X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypecheck%2FInst.lhs;h=b1636a7e221851338f6e1ac9db14614f3c165d38;hb=55e0ee453646be887a27a3fe6b4559d8182bf9fe;hp=db61c6d65c36921c8182e637bc017b23707af304;hpb=288213d7c2c65fa68ca466c1a1a3378e24fa1151;p=ghc-hetmet.git

diff --git a/compiler/typecheck/Inst.lhs b/compiler/typecheck/Inst.lhs
index db61c6d..b1636a7 100644
--- a/compiler/typecheck/Inst.lhs
+++ b/compiler/typecheck/Inst.lhs
@@ -60,7 +60,7 @@ module Inst (
 import {-# SOURCE #-}	TcExpr( tcPolyExpr )
 import {-# SOURCE #-}	TcUnify( boxyUnify, unifyType )
 
-import FastString(FastString)
+import FastString
 import HsSyn
 import TcHsSyn
 import TcRnMonad
@@ -473,19 +473,20 @@ newMethod inst_loc id tys = do
 \begin{code}
 shortCutIntLit :: Integer -> TcType -> Maybe (HsExpr TcId)
 shortCutIntLit i ty
-  | isIntTy ty && inIntRange i 		-- Short cut for Int
-  = Just (HsLit (HsInt i))
-  | isIntegerTy ty 			-- Short cut for Integer
-  = Just (HsLit (HsInteger i ty))
-  | otherwise = Nothing
+  | isIntTy ty && inIntRange i = Just (HsLit (HsInt i))
+  | isIntegerTy ty 	       = Just (HsLit (HsInteger i ty))
+  | otherwise		       = shortCutFracLit (fromInteger i) ty
+	-- The 'otherwise' case is important
+	-- Consider (3 :: Float).  Syntactically it looks like an IntLit,
+	-- so we'll call shortCutIntLit, but of course it's a float
+	-- This can make a big difference for programs with a lot of
+	-- literals, compiled without -O
 
 shortCutFracLit :: Rational -> TcType -> Maybe (HsExpr TcId)
 shortCutFracLit f ty
-  | isFloatTy ty 
-  = Just (mk_lit floatDataCon (HsFloatPrim f))
-  | isDoubleTy ty
-  = Just (mk_lit doubleDataCon (HsDoublePrim f))
-  | otherwise = Nothing
+  | isFloatTy ty  = Just (mk_lit floatDataCon  (HsFloatPrim f))
+  | isDoubleTy ty = Just (mk_lit doubleDataCon (HsDoublePrim f))
+  | otherwise     = Nothing
   where
     mk_lit con lit = HsApp (nlHsVar (dataConWrapId con)) (nlHsLit lit)
 
@@ -727,11 +728,11 @@ traceDFuns ispecs
 
 funDepErr ispec ispecs
   = addDictLoc ispec $
-    addErr (hang (ptext SLIT("Functional dependencies conflict between instance declarations:"))
+    addErr (hang (ptext (sLit "Functional dependencies conflict between instance declarations:"))
 	       2 (pprInstances (ispec:ispecs)))
 dupInstErr ispec dup_ispec
   = addDictLoc ispec $
-    addErr (hang (ptext SLIT("Duplicate instance declarations:"))
+    addErr (hang (ptext (sLit "Duplicate instance declarations:"))
 	       2 (pprInstances [ispec, dup_ispec]))
 
 addDictLoc ispec thing_inside
@@ -823,7 +824,7 @@ lookupSimpleInst (Dict {tci_pred = pred, tci_loc = loc})
 	    Just (dfun_id, mb_inst_tys) -> do
 
     { use_stage <- getStage
-    ; checkWellStaged (ptext SLIT("instance for") <+> quotes (ppr pred))
+    ; checkWellStaged (ptext (sLit "instance for") <+> quotes (ppr pred))
     		      (topIdLvl dfun_id) use_stage
 
  	-- It's possible that not all the tyvars are in
@@ -964,10 +965,10 @@ tcSyntaxName orig ty (std_nm, user_nm_expr) = do
 syntaxNameCtxt name orig ty tidy_env = do
     inst_loc <- getInstLoc orig
     let
-	msg = vcat [ptext SLIT("When checking that") <+> quotes (ppr name) <+> 
-				ptext SLIT("(needed by a syntactic construct)"),
-		    nest 2 (ptext SLIT("has the required type:") <+> ppr (tidyType tidy_env ty)),
-		    nest 2 (ptext SLIT("arising from") <+> pprInstLoc inst_loc)]
+	msg = vcat [ptext (sLit "When checking that") <+> quotes (ppr name) <+> 
+				ptext (sLit "(needed by a syntactic construct)"),
+		    nest 2 (ptext (sLit "has the required type:") <+> ppr (tidyType tidy_env ty)),
+		    nest 2 (ptext (sLit "arising from") <+> pprInstLoc inst_loc)]
     
     return (tidy_env, msg)
 \end{code}