Robin Morisset 79826e015e Lower idempotent RMWs to fence+load
Summary:
I originally tried doing this specifically for X86 in the backend in D5091,
but it was rather brittle and generally running too late to be general.
Furthermore, other targets may want to implement similar optimizations.
So I reimplemented it at the IR-level, fitting it into AtomicExpandPass
as it interacts with that pass (which could not be cleanly done before
at the backend level).

This optimization relies on a new target hook, which is only used by X86
for now, as the correctness of the optimization on other targets remains
an open question. If it is found correct on other targets, it should be
trivial to enable for them.

Details of the optimization are discussed in D5091.

Test Plan: make check-all + a new test

Reviewers: jfb

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5422

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218455 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-25 17:27:43 +00:00
2014-08-14 15:15:09 +00:00
2014-09-02 22:28:02 +00:00
2014-09-12 11:08:59 +00:00
2014-09-25 17:27:43 +00:00
2014-09-25 17:27:43 +00:00
2014-04-07 03:57:04 +00:00
2014-06-25 13:13:36 +00:00
2014-08-14 15:15:09 +00:00
2014-07-16 16:50:34 +00:00
2014-04-26 19:05:45 +00:00

Low Level Virtual Machine (LLVM)
================================

This directory and its subdirectories contain source code for the Low Level
Virtual Machine, a toolkit for the construction of highly optimized compilers,
optimizers, and runtime environments.

LLVM is open source software. You may freely distribute it under the terms of
the license agreement found in LICENSE.txt.

Please see the documentation provided in docs/ for further
assistance with LLVM, and in particular docs/GettingStarted.rst for getting
started with LLVM and docs/README.txt for an overview of LLVM's
documentation setup.

If you're writing a package for LLVM, see docs/Packaging.rst for our
suggestions.
Description
LLVM backend for 6502
Readme 277 MiB
Languages
C++ 48.7%
LLVM 38.5%
Assembly 10.2%
C 0.9%
Python 0.4%
Other 1.2%