Fixes for cross-compiling to a different word size

This patch eliminates a couple of places where we were assuming that
the host word size is the same as the target word size.

Also a little refactoring: Constants now exports the types TargetInt
and TargetWord corresponding to the Int/Word type on the target
platform, and I moved the definitions of tARGET_INT_MAX and friends
from Literal to Constants.

Thanks to Barney Stratford <barney_stratford@fastmail.fm> for helping
track down the problem and fix it.  We now know that GHC can
successfully cross-compile from 32-bit to 64-bit.

1 files changed, 5 insertions, 3 deletions

diff --git a/compiler/prelude/PrelRules.lhs b/compiler/prelude/PrelRules.lhs
index 67eb06f9d9..e35d8dbcce 100644
--- a/compiler/prelude/PrelRules.lhs
+++ b/compiler/prelude/PrelRules.lhs
@@ -45,6 +45,8 @@ import Name		( Name, nameOccName )
 import Outputable
 import FastString
 import StaticFlags      ( opt_SimplExcessPrecision )
+import Constants
+
 import Data.Bits as Bits
 import Data.Word	( Word )
 \end{code}
@@ -353,14 +355,14 @@ litEq op_name is_eq
 -- runtime either, and compilation of completely harmless things like
 --    ((124076834 :: Word32) + (2147483647 :: Word32))
 -- would yield a warning. Instead we simply squash the value into the
--- Int range, but not in a way suitable for cross-compiling... :-(
+-- *target* Int/Word range.
 intResult :: Integer -> Maybe CoreExpr
 intResult result
-  = Just (mkIntVal (toInteger (fromInteger result :: Int)))
+  = Just (mkIntVal (toInteger (fromInteger result :: TargetInt)))
 
 wordResult :: Integer -> Maybe CoreExpr
 wordResult result
-  = Just (mkWordVal (toInteger (fromInteger result :: Word)))
+  = Just (mkWordVal (toInteger (fromInteger result :: TargetWord)))
 \end{code}