llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-13 20:32:21 +00:00

History

Benjamin Kramer d9f32c20da InstSimplify: stripAndComputeConstantOffsets can be called with vectors of pointers too. Prepare it for vectors of pointers and handle simple cases. We don't handle complicated cases because accumulateConstantOffset bails on pointer vectors. Fixes selfhost on i386. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174179 91177308-0d34-0410-b5e6-96231b3b80d8		2013-02-01 15:21:10 +00:00
..
IPA	Begin fleshing out an interface in TTI for modelling the costs of	2013-01-22 11:26:02 +00:00
AliasAnalysis.cpp	Move isKnownNonNull out of AliasAnalysis.h and into ValueTracking.cpp since	2013-01-31 02:40:59 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp	Move the initialization to the Analysis library as well as the pass.	2013-01-07 03:33:08 +00:00
BasicAliasAnalysis.cpp
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt	Sink InlineCost.cpp into IPA -- it is now officially an interprocedural	2013-01-21 12:09:41 +00:00
CodeMetrics.cpp	Begin fleshing out an interface in TTI for modelling the costs of	2013-01-22 11:26:02 +00:00
ConstantFolding.cpp	ConstantFolding: Add a missing folding that leads to a miscompile.	2013-01-24 16:28:28 +00:00
CostModel.cpp	Move TargetTransformInfo to live under the Analysis library. This no	2013-01-07 03:08:10 +00:00
DbgInfoPrinter.cpp
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp	InstSimplify: stripAndComputeConstantOffsets can be called with vectors of pointers too.	2013-02-01 15:21:10 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp	Move isKnownNonNull out of AliasAnalysis.h and into ValueTracking.cpp since	2013-01-31 02:40:59 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	Change GetPointerBaseWithConstantOffset's DataLayout argument from a	2013-01-31 02:00:45 +00:00
LLVMBuild.txt
Loads.cpp	Change GetPointerBaseWithConstantOffset's DataLayout argument from a	2013-01-31 02:00:45 +00:00
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp	Reverting r171325 & r172363. This was causing a mis-compile on the self-hosted LTO build bots.	2013-01-17 21:28:46 +00:00
MemoryDependenceAnalysis.cpp	Change GetPointerBaseWithConstantOffset's DataLayout argument from a	2013-01-31 02:00:45 +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	SCEVExpander fix. RAUW needs to update the InsertedExpressions cache.	2013-01-14 21:00:37 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
TargetTransformInfo.cpp	Begin fleshing out an interface in TTI for modelling the costs of	2013-01-22 11:26:02 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	Move isKnownNonNull out of AliasAnalysis.h and into ValueTracking.cpp since	2013-01-31 02:40:59 +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))

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