#15113: Do not make CAFs from literal strings -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: patch Priority: normal | Milestone: 8.8.1 Component: Compiler | Version: 8.2.2 Resolution: | Keywords: CAFs Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D4717 Wiki Page: | -------------------------------------+------------------------------------- Comment (by osa1): I managed to get nofib running. Here's an example output for runtime SRT traversals: {{{ NoFib Results -------------------------------------------------------------------------------- Program Size Allocs Runtime Elapsed TotalMem SRTScavs -------------------------------------------------------------------------------- ... circsim 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% clausify 0.0% 0.0% 0.013 0.013 0.0% 0.0% comp_lab_zift 0.0% 0.0% 0.068 0.068 0.0% 0.0% compress 0.0% 0.0% 0.054 0.054 0.0% 0.0% compress2 0.0% 0.0% 0.047 0.047 0.0% 0.0% constraints 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% ... Scavenged SRTs ------------------------------------------------------------------------------- Program nofib-log nofib-log ------------------------------------------------------------------------------- CS 627 0.0% CSD 622 0.0% FS 629 0.0% S 16363319 0.0% VS 2529 0.0% VSD 310 0.0% VSM 628 0.0% anna 7951 0.0% ansi 310 0.0% atom 2102 0.0% awards 310 0.0% ... }}} (all 0.0% becuase I used same file twice to run nofib-analyse) I have another program to parse compile-time numbers and generate this: {{{ PGM | SRTs | SRT size fluid | 5 | 25 wave4main | 25 | 112 integer | 17 | 74 ... }}} The code is here: https://github.com/osa1/nofib/tree/print_srt_stuff I also have a GHC branch that implements a new flag `-favoid- cafs=[0|1|2|3]` where 0 means compile as before, 1 means avoid making CAFs for top-level `unpackCString#`s, 2 means in addition to 1 avoid making CAFs for non-top-level `unpackCString#`s, 3 means in addition to 2 avoid making CAFs for CONLIKEs too. Code is here: https://github.com/osa1/ghc/tree/print_srt_stuff However for some reason the flag doesn't actually change number of SRTs or SRT sizes. I don't know why yet, I'll debug further. I think it may be because it's too late to change CAFFY-ness of values in CoreToStg (remember that CAFFY-enss of values are computed in CorePrep, which is before CoreToStg). I'll debug further. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15113#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler