llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-10-04 16:01:46 +00:00

History

Chandler Carruth 49837ef811 Move the old pass manager infrastructure into a legacy namespace and give the files a legacy prefix in the right directory. Use forwarding headers in the old locations to paper over the name change for most clients during the transitional period. No functionality changed here! This is just clearing some space to reduce renaming churn later on with a new system. Even when the new stuff starts to go in, it is going to be hidden behind a flag and off-by-default as it is still WIP and under development. This patch is specifically designed so that very little out-of-tree code has to change. I'm going to work as hard as I can to keep that the case. Only direct forward declarations of the PassManager class are impacted by this change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194324 91177308-0d34-0410-b5e6-96231b3b80d8		2013-11-09 12:26:54 +00:00
..
IPA	Move the old pass manager infrastructure into a legacy namespace and	2013-11-09 12:26:54 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp	Revert r193251 : Use address-taken to disambiguate global variable and indirect memops.	2013-10-27 03:08:44 +00:00
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp	Consider (x == -1) unlikely in BranchProbabilityInfo	2013-11-01 10:58:22 +00:00
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp
CMakeLists.txt
CodeMetrics.cpp
ConstantFolding.cpp	Fix another constant folding address space place I missed.	2013-11-04 20:46:52 +00:00
CostModel.cpp
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp	Quick look-up for block in loop.	2013-10-26 03:08:02 +00:00
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp	fix PR17635: false positive with packed structures	2013-10-24 09:17:24 +00:00
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	Rewrite SCEV's backedge taken count computation.	2013-11-06 02:08:26 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	Fix SCEVExpander: don't try to expand quadratic recurrences outside a loop.	2013-10-25 21:35:56 +00:00
ScalarEvolutionNormalization.cpp	Fix LSR: don't normalize quadratic recurrences.	2013-10-25 21:35:52 +00:00
SparsePropagation.cpp
TargetTransformInfo.cpp
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))

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