Bytestring break failing rewrite to breakByte and failing to eliminate boxing/unboxing
Tyson Whitehead gives a detailed description of the problem here.
- Program fails to rewrite
ByteString.break (== x) chunkto
ByteString.breakByte x chunk
- Missed unboxing opportunity (which led to 34gb additional allocations, which is why he noticed it)
I can reproduce the problem on OSX and Windows with GHC 7.10.3. Haven't tested Linux.
I repost it here to make sure it doesn't go unnoticed.