llvm-6502/lib/Analysis
Sebastian Pop f9cb030376 normalize the last delinearized dimension
in the dependence test, we used to discard some information that the
delinearization provides: the size of the innermost dimension of an array,
i.e., the size of scalars stored in the array, and the remainder of the
delinearization that provides the offset from which the array reads start,
i.e., the base address of the array.

To avoid losing this data in the rest of the data dependence analysis, the fix
is to multiply the access function in the last delinearized dimension by its
size, effectively making the size of the last dimension to always be in bytes,
and then add the remainder of delinearization to the last subscript,
effectively making the last subscript start at the base address of the array.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201867 91177308-0d34-0410-b5e6-96231b3b80d8
2014-02-21 18:15:11 +00:00
..
IPA Rename many DataLayout variables from TD to DL. 2014-02-21 00:06:31 +00:00
AliasAnalysis.cpp Rename some member variables from TD to DL. 2014-02-18 15:33:12 +00:00
AliasAnalysisCounter.cpp Put the functionality for printing a value to a raw_ostream as an 2014-01-09 02:29:41 +00:00
AliasAnalysisEvaluator.cpp Put the functionality for printing a value to a raw_ostream as an 2014-01-09 02:29:41 +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 Put the functionality for printing a value to a raw_ostream as an 2014-01-09 02:29:41 +00:00
Analysis.cpp [PM] Make the verifier work independently of any pass manager. 2014-01-19 02:22:18 +00:00
BasicAliasAnalysis.cpp Rename some member variables from TD to DL. 2014-02-18 15:33:12 +00:00
BlockFrequencyInfo.cpp BlockFrequencyInfo: Readded getEntryFreq. 2013-12-20 22:11:11 +00:00
BranchProbabilityInfo.cpp [block-freq] Teach branch probability how to return the edge weight in between a BasicBlock and one of its successors. 2013-12-14 02:24:25 +00:00
CaptureTracking.cpp Make nocapture analysis work with addrspacecast 2014-01-14 19:11:52 +00:00
CFG.cpp Make succ_iterator a real random access iterator and clean up a couple of users. 2014-02-10 14:17:42 +00:00
CFGPrinter.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
CMakeLists.txt [PM] Add a new "lazy" call graph analysis pass for the new pass manager. 2014-02-06 04:37:03 +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 Add addrspacecast instruction. 2013-11-15 01:34:59 +00:00
CostModel.cpp Reduce code duplication resulting from the ConstantVector/ConstantDataVector split. 2014-02-13 16:48:38 +00:00
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 normalize the last delinearized dimension 2014-02-21 18:15:11 +00:00
DominanceFrontier.cpp [PM] Split DominatorTree into a concrete analysis result object which 2014-01-13 13:07:17 +00:00
DomPrinter.cpp [PM] Split DominatorTree into a concrete analysis result object which 2014-01-13 13:07:17 +00:00
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 Rename many DataLayout variables from TD to DL. 2014-02-21 00:06:31 +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 Rename some member variables from TD to DL. 2014-02-18 15:33:12 +00:00
LazyCallGraph.cpp [PM] Fix horrible typos that somehow didn't cause a failure in a C++11 2014-02-06 05:17:02 +00:00
LazyValueInfo.cpp Rename some member variables from TD to DL. 2014-02-18 15:33:12 +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 Rename many DataLayout variables from TD to DL. 2014-02-21 00:06:31 +00:00
LLVMBuild.txt LLVMBuild: Introduce a common section which currently has a list of the 2011-12-12 22:45:54 +00:00
Loads.cpp Change GetPointerBaseWithConstantOffset's DataLayout argument from a 2013-01-31 02:00:45 +00:00
LoopInfo.cpp [PM] Split DominatorTree into a concrete analysis result object which 2014-01-13 13:07:17 +00:00
LoopPass.cpp Disable most IR-level transform passes on functions marked 'optnone'. 2014-02-06 00:07:05 +00:00
Makefile
MemDepPrinter.cpp Put the functionality for printing a value to a raw_ostream as an 2014-01-09 02:29:41 +00:00
MemoryBuiltins.cpp Update optimization passes to handle inalloca arguments 2014-01-28 02:38:36 +00:00
MemoryDependenceAnalysis.cpp Rename some member variables from TD to DL. 2014-02-18 15:33:12 +00:00
ModuleDebugInfoPrinter.cpp Put the functionality for printing a value to a raw_ostream as an 2014-01-09 02:29:41 +00:00
NoAliasAnalysis.cpp Rename some member variables from TD to DL. 2014-02-18 15:33:12 +00:00
PHITransAddr.cpp Rename some member variables from TD to DL. 2014-02-18 15:33:12 +00:00
PostDominators.cpp [PM] Pull the generic graph algorithms and data structures for dominator 2014-01-13 10:52:56 +00:00
PtrUseVisitor.cpp Hoist the GEP constant address offset computation to a common home on 2012-12-11 10:29:10 +00:00
README.txt
RegionInfo.cpp [PM] Split DominatorTree into a concrete analysis result object which 2014-01-13 13:07:17 +00:00
RegionPass.cpp Remove the the block_node_iterator of Region, replace it by the block_iterator. 2012-08-27 13:49:24 +00:00
RegionPrinter.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ScalarEvolution.cpp Rename some member variables from TD to DL. 2014-02-18 15:33:12 +00:00
ScalarEvolutionAliasAnalysis.cpp Use the new script to sort the includes of every file under lib. 2012-12-03 16:50:05 +00:00
ScalarEvolutionExpander.cpp Rename some member variables from TD to DL. 2014-02-18 15:33:12 +00:00
ScalarEvolutionNormalization.cpp [cleanup] Move the Dominators.h and Verifier.h headers into the IR 2014-01-13 09:26:24 +00:00
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 Make succ_iterator a real random access iterator and clean up a couple of users. 2014-02-10 14:17:42 +00:00
Trace.cpp Put the functionality for printing a value to a raw_ostream as an 2014-01-09 02:29:41 +00:00
TypeBasedAliasAnalysis.cpp TBAA: fix PR17620. 2013-10-22 01:40:25 +00:00
ValueTracking.cpp Allow speculating llvm.sqrt, fma and fmuladd 2014-01-31 00:09:00 +00:00

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))

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