llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-04 22:07:27 +00:00

History

Benjamin Kramer 740cc2672a Simplify code. No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219082 91177308-0d34-0410-b5e6-96231b3b80d8		2014-10-05 12:21:57 +00:00
..
IPA
AliasAnalysis.cpp	Make AAMDNodes ctor and operator bool (!!!) explicit, mop up bugs and weirdness exposed by it.	2014-10-04 22:44:29 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
AssumptionTracker.cpp
BasicAliasAnalysis.cpp	Make AAMDNodes ctor and operator bool (!!!) explicit, mop up bugs and weirdness exposed by it.	2014-10-04 22:44:29 +00:00
BlockFrequencyInfo.cpp
BlockFrequencyInfoImpl.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp
CFLAliasAnalysis.cpp	Adds 'override' to overriding methods. NFC.	2014-10-01 21:00:44 +00:00
CGSCCPassManager.cpp
CMakeLists.txt
CodeMetrics.cpp
ConstantFolding.cpp	Remove duplicate function names from comments. NFC.	2014-10-02 15:13:22 +00:00
CostModel.cpp
Delinearization.cpp
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
FunctionTargetTransformInfo.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
JumpInstrTableInfo.cpp
LazyCallGraph.cpp
LazyValueInfo.cpp	Revert r215343.	2014-10-03 09:29:24 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp	PR21145: Teach LLVM about C++14 sized deallocation functions.	2014-10-03 20:17:06 +00:00
MemoryDependenceAnalysis.cpp	Silence a -Wsign-compare warning. NFC.	2014-10-02 13:17:11 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp	Simplify code. No functionality change.	2014-10-05 12:21:57 +00:00
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp
SparsePropagation.cpp
StratifiedSets.h
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))

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