llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-10-04 00:54:53 +00:00

History

Chris Lattner 6b0dc92043 progress making the world safe to ConstantDataVector. While we're at it, allow PatternMatch's "neg" pattern to match integer vector negations, and enhance ComputeNumSigned bits to handle shl of vectors. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149082 91177308-0d34-0410-b5e6-96231b3b80d8		2012-01-26 21:37:55 +00:00
..
IPA
AliasAnalysis.cpp
AliasAnalysisCounter.cpp	Remove unnecessary default cases in switches that cover all enum values.	2012-01-10 16:47:17 +00:00
AliasAnalysisEvaluator.cpp	Remove unnecessary default cases in switches that cover all enum values.	2012-01-10 16:47:17 +00:00
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp	Move includes to the .cpp file.	2012-01-17 22:16:31 +00:00
CFGPrinter.cpp
CMakeLists.txt
ConstantFolding.cpp	progress making the world safe to ConstantDataVector. While	2012-01-26 21:37:55 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp	Don't avoid recursing for pointer types, just reference types. Expand on	2012-01-11 00:01:29 +00:00
DIBuilder.cpp	Cleanup these asserts to follow common LLVM style and coding	2012-01-10 18:18:52 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InlineCost.cpp	Use precomputed BB size instead of BB->size().	2012-01-25 18:54:13 +00:00
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp	Remove dead code.	2012-01-18 10:10:28 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopDependenceAnalysis.cpp	More dead code removal (using -Wunreachable-code)	2012-01-20 21:51:11 +00:00
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	More dead code removal (using -Wunreachable-code)	2012-01-20 21:51:11 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PathNumbering.cpp
PathProfileInfo.cpp
PathProfileVerifier.cpp
PHITransAddr.cpp	More dead code removal (using -Wunreachable-code)	2012-01-20 21:51:11 +00:00
PostDominators.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	switch SCEV to use the new ConstantFoldLoadThroughGEPIndices function	2012-01-24 05:49:24 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	More dead code removal (using -Wunreachable-code)	2012-01-20 21:51:11 +00:00
ScalarEvolutionNormalization.cpp	More dead code removal (using -Wunreachable-code)	2012-01-20 21:51:11 +00:00
SparsePropagation.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	progress making the world safe to ConstantDataVector. While	2012-01-26 21:37:55 +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.

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

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))

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