llvm-project/llvm
Chandler Carruth cd8522ef44 [canonicalize] Teach InstCombine to canonicalize loads which are only
ever stored to always use a legal integer type if one is available.

Regardless of whether this particular type is good or bad, it ensures we
don't get weird differences in generated code (and resulting
performance) from "equivalent" patterns that happen to end up using
a slightly different type.

After some discussion on llvmdev it seems everyone generally likes this
canonicalization. However, there may be some parts of LLVM that handle
it poorly and need to be fixed. I have at least verified that this
doesn't impede GVN and instcombine's store-to-load forwarding powers in
any obvious cases. Subtle cases are exactly what we need te flush out if
they remain.

Also note that this IR pattern should already be hitting LLVM from Clang
at least because it is exactly the IR which would be produced if you
used memcpy to copy a pointer or floating point between memory instead
of a variable.

llvm-svn: 226781
2015-01-22 05:08:12 +00:00
..
autoconf Trunk is now 3.7.0svn 2015-01-14 17:38:03 +00:00
bindings IR: Return unique_ptr from MDNode::getTemporary() 2015-01-19 21:30:18 +00:00
cmake Don't pass -Wl,z,defs for now. 2015-01-20 22:08:20 +00:00
docs Explicitly describe '///' versus '//' comment delimiters. 2015-01-22 00:19:56 +00:00
examples Reorder. 2015-01-19 00:35:33 +00:00
include ARM: fail less catastrophically on invalid Windows input 2015-01-22 04:03:32 +00:00
lib [canonicalize] Teach InstCombine to canonicalize loads which are only 2015-01-22 05:08:12 +00:00
projects
test [canonicalize] Teach InstCombine to canonicalize loads which are only 2015-01-22 05:08:12 +00:00
tools Assigning and copying command line option objects shouldn't be allowed. 2015-01-22 01:49:59 +00:00
unittests Adding a new cl::HideUnrelatedOptions API to allow clang to migrate off cl::getRegisteredOptions. 2015-01-21 22:45:52 +00:00
utils [lit] Format JSONMetricValue strings better. 2015-01-21 16:38:31 +00:00
.arcconfig
.clang-format
.clang-tidy Enable display of compiler diagnostics in clang-tidy by default. 2014-10-29 17:29:38 +00:00
.gitignore .gitignore: add some rules for tagging programs 2015-01-10 19:11:29 +00:00
CMakeLists.txt Trunk is now 3.7.0svn 2015-01-14 17:38:03 +00:00
CODE_OWNERS.TXT Add myself as SystemZ code owner 2014-12-18 19:27:50 +00:00
CREDITS.TXT
LICENSE.TXT
LLVMBuild.txt
Makefile
Makefile.common
Makefile.config.in Add a check for misbehaving -Wcomment from gcc-4.7 and add 2014-11-05 00:35:15 +00:00
Makefile.rules Add a check for misbehaving -Wcomment from gcc-4.7 and add 2014-11-05 00:35:15 +00:00
README.txt Check commit access 2015-01-16 19:23:34 +00:00
configure Trunk is now 3.7.0svn 2015-01-14 17:38:03 +00:00
llvm.spec.in

README.txt

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

This directory and its subdirectories contain source code for LLVM,
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.