llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-02 22:04:55 +00:00

History

David Blaikie cf57d81b6e [opaque pointer type] More GEP API migrations in IRBuilder uses The plan here is to push the API changes out from the common components (like Constant::getGetElementPtr and IRBuilder::CreateGEP related functions) and just update callers to either pass the type if it's obvious, or pass null. Do this with LoadInst as well and anything else that comes up, then to start porting specific uses to not pass null anymore - this may require some refactoring in each case. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@234042 91177308-0d34-0410-b5e6-96231b3b80d8		2015-04-03 19:41:44 +00:00
..
IPA	Correctly estimate SROA savings for store operands in inline cost analysis.	2015-03-20 18:33:12 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
AssumptionCache.cpp
BasicAliasAnalysis.cpp	[opaque pointer type] Change GetElementPtrInst::getIndexedType to take the pointee type	2015-03-30 21:41:43 +00:00
BlockFrequencyInfo.cpp	Remove superfluous .str() and replace std::string concatenation with Twine.	2015-03-27 17:51:30 +00:00
BlockFrequencyInfoImpl.cpp	Remove 4,096 loop scale limitation.	2015-04-01 17:42:27 +00:00
BranchProbabilityInfo.cpp	Purge unused includes throughout libSupport.	2015-03-23 18:07:13 +00:00
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp	Remove superfluous .str() and replace std::string concatenation with Twine.	2015-03-27 17:51:30 +00:00
CFLAliasAnalysis.cpp	Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.	2015-03-23 19:32:43 +00:00
CGSCCPassManager.cpp
CMakeLists.txt
CodeMetrics.cpp	Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.	2015-03-23 19:32:43 +00:00
ConstantFolding.cpp	[opaque pointer type] API migration for GEP constant factories	2015-04-02 18:55:32 +00:00
CostModel.cpp
Delinearization.cpp
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp	[opaque pointer type] API migration for GEP constant factories	2015-04-02 18:55:32 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyCallGraph.cpp
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopAccessAnalysis.cpp	[LoopAccesses] Handle case when no memchecks are needed after partitioning	2015-04-02 17:51:57 +00:00
LoopInfo.cpp	Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.	2015-03-23 19:32:43 +00:00
LoopPass.cpp	Purge unused includes throughout libSupport.	2015-03-23 18:07:13 +00:00
Makefile
MemDepPrinter.cpp
MemDerefPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	!invariant.load semantics with potentially clobbering calls	2015-03-24 23:54:54 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp	Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.	2015-03-23 19:32:43 +00:00
RegionPrinter.cpp
ScalarEvolution.cpp	[opaque pointer type] API migration for GEP constant factories	2015-04-02 18:55:32 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	[opaque pointer type] More GEP API migrations in IRBuilder uses	2015-04-03 19:41:44 +00:00
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp
SparsePropagation.cpp
StratifiedSets.h
TargetLibraryInfo.cpp	[WinEH] Run cleanup handlers when an exception is thrown	2015-03-30 22:58:10 +00:00
TargetTransformInfo.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	[ValueTracking] Fix PR23011.	2015-03-25 22:33:53 +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))

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