#7411: Exceptions are optimized away in certain situations -------------------------------------+------------------------------------- Reporter: SimonHengel | Owner: tdammers Type: bug | Status: new Priority: high | Milestone: 8.6.1 Component: Compiler | Version: 7.6.1 Resolution: | Keywords: seq, deepseq, | evaluate, exceptions Operating System: Linux | Architecture: x86_64 | (amd64) Type of failure: Incorrect result | Test Case: at runtime | simplCore/should_fail/T7411 Blocked By: | Blocking: Related Tickets: #5129 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by tdammers): I ran two full builds of GHC (`make clean; ./boot; ./configure; make -j2` on a dual-core i5 machine, 4 GB RAM, 7200 RPM HDD, debian stretch, stage0 = GHC 8.4.1), one with the `prof` flavour, the other with a modified `prof` flavour with `GhcLibHcOpts += -fno-state-hack`. It turns out that the `-fno-state-hack` version is slightly faster: Prof build: {{{ real 66m5.407s user 118m50.668s sys 6m7.044s }}] Prof + `-fno-state-hack` build: {{{ real 65m42.784s user 118m32.892s sys 6m5.252s }}} I haven't done any in-depth profiling yet, but it seems to me that removing the state hack would most not make things significantly worse overall. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/7411#comment:32 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler