llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-10-05 07:56:14 +00:00

History

Manman Ren 90842427b2 Check whether a pointer is non-null (isKnownNonNull) in isKnownNonZero. This handles the case where we have an inbounds GEP with alloca as the pointer. This fixes the regression in PR12750 and rdar://13286434. Note that we can also fix this by handling some GEP cases in isKnownNonNull. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177321 91177308-0d34-0410-b5e6-96231b3b80d8		2013-03-18 21:23:25 +00:00
..
IPA	ArrayRef ca accept one element. Simplify code a little bit, also it matches now	2013-03-07 20:01:19 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp	Remove -print-dbginfo as it is unused & bitrotten.	2013-03-08 18:17:46 +00:00
BasicAliasAnalysis.cpp	add getUnderlyingObjectSize()	2013-03-02 11:23:34 +00:00
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp	Remove unneeded #includes. Use forward declarations instead.	2013-03-10 00:34:01 +00:00
CFGPrinter.cpp
CMakeLists.txt	Remove -print-dbginfo as it is unused & bitrotten.	2013-03-08 18:17:46 +00:00
CodeMetrics.cpp
ConstantFolding.cpp	Constant fold vector bitcasts of halves similarly to how floats and doubles are folded. Test case included.	2013-02-26 22:51:07 +00:00
CostModel.cpp	Cost model support for lowered math builtins.	2013-02-28 19:09:33 +00:00
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp	Early exit from getAllocationData() and isFreeCall() for intrinsics.	2013-03-08 21:15:00 +00:00
MemoryDependenceAnalysis.cpp	Memory Dependence Analysis (not mem-dep test) take advantage of "invariant.load" metadata.	2013-03-06 17:48:48 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PathNumbering.cpp
PathProfileInfo.cpp
PathProfileVerifier.cpp
PHITransAddr.cpp
PostDominators.cpp
ProfileDataLoader.cpp
ProfileDataLoaderPass.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
TargetTransformInfo.cpp	Small fix for cost analysis of ptrtoint.	2013-03-12 13:18:30 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	Check whether a pointer is non-null (isKnownNonNull) in isKnownNonZero.	2013-03-18 21:23:25 +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))

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