Owen Anderson a04a0649e1 Completely rework the datastructure GVN uses to represent the value number to leader mapping. Previously, ... this was a tree of hashtables, and a query recursed into the table for the immediate dominator ad infinitum if the initial lookup failed. This led to really bad performance on tall, narrow CFGs. We can instead replace it with what is conceptually a multimap of value numbers to leaders (actually represented by a hashtable with a list of Value*'s as the value type), and then determine which leader from that set to use very cheaply thanks to the DFS numberings maintained by DominatorTree. Because there are typically few duplicates of a given value, this scan tends to be quite fast. Additionally, we use a custom linked list and BumpPtr allocation to avoid any unnecessary allocation in representing the value-side of the multimap. This change brings with it a 15% (!) improvement in the total running time of GVN on 403.gcc, which I think is pretty good considering that includes all the "real work" being done by MemDep as well. The one downside to this approach is that we can no longer use GVN to perform simple conditional progation, but that seems like an acceptable loss since we now have LVI and CorrelatedValuePropagation to pick up the slack. If you see conditional propagation that's not happening, please file bugs against LVI or CVP. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119714 91177308-0d34-0410-b5e6-96231b3b80d8		2010-11-18 18:32:40 +00:00
..
ADCE.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
BasicBlockPlacement.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
CMakeLists.txt	Update CMake.	2010-10-08 02:30:03 +00:00
CodeGenPrepare.cpp	Inline asm multiple alternative constraints development phase 2 - improved basic logic, added initial platform support.	2010-10-29 17:29:13 +00:00
ConstantProp.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
CorrelatedValuePropagation.cpp	Have a few places that want to simplify phi nodes use SimplifyInstruction	2010-11-16 17:41:24 +00:00
DCE.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
DeadStoreElimination.cpp	Enhance DSE to handle the case where a free call makes more than	2010-11-12 02:19:17 +00:00
GEPSplitter.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
GVN.cpp	Completely rework the datastructure GVN uses to represent the value number to leader mapping. Previously,	2010-11-18 18:32:40 +00:00
IndVarSimplify.cpp	Move SCEV::isLoopInvariant and hasComputableLoopEvolution to be member	2010-11-17 21:23:15 +00:00
JumpThreading.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
LICM.cpp	Reference ScalarEvolution by name rather than directly in LICM,	2010-11-17 20:50:07 +00:00
LoopDeletion.cpp	Passes do not need to recursively initialize passes that they preserve, if	2010-10-19 20:08:44 +00:00
LoopRotation.cpp	Passes do not need to recursively initialize passes that they preserve, if	2010-10-19 20:08:44 +00:00
LoopStrengthReduce.cpp	Move SCEV::dominates and properlyDominates to ScalarEvolution.	2010-11-17 21:41:58 +00:00
LoopUnrollPass.cpp	Passes do not need to recursively initialize passes that they preserve, if	2010-10-19 20:08:44 +00:00
LoopUnswitch.cpp	If dom tree information is available, make it possible to pass	2010-11-14 18:36:10 +00:00
LowerAtomic.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
Makefile
MemCpyOptimizer.cpp	slightly simplify code and substantially improve comment. Instead of	2010-11-18 08:07:09 +00:00
Reassociate.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
Reg2Mem.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
Scalar.cpp	Remove LoopIndexSplit pass. It is neither maintained nor used by anyone.	2010-10-07 23:29:37 +00:00
ScalarReplAggregates.cpp	finish a thought.	2010-11-18 07:32:33 +00:00
SCCP.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
SimplifyCFGPass.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
SimplifyHalfPowrLibCalls.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
SimplifyLibCalls.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
Sink.cpp	Add helper functions for computing the Location of load, store,	2010-11-11 21:50:19 +00:00
TailDuplication.cpp	Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which	2010-10-19 17:21:58 +00:00
TailRecursionElimination.cpp	Have a few places that want to simplify phi nodes use SimplifyInstruction	2010-11-16 17:41:24 +00:00