llvm/lib/Analysis
Nick Lewycky b48a18903a Change CaptureTracking to pass a Use* instead of a Value* when a value is
captured. This allows the tracker to look at the specific use, which may be
especially interesting for function calls.

Use this to fix 'nocapture' deduction in FunctionAttrs. The existing one does
not iterate until a fixpoint and does not guarantee that it produces the same
result regardless of iteration order. The new implementation builds up a graph
of how arguments are passed from function to function, and uses a bottom-up walk
on the argument-SCCs to assign nocapture. This gets us nocapture more often, and
does so rather efficiently and independent of iteration order.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147327 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-28 23:24:21 +00:00
..
IPA LLVMBuild: Remove trailing newline, which irked me. 2011-12-12 19:48:00 +00:00
AliasAnalysis.cpp Enhance alias analysis for atomic instructions a bit. Upgrade a couple alias-analysis tests to the new atomic instructions. 2011-09-26 20:15:28 +00:00
AliasAnalysisCounter.cpp Teach AliasAnalysisCounter about PartialAlias. 2010-12-10 19:53:05 +00:00
AliasAnalysisEvaluator.cpp land David Blaikie's patch to de-constify Type, with a few tweaks. 2011-07-18 04:54:35 +00:00
AliasDebugger.cpp Extend the AliasAnalysis::pointsToConstantMemory interface to allow it 2010-11-08 16:45:26 +00:00
AliasSetTracker.cpp Atomic load/store support in LICM. 2011-08-15 20:52:09 +00:00
Analysis.cpp C API functions must be able to see their extern "C" definitions, or it will be impossible to call them from C. 2011-08-19 01:36:54 +00:00
BasicAliasAnalysis.cpp Refactor code to use new attribute getters on CallSite for NoCapture and ByVal. 2011-11-20 19:09:04 +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 Change CaptureTracking to pass a Use* instead of a Value* when a value is 2011-12-28 23:24:21 +00:00
CFGPrinter.cpp Remove all remaining uses of Value::getNameStr(). 2011-11-15 16:27:03 +00:00
CMakeLists.txt build/CMake: Finish removal of add_llvm_library_dependencies. 2011-11-29 19:25:30 +00:00
ConstantFolding.cpp Switch llvm.cttz and llvm.ctlz to accept a second i1 parameter which 2011-12-12 04:26:04 +00:00
DbgInfoPrinter.cpp Fix for DbgInfoPrinter.cpp:174:12: warning: ‘LineNo’ may be used uninitialized in this function. 2011-09-21 23:34:23 +00:00
DebugInfo.cpp Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch 2011-12-20 02:50:00 +00:00
DIBuilder.cpp In DICompositeType, referenced to derived type is either metadata or null. 2011-12-16 17:51:31 +00:00
DominanceFrontier.cpp Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch 2011-12-20 02:50:00 +00:00
DomPrinter.cpp split dom frontier handling stuff out to its own DominanceFrontier header, 2011-01-02 22:09:33 +00:00
InlineCost.cpp Continue counting intrinsics as instructions (except when they aren't, such as 2011-12-21 20:26:03 +00:00
InstCount.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
InstructionSimplify.cpp Add support for vectors of pointers. 2011-12-05 06:29:09 +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 Now with fewer extraneous semicolons! 2010-10-07 22:25:06 +00:00
IVUsers.cpp Slightly more useful tracing. 2011-10-13 17:06:38 +00:00
LazyValueInfo.cpp Clear the new cache. 2011-12-03 15:19:55 +00:00
LibCallAliasAnalysis.cpp Now with fewer extraneous semicolons! 2010-10-07 22:25:06 +00:00
LibCallSemantics.cpp Thread const correctness through a bunch of AliasAnalysis interfaces and 2010-08-03 21:48:53 +00:00
Lint.cpp Fix a few more places where TargetData/TargetLibraryInfo is not being passed. 2011-12-02 01:26:24 +00:00
LLVMBuild.txt LLVMBuild: Introduce a common section which currently has a list of the 2011-12-12 22:45:54 +00:00
Loads.cpp Add some comments here because the lack of a check for volatile/atomic here is a bit unusual. 2011-08-15 21:56:39 +00:00
LoopDependenceAnalysis.cpp Misc analysis passes that need to be aware of atomic load/store. 2011-08-15 20:54:19 +00:00
LoopInfo.cpp Move Instruction::isSafeToSpeculativelyExecute out of VMCore and 2011-12-14 23:49:11 +00:00
LoopPass.cpp Reapply r138695. Fix PassManager stack depths. 2011-08-29 17:07:00 +00:00
Makefile make -fno-rtti the default unless a directory builds with REQUIRES_RTTI. 2010-01-24 20:43:08 +00:00
MemDepPrinter.cpp Fix a stupid typo in MemDepPrinter. 2011-12-14 02:54:39 +00:00
MemoryBuiltins.cpp Validate the return type when checking if a function is malloc. 2011-11-23 17:58:47 +00:00
MemoryDependenceAnalysis.cpp Change CaptureTracking to pass a Use* instead of a Value* when a value is 2011-12-28 23:24:21 +00:00
ModuleDebugInfoPrinter.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
NoAliasAnalysis.cpp Use the new addEscapingValue callback to update GlobalsModRef when GVN adds PHIs of GEPs. For the moment, 2011-01-03 23:51:43 +00:00
PathNumbering.cpp Add this back in for now. There are still a few passes which create unwind instructions at the moment. 2011-08-03 01:07:57 +00:00
PathProfileInfo.cpp Implementation of path profiling. 2011-01-29 01:09:53 +00:00
PathProfileVerifier.cpp Remove all remaining uses of Value::getNameStr(). 2011-11-15 16:27:03 +00:00
PHITransAddr.cpp Move Instruction::isSafeToSpeculativelyExecute out of VMCore and 2011-12-14 23:49:11 +00:00
PostDominators.cpp remove postdom frontiers, because it is dead. Forward dom frontiers are 2011-04-05 21:57:17 +00:00
ProfileEstimatorPass.cpp Remove all remaining uses of Value::getNameStr(). 2011-11-15 16:27:03 +00:00
ProfileInfo.cpp Fix a ton of comment typos found by codespell. Patch by 2011-04-15 05:18:47 +00:00
ProfileInfoLoader.cpp Remove unused STL header includes. 2011-04-23 19:53:52 +00:00
ProfileInfoLoaderPass.cpp Remove all remaining uses of Value::getNameStr(). 2011-11-15 16:27:03 +00:00
ProfileVerifierPass.cpp Move code into anonymous namespaces. 2011-11-26 23:01:57 +00:00
README.txt When checking whether the special handling for an addrec increment which 2010-04-26 21:46:36 +00:00
RegionInfo.cpp Missed some users of Value::getNameStr. 2011-11-15 18:30:06 +00:00
RegionPass.cpp Reapply r138695. Fix PassManager stack depths. 2011-08-29 17:07:00 +00:00
RegionPrinter.cpp RegionPrinter: Ignore back edges when layouting the graph 2011-02-27 04:11:07 +00:00
ScalarEvolution.cpp Fix a few more places where TargetData/TargetLibraryInfo is not being passed. 2011-12-02 01:26:24 +00:00
ScalarEvolutionAliasAnalysis.cpp Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which 2010-10-19 17:21:58 +00:00
ScalarEvolutionExpander.cpp LSR: Fix another corner case in expansion of postinc users. 2011-12-20 01:42:24 +00:00
ScalarEvolutionNormalization.cpp Fix memory corruption I introduced a few checkins ago. 2011-10-13 18:49:23 +00:00
SparsePropagation.cpp Remove all remaining uses of Value::getNameStr(). 2011-11-15 16:27:03 +00:00
Trace.cpp Remove all remaining uses of Value::getNameStr(). 2011-11-15 16:27:03 +00:00
TypeBasedAliasAnalysis.cpp Fix a ton of comment typos found by codespell. Patch by 2011-04-15 05:18:47 +00:00
ValueTracking.cpp ComputeMaskedBits: Make knownzero computation more aggressive for ctlz with undef zero. 2011-12-24 17:31:46 +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))

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