llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-09-30 04:56:49 +00:00

History

Andrew Trick 75ae20366f LSR fix: Add isSimplifiedLoopNest to IVUsers analysis. Only record IVUsers that are dominated by simplified loop headers. Otherwise SCEVExpander will crash while looking for a preheader. I previously tried to work around this in LSR itself, but that was insufficient. This way, LSR can continue to run if some uses are not in simple loops, as long as we don't attempt to analyze those users. Fixes <rdar://problem/11049788> Segmentation fault: 11 in LoopStrengthReduce git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152892 91177308-0d34-0410-b5e6-96231b3b80d8		2012-03-16 03:16:56 +00:00
..
IPA
AliasAnalysis.cpp	Move isKnownNonNull from private implementation detail of BasicAA to a public	2012-02-25 10:56:28 +00:00
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	Remove unnecessary default cases in switches that cover all enum values.	2012-01-10 16:47:17 +00:00
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	Duncan pointed out that if the alignment isn't explicitly specified, it defaults to the ABI alignment. Given that, make this code a bit more aggressive in such cases.	2012-02-27 23:16:46 +00:00
BlockFrequencyInfo.cpp	Add some constantness to BranchProbabilityInfo and BlockFrequnencyInfo.	2011-12-20 20:03:10 +00:00
BranchProbabilityInfo.cpp	Make the unreachable probability much much heavier. The previous	2011-12-22 09:26:37 +00:00
CaptureTracking.cpp	Move includes to the .cpp file.	2012-01-17 22:16:31 +00:00
CFGPrinter.cpp
CMakeLists.txt	build/CMake: Finish removal of add_llvm_library_dependencies.	2011-11-29 19:25:30 +00:00
ConstantFolding.cpp	Convert assert(0) to llvm_unreachable	2012-02-07 05:05:23 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp	Do the right thing on NULL uint64 fields.	2012-03-16 00:21:54 +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	Make the swap code here a bit more obvious what its doing... We're	2012-03-15 00:55:51 +00:00
InstCount.cpp
InstructionSimplify.cpp	Type sizes and fields offsets inside structs are unsigned. This is a highly	2012-03-15 20:14:42 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	LSR fix: Add isSimplifiedLoopNest to IVUsers analysis.	2012-03-16 03:16:56 +00:00
LazyValueInfo.cpp	llvm::SwitchInst	2012-03-11 06:09:17 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp	enhance jump threading to preserve TBAA information when PRE'ing loads,	2012-03-13 18:07:41 +00:00
LoopDependenceAnalysis.cpp	More dead code removal (using -Wunreachable-code)	2012-01-20 21:51:11 +00:00
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp	Don't call dominates on unreachable instructions. Should fix the dragonegg	2012-02-26 05:30:08 +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	Uniformize the InstructionSimplify interface by ensuring that all routines	2012-03-13 11:42:19 +00:00
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	switch SCEV to use the new ConstantFoldLoadThroughGEPIndices function	2012-01-24 05:49:24 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp	Fix this assert. IP can point to an instruction with strange dominance	2012-02-27 02:13:03 +00:00
ScalarEvolutionNormalization.cpp	More dead code removal (using -Wunreachable-code)	2012-01-20 21:51:11 +00:00
SparsePropagation.cpp	Taken into account Duncan's comments for r149481 dated by 2nd Feb 2012:	2012-03-08 07:06:20 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	Factor out the analysis of addition and subtraction in ComputeMaskedBits. Reuse	2012-03-09 09:23:50 +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))

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