+getOpts :: (DynFlags -> [a]) -> IO [a]
+ -- We add to the options from the front, so we need to reverse the list
+getOpts opts = dynFlag opts >>= return . reverse
+
+-- we can only switch between HscC, HscAsmm, and HscILX with dynamic flags
+-- (-fvia-C, -fasm, -filx respectively).
+setLang l = updDynFlags (\ dfs -> case hscLang dfs of
+ HscC -> dfs{ hscLang = l }
+ HscAsm -> dfs{ hscLang = l }
+ HscILX -> dfs{ hscLang = l }
+ _ -> dfs)
+
+getVerbFlag = do
+ verb <- dynFlag verbosity
+ if verb >= 3 then return "-v" else return ""
+
+-----------------------------------------------------------------------------
+-- Setting the optimisation level
+
+setOptLevel :: Int -> IO ()
+setOptLevel n
+ = do dflags <- getDynFlags
+ if hscLang dflags == HscInterpreted && n > 0
+ then putStr "warning: -O conflicts with --interactive; -O ignored.\n"
+ else updDynFlags (setOptLevel' n)
+
+setOptLevel' n dfs
+ = if (n >= 1)
+ then dfs2{ hscLang = HscC, optLevel = n } -- turn on -fvia-C with -O
+ else dfs2{ optLevel = n }
+ where
+ dfs1 = foldr (flip dopt_unset) dfs remove_dopts
+ dfs2 = foldr (flip dopt_set) dfs1 extra_dopts
+
+ extra_dopts
+ | n == 0 = opt_0_dopts
+ | otherwise = opt_1_dopts
+
+ remove_dopts
+ | n == 0 = opt_1_dopts
+ | otherwise = opt_0_dopts
+
+opt_0_dopts = [
+ Opt_IgnoreInterfacePragmas,
+ Opt_OmitInterfacePragmas
+ ]
+
+opt_1_dopts = [
+ Opt_IgnoreAsserts,
+ Opt_DoEtaReduction,
+ Opt_CaseMerge
+ ]
+
+-- Core-to-core phases:
+
+buildCoreToDo :: DynFlags -> [CoreToDo]
+buildCoreToDo dflags = core_todo
+ where
+ opt_level = optLevel dflags
+ max_iter = maxSimplIterations dflags
+ strictness = dopt Opt_Strictness dflags
+ cse = dopt Opt_CSE dflags
+ rule_check = ruleCheck dflags
+
+ core_todo =
+ if opt_level == 0 then
+ [
+ CoreDoSimplify (SimplPhase 0) [
+ MaxSimplifierIterations max_iter
+ ]
+ ]
+
+ else {- opt_level >= 1 -} [
+
+ -- initial simplify: mk specialiser happy: minimum effort please
+ CoreDoSimplify SimplGently [
+ -- Simplify "gently"
+ -- Don't inline anything till full laziness has bitten
+ -- In particular, inlining wrappers inhibits floating
+ -- e.g. ...(case f x of ...)...
+ -- ==> ...(case (case x of I# x# -> fw x#) of ...)...
+ -- ==> ...(case x of I# x# -> case fw x# of ...)...
+ -- and now the redex (f x) isn't floatable any more
+ -- Similarly, don't apply any rules until after full
+ -- laziness. Notably, list fusion can prevent floating.
+
+ NoCaseOfCase,
+ -- Don't do case-of-case transformations.
+ -- This makes full laziness work better
+ MaxSimplifierIterations max_iter
+ ],
+
+ -- Specialisation is best done before full laziness
+ -- so that overloaded functions have all their dictionary lambdas manifest
+ CoreDoSpecialising,
+
+ CoreDoFloatOutwards (FloatOutSw False False),
+ CoreDoFloatInwards,
+
+ CoreDoSimplify (SimplPhase 2) [
+ -- Want to run with inline phase 2 after the specialiser to give
+ -- maximum chance for fusion to work before we inline build/augment
+ -- in phase 1. This made a difference in 'ansi' where an
+ -- overloaded function wasn't inlined till too late.
+ MaxSimplifierIterations max_iter
+ ],
+ case rule_check of { Just pat -> CoreDoRuleCheck 2 pat; Nothing -> CoreDoNothing },
+
+ CoreDoSimplify (SimplPhase 1) [
+ -- Need inline-phase2 here so that build/augment get
+ -- inlined. I found that spectral/hartel/genfft lost some useful
+ -- strictness in the function sumcode' if augment is not inlined
+ -- before strictness analysis runs
+ MaxSimplifierIterations max_iter
+ ],
+ case rule_check of { Just pat -> CoreDoRuleCheck 1 pat; Nothing -> CoreDoNothing },
+
+ CoreDoSimplify (SimplPhase 0) [
+ -- Phase 0: allow all Ids to be inlined now
+ -- This gets foldr inlined before strictness analysis
+
+ MaxSimplifierIterations 3
+ -- At least 3 iterations because otherwise we land up with
+ -- huge dead expressions because of an infelicity in the
+ -- simpifier.
+ -- let k = BIG in foldr k z xs
+ -- ==> let k = BIG in letrec go = \xs -> ...(k x).... in go xs
+ -- ==> let k = BIG in letrec go = \xs -> ...(BIG x).... in go xs
+ -- Don't stop now!
+
+ ],
+ case rule_check of { Just pat -> CoreDoRuleCheck 0 pat; Nothing -> CoreDoNothing },
+
+#ifdef OLD_STRICTNESS
+ CoreDoOldStrictness