llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-10-03 08:55:51 +00:00

History

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
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp
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
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
PHITransAddr.cpp
PointerTracking.cpp
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

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.

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