llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-07 12:07:17 +00:00

History

Rafael Espindola 7481d07a07 Fix typo. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151238 91177308-0d34-0410-b5e6-96231b3b80d8		2012-02-23 05:38:51 +00:00
..
IPA
AliasAnalysis.cpp
AliasAnalysisCounter.cpp	Persuade GCC that there is nothing worth warning about here (there isn't).	2012-02-05 14:20:11 +00:00
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp	Have AliasSet::aliasesUnknownInst use pointer TBAA info when available	2012-02-10 15:52:39 +00:00
Analysis.cpp
BasicAliasAnalysis.cpp	Remove a comment about an alternative approach that wouldn't	2012-02-17 18:33:38 +00:00
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt
ConstantFolding.cpp	Convert assert(0) to llvm_unreachable	2012-02-07 05:05:23 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp	Make this a bit prettier and more obvious when a derived type isn't	2012-02-20 18:04:39 +00:00
DIBuilder.cpp	Add support for runtime languages on our forward declarations.	2012-02-20 18:04:14 +00:00
DominanceFrontier.cpp
DomPrinter.cpp	remove the blank line from previous ci.	2012-02-04 03:18:47 +00:00
InlineCost.cpp
InstCount.cpp
InstructionSimplify.cpp	fold comparisons of gep'd alloca points with null to false,	2012-02-20 00:42:49 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp	SwitchInst refactoring.	2012-02-01 07:49:51 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopDependenceAnalysis.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	The patch resolves the conflict between AddressSanitizer and load widening (GVN).	2012-02-06 22:48:56 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PathNumbering.cpp	[unwind removal] We no longer have 'unwind' instructions being generated, so	2012-02-06 21:16:41 +00:00
PathProfileInfo.cpp
PathProfileVerifier.cpp
PHITransAddr.cpp
PostDominators.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
README.txt
RegionInfo.cpp	Remove extra semi-colons.	2012-02-22 17:25:00 +00:00
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	Fix typo.	2012-02-23 05:38:51 +00:00
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp	SwitchInst refactoring.	2012-02-01 07:49:51 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	Remove some dead code and tidy things up now that vectors use ConstantDataVector	2012-02-06 21:56:39 +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))

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