I worry about the future of haskell (ghc). I know at least three problems<div><br><div>- not memory releasing</div><div>- optimization issues</div><div>- multi-core execution issue  (works bad with more than 4 core) </div>

<div><br></div><div>sadly ... (</div><div><br></div><div><div><div class="gmail_quote">2011/4/16 Michael Snoyman <span dir="ltr">&lt;<a href="mailto:michael@snoyman.com">michael@snoyman.com</a>&gt;</span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">

<div dir="ltr"><br><br><div class="gmail_quote"><div class="im">On Sat, Apr 16, 2011 at 5:54 PM, Chris Casinghino <span dir="ltr">&lt;<a href="mailto:chris.casinghino@gmail.com" target="_blank">chris.casinghino@gmail.com</a>&gt;</span> wrote:<br>

<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

<div>On Sat, Apr 16, 2011 at 10:45 AM, Greg Weber &lt;<a href="mailto:greg@gregweber.info" target="_blank">greg@gregweber.info</a>&gt; wrote:<br>
&gt;  Are you compiling with the development server or doing a cabal build/<br>
<br>
</div>I&#39;m doing a cabal build.  To reproduce this, I run (cabal configure &amp;&amp;<br>
cabal build) from the command line in the project directory.<br>
<div><div></div><div><br></div></div></blockquote><div> </div></div><div>I can confirm that this happens. However, it *only* happens when building with cabal. When building with &quot;ghc --make&quot;, using runghc or wai-handler-devel, everything works fine. So I tried compiling with &quot;ghc --make -O&quot;, and sure enough the same bug appeared.</div>



<div><br></div><div>I don&#39;t think there&#39;s anything we can do in the libraries to avoid this, it looks like a bug in GHC. You can modify your ghc-options line in the cabal file to pass in &quot;-O0&quot; to disable optimizations, though this is obviously not optimal (bad pun intended). I think we need to report this to the GHC team.</div>



<div><br></div><div>I know virtually nothing about GHC internals, but in case this means something to someone else, here&#39;s some of the output from &quot;ghc --make -O -v test.hs&quot;:</div><div><br></div><div><div>*** Simplify:</div>



<div>*** CorePrep:</div><div>*** ByteCodeGen:</div><div>*** Desugar:</div><div>    Result size = 8699</div><div>*** Simplifier SimplMode {Phase = InitialPhase [Gentle],</div><div>                      no inline,</div><div>



                      rules,</div><div>                      eta-expand,</div><div>                      no case-of-case} max-iterations=4:</div><div>    Result size = 9841</div><div>    Result size = 9797</div><div>    Result size = 9797</div>



<div>*** Specialise:</div><div>    Result size = 9797</div><div>*** Float out(FOS {Lam = Just 0, Consts = True, PAPs = False}):</div><div>    Result size = 13259</div><div>*** Float inwards:</div><div>    Result size = 13259</div>



<div>*** Simplifier SimplMode {Phase = 2 [main],</div><div>                      inline,</div><div>                      rules,</div><div>                      eta-expand,</div><div>                      case-of-case} max-iterations=4:</div>



<div>    Result size = 677741</div><div>    Result size = 850762</div><div>    Result size = 1028928</div><div>    Result size = 1028928</div><div>*** Simplifier SimplMode {Phase = 1 [main],</div><div>                      inline,</div>



<div>                      rules,</div><div>                      eta-expand,</div><div>                      case-of-case} max-iterations=4:</div><div>    Result size = 1026905</div><div>    Result size = 1026876</div><div>



    Result size = 1026876</div><div>*** Simplifier SimplMode {Phase = 0 [main],</div><div>                      inline,</div><div>                      rules,</div><div>                      eta-expand,</div><div>                      case-of-case} max-iterations=4:</div>



</div><div><br></div><font color="#888888"><div>Michael</div></font></div></div>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Best regards,<br>Cheshkov Anton <br>Phone: +7 909 005 18 82<br>Skype: cheshkov_anton<br>
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