#11162: T783 regresses severely in allocations with new pattern match checker -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Compile-time Unknown/Multiple | performance bug Test Case: T783 | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The new pattern match checker (Phab:D1535) allocates 115% more than the previous checker on the T783 testcase, {{{ bytes allocated value is too high: Expected T783(normal) bytes allocated: 526230456 +/-10% Lower bound T783(normal) bytes allocated: 473607410 Upper bound T783(normal) bytes allocated: 578853502 Actual T783(normal) bytes allocated: 1134085384 Deviation T783(normal) bytes allocated: 115.5 % *** unexpected stat test failure for T783(normal) }}} I suspect this isn't avoidable as this testcase consists of nothing more than 500 guarded equations, so exercises the checker quite thoroughly. That being said, perhaps it's worth a closer look. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11162 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler