llvm-6502/lib/Analysis
Benjamin Kramer 26eb870d7e Use canonical forms for the branch probability zero heutistic.
- Drop support for X >u 0, it's equivalent to X != 0 and should be canonicalized into the latter.
- Add X < 1 -> unlikely, which is what instcombine canonicalizes X <= 0 into.
- Add X > -1 -> likely, which is what instcombine canonicalizes X >= 0 into.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139110 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-04 23:53:04 +00:00
..
IPA Reapply r138695. Fix PassManager stack depths. 2011-08-29 17:07:00 +00:00
AliasAnalysis.cpp Misc analysis passes that need to be aware of atomic load/store. 2011-08-15 20:54:19 +00:00
AliasAnalysisCounter.cpp
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
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 Explicitly cast narrowing conversions inside {}s that will become errors in 2011-07-27 06:22:51 +00:00
BlockFrequencyInfo.cpp Add more constantness in BlockFrequencyInfo. 2011-08-03 21:30:57 +00:00
BranchProbabilityInfo.cpp Use canonical forms for the branch probability zero heutistic. 2011-09-04 23:53:04 +00:00
CaptureTracking.cpp Don't include Operator.h from InstrTypes.h. 2011-04-11 09:35:34 +00:00
CFGPrinter.cpp
CMakeLists.txt Rewrite the CMake build to use explicit dependencies between libraries, 2011-07-29 00:14:25 +00:00
ConstantFolding.cpp Fixes following the CR by Chris and Duncan: 2011-08-29 19:58:36 +00:00
DbgInfoPrinter.cpp Move DbgInfoPrinter specific utlities inside DbgInfoPrinter.cpp 2011-02-15 17:36:11 +00:00
DebugInfo.cpp After r138010, subroutine type does not have context info. Update type verifier accordingly. 2011-08-31 18:04:31 +00:00
DIBuilder.cpp Whitespace and 80-col. 2011-08-26 21:02:40 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InlineCost.cpp Change condition for determining whether a function is small for inlining metrics so that very long functions 2011-05-24 20:22:24 +00:00
InstCount.cpp
InstructionSimplify.cpp Revert r137781; I agree with Duncan's comment that the situation in question is clearly impossible given the current structure of the code. 2011-08-17 19:31:49 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Teach IVUsers to stop at non-affine expressions unless they are both 2011-07-01 22:05:19 +00:00
LazyValueInfo.cpp land David Blaikie's patch to de-constify Type, with a few tweaks. 2011-07-18 04:54:35 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp land David Blaikie's patch to de-constify Type, with a few tweaks. 2011-07-18 04:54:35 +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 LoopInfo::updateUnloop fix, and verify Block->Loop maps. 2011-08-26 03:06:34 +00:00
LoopPass.cpp Reapply r138695. Fix PassManager stack depths. 2011-08-29 17:07:00 +00:00
Makefile
MemDepPrinter.cpp Misc analysis passes that need to be aware of atomic load/store. 2011-08-15 20:54:19 +00:00
MemoryBuiltins.cpp land David Blaikie's patch to de-constify Type, with a few tweaks. 2011-07-18 04:54:35 +00:00
MemoryDependenceAnalysis.cpp Misc analysis passes that need to be aware of atomic load/store. 2011-08-15 20:54:19 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
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 Fix a ton of comment typos found by codespell. Patch by 2011-04-15 05:18:47 +00:00
PHITransAddr.cpp Shorten some expressions by using ArrayRef::slice(). 2011-07-25 15:13:01 +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 Fix a ton of comment typos found by codespell. Patch by 2011-04-15 05:18:47 +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
ProfileVerifierPass.cpp
README.txt
RegionInfo.cpp Region: Allow user control the printing style of the print function. 2011-04-04 07:19:18 +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 Comment and clarifying assert. 2011-09-02 21:20:46 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp Skip the landingpad instruction when determining the insertion point. 2011-08-24 21:06:46 +00:00
ScalarEvolutionNormalization.cpp Added SCEV::NoWrapFlags to manage unsigned, signed, and self wrap 2011-03-14 16:50:06 +00:00
SparsePropagation.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp Fix a ton of comment typos found by codespell. Patch by 2011-04-15 05:18:47 +00:00
ValueTracking.cpp Migrate LLVM and Clang to use the new makeArrayRef(...) functions where previously explicit non-default constructors were used. 2011-07-18 12:00:32 +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))

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