#12982: Missed constant folding oportunities -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: feature request | Status: new Priority: normal | Milestone: 8.4.1 Component: libraries/hoopl | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- @@ -5,1 +5,1 @@ - {{#!hs + {{{#!hs New description: A work colleague of mine found that some expressions were not being constant folded as expected. For example: {{{#!hs module Test where import Data.Int number :: Int64 number = 2 ^ 10 - 3 }}} compiled using: {{{ ghc -O2 -keep-s-file -c test.hs }}} should result in an assembler file containing the constant `1021` but doesn't. However, if I change the above expression to: {{{ number = 1024 -3 }}} then the output assembler files does contain the value `1021`. I did a bit of a search and found some constant folding code in the `hoopl` library, but that doesn't seem to be what GHC actually uses. -- Comment (by simonpj): I suspect it's just that the constant folding RULES, in `prelude/Build -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12982#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler