llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-10-02 17:55:18 +00:00

History

Benjamin Kramer 563e8fce2e DependenceAnalysis: Print all dependency pairs when dumping. Update all testcases. Part of a patch by Preston Briggs. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167827 91177308-0d34-0410-b5e6-96231b3b80d8		2012-11-13 12:12:02 +00:00
..
IPA
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp	Add a cost model analysis that allows us to estimate the cost of IR-level instructions.	2012-11-02 21:48:17 +00:00
BasicAliasAnalysis.cpp	Don't infer whether a value is captured in the current function from the	2012-11-05 10:48:24 +00:00
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt	Add a cost model analysis that allows us to estimate the cost of IR-level instructions.	2012-11-02 21:48:17 +00:00
CodeMetrics.cpp	Revert the majority of the next patch in the address space series:	2012-11-01 09:14:31 +00:00
ConstantFolding.cpp	llvm/ConstantFolding.cpp: Make ReadDataFromGlobal() and FoldReinterpretLoadFromConstPtr() Big-endian-aware.	2012-11-08 20:34:25 +00:00
CostModel.cpp	CostModel: add support for Vector Insert and Extract.	2012-11-02 22:31:56 +00:00
DbgInfoPrinter.cpp
DependenceAnalysis.cpp	DependenceAnalysis: Print all dependency pairs when dumping. Update all testcases.	2012-11-13 12:12:02 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InlineCost.cpp	Revert the majority of the next patch in the address space series:	2012-11-01 09:14:31 +00:00
InstCount.cpp
InstructionSimplify.cpp	Revert the majority of the next patch in the address space series:	2012-11-01 09:14:31 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp	Hoist out some work done inside a loop doing a linear scan over all	2012-10-26 04:43:47 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	Revert the series of commits starting with r166578 which introduced the	2012-11-01 08:07:29 +00:00
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp	Revert the series of commits starting with r166578 which introduced the	2012-11-01 08:07:29 +00:00
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PathNumbering.cpp
PathProfileInfo.cpp
PathProfileVerifier.cpp
PHITransAddr.cpp
PostDominators.cpp
ProfileDataLoader.cpp	Remove code to saturate profile counts.	2012-10-29 17:27:39 +00:00
ProfileDataLoaderPass.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	Revert the series of commits starting with r166578 which introduced the	2012-11-01 08:07:29 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	Revert the series of commits starting with r166578 which introduced the	2012-11-01 08:07:29 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	Revert the majority of the next patch in the address space series:	2012-11-01 09:14:31 +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))

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