llvm-6502/lib/Analysis
Devang Patel 6ed0ce3240 Rename variable. add comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104274 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-20 20:35:24 +00:00
..
IPA fix PR5009 by making CGSCCPM realize that a call was devirtualized 2010-05-01 06:38:43 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp clean up algorithm and remove operand order assumptions 2010-04-08 16:46:24 +00:00
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp Revert 101465, it broke internal OpenGL testing. 2010-04-16 23:37:20 +00:00
CaptureTracking.cpp rename use_const_iterator to const_use_iterator for consistency's sake 2010-03-25 23:06:16 +00:00
CFGPrinter.cpp
CMakeLists.txt Add a simple module-level debug info printer. It just sets up a 2010-05-07 16:22:32 +00:00
ConstantFolding.cpp Revert 101465, it broke internal OpenGL testing. 2010-04-16 23:37:20 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp Rename variable. add comment. 2010-05-20 20:35:24 +00:00
DomPrinter.cpp Remove dead code in the dotty dominance tree printer. 2010-04-12 15:02:19 +00:00
InlineCost.cpp Clear CachedFunctionInfo upon Pass::releaseMemory. Because ValueMap will abort 2010-05-12 21:48:15 +00:00
InstCount.cpp
InstructionSimplify.cpp move some select simplifications out out instcombine into 2010-04-20 05:32:14 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Remove the Expr member from IVUsers. Instead of remembering the expression, 2010-04-19 21:48:58 +00:00
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp Add lint checks for invalid uses of memory. 2010-04-30 19:05:00 +00:00
LiveValues.cpp rename use_const_iterator to const_use_iterator for consistency's sake 2010-03-25 23:06:16 +00:00
LoopDependenceAnalysis.cpp Define placement new wrappers for BumpPtrAllocator and 2010-03-18 18:49:47 +00:00
LoopInfo.cpp Fix a bunch of namespace polution. 2010-04-15 17:08:50 +00:00
LoopPass.cpp Ok, third time's the charm. No changes from last time except the CMake 2010-04-02 23:17:14 +00:00
Makefile
MemoryBuiltins.cpp Revert 101465, it broke internal OpenGL testing. 2010-04-16 23:37:20 +00:00
MemoryDependenceAnalysis.cpp Revert 101465, it broke internal OpenGL testing. 2010-04-16 23:37:20 +00:00
ModuleDebugInfoPrinter.cpp Add a simple module-level debug info printer. It just sets up a 2010-05-07 16:22:32 +00:00
PHITransAddr.cpp
PointerTracking.cpp Rename isLoopGuardedByCond to isLoopEntryGuardedByCond, to emphasise 2010-04-11 19:27:13 +00:00
PostDominators.cpp Remove unneeded debug in PostDominator runOnFunction() 2010-04-12 15:32:55 +00:00
ProfileEstimatorPass.cpp rename pred_const_iterator to const_pred_iterator for consistency's sake 2010-03-25 23:25:28 +00:00
ProfileInfo.cpp rename pred_const_iterator to const_pred_iterator for consistency's sake 2010-03-25 23:25:28 +00:00
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp rename pred_const_iterator to const_pred_iterator for consistency's sake 2010-03-25 23:25:28 +00:00
ProfileVerifierPass.cpp rename pred_const_iterator to const_pred_iterator for consistency's sake 2010-03-25 23:25:28 +00:00
README.txt When checking whether the special handling for an addrec increment which 2010-04-26 21:46:36 +00:00
ScalarEvolution.cpp Use the SCEVAddRecExpr::getPostIncExpr utility function instead 2010-05-04 01:12:27 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp Use getConstant instead of getIntegerSCEV. The two are basically the 2010-05-03 22:09:21 +00:00
ScalarEvolutionNormalization.cpp Generalize IVUsers to track arbitrary expressions rather than expressions 2010-04-07 22:27:08 +00:00
SparsePropagation.cpp
Trace.cpp
ValueTracking.cpp Revert 101465, it broke internal OpenGL testing. 2010-04-16 23:37:20 +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))

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