[project @ 2005-07-14 10:38:03 by simonmar]

Fix mulMayOflo() on 64-bit archs.  This fixes the arith003 failures on x86_64.

diff --git a/ghc/includes/Stg.h b/ghc/includes/Stg.h
index f11f452..9977d57 100644 (file)
--- a/ghc/includes/Stg.h
+++ b/ghc/includes/Stg.h
@@ -422,15 +422,16 @@ typedef union {
 
 #else
 
-#define HALF_INT  (((I_)1) << (BITS_IN (I_) / 2))
+/* Approximate version when we don't have long arithmetic (on 64-bit archs) */
 
-#define stg_abs(a) (((I_)(a)) < 0 ? -((I_)(a)) : ((I_)(a)))
+#define HALF_POS_INT  (((I_)1) << (BITS_IN (I_) / 2))
+#define HALF_NEG_INT  (-HALF_POS_INT)
 
 #define mulIntMayOflo(a,b)                     \
 ({                                              \
   I_ c;                                        \
-  if (stg_abs(a) >= HALF_INT ||                        \
-      stg_abs(b) >= HALF_INT) {                        \
+  if ((I_)a <= HALF_NEG_INT || a >= HALF_POS_INT    \
+      || (I_)b <= HALF_NEG_INT || b >= HALF_POS_INT) {\
     c = 1;                                     \
   } else {                                     \
     c = 0;                                     \