Separate and optional size thresholds for SpecConstr and LiberateCase

This patch replaces -fspec-threshold by -fspec-constr-threshold and
-fliberate-case-threshold. The thresholds can be disabled by
-fno-spec-constr-threshold and -fno-liberate-case-threshold.

diff --git a/compiler/main/DynFlags.hs b/compiler/main/DynFlags.hs
index c8e999a..44e2aea 100644 (file)
--- a/compiler/main/DynFlags.hs
+++ b/compiler/main/DynFlags.hs
@@ -301,7 +301,8 @@ data DynFlags = DynFlags {
   maxSimplIterations    :: Int,                -- max simplifier iterations
   ruleCheck            :: Maybe String,
 
-  specThreshold                :: Int,         -- Threshold for function specialisation
+  specConstrThreshold   :: Maybe Int,  -- Threshold for SpecConstr
+  liberateCaseThreshold :: Maybe Int,   -- Threshold for LiberateCase 
 
   stolen_x86_regs      :: Int,         
   cmdlineHcIncludes    :: [String],    -- -#includes
@@ -478,7 +479,8 @@ defaultDynFlags =
        optLevel                = 0,
        maxSimplIterations      = 4,
        ruleCheck               = Nothing,
-       specThreshold           = 200,
+       specConstrThreshold     = Just 200,
+        liberateCaseThreshold   = Just 200,
        stolen_x86_regs         = 4,
        cmdlineHcIncludes       = [],
        importPaths             = ["."],
@@ -1140,9 +1142,14 @@ dynamic_flags = [
   ,  ( "fmax-simplifier-iterations", IntSuffix (\n -> 
                upd (\dfs -> dfs{ maxSimplIterations = n })) )
 
-       -- liberate-case-threshold is an old flag for '-fspec-threshold'
-  ,  ( "fspec-threshold",          IntSuffix (\n -> upd (\dfs -> dfs{ specThreshold = n })))
-  ,  ( "fliberate-case-threshold", IntSuffix (\n -> upd (\dfs -> dfs{ specThreshold = n })))
+  ,  ( "fspec-constr-threshold",      IntSuffix (\n ->
+                upd (\dfs -> dfs{ specConstrThreshold = Just n })))
+  ,  ( "fno-spec-constr-threshold",   NoArg (
+                upd (\dfs -> dfs{ specConstrThreshold = Nothing })))
+  ,  ( "fliberate-case-threshold",    IntSuffix (\n ->
+                upd (\dfs -> dfs{ liberateCaseThreshold = Just n })))
+  ,  ( "fno-liberate-case-threshold", NoArg (
+                upd (\dfs -> dfs{ liberateCaseThreshold = Nothing })))
 
   ,  ( "frule-check",     SepArg (\s -> upd (\dfs -> dfs{ ruleCheck = Just s })))
   ,  ( "fcontext-stack"        , IntSuffix $ \n -> upd $ \dfs -> dfs{ ctxtStkDepth = n })

diff --git a/compiler/simplCore/LiberateCase.lhs b/compiler/simplCore/LiberateCase.lhs
index c29d217..9c51103 100644 (file)
--- a/compiler/simplCore/LiberateCase.lhs
+++ b/compiler/simplCore/LiberateCase.lhs
@@ -195,7 +195,8 @@ libCaseBind env (Rec pairs)
 
     rhs_small_enough (id,rhs)
        =  idArity id > 0       -- Note [Only functions!]
-       && couldBeSmallEnoughToInline (bombOutSize env) rhs
+       && maybe True (\size -> couldBeSmallEnoughToInline size rhs)
+                      (bombOutSize env)
 \end{code}
 
 
@@ -349,7 +350,7 @@ topLevel = 0
 \begin{code}
 data LibCaseEnv
   = LibCaseEnv {
-       lc_size :: Int,         -- Bomb-out size for deciding if
+       lc_size :: Maybe Int,   -- Bomb-out size for deciding if
                                -- potential liberatees are too big.
                                -- (passed in from cmd-line args)
 
@@ -377,7 +378,7 @@ data LibCaseEnv
 
 initEnv :: DynFlags -> LibCaseEnv
 initEnv dflags 
-  = LibCaseEnv { lc_size = specThreshold dflags,
+  = LibCaseEnv { lc_size = liberateCaseThreshold dflags,
                 lc_lvl = 0,
                 lc_lvl_env = emptyVarEnv, 
                 lc_rec_env = emptyVarEnv,

diff --git a/compiler/specialise/SpecConstr.lhs b/compiler/specialise/SpecConstr.lhs
index 0478d2e..d1c7499 100644 (file)
--- a/compiler/specialise/SpecConstr.lhs
+++ b/compiler/specialise/SpecConstr.lhs
@@ -456,9 +456,9 @@ specConstrProgram dflags us binds
 %************************************************************************
 
 \begin{code}
-data ScEnv = SCE { sc_size :: Int,     -- Size threshold
+data ScEnv = SCE { sc_size :: Maybe Int,       -- Size threshold
 
-                  sc_subst :: Subst,   -- Current substitution
+                  sc_subst :: Subst,           -- Current substitution
 
                   sc_how_bound :: HowBoundEnv,
                        -- Binds interesting non-top-level variables
@@ -491,7 +491,7 @@ instance Outputable Value where
 
 ---------------------
 initScEnv dflags
-  = SCE { sc_size = specThreshold dflags,
+  = SCE { sc_size = specConstrThreshold dflags,
          sc_subst = emptySubst, 
          sc_how_bound = emptyVarEnv, 
          sc_vals = emptyVarEnv }
@@ -824,7 +824,8 @@ scExpr' env e@(App _ _)
 ----------------------
 scBind :: ScEnv -> CoreBind -> UniqSM (ScEnv, ScUsage, CoreBind)
 scBind env (Rec prs)
-  | not (all (couldBeSmallEnoughToInline (sc_size env)) rhss)
+  | Just threshold <- sc_size env
+  , not (all (couldBeSmallEnoughToInline threshold) rhss)
                -- No specialisation
   = do { let (rhs_env,bndrs') = extendRecBndrs env bndrs
        ; (rhs_usgs, rhss') <- mapAndUnzipUs (scExpr rhs_env) rhss