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Cameron Zwarich 8252ad1351 Speed up dominator computation some more by optimizing bucket processing. When
naively implemented, the Lengauer-Tarjan algorithm requires a separate bucket
for each vertex. However, this is unnecessary, because each vertex is only
placed into a single bucket (that of its semidominator), and each vertex's
bucket is processed before it is added to any bucket itself.

Instead of using a bucket per vertex, we use a single array Buckets that has two
purposes. Before the vertex V with DFS number i is processed, Buckets[i] stores
the index of the first element in V's bucket. After V's bucket is processed,
Buckets[i] stores the index of the next element in the bucket to which V now
belongs, if any.

Reading from the buckets can also be optimized. Instead of processing the bucket
of V's parent at the end of processing V, we process the bucket of V itself at
the beginning of processing V. This means that the case of the root vertex can
be simplified somewhat. It also means that we don't need to look up the DFS
number of the semidominator of every node in the bucket we are processing,
since we know it is the current index being processed.

This is a 6.5% speedup running -domtree on test-suite + SPEC2000/2006, with
larger speedups of around 12% on the larger benchmarks like GCC.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122680 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:03:00 +00:00
autoconf autoconf: Add --disable-embed-stdcxx to suppress linking libstdc++.a into llvm.dll with --enable-shared on Cygming. 2010-12-29 03:59:14 +00:00
bindings Fix OCaml bindings crash, PR8847. 2010-12-23 15:49:26 +00:00
cmake CMake (MSVC): cmake automatically adds the /EHsc and /GR compiler 2010-12-31 19:10:49 +00:00
docs Correct a bunch of mistakes which meant that the example pass didn't 2011-01-01 17:37:07 +00:00
examples Do not re-test for the existence of pthread.h. 2010-12-23 21:27:22 +00:00
include Speed up dominator computation some more by optimizing bucket processing. When 2011-01-02 07:03:00 +00:00
lib teach loop idiom recognition to form memcpy's from simple loops. 2011-01-02 03:37:56 +00:00
projects Regen configure 2010-12-12 21:42:01 +00:00
runtime Rename 'libprofile/exported_symbols.lst' to 'libprofile/libprofile.exports'. 2010-09-03 15:42:45 +00:00
test teach loop idiom recognition to form memcpy's from simple loops. 2011-01-02 03:37:56 +00:00
tools autoconf: Add --disable-embed-stdcxx to suppress linking libstdc++.a into llvm.dll with --enable-shared on Cygming. 2010-12-29 03:59:14 +00:00
unittests fix PR8867: a crash handling fp128. Thanks to Nick for the testcase. 2010-12-29 01:33:36 +00:00
utils Trailing whitespace. 2010-12-24 05:06:32 +00:00
website
.gitignore Cleanup and document .gitignore. 2010-12-17 17:22:50 +00:00
build-for-llvm-top.sh Patch to build llvm with srcdir != objdir from 2009-01-23 08:42:38 +00:00
CMakeLists.txt New cmake option LLVM_APPEND_VC_REV for controlling when the VC 2010-12-20 09:47:13 +00:00
configure autoconf: Add --disable-embed-stdcxx to suppress linking libstdc++.a into llvm.dll with --enable-shared on Cygming. 2010-12-29 03:59:14 +00:00
CREDITS.TXT Another git svn dcommit test. This time let's hope it doesn't kill my repo. 2010-12-10 14:45:10 +00:00
LICENSE.TXT 2010 is upon us. 2010-01-09 18:40:31 +00:00
llvm.spec.in
Makefile Merge System into Support. 2010-11-29 18:16:10 +00:00
Makefile.common Removed trailing whitespace from Makefiles. 2009-01-09 16:44:42 +00:00
Makefile.config.in autoconf: Add --disable-embed-stdcxx to suppress linking libstdc++.a into llvm.dll with --enable-shared on Cygming. 2010-12-29 03:59:14 +00:00
Makefile.rules build: Shared libraries shouldn't used RPATH on Darwin, only main executables 2010-12-08 02:29:26 +00:00
ModuleInfo.txt Remove trailing space. This is just an excuse to poke the 2010-10-05 20:32:15 +00:00
README.txt Undoing test commit blank space. 2010-09-29 17:39:29 +00:00

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