From: John Hughes <john@Calva.COM>
Date: Wed, 28 Mar 2001 08:05:27 +0000 (+0000)
Subject: Check for endianness of long long
X-Git-Tag: v4.5.18~1068
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b8a85a49ae738655cec81bd9e7bcb0bd6f5c9442;p=strace

Check for endianness of long long
---

diff --git a/ChangeLog b/ChangeLog
index 66af8ea8..7b029d6a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2001-03-27  John Hughes <john@Calva.COM>
+
+  * aclocal.m4: add check for endianness of long long.
+  * acconfig.h: add #define for LITTLE_ENDIAN_LONG_LONG.
+  * configure.in: check for endianness of long long.
+  * defs.h: change LONG_LONG macro to wirk with either endianness of
+    long long.
+
 2001-03-27  John Hughes <john@Calva.COM>
 
   * net.c: Make compilable by SCO UDK compiler (doesn't like empty
diff --git a/acconfig.h b/acconfig.h
index eb45d573..b56c34e1 100644
--- a/acconfig.h
+++ b/acconfig.h
@@ -107,3 +107,6 @@
 
 /* Define if have st_gen in struct stat */
 #undef HAVE_ST_GEN
+
+/* Define if have little endiang long long */
+#undef HAVE_LITTLE_ENDIAN_LONG_LONG
diff --git a/aclocal.m4 b/aclocal.m4
index 27a6cc6e..018ca917 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -481,3 +481,31 @@ then
 fi
 ])
 
+dnl ### A macro to determine endianness of long long
+AC_DEFUN(AC_LITTLE_ENDIAN_LONG_LONG,
+[AC_MSG_CHECKING(for little endian long long)
+AC_CACHE_VAL(ac_cv_have_little_endian_long_long,
+[AC_TRY_RUN([
+int main () {
+	union {
+		long long ll;
+		long l [2];
+	} u;
+	u.ll = 0x12345678;
+	if (u.l[0] == 0x12345678) 
+		return 0;
+	return 1;
+}
+],
+ac_cv_have_little_endian_long_long=yes,
+ac_cv_have_little_endian_long_long=no,
+[# Should try to guess here
+ac_cv_have_little_endian_long_long=no
+])])
+AC_MSG_RESULT($ac_cv_have_little_endian_long_long)
+if test "$ac_cv_have_little_endian_long_long" = yes
+then
+	AC_DEFINE(HAVE_LITTLE_ENDIAN_LONG_LONG)
+fi
+])
+
diff --git a/configure.in b/configure.in
index 3847550c..71b26ddc 100644
--- a/configure.in
+++ b/configure.in
@@ -151,6 +151,7 @@ AC_SIG_ATOMIC_T
 AC_STAT64
 AC_SIN6_SCOPE_ID
 AC_LONG_LONG
+AC_LITTLE_ENDIAN_LONG_LONG
 AC_OFF_T_IS_LONG_LONG
 AC_RLIM_T_IS_LONG_LONG
 AC_ST_FLAGS
diff --git a/defs.h b/defs.h
index 29c450e0..41be06bf 100644
--- a/defs.h
+++ b/defs.h
@@ -522,16 +522,7 @@ do {									\
  * _h refers to the higher numbered u_arg
  */
 
-#if 1
-/* This should work, assuming we can do non-aligned 64 bit fetches.
- * if not we'll have to figure out how which of the other versions to use.
- */
-
-#define LONG_LONG(_l,_h) (*(long long *) &(_l))
-
-#else
-
-#if _LITTLE_ENDIAN
+#if HAVE_LITTLE_ENDIAN_LONG_LONG
 #define LONG_LONG(_l,_h) \
     ((long long)((unsigned long long)(_l) | ((unsigned long long)(_h)<<32)))
 #else
@@ -539,4 +530,3 @@ do {									\
     ((long long)((unsigned long long)(_h) | ((unsigned long long)(_l)<<32)))
 #endif
 #endif
-#endif