[project @ 1998-01-08 18:03:08 by simonm]

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

diff --git a/ghc/compiler/basicTypes/UniqSupply.lhs b/ghc/compiler/basicTypes/UniqSupply.lhs
index 1c651cb..23bd2c0 100644 (file)
--- a/ghc/compiler/basicTypes/UniqSupply.lhs
+++ b/ghc/compiler/basicTypes/UniqSupply.lhs
@@ -4,15 +4,13 @@
 \section[UniqSupply]{The @UniqueSupply@ data type and a (monadic) supply thereof}
 
 \begin{code}
-#include "HsVersions.h"
-
 module UniqSupply (
 
        UniqSupply,             -- Abstractly
 
        getUnique, getUniques,  -- basic ops
 
-       SYN_IE(UniqSM),         -- type: unique supply monad
+       UniqSM,         -- type: unique supply monad
        initUs, thenUs, returnUs, fixUs,
        mapUs, mapAndUnzipUs, mapAndUnzip3Us,
        thenMaybeUs, mapAccumLUs,
@@ -21,30 +19,15 @@ module UniqSupply (
        splitUniqSupply
   ) where
 
-IMP_Ubiq(){-uitous-}
+#include "HsVersions.h"
 
 import Unique
 import Util
 
 
-#if __GLASGOW_HASKELL__ == 201
-import PreludeGlaST
-# define WHASH     GHCbase.W#
-#elif __GLASGOW_HASKELL__ >= 202
 import GlaExts
-import STBase
-# if __GLASGOW_HASKELL__ == 202
+import IOBase  ( IO(..), IOResult(..) )
 import PrelBase ( Char(..) )
-# endif
-# define WHASH      GlaExts.W#
-#else
-import PreludeGlaST
-# define WHASH     W#
-#endif
-
-#if __GLASGOW_HASKELL__ >= 209
-import Unsafe ( unsafeInterleaveIO )
-#endif
 
 w2i x = word2Int# x
 i2w x = int2Word# x
@@ -91,41 +74,19 @@ mkSplitUniqSupply (C# c#)
 
        -- 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....
-           -- Too bad it's not 1.3-portable...
-           unsafe_interleave m =
-#if __GLASGOW_HASKELL__ >= 209
-               unsafeInterleaveIO m
-#else
-              MkST ( \ s ->
-               let
-                   (MkST m') = m
-                   ST_RET(r, new_s) = m' s
-               in
-               ST_RET(r, s))
-#endif
-
-       mk_unique = _ccall_ genSymZh            `thenPrimIO` \ (WHASH u#) ->
-                   returnPrimIO (I# (w2i (mask# `or#` u#)))
+
+       mk_unique = _ccall_ genSymZh            >>= \ (W# u#) ->
+                   return (I# (w2i (mask# `or#` u#)))
     in
-#if __GLASGOW_HASKELL__ >= 200
-    primIOToIO mk_supply#      >>= \ s ->
-    return s
-#else
-    mk_supply# `thenPrimIO` \ s ->
-    return s
-#endif
+    mk_supply#
 
 splitUniqSupply (MkSplitUniqSupply _ s1 s2) = (s1, s2)
 \end{code}