llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-04 06:09:05 +00:00

History

Dan Gohman 65924111bf Add a new experimental generalized dependence query interface to AliasAnalysis, and some code for implementing the new query on top of existing implementations by making standard alias and getModRefInfo queries. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113329 91177308-0d34-0410-b5e6-96231b3b80d8		2010-09-08 01:32:20 +00:00
..
IPA	dead method.	2010-09-04 18:19:16 +00:00
AliasAnalysis.cpp	Add a new experimental generalized dependence query interface to	2010-09-08 01:32:20 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp	Don't print two "0x" prefixes. Use a raw_ostream overload instead of llvm::format.	2010-08-30 14:46:53 +00:00
Analysis.cpp
BasicAliasAnalysis.cpp	Add a new experimental generalized dependence query interface to	2010-09-08 01:32:20 +00:00
CaptureTracking.cpp
CFGPrinter.cpp	zap dead code.	2010-09-04 18:12:00 +00:00
CMakeLists.txt
ConstantFolding.cpp
DbgInfoPrinter.cpp
DebugInfo.cpp
DomPrinter.cpp
InlineCost.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	stop forcing a noop AssemblyAnnotationWriter to silence #uses	2010-09-02 23:03:10 +00:00
LazyValueInfo.cpp	Clean up some of the PassRegistry implementation, and pImpl-ize it to reduce #include clutter	2010-09-07 19:16:25 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	zap dead code.	2010-09-04 18:12:00 +00:00
LiveValues.cpp
Loads.cpp
LoopDependenceAnalysis.cpp
LoopInfo.cpp	pull a simple method out of LICM into a new	2010-09-06 01:05:37 +00:00
LoopPass.cpp	zap dead code.	2010-09-04 18:12:00 +00:00
Makefile
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	cleanup some of the lifetime/invariant marker stuff, add a big fixme.	2010-09-06 03:58:04 +00:00
ModuleDebugInfoPrinter.cpp
PHITransAddr.cpp
PointerTracking.cpp
PostDominators.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
README.txt
RegionInfo.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	Reapply r112432, now that the real problem is addressed.	2010-08-31 22:53:17 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp	Disable the asserts that check that normalization is perfectly	2010-09-03 22:12:56 +00:00
SparsePropagation.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	fix PR8063, a crash in globalopt in the malloc analysis code.	2010-09-05 17:20:46 +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))

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