Better simplifier counting

[ghc-hetmet.git] / compiler / simplCore / CoreMonad.lhs

diff --git a/compiler/simplCore/CoreMonad.lhs b/compiler/simplCore/CoreMonad.lhs
index f9ff5e7..7f43ce5 100644 (file)
--- a/compiler/simplCore/CoreMonad.lhs
+++ b/compiler/simplCore/CoreMonad.lhs
@@ -15,7 +15,7 @@ module CoreMonad (
     getCoreToDo, dumpSimplPhase,
 
     -- * Counting
-    SimplCount, doSimplTick, doFreeSimplTick,
+    SimplCount, doSimplTick, doFreeSimplTick, simplCountN,
     pprSimplCount, plusSimplCount, zeroSimplCount, isZeroSimplCount, Tick(..),
 
     -- * The monad
@@ -78,7 +78,7 @@ import qualified ErrUtils as Err
 import Bag
 import Maybes
 import UniqSupply
-import LazyUniqFM       ( UniqFM, mapUFM, filterUFM )
+import UniqFM       ( UniqFM, mapUFM, filterUFM )
 import FiniteMap
 
 import Util            ( split )
@@ -166,6 +166,11 @@ displayLintResults dflags pass warns errs binds
        ; Err.ghcExit dflags 1 }
 
   | not (isEmptyBag warns)
+  , not (case pass of { CoreDesugar -> True; _ -> False })
+       -- Suppress warnings after desugaring pass because some
+       -- are legitimate. Notably, the desugarer generates instance
+       -- methods with INLINE pragmas that form a mutually recursive
+       -- group.  Only afer a round of simplification are they unravelled.
   , not opt_NoDebugOutput
   , showLintWarnings pass
   = printDump (banner "warnings" $$ Err.pprMessageBag warns)
@@ -381,17 +386,11 @@ getCoreToDo dflags
         -- initial simplify: mk specialiser happy: minimum effort please
     simpl_gently = CoreDoSimplify 
                        (SimplGently { sm_rules = True, sm_inline = False })
+                         -- See Note [Gentle mode] and
+                         -- Note [RULEs enabled in SimplGently] in SimplUtils
                        max_iter
                        [
-                        --      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
@@ -546,9 +545,7 @@ plusSimplCount     :: SimplCount -> SimplCount -> SimplCount
 
 \begin{code}
 data SimplCount 
-   = VerySimplZero             -- These two are used when 
-   | VerySimplNonZero  -- we are only interested in 
-                               -- termination info
+   = VerySimplCount !Int       -- Used when don't want detailed stats
 
    | SimplCount        {
        ticks   :: !Int,        -- Total ticks
@@ -564,6 +561,10 @@ data SimplCount
 
 type TickCounts = FiniteMap Tick Int
 
+simplCountN :: SimplCount -> Int
+simplCountN (VerySimplCount n)         = n
+simplCountN (SimplCount { ticks = n }) = n
+
 zeroSimplCount dflags
                -- This is where we decide whether to do
                -- the VerySimpl version or the full-stats version
@@ -571,11 +572,10 @@ zeroSimplCount dflags
   = SimplCount {ticks = 0, details = emptyFM,
                 n_log = 0, log1 = [], log2 = []}
   | otherwise
-  = VerySimplZero
+  = VerySimplCount 0
 
-isZeroSimplCount VerySimplZero             = True
-isZeroSimplCount (SimplCount { ticks = 0 }) = True
-isZeroSimplCount _                         = False
+isZeroSimplCount (VerySimplCount n)                = n==0
+isZeroSimplCount (SimplCount { ticks = n }) = n==0
 
 doFreeSimplTick tick sc@SimplCount { details = dts } 
   = sc { details = dts `addTick` tick }
@@ -587,7 +587,7 @@ doSimplTick tick sc@SimplCount { ticks = tks, details = dts, n_log = nl, log1 =
   where
     sc1 = sc { ticks = tks+1, details = dts `addTick` tick }
 
-doSimplTick _ _ = VerySimplNonZero -- The very simple case
+doSimplTick _ (VerySimplCount n) = VerySimplCount (n+1)
 
 
 -- Don't use plusFM_C because that's lazy, and we want to 
@@ -609,11 +609,11 @@ plusSimplCount sc1@(SimplCount { ticks = tks1, details = dts1 })
             | null (log2 sc2) = sc2 { log2 = log1 sc1 }
             | otherwise       = sc2
 
-plusSimplCount VerySimplZero VerySimplZero = VerySimplZero
-plusSimplCount _             _             = VerySimplNonZero
+plusSimplCount (VerySimplCount n) (VerySimplCount m) = VerySimplCount (n+m)
+plusSimplCount _                  _                  = panic "plusSimplCount"
+       -- We use one or the other consistently
 
-pprSimplCount VerySimplZero    = ptext (sLit "Total ticks: ZERO!")
-pprSimplCount VerySimplNonZero = ptext (sLit "Total ticks: NON-ZERO!")
+pprSimplCount (VerySimplCount n) = ptext (sLit "Total ticks:") <+> int n
 pprSimplCount (SimplCount { ticks = tks, details = dts, log1 = l1, log2 = l2 })
   = vcat [ptext (sLit "Total ticks:    ") <+> int tks,
          blankLine,