Re: [GHC] #10676: silly assembly for comparing the result of comparisons that return Int# against 0#

#10676: silly assembly for comparing the result of comparisons that return Int# against 0# -------------------------------------+------------------------------------- Reporter: rwbarton | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 (CodeGen) | Resolution: duplicate | Keywords: Operating System: Unknown/Multiple | Architecture: x86_64 Type of failure: Runtime | (amd64) performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #8326, #8327 | Differential Revisions: -------------------------------------+------------------------------------- Comment (by Reid Barton ): In [changeset:"7e70c063ad88052ca5f2586eb07e5d1571956acd/ghc" 7e70c063/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="7e70c063ad88052ca5f2586eb07e5d1571956acd" Use isTrue# around primitive comparisons in integer-gmp Summary: The form case na# ==# nb# of 0# -> ... _ -> ... sometimes generates convoluted assembly, see #10676. timesInt2Integer was the most spectacular offender, especially as it is a rather cheap function overall (no calls to gmp). I checked a few instances and some of the old generated assembly was fine already, but I changed them all for consistency. The new form is also more consistent with use of these primops in general. Test Plan: validate Reviewers: hvr, bgamari, goldfire, austin Reviewed By: hvr Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1094 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10676#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler