llvm-6502/lib/Analysis
David Greene 5c8aa950fe Ok, third time's the charm. No changes from last time except the CMake
source addition.  Apparently the buildbots were wrong about failures.

---

Add some switches helpful for debugging:

-print-before=<Pass Name>

Dump IR before running pass <Pass Name>.

-print-before-all

Dump IR before running each pass.

-print-after-all

Dump IR after running each pass.

These are helpful when tracking down a miscompilation.  It is easy to
get IR dumps and do diffs on them, etc.

To make this work well, add a new getPrinterPass API to Pass so that
each kind of pass (ModulePass, FunctionPass, etc.) can create a Pass
suitable for dumping out the kind of object the Pass works on.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100249 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-02 23:17:14 +00:00
..
IPA Ok, third time's the charm. No changes from last time except the CMake 2010-04-02 23:17:14 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp Fix a missing newline in debug output. 2010-03-01 17:42:55 +00:00
AliasAnalysisEvaluator.cpp There are two ways of checking for a given type, for example isa<PointerType>(T) 2010-02-16 11:11:14 +00:00
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp There are two ways of checking for a given type, for example isa<PointerType>(T) 2010-02-16 11:11:14 +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
ConstantFolding.cpp FP16 constfolding 2010-03-19 00:36:35 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp DebugInfoFinder::processModule was foiling my plot by 2010-04-02 20:44:29 +00:00
DomPrinter.cpp
InlineCost.cpp Reapply r99451 with a fix to move the NoInline check to the cost functions 2010-03-25 04:49:10 +00:00
InstCount.cpp
InstructionSimplify.cpp fix incorrect folding of icmp with undef, PR6481. 2010-03-03 19:46:03 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Spelling fixes. 2010-03-01 17:49:51 +00:00
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
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 Add a DominatorTree argument to isLCSSA so that it doesn't have to 2010-03-10 19:38:49 +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 rename use_const_iterator to const_use_iterator for consistency's sake 2010-03-25 23:06:16 +00:00
MemoryDependenceAnalysis.cpp Reapply r97010, the speculative revert failed. 2010-02-24 08:48:04 +00:00
PHITransAddr.cpp Reapply r97010, the speculative revert failed. 2010-02-24 08:48:04 +00:00
PointerTracking.cpp There are two ways of checking for a given type, for example isa<PointerType>(T) 2010-02-16 11:11:14 +00:00
PostDominators.cpp
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
ScalarEvolution.cpp Define placement new wrappers for BumpPtrAllocator and 2010-03-18 18:49:47 +00:00
ScalarEvolutionAliasAnalysis.cpp Add a comment. 2010-03-01 17:56:04 +00:00
ScalarEvolutionExpander.cpp Don't back past debug info intrinsics; SCEVExpander's strategy 2010-03-23 21:53:22 +00:00
SparsePropagation.cpp
Trace.cpp
ValueTracking.cpp Fix a typo in ValueTracking that's causing instcombine to delete needed shift instructions. 2010-03-13 02:20:29 +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.

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