Wei Mi e35a5f5518 [SCEV] Add a local cache for getZeroExtendExpr and getSignExtendExpr to prevent ...

the exponential behavior.

The patch is to fix PR32043. Functions getZeroExtendExpr and getSignExtendExpr
may call themselves recursively more than once. This is potentially a 2^N
complexity behavior. The exponential behavior was not commonly exposed before
because of existing global cache mechnism like UniqueSCEVs or some early return
mechanism when flags FlagNSW or FlagNUW are seen. However, we still have case
which can expose the exponential behavior, like the case in PR32043, so we add
a local cache in getZeroExtendExpr and getSignExtendExpr. If the input of the
functions -- SCEV and type pair have been seen before, we can find the extended
expression directly in the local cache.

Differential Revision: https://reviews.llvm.org/D30350


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300494 91177308-0d34-0410-b5e6-96231b3b80d8

2017-04-17 20:40:05 +00:00

..

AliasAnalysisTest.cpp

Revert @llvm.assume with operator bundles (r289755-r289757)

2016-12-19 08:22:17 +00:00

BlockFrequencyInfoTest.cpp

Add an interface to scale the frequencies of a set of blocks.

2017-01-19 18:53:16 +00:00

BranchProbabilityInfoTest.cpp

Retry: [BPI] Use a safer constructor to calculate branch probabilities

2016-12-17 01:02:08 +00:00

CallGraphTest.cpp

[GraphTraits] Replace all NodeType usage with NodeRef

2016-08-22 21:09:30 +00:00

CFGTest.cpp

…

CGSCCPassManagerTest.cpp

[PM] Introduce the facilities for registering cross-IR-unit dependencies

2016-12-27 08:40:39 +00:00

CMakeLists.txt

MemorySSA: Move to Analysis, from Transforms/Utils. It's used as

2017-04-11 20:06:36 +00:00

LazyCallGraphTest.cpp

Fix signed/unsigned comparison warnings

2017-03-11 13:02:31 +00:00

LoopInfoTest.cpp

[LoopInfo] Add helper methods to compute two useful orderings of the

2017-01-20 02:41:20 +00:00

MemoryBuiltinsTest.cpp

Don't consider allocsize functions to be allocation functions.

2016-12-23 01:18:09 +00:00

MemorySSA.cpp

MemorySSA: Move to Analysis, from Transforms/Utils. It's used as

2017-04-11 20:06:36 +00:00

ProfileSummaryInfoTest.cpp

Refactor the PSI to extract getCallSiteCount and remove checks for profile type.

2017-03-10 19:45:16 +00:00

ScalarEvolutionTest.cpp

[SCEV] Add a local cache for getZeroExtendExpr and getSignExtendExpr to prevent

2017-04-17 20:40:05 +00:00

TargetLibraryInfoTest.cpp

[Analysis] Add LibFunc_ prefix to enums in TargetLibraryInfo. (NFC)

2017-01-23 23:16:46 +00:00

TBAATest.cpp

[TBAA] Don't generate invalid TBAA when merging nodes

2016-12-11 20:07:25 +00:00

UnrollAnalyzer.cpp

Delete a dead argument. NFC

2017-01-15 19:53:59 +00:00

ValueTrackingTest.cpp

[ValueTracking] Avoid undefined behavior in unittest by not making a named ArrayRef from a std::initializer_list

2017-04-14 17:59:19 +00:00