#14951: SpecConstr needs two runs when one should suffice -------------------------------------+------------------------------------- Reporter: nomeata | Owner: (none) Type: task | Status: patch Priority: normal | Milestone: Component: Compiler | Version: 8.2.2 Resolution: | Keywords: SpecConstr Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #14844 | Differential Rev(s): Phab:D4519 Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): !SpecConstr is already trying quite hard to be idempotent, but it is manifestly failing. It would be extremely helpful to distil poster-child examples of when it's not idempotent. `mandel2` is a good starting point because it has a very small kernel. It's also a surprise that the best instruction count improvements seem unrelated to the allocations! I don't know what to make of that. We need more insight. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14951#comment:19 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler