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authortorvald <torvald@138bc75d-0d04-0410-961f-82ee72b054a4>2012-11-09 17:04:40 +0000
committertorvald <torvald@138bc75d-0d04-0410-961f-82ee72b054a4>2012-11-09 17:04:40 +0000
commit5b35a7918cc42521165f68f4fe3975e25103c798 (patch)
tree9fd7bd08f877808bd7bb4eb601fd7482c9c85d6f /libitm/config/posix
parent024c1ad598b7c9037f5417f56e367f7dd6b6ea45 (diff)
downloadgcc-5b35a7918cc42521165f68f4fe3975e25103c798.tar.gz
Add HTM fastpath and use Intel RTM for it on x86.
* beginend.cc (htm_fastpath): New. (gtm_thread::begin_transaction, _ITM_commitTransaction, _ITM_commitTransactionEH): Add HTM fastpath handling. * config/linux/rwlock.h (gtm_rwlock.is_write_locked): New. * config/posix/rwlock.h (gtm_rwlock.is_write_locked): New. * config/x86/target.h (htm_available, htm_init, htm_begin_success, htm_begin, htm_commit, htm_abort, htm_abort_should_retry): New. * configure.tgt: Add -mrtm to XCFLAGS. * method-serial.cc (htm_mg, o_htm_mg, htm_dispatch, dispatch_htm): New. (gtm_thread::serialirr_mode): Add HTM fastpath handling. * libitm_i.h (htm_fastpath, dispatch_htm): Declare. * retry.cc (parse_default_method): Add HTM method parsing. (gtm_thread::number_of_threads_changed): Use HTM by default if available. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@193369 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libitm/config/posix')
-rw-r--r--libitm/config/posix/rwlock.h10
1 files changed, 9 insertions, 1 deletions
diff --git a/libitm/config/posix/rwlock.h b/libitm/config/posix/rwlock.h
index a1a6042e562..79f14296df6 100644
--- a/libitm/config/posix/rwlock.h
+++ b/libitm/config/posix/rwlock.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2009, 2011 Free Software Foundation, Inc.
+/* Copyright (C) 2009, 2011, 2012 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@redhat.com>.
This file is part of the GNU Transactional Memory Library (libitm).
@@ -74,6 +74,14 @@ class gtm_rwlock
bool write_upgrade (gtm_thread *tx);
void write_upgrade_finish (gtm_thread *tx);
+ // Returns true iff there is a concurrent active or waiting writer.
+ // This is primarily useful for simple HyTM approaches, and the value being
+ // checked is loaded with memory_order_relaxed.
+ bool is_write_locked()
+ {
+ return summary.load (memory_order_relaxed) & (a_writer | w_writer);
+ }
+
protected:
bool write_lock_generic (gtm_thread *tx);
};