llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-28 04:33:05 +00:00

History

Bill Wendling d58b50b99b A limit of 500 was still a bit too high for some tests. PR15000 has a testcase where the time to compile was bordering on 30s. When I dropped the limit value to 100, it became a much more managable 6s. The compile time seems to increase in a roughly linear fashion based on increasing the limit value. (See the runtimes below.) So, let's lower the limit to 100 so that they can get a more reasonable compile time. Limit Value Time ----------- ---- 10 0.9744s 20 1.8035s 30 2.3618s 40 2.9814s 50 3.6988s 60 4.5486s 70 4.9314s 80 5.8012s 90 6.4246s 100 7.0852s 110 7.6634s 120 8.3553s 130 9.0552s 140 9.6820s 150 9.8804s 160 10.8901s 170 10.9855s 180 12.0114s 190 12.6816s 200 13.2754s 210 13.9942s 220 13.8097s 230 14.3272s 240 15.7753s 250 15.6673s 260 16.0541s 270 16.7625s 280 17.3823s 290 18.8213s 300 18.6120s 310 20.0333s 320 19.5165s 330 20.2505s 340 20.7068s 350 21.1833s 360 22.9216s 370 22.2152s 380 23.9390s 390 23.4609s 400 24.0426s 410 24.6410s 420 26.5208s 430 27.7155s 440 26.4142s 450 28.5646s 460 27.3494s 470 29.7255s 480 29.4646s 490 30.5001s git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179713 91177308-0d34-0410-b5e6-96231b3b80d8		2013-04-17 20:02:32 +00:00
..
IPA
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp	Support in AAEvaluator to print alias queries of loads/stores with TBAA tags.	2013-03-22 22:34:41 +00:00
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp	Revert r176408 and r176407 to address PR15540.	2013-04-09 18:16:05 +00:00
BlockFrequencyInfo.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt
CodeMetrics.cpp
ConstantFolding.cpp	Fix a scalability issue with complex ConstantExprs.	2013-04-13 12:53:18 +00:00
CostModel.cpp	CostModel: Add parameter to instruction cost to further classify operand values	2013-04-04 23:26:21 +00:00
DependenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp	InstructionSimplify.cpp: Fix a ligature, "fi", to get rid of utf8 in comment.	2013-04-08 23:05:21 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp	Revert r176408 and r176407 to address PR15540.	2013-04-09 18:16:05 +00:00
MemoryDependenceAnalysis.cpp	A limit of 500 was still a bit too high for some tests.	2013-04-17 20:02:32 +00:00
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PathNumbering.cpp
PathProfileInfo.cpp
PathProfileVerifier.cpp	Build fixes for STLPort + GCC	2013-03-29 18:48:45 +00:00
PHITransAddr.cpp
PostDominators.cpp
ProfileDataLoader.cpp
ProfileDataLoaderPass.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp	Build fixes for STLPort + GCC	2013-03-29 18:48:45 +00:00
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp	RegionInfo: Add helpers to replace entry/exit recursively	2013-04-10 06:54:49 +00:00
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	Fix SCEV forgetMemoizedResults should search and destroy backedge exprs.	2013-03-26 03:14:53 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
TargetTransformInfo.cpp	CostModel: Add parameter to instruction cost to further classify operand values	2013-04-04 23:26:21 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp	Aliasing rules for struct-path aware TBAA.	2013-04-11 23:24:18 +00:00
ValueTracking.cpp

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))

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