#8082: Ordering of assembly blocks affects performance -------------------------------------+------------------------------------- Reporter: jstolarek | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (NCG) | Version: 7.6.3 Resolution: | Keywords: Operating System: Linux | Architecture: x86_64 Type of failure: Runtime | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by nomeata): I can confirm that this can cause serious wobbles. When working on #10137, I changed the use of `<` to `>=` when generating if-then-else trees, and some numbers went up and some went down, without any guidance as to which one is better: {{{ Min -0.1% -0.0% -3.2% -3.2% 0.0% Max +0.0% 0.0% +4.4% +4.3% +3.3% Geometric Mean -0.0% -0.0% +0.3% +0.3% +0.1% }}} Looks like without dynamic tracing, this problem is not easily solved. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8082#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler