llvm-6502/lib/Analysis
Dan Gohman 7a64257f94 Just as its not safe to blindly transfer the nsw bit from an add
instruction to an add scev, it's not safe to blindly transfer the
inbounds flag from a gep instruction to an nsw on the scev for the
gep.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107117 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-29 01:41:41 +00:00
..
IPA Create new accessors to get arguments for call/invoke instructions. It breaks 2010-06-07 19:05:06 +00:00
AliasAnalysis.cpp Add an Intraprocedural form of BasicAliasAnalysis, which aims to 2010-06-29 00:50:39 +00:00
AliasAnalysisCounter.cpp Fix a missing newline in debug output. 2010-03-01 17:42:55 +00:00
AliasAnalysisEvaluator.cpp Generalize AAEval so that it can be used both per-function and 2010-06-28 16:01:37 +00:00
AliasDebugger.cpp Fix AliasDebugger to be aware of operand values too. 2010-05-28 22:31:51 +00:00
AliasSetTracker.cpp Change dbgs() back to errs() as Chris requested. 2009-12-23 22:49:57 +00:00
Analysis.cpp "In order to ease automatic bindings generation, it would be helpful if boolean values were distinguishable from integers. The attached patch introduces "typedef int LLVMBool;", and uses LLVMBool instead of int throughout the C API, wherever a boolean value is called for." 2010-01-09 22:27:07 +00:00
BasicAliasAnalysis.cpp Add an Intraprocedural form of BasicAliasAnalysis, which aims to 2010-06-29 00:50:39 +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 Remove includes of Support/Compiler.h that are no longer needed after the 2009-10-25 06:57:41 +00:00
CMakeLists.txt Move FindAvailableLoadedValue isSafeToLoadUnconditionally out of 2010-05-28 16:19:17 +00:00
ConstantFolding.cpp Eliminate unnecessary uses of getZExtValue(). 2010-06-18 14:22:04 +00:00
DbgInfoPrinter.cpp Remove dead debug info intrinsics. 2010-01-05 01:10:40 +00:00
DebugInfo.cpp Use named MDNode, llvm.dbg.sp, to collect subprogram info. This will be used to emit local variable's debug info of deleted functions. 2010-06-28 05:53:08 +00:00
DomPrinter.cpp Remove dead code in the dotty dominance tree printer. 2010-04-12 15:02:19 +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 Change dbgs() back to errs() as Chris requested. 2009-12-23 23:29:28 +00:00
InstructionSimplify.cpp move some select simplifications out out instcombine into 2010-04-20 05:32:14 +00:00
Interval.cpp Change Pass::print to take a raw ostream instead of std::ostream, 2009-08-23 06:03:38 +00:00
IntervalPartition.cpp Change Pass::print to take a raw ostream instead of std::ostream, 2009-08-23 06:03:38 +00:00
IVUsers.cpp Remove the Expr member from IVUsers. Instead of remembering the expression, 2010-04-19 21:48:58 +00:00
LazyValueInfo.cpp Convert debug messages to use dbgs(). Generally this means 2009-12-23 20:43:58 +00:00
LibCallAliasAnalysis.cpp LibCallAliasAnalysis doesn't use TargetData. 2009-07-31 20:56:29 +00:00
LibCallSemantics.cpp Remove Value::getNameLen 2009-07-26 08:34:35 +00:00
Lint.cpp Fix the noalias checking so that it doesn't worry about 2010-06-01 20:51:40 +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 Fix a bunch of namespace polution. 2010-04-15 17:08:50 +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 make -fno-rtti the default unless a directory builds with REQUIRES_RTTI. 2010-01-24 20:43:08 +00:00
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 Reapply r97010, the speculative revert failed. 2010-02-24 08:48:04 +00:00
PointerTracking.cpp Rename isLoopGuardedByCond to isLoopEntryGuardedByCond, to emphasise 2010-04-11 19:27:13 +00:00
PostDominators.cpp Remove unneeded debug in PostDominator runOnFunction() 2010-04-12 15:32:55 +00:00
ProfileEstimatorPass.cpp rename pred_const_iterator to const_pred_iterator for consistency's sake 2010-03-25 23:25:28 +00:00
ProfileInfo.cpp rename pred_const_iterator to const_pred_iterator for consistency's sake 2010-03-25 23:25:28 +00:00
ProfileInfoLoader.cpp Reapplied r81355 with the problems fixed. 2009-09-16 11:35:50 +00:00
ProfileInfoLoaderPass.cpp rename pred_const_iterator to const_pred_iterator for consistency's sake 2010-03-25 23:25:28 +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 Just as its not safe to blindly transfer the nsw bit from an add 2010-06-29 01:41:41 +00:00
ScalarEvolutionAliasAnalysis.cpp Fix a typo in a comment. 2010-06-18 00:53:08 +00:00
ScalarEvolutionExpander.cpp Use A.append(...) instead of A.insert(A.end(), ...) when A is a 2010-06-21 19:47:52 +00:00
ScalarEvolutionNormalization.cpp Fix normalization and de-normalization of non-affine SCEVs. 2010-06-04 19:16:34 +00:00
SparsePropagation.cpp Convert debug messages to use dbgs(). Generally this means 2009-12-23 22:28:01 +00:00
Trace.cpp Convert debug messages to use dbgs(). Generally this means 2009-12-23 22:35:10 +00:00
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))

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