[project @ 2003-07-02 13:12:33 by simonpj]

[ghc-hetmet.git] / ghc / compiler / absCSyn / AbsCUtils.lhs

diff --git a/ghc/compiler/absCSyn/AbsCUtils.lhs b/ghc/compiler/absCSyn/AbsCUtils.lhs
index ac75ca1..893f88a 100644 (file)
--- a/ghc/compiler/absCSyn/AbsCUtils.lhs
+++ b/ghc/compiler/absCSyn/AbsCUtils.lhs
@@ -22,7 +22,7 @@ module AbsCUtils (
 import AbsCSyn
 import CLabel          ( mkMAP_FROZEN_infoLabel )
 import Digraph         ( stronglyConnComp, SCC(..) )
-import DataCon         ( fIRST_TAG, ConTag )
+import DataCon         ( fIRST_TAG, dataConTag )
 import Literal         ( literalPrimRep, mkMachWord, mkMachInt )
 import PrimRep         ( getPrimRepSize, PrimRep(..) )
 import PrimOp          ( PrimOp(..) )
@@ -34,14 +34,13 @@ import CmdLineOpts      ( opt_EmitCExternDecls, opt_Unregisterised )
 import ForeignCall     ( ForeignCall(..), CCallSpec(..),
                          isDynamicTarget, isCasmTarget )
 import StgSyn          ( StgOp(..) )
+import CoreSyn         ( AltCon(..) )
 import SMRep           ( arrPtrsHdrSize, arrWordsHdrSize, fixedHdrSize )
 import Outputable
 import Panic           ( panic )
 import FastTypes
 import Constants       ( wORD_SIZE, wORD_SIZE_IN_BITS )
 
-import Maybe           ( isJust )
-
 infixr 9 `thenFlt`
 \end{code}
 
@@ -108,18 +107,14 @@ mkAbsCStmtList' other r = other : r
 \end{code}
 
 \begin{code}
-mkAlgAltsCSwitch :: CAddrMode -> [(ConTag, AbstractC)] -> AbstractC -> AbstractC
+mkAlgAltsCSwitch :: CAddrMode -> [(AltCon, AbstractC)] -> AbstractC
 
-mkAlgAltsCSwitch scrutinee tagged_alts deflt_absc
- | isJust (nonemptyAbsC deflt_absc) 
-       = CSwitch scrutinee (adjust tagged_alts) deflt_absc
- | otherwise 
-       = CSwitch scrutinee (adjust rest) first_alt
+mkAlgAltsCSwitch scrutinee ((_,first_alt) : rest_alts)
+ = CSwitch scrutinee (adjust rest_alts) first_alt
  where
-   -- it's ok to convert one of the alts into a default if we don't already have
-   -- one, because this is an algebraic case and we're guaranteed that the tag 
-   -- will match one of the branches.
-   ((_,first_alt):rest) = tagged_alts
+   -- We use the first alt as the default.  Either it *is* the DEFAULT,
+   -- (which is always first if present), or the case is exhaustive,
+   -- in which case we can use the first as the default anyway
 
    -- Adjust the tags in the switch to start at zero.
    -- This is the convention used by primitive ops which return algebraic
@@ -128,8 +123,8 @@ mkAlgAltsCSwitch scrutinee tagged_alts deflt_absc
 
    -- We also need to convert to Literals to keep the CSwitch happy
    adjust tagged_alts
-     = [ (mkMachWord (toInteger (tag - fIRST_TAG)), abs_c)
-       | (tag, abs_c) <- tagged_alts ]
+     = [ (mkMachWord (toInteger (dataConTag dc - fIRST_TAG)), abs_c)
+       | (DataAlt dc, abs_c) <- tagged_alts ]
 \end{code}
 
 %************************************************************************