llvm-6502/lib/Analysis
Dan Gohman bbc1da8ded Tweak IVUsers' concept of "interesting" to exclude add recurrences
where the step value is an induction variable from an outer loop, to
avoid trouble trying to re-expand such expressions. This effectively
hides such expressions from indvars and lsr, which prevents them
from getting into trouble.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111317 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-17 22:50:37 +00:00
..
IPA Make dumpPassStructure be a PMDataManager abstraction, rather than 2010-08-16 22:45:12 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
AliasAnalysisEvaluator.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
AliasDebugger.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
AliasSetTracker.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
Analysis.cpp
BasicAliasAnalysis.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
CaptureTracking.cpp
CFGPrinter.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
CMakeLists.txt
ConstantFolding.cpp
DbgInfoPrinter.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
DebugInfo.cpp Even if a variable has constant value all the time, it is still a variable in gdb's eyes. 2010-08-11 23:17:54 +00:00
DomPrinter.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
InlineCost.cpp
InstCount.cpp Revert r111082. No warnings for this common pattern. 2010-08-15 10:27:23 +00:00
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
IVUsers.cpp Tweak IVUsers' concept of "interesting" to exclude add recurrences 2010-08-17 22:50:37 +00:00
LazyValueInfo.cpp Fix another iterator invalidation that caused a *really* nasty miscompilation in 403.gcc. 2010-08-16 23:42:33 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp Revert r111058, the lint check for indirectbr successors that aren't 2010-08-16 14:39:19 +00:00
LiveValues.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
Loads.cpp
LoopDependenceAnalysis.cpp
LoopInfo.cpp
LoopPass.cpp Make dumpPassStructure be a PMDataManager abstraction, rather than 2010-08-16 22:45:12 +00:00
Makefile
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
ModuleDebugInfoPrinter.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
PHITransAddr.cpp
PointerTracking.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
PostDominators.cpp
ProfileEstimatorPass.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
ProfileInfo.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
ProfileVerifierPass.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
README.txt
RegionInfo.cpp RegionInfo: Do not assert if a BB is not part of the dominance tree. 2010-08-10 09:54:35 +00:00
RegionPrinter.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
ScalarEvolution.cpp To create a copy of a SmallVector with an element removed from the 2010-08-16 16:57:24 +00:00
ScalarEvolutionAliasAnalysis.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp Reapply r110396, with fixes to appease the Linux buildbot gods. 2010-08-06 18:33:48 +00:00
ValueTracking.cpp

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))

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