#8311: suboptimal code generated for even :: Int -> Bool by NCG (x86, x86_64) -------------------------------------+------------------------------------ Reporter: rwbarton | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (NCG) | Version: 7.7 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by rwbarton): The source of that code is in GHC.Real in base, but for reproducing, use this: {{{ module Even where myEven :: Int -> Bool myEven n = n `rem` 2 == 0 }}} compiled with `ghc -O2 -o Even.o -c Even.hs`. The LLVM backend (`ghc -O2 -fllvm -o Even.o -c Even.hs`) does produce a `testb $0x1,0x3(%esi)` instruction. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8311#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler