#8256: adding locality levels to prefetch# and friends -------------------------------------+------------------------------------ Reporter: carter | Owner: carter Type: task | Status: closed Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.7 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: #8252 ,#8107 -------------------------------------+------------------------------------ Comment (by carter): Hey Simon, excellent questions 1) the motivation for the can_fail attribute is the following: anyone using prefetch (or at least using prefetch appropriately) are treating the CPU's memory bandwidth as a resource, and accordingly (and conservatively), can_fail prevents let floating/hoisting (if i've read the docs correctly), while still making it "cheap" to inline. It need not have the can_fail attribute, but since prefetches should/will only be used in pretty perf sensitive code, it seems like its a decent arbitrary choice that will help make "when" prefetch happens a bit easier to understand. 2) good points, i'll hack out a patch to docs later this week when i'm not buried with my consulting work -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8256#comment:36 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler