diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 71cdd934b69..1c56ebe37b8 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2012-02-08 Andrew MacLeod + + * optabs.c (expand_atomic_load): Do not assume compare_and_swap will + always succeed for integers larger than a native word. + 2012-02-08 Richard Guenther PR rtl-optimization/52170 diff --git a/gcc/optabs.c b/gcc/optabs.c index 87cce8ef4b0..b0ecdf0513e 100644 --- a/gcc/optabs.c +++ b/gcc/optabs.c @@ -7665,9 +7665,12 @@ expand_atomic_load (rtx target, rtx mem, enum memmodel model) /* Issue val = compare_and_swap (mem, 0, 0). This may cause the occasional harmless store of 0 when the value is already 0, but it seems to be OK according to the standards guys. */ - expand_atomic_compare_and_swap (NULL, &target, mem, const0_rtx, - const0_rtx, false, model, model); - return target; + if (expand_atomic_compare_and_swap (NULL, &target, mem, const0_rtx, + const0_rtx, false, model, model)) + return target; + else + /* Otherwise there is no atomic load, leave the library call. */ + return NULL_RTX; } /* Otherwise assume loads are atomic, and emit the proper barriers. */