#13535: vector test suite uses excessive memory on GHC 8.2 -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #10800 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): Indeed in most phases of simplification the program with all testcases enabled is roughly three to five times larger in `master` than it was in `8.0.2`. After CorePrep, however, the program is nearly a factor of 8 larger, {{{ # 8.0.2 Result size of CorePrep = {terms: 118,005, types: 138,524, coercions: 50,256} # master Result size of CorePrep = {terms: 796,181, types: 907,739, coercions: 1,094,846, joins: 3,382/34,300} }}} It may also be interesting to note that if you sum the allocations of all of the testcases individually, you get something a bit higher than the allocations required to compile the "everything" case. I wonder if So, there are two (possibly related) questions here: 1. Why did the Core get so much larger from 8.0 to 8.2? 2. How was GHC 8.0 able to compile the "everything" case with less than a factor of two of the allocations of the individual cases, while 8.2 requires a factor of five? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13535#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler