepko]

Hi all,

please review small patch for JDK-8196868 - AARCH64: ld/st instructions 
hit guarantee assert while using sp

I found a guarantee assert crash in hotspot while trying to write 
intrinsic with st4 (SIMD load) instruction which write values into 
stack. It is allowed by specification: SP or general-purpose register 
can be used for addressing.


A reason for this was register encoding call rf(...), which was used 
originally. This call doesn't expect SP to be passed for encoding, while 
srf(...) expects SP or general-purpose register.


webrev: http://cr.openjdk.java.net/~dpochepk/8196868/webrev.01/

CR: https://bugs.openjdk.java.net/browse/JDK-8196868


I've tested this patch with my intrinsic and crash is not reproducible 
anymore. I also run part of jtreg hotspot tests as sanity to ensure 
nothing got broken and it looks good.


Thanks,

Dmitrij