1 files changed, 7 insertions, 0 deletions
diff --git a/gcc/opts.c b/gcc/opts.c
index 3ab06c6..19203dc 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -620,6 +620,13 @@ default_options_optimization (struct gcc_options *opts,
      opt2 ? default_param_value (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP) : 1000,
      opts->x_param_values, opts_set->x_param_values);
 
+  /* At -Ofast, allow store motion to introduce potential race conditions.  */
+  maybe_set_param_value
+    (PARAM_ALLOW_STORE_DATA_RACES,
+     opts->x_optimize_fast ? 1
+     : default_param_value (PARAM_ALLOW_STORE_DATA_RACES),
+     opts->x_param_values, opts_set->x_param_values);
+
   if (opts->x_optimize_size)
     /* We want to crossjump as much as possible.  */
     maybe_set_param_value (PARAM_MIN_CROSSJUMP_INSNS, 1,