Tue Nov 30 06:30:14 PST 2010  pho@cielonegro.org
  * FIX #1845 (unconditional relative branch out of range)
  
  Don't use mmap on powerpc-apple-darwin as mmap doesn't support
  reallocating but we need to allocate jump islands just after each
  object images. Otherwise relative branches to jump islands can fail
  due to 24-bits displacement overflow.
diff -rN -u old-ghc/rts/Linker.c new-ghc/rts/Linker.c
--- old-ghc/rts/Linker.c	2011-04-19 01:37:03.000000000 -0700
+++ new-ghc/rts/Linker.c	2011-04-19 01:37:04.000000000 -0700
@@ -69,7 +69,15 @@
 #include <sys/wait.h>
 #endif
 
-#if defined(linux_HOST_OS) || defined(freebsd_HOST_OS) || defined(dragonfly_HOST_OS) || defined(netbsd_HOST_OS) || defined(openbsd_HOST_OS) || defined(darwin_HOST_OS)
+#if defined(linux_HOST_OS    ) || defined(freebsd_HOST_OS) || \
+    defined(dragonfly_HOST_OS) || defined(netbsd_HOST_OS ) || \
+    defined(openbsd_HOST_OS  ) || \
+    ( defined(darwin_HOST_OS ) && !defined(powerpc_HOST_ARCH) )
+/* Don't use mmap on powerpc-apple-darwin as mmap doesn't support
+ * reallocating but we need to allocate jump islands just after each
+ * object images. Otherwise relative branches to jump islands can fail
+ * due to 24-bits displacement overflow.
+ */
 #define USE_MMAP
 #include <fcntl.h>
 #include <sys/mman.h>
@@ -1841,6 +1849,9 @@
    int fd;
 #else
    FILE *f;
+#  if defined(darwin_HOST_OS)
+   int misalignment;
+#  endif
 #endif
    IF_DEBUG(linker, debugBelch("loadObj %s\n", path));