[Qemu-devel] [PATCH 16/32] configure: detect endian via compile test

[Michael Roth <mdroth@linux.vnet.ibm.com>]

From: Mike Frysinger <vapier@gentoo.org>

This avoids needing to execute a program and keeping an (incomplete)
list when cross-compiling.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Tested-by: James Hogan <james.hogan@imgtec.com> [mips]
Message-id: 1372649418-4987-1-git-send-email-vapier@gentoo.org
Signed-off-by: Anthony Liguori <aliguori@amazon.com>
(cherry picked from commit 61cc919f73ea7ca134c0ac41b748981ad63a253b)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 configure |   40 ++++++++++++++--------------------------
 1 file changed, 14 insertions(+), 26 deletions(-)

diff --git a/configure b/configure
index 4cf672d..1399de2 100755
--- a/configure
+++ b/configure
@@ -1394,39 +1394,27 @@ feature_not_found() {
       "configure was not able to find it"
 }
 
-if test -z "$cross_prefix" ; then
-
 # ---
 # big/little endian test
 cat > $TMPC << EOF
-#include <inttypes.h>
-int main(void) {
-        volatile uint32_t i=0x01234567;
-        return (*((uint8_t*)(&i))) == 0x67;
+short big_endian[] = { 0x4269, 0x4765, 0x4e64, 0x4961, 0x4e00, 0, };
+short little_endian[] = { 0x694c, 0x7454, 0x654c, 0x6e45, 0x6944, 0x6e41, 0, };
+extern int foo(short *, short *);
+int main(int argc, char *argv[]) {
+    return foo(big_endian, little_endian);
 }
 EOF
 
-if compile_prog "" "" ; then
-$TMPE && bigendian="yes"
-else
-echo big/little test failed
-fi
-
-else
-
-# if cross compiling, cannot launch a program, so make a static guess
-case "$cpu" in
-  arm)
-    # ARM can be either way; ask the compiler which one we are
-    if check_define __ARMEB__; then
-      bigendian=yes
+if compile_object ; then
+    if grep -q BiGeNdIaN $TMPO ; then
+        bigendian="yes"
+    elif grep -q LiTtLeEnDiAn $TMPO ; then
+        bigendian="no"
+    else
+        echo big/little test failed
     fi
-  ;;
-  hppa|m68k|mips|mips64|ppc|ppc64|s390|s390x|sparc|sparc64)
-    bigendian=yes
-  ;;
-esac
-
+else
+    echo big/little test failed
 fi
 
 ##########################################
-- 
1.7.9.5