#7116: Missing optimisation: strength reduction of floating-point multiplication --------------------------------------------+------------------------------ Reporter: simonmar | Owner: Type: bug | Status: patch Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.4.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime performance bug | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: --------------------------------------------+------------------------------ Comment (by jan.stolarek@…): commit 838e2fda9892e61da85187803cce45b3f815b86e {{{ Author: Jan Stolarek <jan.stolarek@p.lodz.pl> Date: Mon Jul 8 16:20:43 2013 +0100 Add strength reduction rules (Fixes #7116) This patch adds rules for converting floating point multiplication of the form 2.0 * x and x * 2.0 into addition x + x. compiler/prelude/PrelRules.lhs | 33 +++++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-) }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/7116#comment:9> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler