From df79b996a7b21c6ea7847f7927a2e1a294b86c72 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 2 Sep 2016 12:23:57 -0700 Subject: tcg: Add CONFIG_ATOMIC64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- configure | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'configure') diff --git a/configure b/configure index cc3301fa0a..8e10059607 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 > $TMPC << EOF +#include +int main(void) +{ + uint64_t x = 0, y = 0; +#ifdef __ATOMIC_RELAXED + y = __atomic_load_8(&x, 0); + __atomic_store_8(&x, y, 0); + __atomic_compare_exchange_8(&x, &y, x, 0, 0, 0); + __atomic_exchange_8(&x, y, 0); + __atomic_fetch_add_8(&x, y, 0); +#else + typedef char is_host64[sizeof(void *) >= sizeof(uint64_t) ? 1 : -1]; + __sync_lock_test_and_set(&x, y); + __sync_val_compare_and_swap(&x, y, 0); + __sync_fetch_and_add(&x, y); +#endif + return 0; +} +EOF +if compile_prog "" "" ; then + atomic64=yes +fi + ######################################## # check if getauxval is available. @@ -5510,6 +5539,10 @@ if test "$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 -- cgit v1.2.3