llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-01 00:33:09 +00:00

History

Andrew Trick 8aa22019ca SCEV: Add MarkPendingLoopPredicates to avoid recursive isImpliedCond. getUDivExpr attempts to simplify by checking for overflow. isLoopEntryGuardedByCond then evaluates the loop predicate which may lead to the same getUDivExpr causing endless recursion. Fixes PR12868: clang 3.2 segmentation fault. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157092 91177308-0d34-0410-b5e6-96231b3b80d8		2012-05-19 00:48:25 +00:00
..
IPA	Handle intrinsics in GlobalsModRef. Fixes pr12351.	2012-03-28 21:31:24 +00:00
AliasAnalysis.cpp	Move the capture analysis from MemoryDependencyAnalysis to a more general place	2012-05-14 20:35:04 +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
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
BranchProbabilityInfo.cpp
CaptureTracking.cpp	Fix intendation.	2012-05-10 23:38:07 +00:00
CFGPrinter.cpp
CMakeLists.txt	Pull the implementation of the code metrics out of the inline cost	2012-03-16 05:51:52 +00:00
CodeMetrics.cpp	A pile of long over-due refactorings here. There are some very, very	2012-05-04 00:58:03 +00:00
ConstantFolding.cpp	Reapply r155682, making constant folding more consistent, with a fix to work	2012-04-27 17:50:22 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp	Add a line number for the scope of the function (starting at the first	2012-04-03 00:43:49 +00:00
DIBuilder.cpp	Clarify comment.	2012-05-18 00:16:22 +00:00
DominanceFrontier.cpp
DomPrinter.cpp	remove the blank line from previous ci.	2012-02-04 03:18:47 +00:00
InlineCost.cpp	A pile of long over-due refactorings here. There are some very, very	2012-05-04 00:58:03 +00:00
InstCount.cpp
InstructionSimplify.cpp	Remove extraneous ';'.	2012-05-17 20:27:58 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	Cleanup IVUsers::addUsersIfInteresting.	2012-03-22 17:47:33 +00:00
LazyValueInfo.cpp	allow LazyValueInfo::getEdgeValue() to reason about multiple edges from the same switch instruction by doing union of ranges (which may still be conservative, but it's more aggressive than before)	2012-05-18 21:02:10 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	Always compute all the bits in ComputeMaskedBits.	2012-04-04 12:51:34 +00:00
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	Fix 12513: Loop unrolling breaks with indirect branches.	2012-04-10 05:14:42 +00:00
LoopPass.cpp	Take out the debug info probe stuff. It's making some changes to	2012-03-23 03:54:05 +00:00
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp	remove calls to calloc if the allocated memory is not used (it was already being done for malloc)	2012-05-03 22:08:19 +00:00
MemoryDependenceAnalysis.cpp	Move the capture analysis from MemoryDependencyAnalysis to a more general place	2012-05-14 20:35:04 +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	Rename the Region::block_iterator to Region::block_node_iterator, and	2012-05-04 20:55:23 +00:00
RegionPass.cpp	Rename the Region::block_iterator to Region::block_node_iterator, and	2012-05-04 20:55:23 +00:00
RegionPrinter.cpp	Rename the Region::block_iterator to Region::block_node_iterator, and	2012-05-04 20:55:23 +00:00
ScalarEvolution.cpp	SCEV: Add MarkPendingLoopPredicates to avoid recursive isImpliedCond.	2012-05-19 00:48:25 +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	Teach DeadStoreElimination to eliminate exit-block stores with phi addresses.	2012-05-10 18:57:38 +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))

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