llvm/test/Transforms
Chandler Carruth 4f9a7277d1 [SROA] Apply a somewhat heavy and unpleasant hammer to fix PR22093, an
assert out of the new pre-splitting in SROA.

This fix makes the code do what was originally intended -- when we have
a store of a load both dealing in the same alloca, we force them to both
be pre-split with identical offsets. This is really quite hard to do
because we can keep discovering problems as we go along. We have to
track every load over the current alloca which for any resaon becomes
invalid for pre-splitting, and go back to remove all stores of those
loads. I've included a couple of test cases derived from PR22093 that
cover the different ways this can happen. While that PR only really
triggered the first of these two, its the same fundamental issue.

The other challenge here is documented in a FIXME now. We end up being
quite a bit more aggressive for pre-splitting when loads and stores
don't refer to the same alloca. This aggressiveness comes at the cost of
introducing potentially redundant loads. It isn't clear that this is the
right balance. It might be considerably better to require that we only
do pre-splitting when we can presplit every load and store involved in
the entire operation. That would give more consistent if conservative
results. Unfortunately, it requires a non-trivial change to the actual
pre-splitting operation in order to correctly handle cases where we end
up pre-splitting stores out-of-order. And it isn't 100% clear that this
is the right direction, although I'm starting to suspect that it is.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225149 91177308-0d34-0410-b5e6-96231b3b80d8
2015-01-05 04:17:53 +00:00
..
ADCE
AddDiscriminators IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
AlignmentFromAssumptions
ArgumentPromotion IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
AtomicExpand/ARM
BBVectorize IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
BranchFolding
CodeExtractor
CodeGenPrepare
ConstantHoisting
ConstantMerge
ConstProp
CorrelatedValuePropagation LazyValueInfo: Actually re-visit partially solved block-values in solveBlockValue() 2014-11-25 17:23:05 +00:00
DeadArgElim IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
DeadStoreElimination IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
EarlyCSE
FunctionAttrs
GCOVProfiling IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
GlobalDCE
GlobalOpt IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
GVN IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
IndVarSimplify Teach ScalarEvolution to exploit min and max expressions when proving 2014-12-15 22:50:15 +00:00
Inline IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
InstCombine InstCombine: match can find ConstantExprs, don't assume we have a Value 2015-01-04 07:36:02 +00:00
InstMerge Added 5 more tests related to sink store revision 224247 2014-12-17 08:12:59 +00:00
InstSimplify InstSimplify: Optimize away pointless comparisons 2014-12-20 03:04:38 +00:00
Internalize
IPConstantProp
JumpThreading ValueTracking: ComputeNumSignBits should tolerate misshapen phi nodes 2015-01-04 07:06:53 +00:00
LCSSA [LCSSA] Handle PHI insertion in disjoint loops 2014-12-22 22:35:46 +00:00
LICM Refine the notion of MayThrow in LICM to include a header specific version 2014-12-29 23:00:57 +00:00
LoadCombine
LoopDeletion
LoopIdiom IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
LoopReroll
LoopRotate IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
LoopSimplify
LoopStrengthReduce IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
LoopUnroll IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
LoopUnswitch
LoopVectorize Masked Load and Store Intrinsics in loop vectorizer. 2014-12-16 11:50:42 +00:00
LowerAtomic
LowerExpectIntrinsic IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
LowerInvoke
LowerSwitch
Mem2Reg IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
MemCpyOpt
MergeFunc IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
MetaRenamer
ObjCARC IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
PartiallyInlineLibCalls
PhaseOrdering
PruneEH
Reassociate Revert "[Reassociate] As the expression tree is rewritten make sure the operands are" 2014-11-19 23:21:20 +00:00
Reg2Mem
SampleProfile IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
Scalarizer IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
ScalarRepl IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
SCCP
SeparateConstOffsetFromGEP/NVPTX
SimplifyCFG [SimplifyCFG] Revise common code sinking 2014-12-23 08:26:55 +00:00
Sink
SLPVectorizer Revert 224119 "This patch recognizes (+ (+ v0, v1) (+ v2, v3)), reorders them for bundling into vector of loads, 2014-12-17 10:34:27 +00:00
SROA [SROA] Apply a somewhat heavy and unpleasant hammer to fix PR22093, an 2015-01-05 04:17:53 +00:00
StripSymbols IR: Make metadata typeless in assembly 2014-12-15 19:07:53 +00:00
StructurizeCFG StructurizeCFG: Use LoopInfo analysis for better loop detection 2014-12-03 04:28:32 +00:00
TailCallElim Fix tail recursion elimination 2014-11-19 13:32:51 +00:00
TailDup
Util [SwitchLowering] Handle destinations on multiple phi instructions 2014-12-02 18:31:53 +00:00