Merge remote-tracking branch 'public/bug3122_memcmp_022' into bug3122_memcmp_023

Conflicts in various places, mainly node-related.  Resolved them in
favor of HEAD, with copying of tor_mem* operations from bug3122_memcmp_022.

	src/common/Makefile.am
	src/or/circuitlist.c
	src/or/connection_edge.c
	src/or/directory.c
	src/or/microdesc.c
	src/or/networkstatus.c
	src/or/router.c
	src/or/routerlist.c
	src/test/test_util.c

1 files changed, 18 insertions, 0 deletions

diff --git a/configure.in b/configure.in
index 26c933b156..e5db37060f 100644
--- a/configure.in
+++ b/configure.in
@@ -905,6 +905,24 @@ if test "$tor_cv_twos_complement" != no ; then
             [Define to 1 iff we represent negative integers with two's complement])
 fi
 
+# What does shifting a negative value do?
+AC_CACHE_CHECK([whether right-shift on negative values does sign-extension], tor_cv_sign_extend,
+[AC_RUN_IFELSE([AC_LANG_SOURCE(
+[[int main () { int okay = (-60 >> 8) == -1; return okay ? 0 : 1; }]])],
+       [tor_cv_sign_extend=yes],
+       [tor_cv_sign_extend=no],
+       [tor_cv_sign_extend=cross])])
+
+if test "$tor_cv_sign_extend" = cross ; then
+  # Cross-compiling; let's hope that the target isn't raving mad.
+  AC_MSG_NOTICE([Cross-compiling: we'll assume that right-shifting negative integers causes sign-extension])
+fi
+
+if test "$tor_cv_sign_extend" != no ; then
+  AC_DEFINE([RSHIFT_DOES_SIGN_EXTEND], 1,
+            [Define to 1 iff right-shifting a negative value performs sign-extension])
+fi
+
 # Whether we should use the dmalloc memory allocation debugging library.
 AC_MSG_CHECKING(whether to use dmalloc (debug memory allocation library))
 AC_ARG_WITH(dmalloc,