LLVM backend for 6502
Go to file
Hal Finkel 8f609696e0 Improve BasicAA CS-CS queries (redux)
This reverts, "r213024 - Revert r212572 "improve BasicAA CS-CS queries", it
causes PR20303." with a fix for the bug in pr20303. As it turned out, the
relevant code was both wrong and over-conservative (because, as with the code
it replaced, it would return the overall ModRef mask even if just Ref had been
implied by the argument aliasing results). Hopefully, this correctly fixes both
problems.

Thanks to Nick Lewycky for reducing the test case for pr20303 (which I've
cleaned up a little and added in DSE's test directory). The BasicAA test has
also been updated to check for this error.

Original commit message:

BasicAA contains knowledge of certain intrinsics, such as memcpy and memset,
and uses that information to form more-accurate answers to CallSite vs. Loc
ModRef queries. Unfortunately, it did not use this information when answering
CallSite vs. CallSite queries.

Generically, when an intrinsic takes one or more pointers and the intrinsic is
marked only to read/write from its arguments, the offset/size is unknown. As a
result, the generic code that answers CallSite vs. CallSite (and CallSite vs.
Loc) queries in AA uses UnknownSize when forming Locs from an intrinsic's
arguments. While BasicAA's CallSite vs. Loc override could use more-accurate
size information for some intrinsics, it did not do the same for CallSite vs.
CallSite queries.

This change refactors the intrinsic-specific logic in BasicAA into a generic AA
query function: getArgLocation, which is overridden by BasicAA to supply the
intrinsic-specific knowledge, and used by AA's generic implementation. This
allows the intrinsic-specific knowledge to be used by both CallSite vs. Loc and
CallSite vs. CallSite queries, and simplifies the BasicAA implementation.

Currently, only one function, Mac's memset_pattern16, is handled by BasicAA
(all the rest are intrinsics). As a side-effect of this refactoring, BasicAA's
getModRefBehavior override now also returns OnlyAccessesArgumentPointees for
this function (which is an improvement).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213219 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-17 01:28:25 +00:00
autoconf Track clang r213171 2014-07-16 16:50:34 +00:00
bindings [OCaml] Documentation improvements. 2014-07-02 22:17:20 +00:00
cmake CMake: avoid a reconfigure loop from r213091 2014-07-15 22:11:54 +00:00
docs Fix a typo in the inalloca description 2014-07-16 21:22:46 +00:00
examples [CMake] Update libdeps. 2014-07-14 05:01:53 +00:00
include Improve BasicAA CS-CS queries (redux) 2014-07-17 01:28:25 +00:00
lib Improve BasicAA CS-CS queries (redux) 2014-07-17 01:28:25 +00:00
projects Remove projects/sample. 2014-03-12 22:40:22 +00:00
test Improve BasicAA CS-CS queries (redux) 2014-07-17 01:28:25 +00:00
tools Add the "-x" flag to llvm-nm for Mach-O files that prints the fields of a symbol in hex. 2014-07-16 17:38:26 +00:00
unittests unittests: Actually test reverse iterators in Path tests 2014-07-16 08:18:58 +00:00
utils Move Post RA Scheduling flag bit into SchedMachineModel 2014-07-15 22:39:58 +00:00
.arcconfig Updated phabricator server. 2014-04-07 03:57:04 +00:00
.clang-format Test commit. 2014-03-02 13:08:46 +00:00
.gitignore Add Polly to the ignored trees. 2014-06-25 13:13:36 +00:00
CMakeLists.txt [CMake] Introduce LLVM_SHLIB_OUTPUT_INTDIR. 2014-07-04 04:23:26 +00:00
CODE_OWNERS.TXT ARM Linux support 2014-04-02 23:03:28 +00:00
configure Touch configure to force clang's config.h.in reconfiguration on the build servers 2014-06-06 10:36:38 +00:00
CREDITS.TXT Update Credits. 2014-05-29 19:59:58 +00:00
LICENSE.TXT Remove projects/sample. 2014-03-12 22:40:22 +00:00
llvm.spec.in
LLVMBuild.txt Remove the very substantial, largely unmaintained legacy PGO 2013-10-02 15:42:23 +00:00
Makefile [configure/make] Propagate names of build host tools when making BuildTools 2014-03-25 21:45:41 +00:00
Makefile.common Makefile.common: Update a description, s/Source/SOURCES/ , according to MakefileGuide.html#control-variables . 2012-12-07 01:43:23 +00:00
Makefile.config.in Track clang r213171 2014-07-16 16:50:34 +00:00
Makefile.rules [Make] Fix dependencies for td.expanded 2014-06-20 19:00:41 +00:00
README.txt Trivial test commit. 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.