-O/-O2 causes program to run too slow
dnspies at gmail.com
Sun Dec 7 19:43:43 UTC 2014
Ok, so I found that it was an instance of this:
and I read through this whole thread:
I don't understand the state-hack optimization. It's clearly not safe and
I'm not convinced that it actually is an optimization. In what
circumstances does the state-hack identify a single-entry function that
can't be identified as single-entry by some other (safe) method?
On Sun, Dec 7, 2014 at 10:52 AM, David Spies <dnspies at gmail.com> wrote:
> I have a program I wrote to submit for the Car Game problem on Kattis:
> but it runs over the 5-second time-limit
> I downloaded the test data and found that on GHC 7.8.3, if I switch from
> -O2 to -O0, it runs three times faster (almost certainly fast enough for
> Kattis to accept). Can someone tell me what's going on? Is this a bug?
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