llvm-6502/lib/Analysis
Dan Gohman fc3678a346 Fix SCEV denormalization of expressions where the exit value from
one loop is involved in the increment of an addrec for another
loop. This fixes rdar://8168938.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108863 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-20 17:06:20 +00:00
..
IPA Speculatively revert r108813, in an attempt to get the self-host buildbots working again. I don't see why this patch 2010-07-20 08:26:15 +00:00
AliasAnalysis.cpp Remove interprocedural-basic-aa and associated code. The AliasAnalysis 2010-07-07 14:27:09 +00:00
AliasAnalysisCounter.cpp Speculatively revert r108813, in an attempt to get the self-host buildbots working again. I don't see why this patch 2010-07-20 08:26:15 +00:00
AliasAnalysisEvaluator.cpp Remove interprocedural-basic-aa and associated code. The AliasAnalysis 2010-07-07 14:27:09 +00:00
AliasDebugger.cpp Speculatively revert r108813, in an attempt to get the self-host buildbots working again. I don't see why this patch 2010-07-20 08:26:15 +00:00
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp Speculatively revert r108813, in an attempt to get the self-host buildbots working again. I don't see why this patch 2010-07-20 08:26:15 +00:00
CaptureTracking.cpp rename use_const_iterator to const_use_iterator for consistency's sake 2010-03-25 23:06:16 +00:00
CFGPrinter.cpp
CMakeLists.txt Move FindAvailableLoadedValue isSafeToLoadUnconditionally out of 2010-05-28 16:19:17 +00:00
ConstantFolding.cpp eliminate CallInst::ArgOffset 2010-07-16 09:38:02 +00:00
DbgInfoPrinter.cpp
DebugInfo.cpp Correct line info for declarations/definitions. Radar 8063111. 2010-07-19 23:56:30 +00:00
DomPrinter.cpp Convert some tab stops into spaces. 2010-07-12 08:16:59 +00:00
InlineCost.cpp Pulled CodeMetrics out of InlineCost.h and made it a bit more general, so it can be reused from PartialSpecializationCost 2010-06-09 15:11:37 +00:00
InstCount.cpp
InstructionSimplify.cpp Fix PR7647, handling the case when 'To' ends up being 2010-07-15 06:36:08 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Remove the Expr member from IVUsers. Instead of remembering the expression, 2010-04-19 21:48:58 +00:00
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp Add a lint check for mismatched return types, inspired by PR6944. 2010-07-12 18:02:04 +00:00
LiveValues.cpp rename use_const_iterator to const_use_iterator for consistency's sake 2010-03-25 23:06:16 +00:00
Loads.cpp Move FindAvailableLoadedValue isSafeToLoadUnconditionally out of 2010-05-28 16:19:17 +00:00
LoopDependenceAnalysis.cpp Define placement new wrappers for BumpPtrAllocator and 2010-03-18 18:49:47 +00:00
LoopInfo.cpp cache result of operator* 2010-07-09 14:28:41 +00:00
LoopPass.cpp Ok, third time's the charm. No changes from last time except the CMake 2010-04-02 23:17:14 +00:00
Makefile
MemoryBuiltins.cpp minor enhancement to llvm::isFreeCall API: return CallInst; no functional change 2010-06-23 21:51:12 +00:00
MemoryDependenceAnalysis.cpp use the new isFreeCall API and ArgOperand accessors 2010-06-23 22:48:06 +00:00
ModuleDebugInfoPrinter.cpp Add a simple module-level debug info printer. It just sets up a 2010-05-07 16:22:32 +00:00
PHITransAddr.cpp
PointerTracking.cpp Rename isLoopGuardedByCond to isLoopEntryGuardedByCond, to emphasise 2010-04-11 19:27:13 +00:00
PostDominators.cpp cache result of operator* 2010-07-09 15:52:36 +00:00
ProfileEstimatorPass.cpp Speculatively revert r108813, in an attempt to get the self-host buildbots working again. I don't see why this patch 2010-07-20 08:26:15 +00:00
ProfileInfo.cpp Speculatively revert r108813, in an attempt to get the self-host buildbots working again. I don't see why this patch 2010-07-20 08:26:15 +00:00
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp Speculatively revert r108813, in an attempt to get the self-host buildbots working again. I don't see why this patch 2010-07-20 08:26:15 +00:00
ProfileVerifierPass.cpp rename pred_const_iterator to const_pred_iterator for consistency's sake 2010-03-25 23:25:28 +00:00
README.txt When checking whether the special handling for an addrec increment which 2010-04-26 21:46:36 +00:00
ScalarEvolution.cpp Add a fast path for x - x. 2010-07-20 16:53:00 +00:00
ScalarEvolutionAliasAnalysis.cpp Speculatively revert r108813, in an attempt to get the self-host buildbots working again. I don't see why this patch 2010-07-20 08:26:15 +00:00
ScalarEvolutionExpander.cpp Simplify this code; LoopInfo::getCanonicalInductionVariable will only 2010-07-20 16:46:58 +00:00
ScalarEvolutionNormalization.cpp Fix SCEV denormalization of expressions where the exit value from 2010-07-20 17:06:20 +00:00
SparsePropagation.cpp
Trace.cpp
ValueTracking.cpp use ArgOperand accessors 2010-06-23 23:38:07 +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))

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