From: simonmar <unknown>
Date: Thu, 23 Mar 2000 09:32:13 +0000 (+0000)
Subject: [project @ 2000-03-23 09:32:13 by simonmar]
X-Git-Tag: Approximately_9120_patches~4925
X-Git-Url: http://git.megacz.com/?a=commitdiff_plain;h=e5af99b182f60288a0a9098e69ab9028f612c55e;p=ghc-hetmet.git

[project @ 2000-03-23 09:32:13 by simonmar]
Disable some of the special cases in remInteger and quotInteger, which
turned out to be wrong.
---

diff --git a/ghc/lib/std/PrelNum.lhs b/ghc/lib/std/PrelNum.lhs
index be3abc8..9af9ffa 100644
--- a/ghc/lib/std/PrelNum.lhs
+++ b/ghc/lib/std/PrelNum.lhs
@@ -169,11 +169,15 @@ remInteger ia 0
   = error "Prelude.Integral.rem{Integer}: divide by 0"
 remInteger a@(S# (-2147483648#)) b = remInteger (toBig a) b
 remInteger (S# a) (S# b) = S# (remInt# a b)
+{- Special case doesn't work, because a 1-element J# has the range
+   -(2^32-1) -- 2^32-1, whereas S# has the range -2^31 -- (2^31-1)
 remInteger ia@(S# a) (J# sb b)
   | sb ==# 1#  = S# (remInt# a (word2Int# (integer2Word# sb b)))
   | sb ==# -1# = S# (remInt# a (0# -# (word2Int# (integer2Word# sb b))))
   | 0# <# sb   = ia
   | otherwise  = S# (0# -# a)
+-}
+remInteger ia@(S# _) ib@(J# _ _) = remInteger (toBig ia) ib
 remInteger (J# sa a) (S# b)
   = case int2Integer# b of { (# sb, b #) ->
     case remInteger# sa a sb b of { (# sr, r #) ->
@@ -186,10 +190,13 @@ quotInteger ia 0
   = error "Prelude.Integral.quot{Integer}: divide by 0"
 quotInteger a@(S# (-2147483648#)) b = quotInteger (toBig a) b
 quotInteger (S# a) (S# b) = S# (quotInt# a b)
+{- Special case disabled, see remInteger above
 quotInteger (S# a) (J# sb b)
   | sb ==# 1#  = S# (quotInt# a (word2Int# (integer2Word# sb b)))
   | sb ==# -1# = S# (quotInt# a (0# -# (word2Int# (integer2Word# sb b))))
   | otherwise  = zeroInteger
+-}
+quotInteger ia@(S# _) ib@(J# _ _) = quotInteger (toBig ia) ib
 quotInteger (J# sa a) (S# b)
   = case int2Integer# b of { (# sb, b #) ->
     case quotInteger# sa a sb b of (# sq, q #) -> J# sq q }