llvm-6502/lib/Analysis
David Peixotto ea468dddfe Ignore annotation function calls in cost computation
The annotation instructions are dropped during codegen and have no
impact on size.  In some cases, the annotations were preventing the
unroller from unrolling a loop because the annotation calls were
pushing the cost over the unrolling threshold.

Differential Revision: http://reviews.llvm.org/D5335



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218525 91177308-0d34-0410-b5e6-96231b3b80d8
2014-09-26 17:48:40 +00:00
..
IPA Add functions for finding ephemeral values 2014-09-07 13:49:57 +00:00
AliasAnalysis.cpp AA metadata refactoring (introduce AAMDNodes) 2014-07-24 12:16:19 +00:00
AliasAnalysisCounter.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
AliasAnalysisEvaluator.cpp AA metadata refactoring (introduce AAMDNodes) 2014-07-24 12:16:19 +00:00
AliasDebugger.cpp [C++11] Add 'override' keyword to virtual methods that override their base class. 2014-03-05 07:30:04 +00:00
AliasSetTracker.cpp AA metadata refactoring (introduce AAMDNodes) 2014-07-24 12:16:19 +00:00
Analysis.cpp Add a CFL Alias Analysis implementation 2014-09-02 21:43:13 +00:00
AssumptionTracker.cpp Add an Assumption-Tracking Pass 2014-09-07 12:44:26 +00:00
BasicAliasAnalysis.cpp Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.) 2014-09-07 18:57:58 +00:00
BlockFrequencyInfo.cpp Revert "Introduce a string_ostream string builder facilty" 2014-06-26 22:52:05 +00:00
BlockFrequencyInfoImpl.cpp BFI: Add constructor for Weight 2014-07-12 00:26:00 +00:00
BranchProbabilityInfo.cpp Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges." 2014-07-21 17:06:51 +00:00
CaptureTracking.cpp Match semantics of PointerMayBeCapturedBefore to its name by default 2014-07-21 21:30:22 +00:00
CFG.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
CFGPrinter.cpp Modernize raw_fd_ostream's constructor a bit. 2014-08-25 18:16:47 +00:00
CFLAliasAnalysis.cpp [CFLAA] Remove one final initializer list 2014-09-03 00:06:47 +00:00
CGSCCPassManager.cpp [PM] Add a new-PM-style CGSCC pass manager using the newly added 2014-04-21 11:12:00 +00:00
CMakeLists.txt Add file to CMake build as well. 2014-09-18 00:39:20 +00:00
CodeMetrics.cpp Add functions for finding ephemeral values 2014-09-07 13:49:57 +00:00
ConstantFolding.cpp Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size. 2014-08-21 05:55:13 +00:00
CostModel.cpp [CostModel][x86] Improved cost model for alternate shuffles. 2014-07-03 22:24:18 +00:00
Delinearization.cpp remove BasePointer before delinearizing 2014-05-27 22:41:51 +00:00
DependenceAnalysis.cpp Analysis: cleanup 2014-08-26 02:03:40 +00:00
DominanceFrontier.cpp Templatify DominanceFrontier. 2014-07-12 21:59:52 +00:00
DomPrinter.cpp [PM] Split DominatorTree into a concrete analysis result object which 2014-01-13 13:07:17 +00:00
FunctionTargetTransformInfo.cpp Add a new pass FunctionTargetTransformInfo. This pass serves as a 2014-09-18 00:34:14 +00:00
InstCount.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
InstructionSimplify.cpp InstSimplify: Don't allow (x srem y) urem y -> x srem y 2014-09-17 04:16:35 +00:00
Interval.cpp Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges." 2014-07-21 17:06:51 +00:00
IntervalPartition.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
IVUsers.cpp Repace SmallPtrSet with SmallPtrSetImpl in function arguments to avoid needing to mention the size. 2014-08-21 05:55:13 +00:00
JumpInstrTableInfo.cpp Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute. 2014-06-05 19:29:43 +00:00
LazyCallGraph.cpp Fix typos 2014-05-15 01:52:21 +00:00
LazyValueInfo.cpp Add two thresholds lvi-overdefined-BB-threshold and lvi-overdefined-threshold 2014-09-22 02:23:05 +00:00
LibCallAliasAnalysis.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
LibCallSemantics.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
Lint.cpp Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.) 2014-09-07 18:57:58 +00:00
LLVMBuild.txt
Loads.cpp AA metadata refactoring (introduce AAMDNodes) 2014-07-24 12:16:19 +00:00
LoopInfo.cpp Revert "[C++11] Add predecessors(BasicBlock *) / successors(BasicBlock *) iterator ranges." 2014-07-21 17:06:51 +00:00
LoopPass.cpp Fix assertion in LICM doFinalization() 2014-09-24 16:48:31 +00:00
Makefile
MemDepPrinter.cpp [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr. 2014-04-15 04:59:12 +00:00
MemoryBuiltins.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
MemoryDependenceAnalysis.cpp Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.) 2014-09-07 18:57:58 +00:00
ModuleDebugInfoPrinter.cpp [C++11] Change DebugInfoFinder to use range-based loops 2014-03-18 09:41:07 +00:00
NoAliasAnalysis.cpp Improve BasicAA CS-CS queries (redux) 2014-07-17 01:28:25 +00:00
PHITransAddr.cpp Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.) 2014-09-07 18:57:58 +00:00
PostDominators.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
PtrUseVisitor.cpp [C++11] Add range based accessors for the Use-Def chain of a Value. 2014-03-09 03:16:01 +00:00
README.txt
RegionInfo.cpp Fix msc17 build. RegionInfo::RegionInfo::recalculate() doesn't make sense. 2014-07-20 03:57:51 +00:00
RegionPass.cpp Templatify RegionInfo so it works on MachineBasicBlocks 2014-07-19 18:29:29 +00:00
RegionPrinter.cpp Templatify RegionInfo so it works on MachineBasicBlocks 2014-07-19 18:29:29 +00:00
ScalarEvolution.cpp Make use @llvm.assume for loop guards in ScalarEvolution 2014-09-07 21:37:59 +00:00
ScalarEvolutionAliasAnalysis.cpp AA metadata refactoring (introduce AAMDNodes) 2014-07-24 12:16:19 +00:00
ScalarEvolutionExpander.cpp Make use of @llvm.assume in ValueTracking (computeKnownBits, etc.) 2014-09-07 18:57:58 +00:00
ScalarEvolutionNormalization.cpp Fix typos in comments, NFC 2014-08-29 21:53:01 +00:00
ScopedNoAliasAA.cpp Add override to overriden virtual methods, remove virtual keywords. 2014-09-03 11:41:21 +00:00
SparsePropagation.cpp [Modules] Fix potential ODR violations by sinking the DEBUG_TYPE 2014-04-22 02:48:03 +00:00
StratifiedSets.h [CFLAA] And even more MSVC fixes 2014-09-02 23:50:01 +00:00
TargetTransformInfo.cpp Ignore annotation function calls in cost computation 2014-09-26 17:48:40 +00:00
Trace.cpp Put the functionality for printing a value to a raw_ostream as an 2014-01-09 02:29:41 +00:00
TypeBasedAliasAnalysis.cpp Add scoped-noalias metadata 2014-07-24 14:25:39 +00:00
ValueTracking.cpp Fix an ODR violation consisting of two 'struct Query' in the global namespace. 2014-09-12 08:56:53 +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))

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