<div dir="ltr">Hi Chrises,<div><br></div><div> my vote would be to write these as 12 numbered primitives, (2,4 & 8 bytes) * (at: & at:put:) * (big & little endian) because they can be performance critical and implementing them like this means the maximum efficiency in both 32-bit and 64-bit Spur, plus the possibility of the JIT implementing the primitives.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Aug 30, 2015 at 10:01 PM, Chris Cunningham <span dir="ltr"><<a href="mailto:cunningham.cb@gmail.com" target="_blank">cunningham.cb@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Chris,<div><br></div><div>I'm all for having the fastest that in the image that works. If you could make your version handle endianess, then I'm all for including it (at least in the 3 variants that are faster). My first use for this (interface for KAFKA) apparently requires bigEndianess, so I really want that supported.</div><div><br></div><div>It might be best to keep my naming, though - it follows the name pattern that is already in the class. Or will yours also support 128?</div><div><br></div><div>-cbc</div></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Aug 30, 2015 at 2:38 PM, Chris Muller <span dir="ltr"><<a href="mailto:asqueaker@gmail.com" target="_blank">asqueaker@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Chris, I think these methods belong in the image with the fastest<br>
implementation we can do.<br>
<br>
I implemented 64-bit unsigned access for Ma Serializer back in 2005.<br>
I modeled my implementation after Andreas' original approach which<br>
tries to avoid LI arithmetic. I was curious whether your<br>
implementations would be faster, because if they are then it could<br>
benefit Magma. After loading "Ma Serializer" 1.5 (or head) into a<br>
trunk image, I used the following script to take comparison<br>
measurements:<br>
<br>
| smallN largeN maBa cbBa | smallN := ((2 raisedTo: 13) to: (2<br>
raisedTo: 14)) atRandom.<br>
largeN := ((2 raisedTo: 63) to: (2 raisedTo: 64)) atRandom.<br>
maBa := ByteArray new: 8.<br>
cbBa := ByteArray new: 8.<br>
maBa maUint: 64 at: 0 put: largeN.<br>
cbBa unsignedLong64At: 1 put: largeN bigEndian: false.<br>
self assert: (cbBa maUnsigned64At: 1) = (maBa unsignedLong64At: 1<br>
bigEndian: false).<br>
{ 'cbc smallN write' -> [ cbBa unsignedLong64At: 1 put: smallN<br>
bigEndian: false] bench.<br>
'ma smallN write' -> [cbBa maUint: 64 at: 0 put: smallN ] bench.<br>
'cbc smallN access' -> [ cbBa unsignedLong64At: 1 bigEndian: false. ] bench.<br>
'ma smallN access' -> [ cbBa maUnsigned64At: 1] bench.<br>
'cbc largeN write' -> [ cbBa unsignedLong64At: 1 put: largeN<br>
bigEndian: false] bench.<br>
'ma largeN write' -> [cbBa maUint: 64 at: 0 put: largeN ] bench.<br>
'cbc largeN access' -> [ cbBa unsignedLong64At: 1 bigEndian: false ] bench.<br>
'ma largeN access' -> [ cbBa maUnsigned64At: 1] bench.<br>
}<br>
<br>
Here are the results:<br>
<br>
'cbc smallN write'->'3,110,000 per second. 322 nanoseconds per run.' .<br>
'ma smallN write'->'4,770,000 per second. 210 nanoseconds per run.' .<br>
'cbc smallN access'->'4,300,000 per second. 233 nanoseconds per run.' .<br>
'ma smallN access'->'16,400,000 per second. 60.9 nanoseconds per run.' .<br>
'cbc largeN write'->'907,000 per second. 1.1 microseconds per run.' .<br>
'ma largeN write'->'6,620,000 per second. 151 nanoseconds per run.' .<br>
'cbc largeN access'->'1,900,000 per second. 527 nanoseconds per run.' .<br>
'ma largeN access'->'1,020,000 per second. 982 nanoseconds per run.'<br>
<br>
It looks like your 64-bit access is 86% faster for accessing the<br>
high-end of the 64-bit range, but slower in the other 3 metrics.<br>
Noticeably, it was only 14% as fast for writing the high-end of the<br>
64-bit range, and similarly as much slower for small-number access..<br>
<div><div><br>
<br>
On Fri, Aug 28, 2015 at 6:01 PM, Chris Cunningham<br>
<<a href="mailto:cunningham.cb@gmail.com" target="_blank">cunningham.cb@gmail.com</a>> wrote:<br>
> Hi.<br>
><br>
> I've committed a change to the inbox with changes to allow getting/putting<br>
> 64bit values to ByteArrays (similar to 32 and 16 bit accessors). Could this<br>
> be added to trunk?<br>
><br>
> Also, first time I used the selective commit function - very nice! the<br>
> changes I didn't want committed didn't, in fact, get commited. Just the<br>
> desirable bits!<br>
><br>
> -cbc<br>
><br>
><br>
><br>
<br>
</div></div></blockquote></div><br></div>
</div></div><br><br>
<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div dir="ltr"><div><span style="font-size:small;border-collapse:separate"><div>_,,,^..^,,,_<br></div><div>best, Eliot</div></span></div></div></div>
</div>