llvm-6502/lib/Analysis
Duncan Sands cd6636c737 Teach InstructionSimplify about phi nodes. I chose to have it simply
offload the work to hasConstantValue rather than do something more
complicated (such handling mutually recursive phis) because (1) it is
not clear it is worth it; and (2) if it is worth it, maybe such logic
would be better placed in hasConstantValue.  Adjust some GVN tests
which are now cleaned up much further (eg: all phi nodes are removed).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119043 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-14 13:30:18 +00:00
..
IPA Make ModRefBehavior a lattice. Use this to clean up AliasAnalysis 2010-11-10 01:02:18 +00:00
AliasAnalysis.cpp Add helper functions for computing the Location of load, store, 2010-11-11 21:50:19 +00:00
AliasAnalysisCounter.cpp Extend the AliasAnalysis::pointsToConstantMemory interface to allow it 2010-11-08 16:45:26 +00:00
AliasAnalysisEvaluator.cpp Reapply r116831 and r116839, converting AliasAnalysis to use 2010-10-19 22:54:46 +00:00
AliasDebugger.cpp Extend the AliasAnalysis::pointsToConstantMemory interface to allow it 2010-11-08 16:45:26 +00:00
AliasSetTracker.cpp Don't forget the TBAA info, if available. 2010-11-11 21:27:26 +00:00
Analysis.cpp Add initialization routines for Analysis and IPA. 2010-10-07 18:31:00 +00:00
BasicAliasAnalysis.cpp Make ModRefBehavior a lattice. Use this to clean up AliasAnalysis 2010-11-10 01:02:18 +00:00
CaptureTracking.cpp VAArg doesn't capture its operand. 2010-11-09 20:09:35 +00:00
CFGPrinter.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
CMakeLists.txt Introduce DIBuilder. It is intended to be a front-end friendly interface to emit debuggging information entries in LLVM IR. 2010-11-04 15:01:38 +00:00
ConstantFolding.cpp Boost the power of phi node constant folding slightly: if all 2010-11-14 12:53:18 +00:00
DbgInfoPrinter.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
DebugInfo.cpp Take care of special characters while creating named MDNode name to hold function specific local variable's info. 2010-11-10 22:19:21 +00:00
DIBuilder.cpp Use arrays instead of constant-sized SmallVectors. 2010-11-04 18:45:27 +00:00
DomPrinter.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
InlineCost.cpp Now using a variant of the existing inlining heuristics to decide whether to create a given specialization of a function in PartialSpecialization. If the total performance bonus across all callsites passing the same constant exceeds the specialization cost, we create the specialization. 2010-10-09 22:06:36 +00:00
InstCount.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
InstructionSimplify.cpp Teach InstructionSimplify about phi nodes. I chose to have it simply 2010-11-14 13:30:18 +00:00
Interval.cpp Change Pass::print to take a raw ostream instead of std::ostream, 2009-08-23 06:03:38 +00:00
IntervalPartition.cpp Now with fewer extraneous semicolons! 2010-10-07 22:25:06 +00:00
IVUsers.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
LazyValueInfo.cpp Now with fewer extraneous semicolons! 2010-10-07 22:25:06 +00:00
LibCallAliasAnalysis.cpp Now with fewer extraneous semicolons! 2010-10-07 22:25:06 +00:00
LibCallSemantics.cpp Thread const correctness through a bunch of AliasAnalysis interfaces and 2010-08-03 21:48:53 +00:00
Lint.cpp Avoid calling alias on non-pointer values. 2010-11-11 19:23:51 +00:00
LiveValues.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
Loads.cpp Reapply r116831 and r116839, converting AliasAnalysis to use 2010-10-19 22:54:46 +00:00
LoopDependenceAnalysis.cpp Begin adding static dependence information to passes, which will allow us to 2010-10-12 19:48:12 +00:00
LoopInfo.cpp Fix typo pointed out by Trevor Harmon. 2010-11-13 12:16:27 +00:00
LoopPass.cpp zap dead code. 2010-09-04 18:12:00 +00:00
Makefile make -fno-rtti the default unless a directory builds with REQUIRES_RTTI. 2010-01-24 20:43:08 +00:00
MemDepPrinter.cpp Add helper functions for computing the Location of load, store, 2010-11-11 21:50:19 +00:00
MemoryBuiltins.cpp minor enhancement to llvm::isFreeCall API: return CallInst; no functional change 2010-06-23 21:51:12 +00:00
MemoryDependenceAnalysis.cpp Add helper functions for computing the Location of load, store, 2010-11-11 21:50:19 +00:00
ModuleDebugInfoPrinter.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
NoAliasAnalysis.cpp Extend the AliasAnalysis::pointsToConstantMemory interface to allow it 2010-11-08 16:45:26 +00:00
PHITransAddr.cpp Reapply r97010, the speculative revert failed. 2010-02-24 08:48:04 +00:00
PostDominators.cpp Begin adding static dependence information to passes, which will allow us to 2010-10-12 19:48:12 +00:00
ProfileEstimatorPass.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
ProfileInfo.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
ProfileInfoLoader.cpp Reapplied r81355 with the problems fixed. 2009-09-16 11:35:50 +00:00
ProfileInfoLoaderPass.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
ProfileVerifierPass.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
README.txt When checking whether the special handling for an addrec increment which 2010-04-26 21:46:36 +00:00
RegionInfo.cpp Make some symbols static, move classes into anonymous namespaces. 2010-10-22 17:35:07 +00:00
RegionPass.cpp Add RegionPass support. 2010-10-20 01:54:44 +00:00
RegionPrinter.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
ScalarEvolution.cpp Make ScalarEvolution::forgetLoop forget all contained loops too, because 2010-10-29 20:16:10 +00:00
ScalarEvolutionAliasAnalysis.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
ScalarEvolutionExpander.cpp Fix SCEVExpander::visitAddRecExpr so that it remembers the induction variable 2010-07-26 18:28:14 +00:00
ScalarEvolutionNormalization.cpp Disable the asserts that check that normalization is perfectly 2010-09-03 22:12:56 +00:00
SparsePropagation.cpp Convert debug messages to use dbgs(). Generally this means 2009-12-23 22:28:01 +00:00
Trace.cpp Convert debug messages to use dbgs(). Generally this means 2009-12-23 22:35:10 +00:00
TypeBasedAliasAnalysis.cpp Re-disable TBAA for now; it broke MultiSource/Applications/JM/lencod, 2010-11-12 11:21:08 +00:00
ValueTracking.cpp fix PR8063, a crash in globalopt in the malloc analysis code. 2010-09-05 17:20:46 +00:00

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))

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