llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-03 13:31:05 +00:00

History

Chandler Carruth 974a445bd9 Re-sort all of the includes with ./utils/sort_includes.py so that subsequent changes are easier to review. About to fix some layering issues, and wanted to separate out the necessary churn. Also comment and sink the include of "Windows.h" in three .inc files to match the usage in Memory.inc. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198685 91177308-0d34-0410-b5e6-96231b3b80d8		2014-01-07 11:48:04 +00:00
..
IPA	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
AliasAnalysis.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
BasicAliasAnalysis.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
CFGPrinter.cpp
CMakeLists.txt
CodeMetrics.cpp
ConstantFolding.cpp
CostModel.cpp
Delinearization.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
TargetTransformInfo.cpp	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
Trace.cpp
TypeBasedAliasAnalysis.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))

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