diff --git a/gcc/ChangeLog b/gcc/ChangeLog index cbdecf83d20..c51d139850e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2014-02-20 Richard Henderson + + PR c++/60272 + * builtins.c (expand_builtin_atomic_compare_exchange): Always make + a new pseudo for OLDVAL. + 2014-02-20 Jakub Jelinek PR target/57896 diff --git a/gcc/builtins.c b/gcc/builtins.c index 09fefe50a8d..35969ad4184 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -5332,9 +5332,12 @@ expand_builtin_atomic_compare_exchange (enum machine_mode mode, tree exp, if (target == const0_rtx) target = NULL; - oldval = expect; - if (!expand_atomic_compare_and_swap (&target, &oldval, mem, oldval, desired, + /* Lest the rtl backend create a race condition with an imporoper store + to memory, always create a new pseudo for OLDVAL. */ + oldval = NULL; + + if (!expand_atomic_compare_and_swap (&target, &oldval, mem, expect, desired, is_weak, success, failure)) return NULL_RTX;