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History

Chandler Carruth 4478e73ac5 Rename the Region::block_iterator to Region::block_node_iterator, and add a new Region::block_iterator which actually iterates over the basic blocks of the region. The old iterator, now call 'block_node_iterator' iterates over RegionNodes which contain a single basic block. This works well with the GraphTraits-based iterator design, however most users actually want an iterator over the BasicBlocks inside these RegionNodes. Now the 'block_iterator' is a wrapper which exposes exactly this interface. Internally it uses the block_node_iterator to walk all nodes which are single basic blocks, but transparently unwraps the basic block to make user code simpler. While this patch is a bit of a wash, most of the updates are to internal users, not external users of the RegionInfo. I have an accompanying patch to Polly that is a strict simplification of every user of this interface, and I'm working on a pass that also wants the same simplified interface. This patch alone should have no functional impact. llvm-svn: 156202		2012-05-04 20:55:23 +00:00
..
IPA	Handle intrinsics in GlobalsModRef. Fixes pr12351.	2012-03-28 21:31:24 +00:00
AliasAnalysis.cpp	Move isKnownNonNull from private implementation detail of BasicAA to a public	2012-02-25 10:56:28 +00:00
AliasAnalysisCounter.cpp
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
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	Allow forward declarations to take a context. This helps the debugger	2012-04-23 19:00:11 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
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	Revert r153521 as it's causing large regressions on the nightly testers.	2012-03-28 18:42:50 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	Cleanup IVUsers::addUsersIfInteresting.	2012-03-22 17:47:33 +00:00
LazyValueInfo.cpp	llvm::SwitchInst	2012-03-11 06:09:17 +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
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	Don't call dominates on unreachable instructions. Should fix the dragonegg	2012-02-26 05:30:08 +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	Revert "SCEV: When expanding a GEP the final addition to the base pointer has NUW but not NSW."	2012-04-17 06:33:57 +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
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	Just mark the sign bit as known zero, rather than any other irrelevant bits	2012-04-30 11:56:58 +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))

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