[project @ 1998-11-26 09:17:22 by sof]

[ghc-hetmet.git] / ghc / compiler / basicTypes / UniqSupply.lhs

diff --git a/ghc/compiler/basicTypes/UniqSupply.lhs b/ghc/compiler/basicTypes/UniqSupply.lhs
index d9ae896..4b83b52 100644 (file)
--- a/ghc/compiler/basicTypes/UniqSupply.lhs
+++ b/ghc/compiler/basicTypes/UniqSupply.lhs
@@ -4,33 +4,32 @@
 \section[UniqSupply]{The @UniqueSupply@ data type and a (monadic) supply thereof}
 
 \begin{code}
-#include "HsVersions.h"
-
 module UniqSupply (
 
        UniqSupply,             -- Abstractly
 
        getUnique, getUniques,  -- basic ops
 
-       UniqSM(..),             -- type: unique supply monad
-       initUs, thenUs, returnUs,
+       UniqSM,         -- type: unique supply monad
+       initUs, thenUs, returnUs, fixUs,
        mapUs, mapAndUnzipUs, mapAndUnzip3Us,
        thenMaybeUs, mapAccumLUs,
 
        mkSplitUniqSupply,
-       splitUniqSupply,
-
-       -- and the access functions for the `builtin' UniqueSupply
-       getBuiltinUniques, mkBuiltinUnique,
-       mkPseudoUnique1, mkPseudoUnique2, mkPseudoUnique3
+       splitUniqSupply
   ) where
 
-import Ubiq{-uitous-}
+#include "HsVersions.h"
 
 import Unique
 import Util
 
-import PreludeGlaST
+import GlaExts
+
+#if __GLASGOW_HASKELL__ < 301
+import IOBase          ( IO(..), IOResult(..) )
+#else
+#endif
 
 w2i x = word2Int# x
 i2w x = int2Word# x
@@ -71,46 +70,37 @@ getUniques :: Int -> UniqSupply -> [Unique]
 \end{code}
 
 \begin{code}
-mkSplitUniqSupply (MkChar c#)
+mkSplitUniqSupply (C# c#)
   = let
        mask# = (i2w (ord# c#)) `shiftL#` (i2w_s 24#)
 
        -- here comes THE MAGIC:
 
+       -- This is one of the most hammered bits in the whole compiler
        mk_supply#
-         = unsafe_interleave (
-               mk_unique   `thenPrimIO` \ uniq ->
-               mk_supply#  `thenPrimIO` \ s1 ->
-               mk_supply#  `thenPrimIO` \ s2 ->
-               returnPrimIO (MkSplitUniqSupply uniq s1 s2)
+         = unsafeInterleaveIO (
+               mk_unique   >>= \ uniq ->
+               mk_supply#  >>= \ s1 ->
+               mk_supply#  >>= \ s2 ->
+               return (MkSplitUniqSupply uniq s1 s2)
            )
-         where
-           -- inlined copy of unsafeInterleavePrimIO;
-           -- this is the single-most-hammered bit of code
-           -- in the compiler....
-           unsafe_interleave m s
-             = let
-                   (r, new_s) = m s
-               in
-               (r, s)
-
-       mk_unique = _ccall_ genSymZh            `thenPrimIO` \ (W# u#) ->
-                   returnPrimIO (MkInt (w2i (mask# `or#` u#)))
+
+       mk_unique = _ccall_ genSymZh            >>= \ (W# u#) ->
+                   return (I# (w2i (mask# `or#` u#)))
     in
-    mk_supply# `thenPrimIO` \ s ->
-    return s
+    mk_supply#
 
 splitUniqSupply (MkSplitUniqSupply _ s1 s2) = (s1, s2)
 \end{code}
 
 \begin{code}
-getUnique (MkSplitUniqSupply (MkInt n) _ _) = mkUniqueGrimily n
+getUnique (MkSplitUniqSupply (I# n) _ _) = mkUniqueGrimily n
 
-getUniques i@(MkInt i#) supply = i# `get_from` supply
+getUniques (I# i) supply = i `get_from` supply
   where
     get_from 0# _ = []
-    get_from n# (MkSplitUniqSupply (MkInt u#) _ s2)
-      = mkUniqueGrimily u# : get_from (n# `minusInt#` 1#) s2
+    get_from n (MkSplitUniqSupply (I# u) _ s2)
+      = mkUniqueGrimily u : get_from (n -# 1#) s2
 \end{code}
 
 %************************************************************************
@@ -124,11 +114,9 @@ type UniqSM result = UniqSupply -> result
 
 -- the initUs function also returns the final UniqSupply
 
-initUs :: UniqSupply -> UniqSM a -> (UniqSupply, a)
+initUs :: UniqSupply -> UniqSM a -> a
 
-initUs init_us m
-  = case (splitUniqSupply init_us) of { (s1, s2) ->
-    (s2, m s1) }
+initUs init_us m = m init_us
 
 {-# INLINE thenUs #-}
 {-# INLINE returnUs #-}
@@ -137,6 +125,10 @@ initUs init_us m
 
 @thenUs@ is where we split the @UniqSupply@.
 \begin{code}
+fixUs :: (a -> UniqSM a) -> UniqSM a
+fixUs m us
+  = r  where  r = m r us
+
 thenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b
 
 thenUs expr cont us
@@ -190,28 +182,3 @@ mapAccumLUs f b (x:xs)
     mapAccumLUs f b__2 xs          `thenUs` \ (b__3, xs__2) ->
     returnUs (b__3, x__2:xs__2)
 \end{code}
-
-%************************************************************************
-%*                                                                     *
-\subsubsection[UniqueSupplies-compiler]{@UniqueSupplies@ specific to the compiler}
-%*                                                                     *
-%************************************************************************
-
-\begin{code}
-mkPseudoUnique1, mkPseudoUnique2, mkPseudoUnique3,
- mkBuiltinUnique :: Int -> Unique
-
-mkBuiltinUnique i = mkUnique 'B' i
-mkPseudoUnique1 i = mkUnique 'C' i -- used for uniqueOf on Regs
-mkPseudoUnique2 i = mkUnique 'D' i -- ditto
-mkPseudoUnique3 i = mkUnique 'E' i -- ditto
-
-getBuiltinUniques :: Int -> [Unique]
-getBuiltinUniques n = map (mkUnique 'B') [1 .. n]
-\end{code}
-
-The following runs a uniq monad expression, using builtin uniq values:
-\begin{code}
---runBuiltinUs :: UniqSM a -> a
---runBuiltinUs m = snd (initUs uniqSupply_B m)
-\end{code}