llvm-capstone/llvm
Matthias Braun e48484c64f InstCombineSimplifyDemanded: Remove nsw/nuw flags when optimizing demanded bits
When optimizing demanded bits of the operands of an Add we have to
remove the nsw/nuw flags as we have no guarantee anymore that we don't
wrap.  This is legal here because the top bit is not demanded.  In fact
this operaion was already performed but missed in the case of an Add
with a constant on the right side.  To fix this this patch refactors the
code to unify the code paths in SimplifyDemandedUseBits() handling of
Add/Sub:

- The transformation of Add->Or is removed from the simplify demand
  code because the equivalent transformation exists in
  InstCombiner::visitAdd()
- KnownOnes/KnownZero are not adjusted for Add x, C anymore as
  computeKnownBits() already performs these computations.
- The simplification of the operands is unified. In this new version
  constant on the right side of a Sub are shrunk now as I could not find
  a reason why not to do so.
- The special case for clearing nsw/nuw in ShrinkDemandedConstant() is
  not necessary anymore as the caller does that already.

Differential Revision: http://reviews.llvm.org/D9415

llvm-svn: 236269
2015-04-30 22:05:30 +00:00
..
autoconf Clean up docs references to './configure' in preparation for deprecating in-source builds 2015-04-29 20:06:41 +00:00
bindings IR: Give 'DI' prefix to debug info metadata 2015-04-29 16:38:44 +00:00
cmake Allow building the gold plugin even if the gold binary is not found. 2015-04-27 21:08:47 +00:00
docs Add a note about permitting default member initializers 2015-04-30 18:17:12 +00:00
examples IR: Give 'DI' prefix to debug info metadata 2015-04-29 16:38:44 +00:00
include Exhaustively test all triples in TripleTest. 2015-04-30 20:08:44 +00:00
lib InstCombineSimplifyDemanded: Remove nsw/nuw flags when optimizing demanded bits 2015-04-30 22:05:30 +00:00
projects build: make libunwind a proper project 2015-04-25 01:47:39 +00:00
test InstCombineSimplifyDemanded: Remove nsw/nuw flags when optimizing demanded bits 2015-04-30 22:05:30 +00:00
tools For llvm-objdump, with the -archive-headers and -macho options, use the -non-verbose 2015-04-30 20:30:42 +00:00
unittests Exhaustively test all triples in TripleTest. 2015-04-30 20:08:44 +00:00
utils [NFC] Updating FileCheck to reduce the std::vector interface used via cl::list. 2015-04-29 21:45:24 +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 Ignore compile_commands.json only at the root of the tree. 2015-03-26 18:55:42 +00:00
CMakeLists.txt [CMake] Updates to llvm-shlib to support overriding exports list and added an option to export all symbols. 2015-04-13 21:29:46 +00:00
CODE_OWNERS.TXT Add myself as the Constant Folder owner. 2015-04-20 23:19:10 +00:00
configure Clean up docs references to './configure' in preparation for deprecating in-source builds 2015-04-29 20:06:41 +00:00
CREDITS.TXT
LICENSE.TXT Update for a new year. 2015-03-12 01:25:29 +00:00
llvm.spec.in
LLVMBuild.txt
Makefile
Makefile.common
Makefile.config.in Try to unbreak Clang build to export LLVM_ABI_BREAKING_CHECKS, fixup for r233310. 2015-04-01 11:46:15 +00:00
Makefile.rules Add support for SunOS function/data sections and associated 2015-03-03 20:54:29 +00:00
README.txt Revert test commit at revision 233535. 2015-03-30 12:39:03 +00:00

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

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