llvm-6502/lib/Analysis
Duncan Sands f24ed77d24 Move some rem transforms out of instcombine and into instsimplify.
This automagically provides a transform noticed by my super-optimizer
as occurring quite often: "rem x, (select cond, x, 1)" -> 0.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130694 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-02 16:27:02 +00:00
..
IPA Fix a ton of comment typos found by codespell. Patch by 2011-04-15 05:18:47 +00:00
AliasAnalysis.cpp When analyzing functions known to only access argument pointees, 2011-04-27 18:39:03 +00:00
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp PR9604; try to deal with RAUW updates correctly in the AST. I'm not convinced 2011-04-09 06:55:46 +00:00
Analysis.cpp remove postdom frontiers, because it is dead. Forward dom frontiers are 2011-04-05 21:57:17 +00:00
BasicAliasAnalysis.cpp Teach BasicAA about arm.neon.vld1 and vst1. 2011-04-27 20:44:28 +00:00
CaptureTracking.cpp Don't include Operator.h from InstrTypes.h. 2011-04-11 09:35:34 +00:00
CFGPrinter.cpp
CMakeLists.txt Unbreak CMake build. 2011-03-01 00:02:51 +00:00
ConstantFolding.cpp Don't include Operator.h from InstrTypes.h. 2011-04-11 09:35:34 +00:00
DbgInfoPrinter.cpp Move DbgInfoPrinter specific utlities inside DbgInfoPrinter.cpp 2011-02-15 17:36:11 +00:00
DebugInfo.cpp Remove DIFactory. Patch by Devang. 2011-03-02 20:30:37 +00:00
DIBuilder.cpp Fix an off by one error while accessing complex address element of a DIVariable. 2011-04-26 18:24:39 +00:00
DominanceFrontier.cpp Move DominanceFrontier from VMCore to Analysis. 2011-01-18 06:06:27 +00:00
DomPrinter.cpp
InlineCost.cpp Fix a ton of comment typos found by codespell. Patch by 2011-04-15 05:18:47 +00:00
InstCount.cpp
InstructionSimplify.cpp Move some rem transforms out of instcombine and into instsimplify. 2011-05-02 16:27:02 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp Avoid creating canonical induction variables for non-native types. 2011-03-18 16:50:32 +00:00
LazyValueInfo.cpp Remove unused STL header includes. 2011-04-23 19:53:52 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp PR9214: Convert ConstantExpr::getIndices() to return an ArrayRef, plus 2011-04-13 15:22:40 +00:00
Loads.cpp Don't include Operator.h from InstrTypes.h. 2011-04-11 09:35:34 +00:00
LoopDependenceAnalysis.cpp
LoopInfo.cpp
LoopPass.cpp Introduce DebugInfoProbe. This is used to monitor how llvm optimizer is treating debugging information. 2011-03-10 00:21:25 +00:00
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp Add comments for the demanglings. Correct mangled form of operator delete! 2011-03-17 05:20:12 +00:00
MemoryDependenceAnalysis.cpp teach GVN to widen integer loads when they are overaligned, when doing an 2011-04-28 07:29:08 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PathNumbering.cpp Remove unused STL header includes. 2011-04-23 19:53:52 +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 Don't include Operator.h from InstrTypes.h. 2011-04-11 09:35:34 +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
RegionPrinter.cpp RegionPrinter: Ignore back edges when layouting the graph 2011-02-27 04:11:07 +00:00
ScalarEvolution.cpp Corrects an old, old typo in a case that doesn't seem to be reached in practice. 2011-04-27 18:17:36 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp Remove PHINode::reserveOperandSpace(). Instead, add a parameter to 2011-03-30 11:28:46 +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 Fix a ton of comment typos found by codespell. Patch by 2011-04-15 05:18:47 +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))

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