| > ghc-6.12.3: | > 89,330,672 bytes allocated in the heap | > 15,092 bytes copied during GC | > 35,980 bytes maximum residency (1 sample(s)) | > 29,556 bytes maximum slop | > 2 MB total memory in use (0 MB lost due to fragmentation) | > | > ghc-6.13.20100831: | > 475,305,720 bytes allocated in the heap | > 89,272 bytes copied during GC | > 68,860 bytes maximum residency (1 sample(s)) | > 29,444 bytes maximum slop | > 2 MB total memory in use (0 MB lost due to fragmentation) | | Can you put your benchmark code somewhere? Likely a GHC regression. Indeed bad. If someone could characterise the regression more precisely (e.g. "fusion isn't happening here") that would be jolly helpful. Simon