Chandler Carruth 1c49fda408 Fix a miscompile in the DAG combiner. Previously, we would incorrectly
try to reduce the width of this load, and would end up transforming:

  (truncate (lshr (sextload i48 <ptr> as i64), 32) to i32)
to
  (truncate (zextload i32 <ptr+4> as i64) to i32)

We lost the sext attached to the load while building the narrower i32
load, and replaced it with a zext because lshr always zext's the
results. Instead, bail out of this combine when there is a conflict
between a sextload and a zext narrowing. The rest of the DAG combiner
still optimize the code down to the proper single instruction:

  movswl 6(...),%eax

Which is exactly what we wanted. Previously we read past the end *and*
missed the sign extension:

  movl 6(...), %eax

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169802 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-11 00:36:57 +00:00
2012-11-19 19:31:02 +00:00
2012-12-10 21:33:45 +00:00
2012-12-11 00:23:07 +00:00
2012-10-09 23:48:34 +00:00
2012-11-19 19:31:02 +00:00
2012-11-29 21:17:26 +00:00
2012-11-14 22:13:56 +00:00
2012-11-29 16:19:11 +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 HTML documentation provided in docs/index.html for further
assistance with LLVM.

If you're writing a package for LLVM, see docs/Packaging.html 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%