llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-17 18:10:31 +00:00

History

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
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp
CaptureTracking.cpp
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
DbgInfoPrinter.cpp
DebugInfo.cpp	Rename variable. add comment.	2010-05-20 20:35:24 +00:00
DomPrinter.cpp
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
LoopDependenceAnalysis.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp
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
PostDominators.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
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
SparsePropagation.cpp
Trace.cpp
ValueTracking.cpp

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))

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