#9786: Make quot/rem/div/mod with known divisors fast -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: task | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.9 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Runtime Blocked By: | performance bug Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- GHC (with NCG) currently optimizes `Int` division by powers of two, but not by other known divisors. The Intel Optimization Manual section 9.2.4 describes a general technique for replacing division by known, sufficiently small, divisors with multiplication. LLVM appears to go further in some fashion. There's no reason we can't do something similar. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9786 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler