llvm-6502/lib/Analysis
Dan Gohman 97b44f9b80 Use ConstantExpr::getExtractElement when constant-folding vectors
instead of getAggregateElement. This has the advantage of being
more consistent and allowing higher-level constant folding to
procede even if an inner extract element cannot be folded.

Make ConstantFoldInstruction call ConstantFoldConstantExpression
on the instruction's operands, making it more consistent with 
ConstantFoldConstantExpression itself. This makes sure that
ConstantExprs get TargetData-aware folding before being handed
off as operands for further folding.

This causes more expressions to be folded, but due to a known
shortcoming in constant folding, this currently has the side effect
of stripping a few more nuw and inbounds flags in the non-targetdata
side of constant-fold-gep.ll. This is mostly harmless.

This fixes rdar://11324230.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155682 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-27 00:54:36 +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 Persuade GCC that there is nothing worth warning about here (there isn't). 2012-02-05 14:20:11 +00:00
AliasAnalysisEvaluator.cpp Remove unnecessary default cases in switches that cover all enum values. 2012-01-10 16:47:17 +00:00
AliasDebugger.cpp Extend the AliasAnalysis::pointsToConstantMemory interface to allow it 2010-11-08 16:45:26 +00:00
AliasSetTracker.cpp Have AliasSet::aliasesUnknownInst use pointer TBAA info when available 2012-02-10 15:52:39 +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 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 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 Move includes to the .cpp file. 2012-01-17 22:16:31 +00:00
CFGPrinter.cpp Remove all remaining uses of Value::getNameStr(). 2011-11-15 16:27:03 +00:00
CMakeLists.txt Pull the implementation of the code metrics out of the inline cost 2012-03-16 05:51:52 +00:00
CodeMetrics.cpp Initial commit for the rewrite of the inline cost analysis to operate 2012-03-31 12:42:41 +00:00
ConstantFolding.cpp Use ConstantExpr::getExtractElement when constant-folding vectors 2012-04-27 00:54:36 +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 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 Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch 2011-12-20 02:50:00 +00:00
DomPrinter.cpp remove the blank line from previous ci. 2012-02-04 03:18:47 +00:00
InlineCost.cpp Add two statistics to help track how we are computing the inline cost. 2012-04-11 10:15:10 +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 Revert r153521 as it's causing large regressions on the nightly testers. 2012-03-28 18:42:50 +00:00
Interval.cpp
IntervalPartition.cpp Now with fewer extraneous semicolons! 2010-10-07 22:25:06 +00:00
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 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 Always compute all the bits in ComputeMaskedBits. 2012-04-04 12:51:34 +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 enhance jump threading to preserve TBAA information when PRE'ing loads, 2012-03-13 18:07:41 +00:00
LoopDependenceAnalysis.cpp More dead code removal (using -Wunreachable-code) 2012-01-20 21:51:11 +00:00
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 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 Don't call dominates on unreachable instructions. Should fix the dragonegg 2012-02-26 05:30:08 +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 [unwind removal] We no longer have 'unwind' instructions being generated, so 2012-02-06 21:16:41 +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 Uniformize the InstructionSimplify interface by ensuring that all routines 2012-03-13 11:42:19 +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 Remove extra semi-colons. 2012-02-22 17:25:00 +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 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 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 Fix this assert. IP can point to an instruction with strange dominance 2012-02-27 02:13:03 +00:00
ScalarEvolutionNormalization.cpp More dead code removal (using -Wunreachable-code) 2012-01-20 21:51:11 +00:00
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 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 Fix ValueTracking to conclude that debug intrinsics are safe to 2012-04-07 19:22:18 +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))

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