X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FsimplCore%2FSimplCore.lhs;h=9a4c1eb289a6bf0c3b13161342dc80561b9755c5;hb=00fe4381668528eb2f60496eea97e433528d2bb8;hp=a7671a42443626e517c1061be75a0187e8c6321f;hpb=5952ef0dfd1a9eec38bd2756b37d040feb2b09d8;p=ghc-hetmet.git diff --git a/compiler/simplCore/SimplCore.lhs b/compiler/simplCore/SimplCore.lhs index a7671a4..9a4c1eb 100644 --- a/compiler/simplCore/SimplCore.lhs +++ b/compiler/simplCore/SimplCore.lhs @@ -17,7 +17,7 @@ module SimplCore ( core2core, simplifyExpr ) where import DynFlags ( CoreToDo(..), SimplifierSwitch(..), SimplifierMode(..), DynFlags, DynFlag(..), dopt, - getCoreToDo ) + getCoreToDo, shouldDumpSimplPhase ) import CoreSyn import HscTypes import CSE ( cseProgram ) @@ -35,7 +35,7 @@ import Simplify ( simplTopBinds, simplExpr ) import SimplEnv ( SimplEnv, simplBinders, mkSimplEnv, setInScopeSet ) import SimplMonad import ErrUtils ( dumpIfSet, dumpIfSet_dyn, showPass ) -import CoreLint ( endPass, endIteration ) +import CoreLint ( endPassIf, endIteration ) import FloatIn ( floatInwards ) import FloatOut ( floatOutwards ) import FamInstEnv @@ -57,11 +57,13 @@ import StrictAnal ( saBinds ) import CprAnalyse ( cprAnalyse ) #endif import Vectorise ( vectorise ) +import Util import UniqSupply ( UniqSupply, mkSplitUniqSupply, splitUniqSupply ) import IO ( hPutStr, stderr ) import Outputable -import List ( partition ) +import Control.Monad +import List ( partition, intersperse ) import Maybes \end{code} @@ -153,7 +155,7 @@ doCorePass CoreCSE = {-# SCC "CommonSubExpr" #-} trBinds cseProgram doCorePass CoreLiberateCase = {-# SCC "LiberateCase" #-} liberateCase doCorePass CoreDoFloatInwards = {-# SCC "FloatInwards" #-} trBinds floatInwards doCorePass (CoreDoFloatOutwards f) = {-# SCC "FloatOutwards" #-} trBindsU (floatOutwards f) -doCorePass CoreDoStaticArgs = {-# SCC "StaticArgs" #-} trBinds doStaticArgs +doCorePass CoreDoStaticArgs = {-# SCC "StaticArgs" #-} trBindsU doStaticArgs doCorePass CoreDoStrictness = {-# SCC "Stranal" #-} trBinds dmdAnalPgm doCorePass CoreDoWorkerWrapper = {-# SCC "WorkWrap" #-} trBindsU wwTopBinds doCorePass CoreDoSpecialising = {-# SCC "Specialise" #-} trBindsU specProgram @@ -337,12 +339,19 @@ updateBinders local_rules binds -- arising from specialisation pragmas \end{code} - -We must do some gentle simplification on the template (but not the RHS) -of each rule. The case that forced me to add this was the fold/build rule, +Note [Simplifying the left-hand side of a RULE] +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +We must do some gentle simplification on the lhs (template) of each +rule. The case that forced me to add this was the fold/build rule, which without simplification looked like: fold k z (build (/\a. g a)) ==> ... This doesn't match unless you do eta reduction on the build argument. +Similarly for a LHS like + augment g (build h) +we do not want to get + augment (\a. g a) (build h) +otherwise we don't match when given an argument like + augment (\a. h a a) (build h) \begin{code} simplRule env rule@(BuiltinRule {}) @@ -373,11 +382,17 @@ simplExprGently :: SimplEnv -> CoreExpr -> SimplM CoreExpr -- alone leaves tons of crud. -- Used (a) for user expressions typed in at the interactive prompt -- (b) the LHS and RHS of a RULE +-- (c) Template Haskell splices -- -- The name 'Gently' suggests that the SimplifierMode is SimplGently, -- and in fact that is so.... but the 'Gently' in simplExprGently doesn't -- enforce that; it just simplifies the expression twice +-- It's important that simplExprGently does eta reduction; see +-- Note [Simplifying the left-hand side of a RULE] above. The +-- simplifier does indeed do eta reduction (it's in Simplify.completeLam) +-- but only if -O is on. + simplExprGently env expr = do expr1 <- simplExpr env (occurAnalyseExpr expr) simplExpr env (occurAnalyseExpr expr1) @@ -448,22 +463,28 @@ simplifyPgm mode switches hsc_env us imp_rule_base guts (termination_msg, it_count, counts_out, binds') <- do_iteration us 1 (zeroSimplCount dflags) (mg_binds guts) ; - dumpIfSet (dopt Opt_D_verbose_core2core dflags - && dopt Opt_D_dump_simpl_stats dflags) + dumpIfSet (dump_phase && dopt Opt_D_dump_simpl_stats dflags) "Simplifier statistics" (vcat [text termination_msg <+> text "after" <+> ppr it_count <+> text "iterations", text "", pprSimplCount counts_out]); - endPass dflags ("Simplify phase " ++ phase_info ++ " done") Opt_D_dump_simpl_phases binds'; + endPassIf dump_phase dflags + ("Simplify phase " ++ phase_info ++ " done") + Opt_D_dump_simpl_phases binds'; return (counts_out, guts { mg_binds = binds' }) } where dflags = hsc_dflags hsc_env phase_info = case mode of - SimplGently -> "gentle" - SimplPhase n -> show n + SimplGently -> "gentle" + SimplPhase n ss -> shows n + . showString " [" + . showString (concat $ intersperse "," ss) + $ "]" + + dump_phase = shouldDumpSimplPhase dflags mode sw_chkr = isAmongSimpl switches max_iterations = intSwitchSet sw_chkr MaxSimplifierIterations `orElse` 2 @@ -473,17 +494,13 @@ simplifyPgm mode switches hsc_env us imp_rule_base guts -- about to begin, with '1' for the first | iteration_no > max_iterations -- Stop if we've run out of iterations = do { -#ifdef DEBUG - if max_iterations > 2 then - hPutStr stderr ("NOTE: Simplifier still going after " ++ + when (debugIsOn && (max_iterations > 2)) $ + hPutStr stderr ("NOTE: Simplifier still going after " ++ show max_iterations ++ " iterations; bailing out. Size = " ++ show (coreBindsSize binds) ++ "\n" ) - else - return (); -#endif -- Subtract 1 from iteration_no to get the -- number of iterations we actually completed - return ("Simplifier baled out", iteration_no - 1, counts, binds) + ; return ("Simplifier bailed out", iteration_no - 1, counts, binds) } -- Try and force thunks off the binds; significantly reduces