llvm-6502

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

History

Hal Finkel 9da65a8644 Match semantics of PointerMayBeCapturedBefore to its name by default As it turns out, the capture tracker named CaptureBefore used by AA, and now available via the PointerMayBeCapturedBefore function, would have been more-aptly named CapturedBeforeOrAt, because it considers captures at the instruction provided. This is not always what one wants, and it is difficult to get the strictly-before behavior given only the current interface. This adds an additional parameter which controls whether or not you want to include captures at the provided instruction. The default is not to include the instruction provided, so that 'Before' matches its name. No functionality change intended. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213582 91177308-0d34-0410-b5e6-96231b3b80d8		2014-07-21 21:30:22 +00:00
..
IPA	Remove uses of the redundant ".reset(nullptr)" of unique_ptr, in favor of ".reset()"	2014-07-19 01:05:11 +00:00
AliasAnalysis.cpp	Match semantics of PointerMayBeCapturedBefore to its name by default	2014-07-21 21:30:22 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp	Templatify RegionInfo so it works on MachineBasicBlocks	2014-07-19 18:29:29 +00:00
BasicAliasAnalysis.cpp	Move isIdentifiedFunctionLocal from BasicAA to AA	2014-07-21 12:27:23 +00:00
BlockFrequencyInfo.cpp	Revert "Introduce a string_ostream string builder facilty"	2014-06-26 22:52:05 +00:00
BlockFrequencyInfoImpl.cpp	BFI: Add constructor for Weight	2014-07-12 00:26:00 +00:00
BranchProbabilityInfo.cpp	Revert "[C++11] Add predecessors(BasicBlock ) / successors(BasicBlock ) iterator ranges."	2014-07-21 17:06:51 +00:00
CaptureTracking.cpp	Match semantics of PointerMayBeCapturedBefore to its name by default	2014-07-21 21:30:22 +00:00
CFG.cpp
CFGPrinter.cpp
CGSCCPassManager.cpp
CMakeLists.txt
CodeMetrics.cpp
ConstantFolding.cpp	Look through addrspacecast in IsConstantOffsetFromGlobal	2014-07-14 22:39:26 +00:00
CostModel.cpp	[CostModel][x86] Improved cost model for alternate shuffles.	2014-07-03 22:24:18 +00:00
Delinearization.cpp
DependenceAnalysis.cpp
DominanceFrontier.cpp	Templatify DominanceFrontier.	2014-07-12 21:59:52 +00:00
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp	Rectify r213231. Use proper version of 'ComputeNumSignBits'.	2014-07-17 19:07:00 +00:00
Interval.cpp	Revert "[C++11] Add predecessors(BasicBlock ) / successors(BasicBlock ) iterator ranges."	2014-07-21 17:06:51 +00:00
IntervalPartition.cpp
IVUsers.cpp	Add back functionality removed in r210497.	2014-06-21 02:43:02 +00:00
JumpInstrTableInfo.cpp
LazyCallGraph.cpp
LazyValueInfo.cpp	Revert "[C++11] Add predecessors(BasicBlock ) / successors(BasicBlock ) iterator ranges."	2014-07-21 17:06:51 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	Revert "Introduce a string_ostream string builder facilty"	2014-06-26 22:52:05 +00:00
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp	Revert "[C++11] Add predecessors(BasicBlock ) / successors(BasicBlock ) iterator ranges."	2014-07-21 17:06:51 +00:00
LoopPass.cpp	Add back functionality removed in r210497.	2014-06-21 02:43:02 +00:00
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp	Improve BasicAA CS-CS queries (redux)	2014-07-17 01:28:25 +00:00
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp	Fix msc17 build. RegionInfo::RegionInfo::recalculate() doesn't make sense.	2014-07-20 03:57:51 +00:00
RegionPass.cpp	Templatify RegionInfo so it works on MachineBasicBlocks	2014-07-19 18:29:29 +00:00
RegionPrinter.cpp	Templatify RegionInfo so it works on MachineBasicBlocks	2014-07-19 18:29:29 +00:00
ScalarEvolution.cpp	Revert "[C++11] Add predecessors(BasicBlock ) / successors(BasicBlock ) iterator ranges."	2014-07-21 17:06:51 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	SCEVExpander: Fold constant PHIs harder. The logic below only understands proper IVs.	2014-06-21 11:47:18 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
TargetTransformInfo.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	Add a dereferenceable attribute	2014-07-18 15:51:28 +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))

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