llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-10-07 05:55:44 +00:00

History

Eric Christopher 0115a4ef95 Remove unnecessary llvm:: qualification. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202316 91177308-0d34-0410-b5e6-96231b3b80d8		2014-02-26 23:27:16 +00:00
..
IPA	Remove unnecessary llvm:: qualification.	2014-02-26 23:27:16 +00:00
AliasAnalysis.cpp	Make DataLayout a plain object, not a pass.	2014-02-25 17:30:31 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp	Rename a few more DataLayout variables from TD to DL.	2014-02-21 18:34:28 +00:00
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp	Replace the F_Binary flag with a F_Text one.	2014-02-24 18:20:12 +00:00
CMakeLists.txt
CodeMetrics.cpp
ConstantFolding.cpp
CostModel.cpp
Delinearization.cpp
DependenceAnalysis.cpp	normalize the last delinearized dimension	2014-02-21 18:15:11 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp	Rename many DataLayout variables from TD to DL.	2014-02-21 00:06:31 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	Make DataLayout a plain object, not a pass.	2014-02-25 17:30:31 +00:00
LazyCallGraph.cpp
LazyValueInfo.cpp	Make DataLayout a plain object, not a pass.	2014-02-25 17:30:31 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	Make DataLayout a plain object, not a pass.	2014-02-25 17:30:31 +00:00
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp	Constify the Optnone checks in IR passes.	2014-02-26 01:23:26 +00:00
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	Make DataLayout a plain object, not a pass.	2014-02-25 17:30:31 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp	Make DataLayout a plain object, not a pass.	2014-02-25 17:30:31 +00:00
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	Make DataLayout a plain object, not a pass.	2014-02-25 17:30:31 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
TargetTransformInfo.cpp	Make DataLayout a plain object, not a pass.	2014-02-25 17:30:31 +00:00
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))

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