Chandler Carruth c1a9c38190 [PM/AA] Remove the addEscapingUse update API that won't be easy to ... directly model in the new PM. This also was an incredibly brittle and expensive update API that was never fully utilized by all the passes that claimed to preserve AA, nor could it reasonably have been extended to all of them. Any number of places add uses of values. If we ever wanted to reliably instrument this, we would want a callback hook much like we have with ValueHandles, but doing this for every use addition seems *extremely* expensive in terms of compile time. The only user of this update mechanism is GlobalsModRef. The idea of using this to keep it up to date doesn't really work anyways as its analysis requires a symmetric analysis of two different memory locations. It would be very hard to make updates be sufficiently rigorous to *guarantee* symmetric analysis in this way, and it pretty certainly isn't true today. However, folks have been using GMR with this update for a long time and seem to not be hitting the issues. The reported issue that the update hook fixes isn't even a problem any more as other changes to GetUnderlyingObject worked around it, and that issue stemmed from *many* years ago. As a consequence, a prior patch provided a flag to control the unsafe behavior of GMR, and this patch removes the update mechanism that has questionable compile-time tradeoffs and is causing problems with moving to the new pass manager. Note the lack of test updates -- not one test in tree actually requires this update, even for a contrived case. All of this was extensively discussed on the dev list, this patch will just enact what that discussion decides on. I'm sending it for review in part to show what I'm planning, and in part to show the *amazing* amount of work this avoids. Every call to the AA here is something like three to six indirect function calls, which in the non-LTO pipeline never do any work! =[ Differential Revision: http://reviews.llvm.org/D11214 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242605 91177308-0d34-0410-b5e6-96231b3b80d8		2015-07-18 03:26:46 +00:00
..
ADCE.cpp	Revert the new EH instructions	2015-07-10 07:15:17 +00:00
AlignmentFromAssumptions.cpp
BDCE.cpp	Revert the new EH instructions	2015-07-10 07:15:17 +00:00
CMakeLists.txt
ConstantHoisting.cpp
ConstantProp.cpp
CorrelatedValuePropagation.cpp
DCE.cpp
DeadStoreElimination.cpp
EarlyCSE.cpp
FlattenCFGPass.cpp
Float2Int.cpp
GVN.cpp	[PM/AA] Remove the addEscapingUse update API that won't be easy to	2015-07-18 03:26:46 +00:00
InductiveRangeCheckElimination.cpp	Create a wrapper pass for BranchProbabilityInfo.	2015-07-15 22:48:29 +00:00
IndVarSimplify.cpp
JumpThreading.cpp	Revert the new EH instructions	2015-07-10 07:15:17 +00:00
LICM.cpp	[LICM] Don't try to sink values out of loops without any exits	2015-07-12 03:53:05 +00:00
LLVMBuild.txt
LoadCombine.cpp
LoopDeletion.cpp
LoopDistribute.cpp	[LAA] Introduce RuntimePointerChecking::PointerInfo, NFC	2015-07-14 22:32:50 +00:00
LoopIdiomRecognize.cpp	Loop idiom recognizer was replacing too many uses of popcount.	2015-07-13 21:25:33 +00:00
LoopInstSimplify.cpp
LoopInterchange.cpp	Avoid using Loop::getSubLoopsVector.	2015-07-13 17:21:14 +00:00
LoopRerollPass.cpp
LoopRotation.cpp
LoopStrengthReduce.cpp
LoopUnrollPass.cpp	[LoopUnrolling] Handle cast instructions.	2015-07-15 00:19:51 +00:00
LoopUnswitch.cpp	[LoopUnswitch] Add an else clause to IsTrivialUnswitchCondition() when checking HeaderTerm instruction type	2015-07-15 22:41:13 +00:00
LowerAtomic.cpp
LowerExpectIntrinsic.cpp
Makefile
MemCpyOptimizer.cpp
MergedLoadStoreMotion.cpp	[PM/AA] Remove the addEscapingUse update API that won't be easy to	2015-07-18 03:26:46 +00:00
NaryReassociate.cpp
PartiallyInlineLibCalls.cpp
PlaceSafepoints.cpp
Reassociate.cpp
Reg2Mem.cpp
RewriteStatepointsForGC.cpp
SampleProfile.cpp
Scalar.cpp
Scalarizer.cpp
ScalarReplAggregates.cpp
SCCP.cpp	Revert the new EH instructions	2015-07-10 07:15:17 +00:00
SeparateConstOffsetFromGEP.cpp
SimplifyCFGPass.cpp
Sink.cpp
SpeculativeExecution.cpp
SROA.cpp	[SROA] Don't de-atomic volatile loads and stores	2015-07-14 06:19:58 +00:00
StraightLineStrengthReduce.cpp
StructurizeCFG.cpp
TailRecursionElimination.cpp