llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-17 18:31:04 +00:00

History

Chandler Carruth 5c1c0bd714 [PM] Add a definition for the static PassID in the CallGraphAnalysis. Missed this when adding the skeleton analysis. Caught by a build break in the next patch I'm working on when trying to use the analysis. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198556 91177308-0d34-0410-b5e6-96231b3b80d8		2014-01-05 10:38:52 +00:00
..
IPA	[PM] Add a definition for the static PassID in the CallGraphAnalysis.	2014-01-05 10:38:52 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp	BasicAA: Use reachabilty instead of dominance for checking value equality in phi	2014-01-03 05:47:03 +00:00
BlockFrequencyInfo.cpp	BlockFrequencyInfo: Readded getEntryFreq.	2013-12-20 22:11:11 +00:00
BranchProbabilityInfo.cpp	[block-freq] Teach branch probability how to return the edge weight in between a BasicBlock and one of its successors.	2013-12-14 02:24:25 +00:00
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp
CMakeLists.txt
CodeMetrics.cpp
ConstantFolding.cpp	Add addrspacecast instruction.	2013-11-15 01:34:59 +00:00
CostModel.cpp
Delinearization.cpp	add more comments around the delinearization of arrays	2013-11-13 22:37:58 +00:00
DependenceAnalysis.cpp	add more comments around the delinearization of arrays	2013-11-13 22:37:58 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp	Fix typo.	2013-12-04 23:55:09 +00:00
MemoryBuiltins.cpp	Teach MemoryBuiltins about address spaces	2013-12-14 00:27:48 +00:00
MemoryDependenceAnalysis.cpp	Fixing a heisenbug where the memory dependence analysis behaves differently	2013-11-14 01:10:52 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp	Correct word hyphenations	2013-12-05 05:44:44 +00:00
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	Annotate APInt methods where it's not clear whether they are in place with warn_unused_result.	2013-11-16 16:25:41 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	Don't #include heavy Dominators.h file in LoopInfo.h. This change reduces	2013-12-07 21:20:17 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
TargetTransformInfo.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	Don't speculate loads under ThreadSanitizer	2013-11-21 07:29:28 +00:00

README.txt

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))

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