llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-14 11:32:34 +00:00

History

Shuxin Yang 985dac6579 Memory Dependence Analysis (not mem-dep test) take advantage of "invariant.load" metadata. The "invariant.load" metadata indicates the memory unit being accessed is immutable. A load annotated with this metadata can be moved across any store. As I am not sure if it is legal to move such loads across barrier/fence, this change dose not allow such transformation. rdar://11311484 Thank Arnold for code review. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176562 91177308-0d34-0410-b5e6-96231b3b80d8		2013-03-06 17:48:48 +00:00
..
IPA	Begin fleshing out an interface in TTI for modelling the costs of	2013-01-22 11:26:02 +00:00
AliasAnalysis.cpp	Move isKnownNonNull out of AliasAnalysis.h and into ValueTracking.cpp since	2013-01-31 02:40:59 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
AliasDebugger.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
AliasSetTracker.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
Analysis.cpp	Move the initialization to the Analysis library as well as the pass.	2013-01-07 03:33:08 +00:00
BasicAliasAnalysis.cpp	add getUnderlyingObjectSize()	2013-03-02 11:23:34 +00:00
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt	Sink InlineCost.cpp into IPA -- it is now officially an interprocedural	2013-01-21 12:09:41 +00:00
CodeMetrics.cpp	Begin fleshing out an interface in TTI for modelling the costs of	2013-01-22 11:26:02 +00:00
ConstantFolding.cpp	Constant fold vector bitcasts of halves similarly to how floats and doubles are folded. Test case included.	2013-02-26 22:51:07 +00:00
CostModel.cpp	Cost model support for lowered math builtins.	2013-02-28 19:09:33 +00:00
DbgInfoPrinter.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
DependenceAnalysis.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
InstructionSimplify.cpp	Identify and simplify idempotent intrinsics. Test case included.	2013-02-07 19:26:05 +00:00
Interval.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
IntervalPartition.cpp
IVUsers.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
LazyValueInfo.cpp	Move isKnownNonNull out of AliasAnalysis.h and into ValueTracking.cpp since	2013-01-31 02:40:59 +00:00
LibCallAliasAnalysis.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
LibCallSemantics.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
Lint.cpp	Change GetPointerBaseWithConstantOffset's DataLayout argument from a	2013-01-31 02:00:45 +00:00
LLVMBuild.txt
Loads.cpp	Change GetPointerBaseWithConstantOffset's DataLayout argument from a	2013-01-31 02:00:45 +00:00
LoopInfo.cpp	Metadata for annotating loops as parallel. The first consumer for this	2013-02-13 18:08:57 +00:00
LoopPass.cpp
Makefile
MemDepPrinter.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
MemoryBuiltins.cpp	recommit r172363 & r171325 (reverted in r172756)	2013-03-02 11:36:24 +00:00
MemoryDependenceAnalysis.cpp	Memory Dependence Analysis (not mem-dep test) take advantage of "invariant.load" metadata.	2013-03-06 17:48:48 +00:00
ModuleDebugInfoPrinter.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
NoAliasAnalysis.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
PathNumbering.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
PathProfileInfo.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
PathProfileVerifier.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
PHITransAddr.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
PostDominators.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
ProfileDataLoader.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
ProfileDataLoaderPass.cpp	Revert "Add LLVMContext::emitWarning methods and use them. <rdar://problem/12867368>"	2013-02-08 21:48:29 +00:00
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
ProfileInfoLoaderPass.cpp	Revert "Add LLVMContext::emitWarning methods and use them. <rdar://problem/12867368>"	2013-02-08 21:48:29 +00:00
ProfileVerifierPass.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	SCEVExpander fix. RAUW needs to update the InsertedExpressions cache.	2013-01-14 21:00:37 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
TargetTransformInfo.cpp	ARM cost model: Address computation in vector mem ops not free	2013-02-08 14:50:48 +00:00
Trace.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
TypeBasedAliasAnalysis.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
ValueTracking.cpp	Use dyn_cast instead of isa && cast. No functionality change.	2013-03-06 00:16:16 +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))

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