llvm-6502/lib/Analysis
Benjamin Kramer b69143c6a9 Annotate APInt methods where it's not clear whether they are in place with warn_unused_result.
Fix ScalarEvolution bugs uncovered by this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194928 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-16 16:25:41 +00:00
..
IPA Move the old pass manager infrastructure into a legacy namespace and 2013-11-09 12:26:54 +00:00
AliasAnalysis.cpp Reimplement isPotentiallyReachable to make nocapture deduction much stronger. 2013-07-27 01:24:00 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp In AliasSetTracker, do not change the alias set to "mod/ref" when adding 2013-09-12 20:15:50 +00:00
Analysis.cpp delinearization of arrays 2013-11-12 22:47:20 +00:00
BasicAliasAnalysis.cpp Use correct size for address space in BasicAA. 2013-11-16 00:36:43 +00:00
BlockFrequencyInfo.cpp Added BlockFrequencyInfo::view for displaying the block frequency propagation graph via graphviz. 2013-11-14 02:27:46 +00:00
BranchProbabilityInfo.cpp Consider (x == -1) unlikely in BranchProbabilityInfo 2013-11-01 10:58:22 +00:00
CaptureTracking.cpp CaptureTracking: Plug a loophole in the "too many uses" heuristic. 2013-10-03 13:24:02 +00:00
CFG.cpp Add some constantness. 2013-08-20 23:04:15 +00:00
CFGPrinter.cpp
CMakeLists.txt delinearization of arrays 2013-11-12 22:47:20 +00:00
CodeMetrics.cpp
ConstantFolding.cpp Add addrspacecast instruction. 2013-11-15 01:34:59 +00:00
CostModel.cpp Move variable into assert to avoid unused variable warning. 2013-09-17 21:13:57 +00:00
Delinearization.cpp add more comments around the delinearization of arrays 2013-11-13 22:37:58 +00:00
DependenceAnalysis.cpp add more comments around the delinearization of arrays 2013-11-13 22:37:58 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp Teach MemoryBuiltins and InstructionSimplify that operator new never returns NULL. 2013-09-24 16:37:51 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp Use SmallVectorImpl::iterator/const_iterator instead of SmallVector to avoid specifying the vector size. 2013-07-04 01:31:24 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp Use size function instead of manually calculating it. 2013-11-10 03:18:50 +00:00
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp Simplify code. No functionality change. 2013-11-13 20:18:38 +00:00
LoopPass.cpp Comment: try to clarify loop iteration order. 2013-07-20 23:10:31 +00:00
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp fix PR17635: false positive with packed structures 2013-10-24 09:17:24 +00:00
MemoryDependenceAnalysis.cpp Fixing a heisenbug where the memory dependence analysis behaves differently 2013-11-14 01:10:52 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp Reorder headers according to lint. 2013-08-21 21:14:19 +00:00
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp Annotate APInt methods where it's not clear whether they are in place with warn_unused_result. 2013-11-16 16:25:41 +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 Costmodel: Add support for horizontal vector reductions 2013-09-17 18:06:50 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp TBAA: fix PR17620. 2013-10-22 01:40:25 +00:00
ValueTracking.cpp Remove x86_sse42_crc32_64_8 intrinsic. It has no functional difference from x86_sse42_crc32_32_8 and was not mapped to a clang builtin. I'm not even sure why this form of the instruction is even called out explicitly in the docs. Also add AutoUpgrade support to convert it into the other intrinsic with appropriate trunc and zext. 2013-10-15 05:20:47 +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))

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