From e93ca5cadeb71a04b2f8ef2ebcbadb2f0213d878 Mon Sep 17 00:00:00 2001 From: Ramana Radhakrishnan Date: Thu, 4 Jun 2015 09:19:51 +0000 Subject: Remove TARGET_RELAXED_ORDERING and optimize for weak memory models. This patch removes the special casing for targets with relaxed memory ordering and handles guard accesses with equivalent atomic load acquire operations. In this process we change the algorithm to load the guard variable with an atomic load that has ACQUIRE semantics. This then means that on targets which have weak memory models, the fast path is inlined and can directly use a load-acquire instruction where available (and yay! one more hook gone). 2015-06-04 Ramana Radhakrishnan PR c++/66192 PR target/66200 * doc/tm.texi: Regenerate. * doc/tm.texi.in (TARGET_RELAXED_ORDERING): Delete. * target.def (TARGET_RELAXED_ORDERING): Likewise. * config/alpha/alpha.c (TARGET_RELAXED_ORDERING): Likewise. * config/ia64/ia64.c (TARGET_RELAXED_ORDERING): Likewise. * config/rs6000/rs6000.c (TARGET_RELAXED_ORDERING): Likewise. * config/sparc/linux.h (SPARC_RELAXED_ORDERING): Likewise. * config/sparc/linux64.h (SPARC_RELAXED_ORDERING): Likewise. * config/sparc/sparc.c (TARGET_RELAXED_ORDERING): Likewise. * config/sparc/sparc.h (SPARC_RELAXED_ORDERING): Likewise. * system.h (TARGET_RELAXED_ORDERING): Poison. 2015-06-04 Ramana Radhakrishnan PR c++/66192 PR target/66200 * cp-tree.h (get_guard_cond): Adjust declaration * decl.c (expand_static_init): Use atomic load acquire and adjust call to get_guard_cond. * decl2.c (build_atomic_load_byte): New function. (get_guard_cond): Handle thread_safety. (one_static_initialization_or_destruction): Adjust call to get_guard_cond. From-SVN: r224118 --- gcc/config/alpha/alpha.c | 6 ------ 1 file changed, 6 deletions(-) (limited to 'gcc/config/alpha') diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c index 1ba99d0..857c9ac 100644 --- a/gcc/config/alpha/alpha.c +++ b/gcc/config/alpha/alpha.c @@ -9987,12 +9987,6 @@ alpha_atomic_assign_expand_fenv (tree *hold, tree *clear, tree *update) #undef TARGET_EXPAND_BUILTIN_VA_START #define TARGET_EXPAND_BUILTIN_VA_START alpha_va_start -/* The Alpha architecture does not require sequential consistency. See - http://www.cs.umd.edu/~pugh/java/memoryModel/AlphaReordering.html - for an example of how it can be violated in practice. */ -#undef TARGET_RELAXED_ORDERING -#define TARGET_RELAXED_ORDERING true - #undef TARGET_OPTION_OVERRIDE #define TARGET_OPTION_OVERRIDE alpha_option_override -- cgit v1.1