[
https://issues.apache.org/jira/browse/CASSANDRA-11519?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15329700#comment-15329700
]
Joshua McKenzie commented on CASSANDRA-11519:
---------------------------------------------
[~ReiOdaira]: From [this
link|https://www.ibm.com/developerworks/library/pa-dalign/]:
bq. On the other hand, modern PowerPC processors lack hardware support for
unaligned 64-bit floating-point access. When asked to load an unaligned
floating-point number from memory, modern PowerPC processors will throw an
exception and have the operating system perform the alignment chores in
software. Performing alignment in software is much slower than performing it in
hardware.
So what I'm gathering is that there's a pretty significant hit on 64-bit
unaligned accesses as they don't have hardware support on the platform. Do you
have numbers to indicate that the unsafe.get* versions of accessors, unaligned
w/processor exception, are preferable to the path the code takes w/unaligned
false in Memory.java?
> Add support for IBM POWER
> -------------------------
>
> Key: CASSANDRA-11519
> URL: https://issues.apache.org/jira/browse/CASSANDRA-11519
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Environment: POWER architecture
> Reporter: Rei Odaira
> Assignee: Rei Odaira
> Priority: Minor
> Fix For: 2.1.x, 2.2.x, 3.0.x, 3.x
>
> Attachments: 11519-2.1.txt, 11519-3.0.txt
>
>
> Add support for the IBM POWER architecture (ppc, ppc64, and ppc64le) in
> org.apache.cassandra.utils.FastByteOperations,
> org.apache.cassandra.utils.memory.MemoryUtil, and
> org.apache.cassandra.io.util.Memory.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
