aboutsummaryrefslogtreecommitdiff
path: root/configure
diff options
context:
space:
mode:
authorRichard Henderson <rth@twiddle.net>2016-09-02 12:23:57 -0700
committerRichard Henderson <rth@twiddle.net>2016-10-26 08:29:01 -0700
commitdf79b996a7b21c6ea7847f7927a2e1a294b86c72 (patch)
tree878779e7214c310b0b0929ca115e286a9f0ba12f /configure
parent7ebee43ee3e2fcd7b5063058b7ef74bc43216733 (diff)
downloadqemu-df79b996a7b21c6ea7847f7927a2e1a294b86c72.zip
qemu-df79b996a7b21c6ea7847f7927a2e1a294b86c72.tar.gz
qemu-df79b996a7b21c6ea7847f7927a2e1a294b86c72.tar.bz2
tcg: Add CONFIG_ATOMIC64
Allow qemu to build on 32-bit hosts without 64-bit atomic ops. Even if we only allow 32-bit hosts to multi-thread emulate 32-bit guests, we still need some way to handle the 32-bit guest using a 64-bit atomic operation. Do so by dropping back to single-step. Reviewed-by: Emilio G. Cota <cota@braap.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'configure')
-rwxr-xr-xconfigure33
1 files changed, 33 insertions, 0 deletions
diff --git a/configure b/configure
index cc3301f..8e10059 100755
--- a/configure
+++ b/configure
@@ -4544,6 +4544,35 @@ EOF
fi
fi
+#########################################
+# See if 64-bit atomic operations are supported.
+# Note that without __atomic builtins, we can only
+# assume atomic loads/stores max at pointer size.
+
+cat > $TMPC << EOF
+#include <stdint.h>
+int main(void)
+{
+ uint64_t x = 0, y = 0;
+#ifdef __ATOMIC_RELAXED
+ y = __atomic_load_8(&x, 0);
+ __atomic_store_8(&x, y, 0);
+ __atomic_compare_exchange_8(&x, &y, x, 0, 0, 0);
+ __atomic_exchange_8(&x, y, 0);
+ __atomic_fetch_add_8(&x, y, 0);
+#else
+ typedef char is_host64[sizeof(void *) >= sizeof(uint64_t) ? 1 : -1];
+ __sync_lock_test_and_set(&x, y);
+ __sync_val_compare_and_swap(&x, y, 0);
+ __sync_fetch_and_add(&x, y);
+#endif
+ return 0;
+}
+EOF
+if compile_prog "" "" ; then
+ atomic64=yes
+fi
+
########################################
# check if getauxval is available.
@@ -5510,6 +5539,10 @@ if test "$atomic128" = "yes" ; then
echo "CONFIG_ATOMIC128=y" >> $config_host_mak
fi
+if test "$atomic64" = "yes" ; then
+ echo "CONFIG_ATOMIC64=y" >> $config_host_mak
+fi
+
if test "$getauxval" = "yes" ; then
echo "CONFIG_GETAUXVAL=y" >> $config_host_mak
fi