From 83f25afc41b66b08c4022501a841f6e79938b311 Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Tue, 23 Feb 2010 00:29:17 +0000
Subject: [PATCH] add address_bits flag (request from Paulo Moura).

---
 C/sysbits.c       | 11 +++++++++++
 pl/directives.yap | 10 ++++++++++
 2 files changed, 21 insertions(+)

diff --git a/C/sysbits.c b/C/sysbits.c
index 29080b069..a6afde9db 100755
--- a/C/sysbits.c
+++ b/C/sysbits.c
@@ -2972,6 +2972,16 @@ p_ld_path(void)
   return Yap_unify(ARG1,MkAtomTerm(Yap_LookupAtom(YAP_LIBDIR)));
 }
 
+static Int
+p_address_bits(void)
+{
+#if SIZEOF_INT_P==4
+  return Yap_unify(ARG1,MkIntTerm(32));
+#else
+  return Yap_unify(ARG1,MkIntTerm(64));
+#endif
+}
+
 
 
 #ifdef _WIN32
@@ -3193,6 +3203,7 @@ Yap_InitSysPreds(void)
   Yap_InitCPred ("$unix", 0, p_unix, SafePredFlag);
   Yap_InitCPred ("$win32", 0, p_win32, SafePredFlag);
   Yap_InitCPred ("$ld_path", 1, p_ld_path, SafePredFlag);
+  Yap_InitCPred ("$address_bits", 1, p_address_bits, SafePredFlag);
 #ifdef _WIN32
   Yap_InitCPred ("win_registry_get_value", 3, p_win_registry_get_value,0);
 #endif
diff --git a/pl/directives.yap b/pl/directives.yap
index 93a08c43b..3eac18043 100644
--- a/pl/directives.yap
+++ b/pl/directives.yap
@@ -876,10 +876,20 @@ yap_flag(max_threads,X) :-
 yap_flag(max_threads,X) :-
 	'$do_error'(domain_error(flag_value,max_threads+X),yap_flag(max_threads,X)).
 
+yap_flag(address_bits,X) :-
+	var(X), !,
+	'$address_bits'(X).
+yap_flag(address_bits,X) :-
+	integer(X), X > 0, !,
+	'$do_error'(permission_error(modify,flag,address_bits),yap_flag(address_bits,X)).
+yap_flag(address_bits,X) :-
+	'$do_error'(domain_error(flag_value,address_bits+X),yap_flag(address_bits,X)).
+
 yap_flag(dialect,yap).
 
 '$show_yap_flag_opts'(V,Out) :-
 	(
+		V = address_bits ;
 		V = answer_format ;
 		V = argv ;
 		V = bounded ;