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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D">Dear GHC users,
<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:36.0pt"><b>
<o:p></o:p></b></p>
<p class="MsoNormal" style="margin-left:36.0pt"><b>Carter</b>: Will this RTS update make it into ghc 7.8 update thats coming up in the next monthish?<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:36.0pt"><b>Andreas</b>: We are almost there - we are now trying to sort out a problem on mac os x. It would be helpful to know if there is a cutoff date for getting things into 7.8. <o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D">Simon, Ian, and I have just been discussing 7.8, and would be interested in what you guys think.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D"><br>
At ICFP we speculated that we’d make a release of GHC soon after Christmas to embody tons of stuff that has been included since 7.6, specifically:<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-family:"Verdana","sans-serif";color:#1F497D;mso-fareast-language:EN-GB">major improvements in DPH (vectorisation avoidance, new vectoriser)<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-family:"Verdana","sans-serif";color:#1F497D;mso-fareast-language:EN-GB">type holes<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-family:"Verdana","sans-serif";color:#1F497D;mso-fareast-language:EN-GB">rebindable list syntax<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-family:"Verdana","sans-serif";color:#1F497D;mso-fareast-language:EN-GB">major changes to the type inference engine<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-family:"Verdana","sans-serif";color:#1F497D;mso-fareast-language:EN-GB">type level natural numbers<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-family:"Verdana","sans-serif";color:#1F497D;mso-fareast-language:EN-GB">overlapping type families<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-family:"Verdana","sans-serif";color:#1F497D;mso-fareast-language:EN-GB">the new code generator<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-family:"Verdana","sans-serif";color:#1F497D;mso-fareast-language:EN-GB">support for vector (SSE/AVX) instructions<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D">Whenever it comes it would definitely be great to include Andreas & friends’ work:<o:p></o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="font-size:11.0pt;font-family:Symbol;color:#1F497D"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D">Scheduler changes to the RTS to improve latency<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D">The original major reason for proposing a post-Xmas release was to get DPH in a working state out into the wild. However, making a proper release imposes costs
on everyone else. Library authors have to scurry around to make their libraries work, etc. Some of the new stuff hasn’t been in HEAD for that long, and hence has not been very thoroughly tested. (But of course making a release unleashes a huge wave of
testing that doesn’t happen otherwise.)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D">So another alternative is to leave it all as HEAD, and wait another few months before making a release. You can still use all the new stuff by compiling HEAD,
or grabbing a snapshot distribution. And it makes it hard for the Haskell platform if GHC moves too fast. Many people are still on 7.4.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D">There seem to be pros and cons each way. I don’t have a strong opinion. If you have a view, let us know.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D">Simon<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Verdana","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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