Memory usage exploding for complex pattern matching

Ben Gamari ben at
Fri Mar 30 14:46:02 UTC 2018

"Victor Miraldo (UU)" <v.cacciarimiraldo at> writes:

> Hello,
>>> I have just tried compiling my code with 8.4.2 and using
>>> -fmax-pmcheck-iterations=0,
>>> I gave GHC 12GB of ram and it still ran out (through `ulimit
>>> -v$((1024*1024*12))`).
>> Hmmm, I'm a bit confused. Why are our results so different? How
>> precisely are you invoking GHC?
> Here I meant my whole code, not just the repro. I could have been more clear.
> Nevertheless, I'm calling it through stack:
I'll admit that I am a bit lost; Minimal.hs compiles for me with a
maximum residency of ~3.5 GBytes with both -O1 and the PM check enabled
using GHC 8.4.1. Is this not the repro you are referring to?


- Ben
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