<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 10 sep 2012, at 19:03, Thomas Lindgren <<a href="mailto:thomasl_erlang@yahoo.com">thomasl_erlang@yahoo.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><br><br><br><br><br><blockquote type="cite">________________________________<br>From: Kostis Sagonas <<a href="mailto:kostis@cs.ntua.gr">kostis@cs.ntua.gr</a>><br><br><br>I do not know why Thomas thinks that HiPE should be able to confortably beat BEAM on this sort of code (care to elaborate?). From a brief glance it seems to me that the code spends a lot of time in BIFs written in C (most notably list_to_tuple/1 and element/2, but also trunc/1, abs/1 and math:sin/1. All of these are outside the reach of the native code compiler.<br></blockquote><br><br>The regular MD5 algorithm is basically a loop doing lots of integer arithmetic and bit operations as well as accessing a few arrays. This ought on the face of it to be quite amenable to native code compilation. I'm amazed that the implementation Tony used managed to get trunc/abs/sin into the inner loop, but that might as you say well explain the problem.<br></blockquote><div><br></div>My goal with this implementation was not speed. I really wanted something simple to look at. erlang:md5 already exists, and</div><div>there is no point competing with that. I just compiled it native for fun. So do not be amazed! :-)</div><div>But as shown by kostis and others it looks like it is my computer that behaves badly, I will have a look.</div><div><br></div><div>Thanks</div><div><br></div><div>/Tony</div><div><br></div><div><br></div><div><br></div><div><blockquote type="cite"><br><blockquote type="cite"><br><blockquote type="cite">Unfortunately, 'pp_native' gave broken/confusing output so it's hard to trace what happens.<br></blockquote><br>Well, this happens because the HiPE compiler compiles in parallel by default (!). If you want to see the native code in the non-scrambled version use:<br><br> c(md5, [native, {hipe, [no_concurrent_comp, pp_native]}]).<br></blockquote><br><br>Well well, you learn something new every day.<br><br>Best,<br>Thomas<br></blockquote></div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div><span class="Apple-style-span" style="color: rgb(51, 51, 51); font-family: Geneva, Arial, Helvetica, sans-serif; font-size: 12px; ">"Installing applications can lead to corruption over time. </span><span class="Apple-style-span" style="color: rgb(51, 51, 51); font-family: Geneva, Arial, Helvetica, sans-serif; font-size: 12px; ">Applications gradually write over each other's libraries, partial upgrades occur, user and system errors happen, and minute changes may be unnoticeable and difficult to fix"</span></div><div><span class="Apple-style-span" style="color: rgb(51, 51, 51); font-family: Geneva, Arial, Helvetica, sans-serif; font-size: 12px; "><br></span></div></span><br class="Apple-interchange-newline">
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