llvm-6502/lib/Analysis
Chad Rosier 3ad549487e Avoid calls to dumpPassInfo and RegionBase<Tr>::getNameStr() in RGPassManager if
-debug-pass is not specified, as the string is only used when dumping pass
information.  There is a big cost of determining the name in
ReginBase<Tr>:getNameStr() if the region's entry or exit block doesn't have a
name.  This is the case for the Release build, as names are not preserved by the
front-end.

RegionPass is mainly used by Polly, resulting in long compile time for one file
of a customer application with the Release build (1m24s) vs Release+Asserts
build (10s) when Polly is used.  With this change, the compile time with the
Release build went down to 8s.

Patch by Sanjin Sijaric <ssijaric@codeaurora.org>!
Phabricator: http://reviews.llvm.org/D8076

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231485 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 16:15:04 +00:00
..
IPA Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasAnalysisCounter.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
AliasSetTracker.cpp
Analysis.cpp Remove the Forward Control Flow Integrity pass and its dependencies. 2015-02-27 19:03:38 +00:00
AssumptionCache.cpp [PM] Actually add the new pass manager support for the assumption cache. 2015-01-22 21:53:09 +00:00
BasicAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
BlockFrequencyInfo.cpp
BlockFrequencyInfoImpl.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp
CFLAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
CGSCCPassManager.cpp
CMakeLists.txt Remove the Forward Control Flow Integrity pass and its dependencies. 2015-02-27 19:03:38 +00:00
CodeMetrics.cpp
ConstantFolding.cpp
CostModel.cpp [multiversion] Thread a function argument through all the callers of the 2015-02-01 12:01:35 +00:00
Delinearization.cpp
DependenceAnalysis.cpp Reformat. 2015-03-05 01:25:19 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp InstSimplify: simplify 0 / X if nnan and nsz 2015-02-23 18:30:25 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LazyCallGraph.cpp
LazyValueInfo.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LibCallAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LibCallSemantics.cpp Unify the two EH personality classification routines I wrote 2015-02-14 00:21:02 +00:00
Lint.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LLVMBuild.txt
Loads.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LoopAccessAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp MemDepPrinter: Fix some nits introduced in r228596 2015-02-25 23:55:00 +00:00
MemDerefPrinter.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
ModuleDebugInfoPrinter.cpp DebugInfo: Move new hierarchy into place 2015-03-03 17:24:31 +00:00
NoAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp Avoid calls to dumpPassInfo and RegionBase<Tr>::getNameStr() in RGPassManager if 2015-03-06 16:15:04 +00:00
RegionPrinter.cpp
ScalarEvolution.cpp ScalarEvolution.cpp: Appease g++-4.7. He missed implicit "this" in lambda. 2015-03-05 01:02:45 +00:00
ScalarEvolutionAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
ScalarEvolutionExpander.cpp SCEVExpander incorrectly marks generated subtractions as nuw/nsw 2015-02-26 19:51:35 +00:00
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
SparsePropagation.cpp
StratifiedSets.h
TargetLibraryInfo.cpp Move TargetLibraryInfo data from two files into one common .def file. 2015-03-03 23:41:58 +00:00
TargetTransformInfo.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp Make DataLayout Non-Optional in the Module 2015-03-04 18:43:29 +00:00
ValueTracking.cpp Teach ComputeNumSignBits about signed reminder. 2015-03-06 00:23:58 +00:00

Analysis Opportunities:

//===---------------------------------------------------------------------===//

In test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll, the
ScalarEvolution expression for %r is this:

  {1,+,3,+,2}<loop>

Outside the loop, this could be evaluated simply as (%n * %n), however
ScalarEvolution currently evaluates it as

  (-2 + (2 * (trunc i65 (((zext i64 (-2 + %n) to i65) * (zext i64 (-1 + %n) to i65)) /u 2) to i64)) + (3 * %n))

In addition to being much more complicated, it involves i65 arithmetic,
which is very inefficient when expanded into code.

//===---------------------------------------------------------------------===//

In formatValue in test/CodeGen/X86/lsr-delayed-fold.ll,

ScalarEvolution is forming this expression:

((trunc i64 (-1 * %arg5) to i32) + (trunc i64 %arg5 to i32) + (-1 * (trunc i64 undef to i32)))

This could be folded to

(-1 * (trunc i64 undef to i32))

//===---------------------------------------------------------------------===//