llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-18 10:31:57 +00:00

History

Tobias Grosser 144ffd6624 Delinearize: Extend informationin -analyze output git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205838 91177308-0d34-0410-b5e6-96231b3b80d8		2014-04-09 07:53:49 +00:00
..
IPA	Handle vlas during inline cost computation if they'll be turned	2014-04-07 13:36:21 +00:00
AliasAnalysis.cpp	IR: add a second ordering operand to cmpxhg for failure	2014-03-11 10:48:52 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp	PR15967 Fix in basicaa for faulty returning no alias.	2014-03-26 21:30:19 +00:00
BlockFrequencyInfo.cpp	blockfreq: Implement Pass::releaseMemory()	2014-03-25 18:01:38 +00:00
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp	Simplify loop that worked around bugs in old GCC/Xcode.	2014-03-25 09:06:18 +00:00
CFGPrinter.cpp
CMakeLists.txt
CodeMetrics.cpp	Consistent use of the noduplicate attribute.	2014-03-17 16:19:07 +00:00
ConstantFolding.cpp	Allow constant folding of ceil function whenever feasible	2014-03-24 04:36:06 +00:00
CostModel.cpp
Delinearization.cpp	Delinearize: Extend informationin -analyze output	2014-04-09 07:53:49 +00:00
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	PR17473:	2014-03-12 21:31:05 +00:00
LazyCallGraph.cpp
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp	Consistent use of the noduplicate attribute.	2014-03-17 16:19:07 +00:00
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp	[C++11] Change DebugInfoFinder to use range-based loops	2014-03-18 09:41:07 +00:00
NoAliasAnalysis.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	divide by the result of the gcd	2014-04-08 21:21:13 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp	Add stride normalization to SCEV Normalize/Denormalize transformation.	2014-03-18 17:34:03 +00:00
SparsePropagation.cpp
TargetTransformInfo.cpp	Use TopTTI->getGEPCost from within getUserCost	2014-04-01 18:50:06 +00:00
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))

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