#9577: String literals are wasting space -------------------------------------+------------------------------------- Reporter: xnyhps | Owner: xnyhps Type: bug | Status: new Priority: low | Milestone: Component: Compiler | Version: 7.8.2 (NCG) | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: Runtime | Related Tickets: performance bug | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by dfeuer): Replying to [comment:15 carter]:
One question I've got about this whole thread is this: What would this improve? I'm trying to understand how this will impact application performance or binary sizes (though I understand the latter is definitely neglible)
Very good question. As someone who knows very little about these issues, it seems to me that there are probably approximately three related issues that will affect performance: 1. Aligning strings to word boundaries seems to be good for all sorts of reasons (comparison, copying, searching, etc.). 2. Arranging for code that (exclusively) uses a string to be likely to bring the beginning of the string in on its cache line should often be good. This kind of thing goes beyond strings, of course, and I have no idea what GHC does about it in general. 3. Dragging an error message fragment in on a cache line should always be bad. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9577#comment:16 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler