llvm-6502

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

History

Chandler Carruth 5a2d01e5b8 [PM] Now that LoopInfo isn't in the Pass type hierarchy, it is much cleaner to derive from the generic base. Thise removes a ton of boiler plate code and somewhat strange and pointless indirections. It also remove a bunch of the previously needed friend declarations. To fully remove these, I also lifted the verify logic into the generic LoopInfoBase, which seems good anyways -- it is generic and useful logic even for the machine side. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226385 91177308-0d34-0410-b5e6-96231b3b80d8		2015-01-18 01:25:51 +00:00
..
IPA
AliasAnalysis.cpp	[PM] Separate the TargetLibraryInfo object from the immutable pass.	2015-01-15 10:41:28 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
AssumptionCache.cpp
BasicAliasAnalysis.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
BlockFrequencyInfo.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
BlockFrequencyInfoImpl.cpp
BranchProbabilityInfo.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp
CFLAliasAnalysis.cpp
CGSCCPassManager.cpp
CMakeLists.txt	[PM] Move TargetLibraryInfo into the Analysis library.	2015-01-15 02:16:27 +00:00
CodeMetrics.cpp
ConstantFolding.cpp	[PM] Move TargetLibraryInfo into the Analysis library.	2015-01-15 02:16:27 +00:00
CostModel.cpp
Delinearization.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
DependenceAnalysis.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
FunctionTargetTransformInfo.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
JumpInstrTableInfo.cpp
LazyCallGraph.cpp
LazyValueInfo.cpp	[PM] Separate the TargetLibraryInfo object from the immutable pass.	2015-01-15 10:41:28 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	[PM] Separate the TargetLibraryInfo object from the immutable pass.	2015-01-15 10:41:28 +00:00
LLVMBuild.txt	Update libdeps since TLI was moved from Target to Analysis in r226078.	2015-01-15 05:21:00 +00:00
Loads.cpp
LoopInfo.cpp	[PM] Now that LoopInfo isn't in the Pass type hierarchy, it is much	2015-01-18 01:25:51 +00:00
LoopPass.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp	[PM] Move TargetLibraryInfo into the Analysis library.	2015-01-15 02:16:27 +00:00
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	[PM] Split the LoopInfo object apart from the legacy pass, creating	2015-01-17 14:16:18 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp
SparsePropagation.cpp
StratifiedSets.h
TargetLibraryInfo.cpp	[PM] Port TargetLibraryInfo to the new pass manager, provided by the	2015-01-15 11:39:46 +00:00
TargetTransformInfo.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp

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))

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