LLVM backend for 6502
Go to file
Chandler Carruth 92ffb676af Disable transforms that introduce calls to exp10*() on Linux due to
widespread glibc bugs.

The glibc implementation of exp10 has a very serious precision bug in
version 2.15 (and older versions). This is still very widely used (the
current Ubuntu LTS for example uses it) and so it isn't reasonable to
make transforms that produce these functions. This fixes many
miscompiles introduced when we started transforming pow(10.0, ...) into
exp10, and it may have fixed other latent miscompiles where exp10
provided sufficient precision but exp10f did not.

This is all really horrible. The primary bug has been fixed for over
a year and glibc 2.18 works correctly for the test cases I have, but it
will be 2017 before the LTS using 2.15 is no longer supported by Ubuntu
(and thus reasonable for folks to be relying on). =[ We're either going
to need to live without these optimizations, or find a way to switch
behavior more dynamically than using simply the fact that the OS is
"Linux".

To make matters worse, there appears to be significant testing and
fixing of numerous other bugs in the exp10 family of functions right now
in glibc. While those haven't been causing problems I've seen in the
wild, it gives me concerns that we may need to wait until an even later
release of glibc before we can reliably transform code into exp10.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198093 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-28 02:40:19 +00:00
autoconf Update to reflect the next release. 2013-11-20 10:10:50 +00:00
bindings Makefile.ocaml: Tweak to use --system-libs. 2013-12-20 00:36:59 +00:00
cmake Fix documentation typos 2013-12-20 00:33:39 +00:00
docs Remove link to unexisting llvm-prof docs 2013-12-24 19:58:49 +00:00
examples [CMake] Update LLVM_LINK_COMPONENTS for each CMakeLists.txt. 2013-12-10 11:13:32 +00:00
include Remove AsmPrinter::needsRelocationsForDwarfStringPool() since it's 2013-12-28 01:39:17 +00:00
lib Disable transforms that introduce calls to exp10*() on Linux due to 2013-12-28 02:40:19 +00:00
projects Revert "Revert "Windows: Add support for unicode command lines"" 2013-10-07 01:00:07 +00:00
test Disable transforms that introduce calls to exp10*() on Linux due to 2013-12-28 02:40:19 +00:00
tools Strip dead code when linking by default with BFD ld (linux, ...) and ld64 (os x). 2013-12-27 22:38:59 +00:00
unittests Attempt to fix JIT unit tests after r198087. 2013-12-27 23:36:22 +00:00
utils AVX-512: decoder for AVX-512, made by Alexey Bader. 2013-12-25 11:40:51 +00:00
.arcconfig Add .arcconfig to the repository. Useful if someone wants to use phabricator's command line tool. 2012-12-01 12:07:58 +00:00
.clang-format Add a clang-format file so that the tool can automatically detect the 2013-09-02 07:19:04 +00:00
.gitignore Add extra vim swap file pattern 2012-10-09 23:48:34 +00:00
CMakeLists.txt Resinstate the command line taking priority over CMakeLists in setting CMAKE_INSTALL_RPATH 2013-12-20 18:13:12 +00:00
CODE_OWNERS.TXT Update email address. 2013-12-04 09:42:49 +00:00
configure Update to reflect the next release. 2013-11-20 10:10:50 +00:00
CREDITS.TXT Fix documentation typos 2013-12-20 00:33:39 +00:00
LICENSE.TXT Be more specific and capitalize filenames. 2013-05-21 21:22:34 +00:00
llvm.spec.in
LLVMBuild.txt Remove the very substantial, largely unmaintained legacy PGO 2013-10-02 15:42:23 +00:00
Makefile llvm-config: Fixup r197380, tweak for cross compilation. SYSTEM_LIBS should be --host's in BuildTools/llvm-config. 2013-12-16 13:09:06 +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 Add an autoconf option for turning on -gsplit-dwarf by default 2013-06-25 01:12:25 +00:00
Makefile.rules Strip dead code when linking by default with BFD ld (linux, ...) and ld64 (os x). 2013-12-27 22:38:59 +00:00
README.txt Revert "Test commit to check e-mail address. Please discard this." 2013-10-04 10:59:13 +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.