From: Andrew MacLeod Date: Wed, 8 Feb 2012 15:26:02 +0000 (+0000) Subject: optabs.c (expand_atomic_load): Do not assume compare_and_swap will succeed for larger... X-Git-Tag: releases/gcc-4.7.0~507 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c51ec0a3d68c86ba9b2e2d0c61556fee8308d570;p=thirdparty%2Fgcc.git optabs.c (expand_atomic_load): Do not assume compare_and_swap will succeed for larger than word integers. * optabs.c (expand_atomic_load): Do not assume compare_and_swap will succeed for larger than word integers. From-SVN: r184009 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 71cdd934b69b..1c56ebe37b8e 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 87cce8ef4b04..b0ecdf0513ee 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. */